模拟油砂的二氧化硅微粒在非水溶剂中的团聚
|
摘要
油砂(oil sands)又称焦油砂,或称沥青砂,是一种沥青(bitumen)、砂石、富矿粘土和水的混合物。全球油砂所含原油约5.5兆桶,占世界石油储量的66%。其中加拿大是油砂资源最为丰富的国家,约占全球总量的77%,包括油砂储量在内的探明石油储量仅次于沙特阿拉伯居世界第二。我国的油砂储量居世界第五位。加拿大95%的油砂储量集中在Alberta省,油砂资源分布面积达14.1万平方公里,并且主要集中在该省北部的Athabasca,Cold Lake还有Peace River地区。其中Athabasca区域的油砂是世界上最大的已知油砂资源。Alberta油砂中沥青含量为10～12%,沙和粘土等矿物的含量为80～85%(其中含～95%的石英、2～3%的长石和2～3%的云母和粘土),水含量为4～6%。沥青是一种复杂的混合物,其中碳含量为83.0～86.0%,氢为10.2～10.4%、硫为4.5～5.3%、氧为0.8～1.4%、氮为0.3～0.5%,还含有其他微量的重金属钒、镍、铁等。一般把沥青中不溶于非极性低分子正构烷烃而溶于苯的物质称为沥青质(asphaltene),其余部分称做软沥青(maltenes),maltenes又可分为以下三大类:饱和烃(Saturates),芳香烃(Aromatics)和胶质(Resins)。因此通常在研究中直接将沥青分为SARA四部分,即Saturates,Aromatics,Resins和Asphaltene。其中引起最多关注的是asphaltene组分(在Athabasca油砂沥青中占16~25%),asphaltene在原油生产过程中由于压力、温度和组分的变化,会沉淀并堆积在泵、油管、井口、安全阀、出油管线和地面设施等诸多区域,影响整个生产过程。同时asphaltene也是沥青中存在的天然表面活性物质,易于附着在油水界面以及微细颗粒表面,从而增加了沥青提纯的难度。
沥青是重质原油,其密度比传统原油高很多;在浅部地层中的沥青粘度相当高,流动性很小甚至几乎不流动,一般不能以打井开采原油、稠油的方法来提取油砂中的沥青。目前开采油砂的方式一般分为露天开采法与井下开采法两种。加拿大的油砂开采中,大约有20%使用露天开采法,80%使用井下开采法。露天开采仅用于埋深小于75米的油砂矿,这个方法实际上就是将地表的土壤,植被等用卡车和铲子除去,露出油砂直接开采,具有资源回收率高、可用大型自动化机械设备、生产安全等特点。井下开采方式适用于埋深大于75米的油砂矿,主要技术有:蒸汽吞吐(CSS)、蒸汽辅助重力驱油(SAGD)和汽化萃取(VAPEX)等。
目前,露天开采在技术上较为成熟,加拿大及委内瑞拉等都已形成大规模的工业开采。其主要过程是:油砂被挖掘后由装载量达数百吨的巨型卡车运到粉碎系统,被粉碎机粉碎到颗粒粒度为30～40cm左右,再传送到下一级滚筒粉碎系统,在这个系统中,没有利用价值的岩石先从油砂中分离出来,剩下的油砂再与40°C左右的大量热水充分混合、粉碎,得到颗粒粒度大约5cm左右的浆状油砂。浆状油砂被泵送到下游的萃取分离装置,在输送的过程中,油砂在管道中进一步得到混合。在主分离器中,油砂被初步分离成粗沥青、水和沙子。接下来,粗沥青被送入重力分离容器中,通入工业风,沥青随工业风鼓泡而出,形成飘在表面的泡沫沥青。沙砾、泥浆、水等残留物沉入容器底部,并被泵送到残渣处理系统。生成的泡沫沥青(沥青含量为60%,水含量为30%,固体颗粒为10%)被送入泡沫沥青处理系统(froth treatment),在该系统中加入石脑油做溶剂,降低沥青的粘度,并进一步将水、固体颗粒与沥青分离,得到较高纯度、粘度适中并便于管道输送的沥青。当这种稀释了的沥青被送到改质装置后,石脑油则从沥青中被分离出来,并被送回到froth treatment系统循环利用,沥青则被送入到下一道工序生产合成原油。
当前有利的高油价形势和丰富的油砂资源储量,为加拿大油砂工业带来了广阔的发展前景。目前加拿大的油砂开采工艺主要是依靠使用大量热(温)水来进行沥青的提纯(water-based extraction)。然而大规模油砂的开发与开采,对环境造成了极大的危害。大量热(温)水的耗用,对水资源与能源是极大的浪费与污染。首先大量的水资源从Athabasca河抽提,造成河周围城市的用水紧张,同时加热用水,耗费大量的能源,尤其在冬季更加速了温室气体的排放(以油砂为原料制造一桶原油所释放的二氧化碳是传统油井制造同样原油的三倍,虽然其排放二氧化碳的总量在全球比例很小,但是燃料资源已经成为加拿大最快速增长的温室气体排放物)。其次这些过程用水在提纯沥青过程中受到污染,夹带有固体颗粒以及沥青,不能排放回Athabasca河,并被放置在尾矿池中。这些尾矿会污染地下水,随地下水的流动而污染更多区域,并有从尾矿池大坝泄漏到周边土壤和地表水中的巨大风险。此外,加拿大能源署还指出,油砂开采导致土地破坏,复垦的土地产量和土壤稳定性均发生退化。然而除此之外,这种基于以水为主的沥青提纯方式仍不能达到工业上的期望。提纯后的沥青中仍存在2～5%的水,以及0.5～1%的固体微细颗粒(这些水以乳化水的形式存在,并且水的表面富集微细颗粒,使得这些乳化水及微细固体颗粒能够稳定地存在于沥青中;同时沥青中的两性分子asphaltene具有表面活性,也能够稳定水的存在,使之成为稳定的油包水乳液),这些微量存在的物质在接下来沥青的炼制过程中将造成严重的危害。乳化水中存在的氯离子会腐蚀下游装置,微细颗粒则会结焦并使催化剂失活。另外,这种基于以水为主的沥青提纯方式不能全部将附着在砂石表面的沥青提取干净,造成沥青的回收率降低。因此,在近年来油砂大量开采的情况下,更加迫切地需要找到可以更好地提纯沥青并解决油砂开采中对水资源以及其他能源浪费与污染问题的方法。
近来,提出了采用非水(即使用溶剂)的方式进行沥青的提纯(non-aqueous extraction),此方法避免了使用大量的水资源,转而使用少量的溶剂,希望可以从根本上解决以上因使用大量的水而产生的各种问题。这种方式简单上说,是将溶剂与油砂混合,然后使用常规的分离手段(过滤,沉降等)除去水以及固体杂质从而得到“洁净”的沥青。但是此方法目前仍没有进行工业化生产。其主要原因是不能彻底去除沥青中的微细颗粒(<0.3μm)。最近发现在泡沫沥青的处理上(即froth treatment),如果加入直链正构烷烃(如正戊烷,正己烷或正庚烷)来代替石脑油(此过程为Paraffinic Froth Treatment,或称PFT过程),可彻底除去沥青中的杂质水以及固体颗粒,就连沥青中的asphaltene也会絮凝沉淀析出,得到满足工业要求的“洁净”沥青。从使用非水溶剂,彻底除去杂质,提纯“洁净”的沥青角度,PFT过程与理想中的采用非水方式提纯沥青如出一辙,因此可以借鉴PFT过程,进一步完善非水提纯沥青的方式。然而,有关PFT过程的机理至今没有达成共识。目前被广泛认可的PFT机理认为:正构烷烃的加入,使得沥青中的asphaltene絮凝并沉降析出,沥青中存在的乳化水以及微细颗粒会陷于asphaltene的絮凝团中并伴随着asphaltene的沉降而沉降。但是乳化水以及微细颗粒沉降析出是否一定与asphaltene的絮凝沉降有关,还未有相应的文献报道。如果能够了解PFT过程的机理,将对非水提纯沥青的方式起到重要的推动作用,更是对目前油砂开采业的一场革命性变革。本文意在研究PFT过程的机理,主要考察微细颗粒在纯有机溶剂中(即没有水,没有沥青,没有asphaltene絮凝沉淀的情况下)二氧化硅微球的分散状态及原因。
本文分别在宏观与微观的条件下研究了微米级二氧化硅微球(0.25μm)在非水(有机溶液)溶剂中的团聚。非水溶剂为甲苯-正庚烷按照不同体积配比得到的混合溶液,溶液通过改变甲苯的体积分数来改变溶液的芳香度。二氧化硅通过表面改性,分别使用未改性的(即干净的)以及沥青改性的(即沥青分子不可逆地吸附于二氧化硅表面)微球作为研究对象。在宏观的条件下考察了二氧化硅微球(表面未改性的以及沥青改性的)在非水溶剂中的自由沉降,沉降速度通过焙烧法由沉降曲线获得(使用超声振荡的方法均匀分散含有一定质量分数的二氧化硅微球的有机溶剂,停止超声,并开始计时,在零时刻,二氧化硅微球开始自由沉降,然后在相同的取样位置,不同的时间点,选取同样体积的样品,经过焙烧,采用差重法得到不同时间点固体颗粒的质量,然后用固体的质量对时间作图,得到一条近似幂函数的曲线,曲线的最初斜率则被认为是颗粒的沉降速度)。实验结果表明,沥青改性的二氧化硅微球在甲苯-正庚烷混合液中的自由沉降速度受混合溶液中甲苯体积分数的影响较大,即受溶液芳香度的影响较大。颗粒在100%甲苯中的自由沉降速度接近斯托克斯自由沉降速度(0.25μm单个二氧化硅微球在甲苯溶液中的自由沉降速度)。相反,在0%甲苯(100%正庚烷)中沥青改性的二氧化硅微球的自由沉降速度则远远大于其斯托克斯自由沉降速度。未改性的二氧化硅微球的沉降速度则受溶液芳香度的影响较小,并远远大于沥青改性的二氧化硅微球的沉降速度。
在微观实验中,首先通过显微镜观察了沥青改性的二氧化硅微球在甲苯-正庚烷的混合溶液中的分散状态。观察结果表明:二氧化硅微球在100%甲苯溶液中分散均匀,没有团聚现象发生。在含有50%的甲苯混合液中二氧化硅微球则形成了较小的团聚体,但是在0%甲苯(即100%正庚烷)溶液中则形成了较大的团聚体。正是这种在溶液中的不同分散状态,导致了宏观实验中二氧化硅微球在甲苯-正庚烷混合溶液中表现出不同的沉降速度。颗粒分散较均匀,则沉降速度较慢,颗粒易于团聚则沉降速度较快。然而颗粒的团聚与否与颗粒之间的相互作用密切相关,因此接下来,同样在微观的条件下,使用了micropipette技术更深一层研究玻璃(与二氧化硅性质相似)微球之间在甲苯或者正庚烷溶液中的作用。Micropipette是用毛细玻璃管在显微镜下研究微米级物质的状态及行为的一种技术。最初应用于医学和生物学领域,近年来被应用在工程领域以及油砂的研究当中。研究中将经过实验室锻造的市售毛细玻璃管放置在可三维调控的操作平台(micromanipulator)上,并将毛细管的顶端插入操作器皿中(器皿中已盛放有被研究的物质,由于本实验所有的操作必须都在有机溶剂的环境下进行,因此操作器皿也是特殊制造的,可操作的范围为0.5cm宽×2cm长×0.1cm高,有机溶剂由毛细力被限制在操作范围内,并全部由水覆盖,确保了操作环境的安全及结果的准确)在显微镜下对研究对象进行测试,实验的结果可以由连接的电脑进行实时监控。本实验的关键是毛细玻璃管的锻造,以及操作者对整套流程的熟练把握。使用的毛细玻璃管规格为外径1mm,内径0.7mm,首先使用市售拉伸仪器,加热毛细玻璃管的中间部分并轴向拉伸,制作成两段顶端成锥体形状并密闭的玻璃管,然后将密闭的玻璃管顶端在自行设计的仪器上锻造,将锥体的端部整齐平滑的切断,形成内径约为10μm的平整切口,毛细玻璃管的尾部则与针管相连接,依靠吸力来捕捉被研究的玻璃微球。玻璃微球也经过相同的表面改性,分为未改性的以及沥青改性的两种。实验中,由抽气针管控制,用开口的毛细玻璃管去捕捉被研究的玻璃微球,然后通过控制三维操作平台来移动毛细玻璃管,在有机溶剂中用被捕捉到的玻璃微球去触碰其它玻璃微球(测试包括能否在剪切力存在的情况下带动其他玻璃微球),来测试玻璃微球之间在不同有机溶液中作用力的大小。实验结果表明,未改性的玻璃微球之间在甲苯或正庚烷溶液中,以及沥青改性的玻璃微球之间在正庚烷溶液中都存在着较大的吸引力,被捕捉的玻璃微球即使在剪切力的存在下也可带动其他玻璃微球。然而经沥青改性的玻璃微球在甲苯溶液中未发现任何吸引力的存在。
颗粒之间的这种相互吸引力随后利用microcantilever技术进行了定量的测定。Microcantilever技术是micropipette技术的延伸,是将用于micropipette技术的毛细玻璃管制作成“潜望镜”的形状,即将毛细玻璃管锻造成带有两个直角弯并保持在同一水平面上。这种带有两个直角弯的micropipette即称为microcantilever。(直角弯均在自行设计的仪器上锻造完成,本实验中microcantilever的第一个直角弯距离micropipette的顶端约0.5mm,第二个直角弯折向相反方向,并距离第一个直角弯约5～6mm。)如果固定microcantilever的末端,并在microcantilever的前端施加一定的作用力,则必使悬臂产生形变,根据形变的大小以及microcantilever的弹性指数(根据玻璃的杨氏模量,由线性梁理论计算得到,每一个microcantilever的弹性指数根据其特有的尺寸都有所不同)即可计算得出作用力的数值,测量误差为±1mN/m。本实验首先将拉伸成锥形并前端密闭的毛细玻璃管顶部的玻璃融化成玻璃微球(直径约为30μm)作为考察对象(与micropipette实验中的玻璃微球相对应),然后再锻造成microcantilever,并放置在三维可操控平台的右侧。为完成玻璃微球之间作用力的测定,还需要另外一个玻璃微球,因此接下来,制作一个前端玻璃融化成微球的直的micropipette并放置在三维可操控平台的左侧。通过控制操作平台,将左右两侧的玻璃微球均放置在操作器皿中(与micropipette实验相同,均在有机溶剂中进行,并由水覆盖)使得两个微球的中心处于同一水平面,固定右侧的microcantilever,缓慢移动左侧的micropipette,使得micropipette顶端的玻璃微球接触到microcantilever顶端的微球,并缓慢往回拉动micropipette直到两个微球分开,此时microcantilever顶端的微球回复到初始位置。记录microcantilever顶端微球的变化位置,根据已经计算得到的该microcantilever的弹性指数即可计算出这两个玻璃微球在此有机溶剂中的吸引力。为确保实验的准确度,microcantilever以及micropipette不重复使用。玻璃微球也按照同样的方式分别进行表面改性。实验结果与宏观颗粒沉降实验结果相比较得到:未改性的玻璃微球在甲苯-正庚烷混合溶液中的吸引力较大,并且随着溶液中甲苯体积分数的增加而减少,颗粒的沉降速度与其相互作用力没有明显的关联。这是因为即使在玻璃微球之间作用力最小的情况下(即在100%甲苯溶液中),颗粒之间的作用力也足够使得颗粒团聚并快速地沉降。经沥青改性的玻璃微球在甲苯-正庚烷混合溶液中的吸引力与颗粒的沉降速度有明显的关联,作用力越大则颗粒的沉降速度越快,颗粒之间作用力的大小也随着溶液中甲苯体积分数的增加而减少,在100%甲苯溶液中,颗粒之间未发现有吸引力的存在。
不同表面改性的二氧化硅微球经由X射线光电子能谱分析与比较后发现,在未改性的二氧化硅微球表面探测到强烈的氧,硅元素信号;在沥青改性的二氧化硅表面除了发现以上元素信号外,还发现了硫和氮的信号(可以用来评估沥青是否吸附在二氧化硅的表面),分析结果还表明沥青改性的二氧化硅表面吸附的沥青层厚度小于5nm。
沥青改性的二氧化硅微球在含有沥青的有机溶液中的团聚也进行了探索性的研究。宏观的颗粒沉降实验表明,溶液中沥青的含量越高,二氧化硅微球分散的越好,沉降速度越低。同时,经asphaltene改性,以及经不含asphaltene的沥青改性的二氧化硅微球在甲苯-正庚烷混合溶液中的沉降速度也进行了测定,结果发现与沥青改性的二氧化硅微球的沉降速度相类似。由于沥青中的asphaltene组分会在正庚烷溶剂的作用下絮凝,从而影响颗粒之间作用力的测定,因此沥青改性的二氧化硅微球之间在沥青-甲苯-正庚烷混合溶液中的作用力在本论文中没有进行论述。
The aggregation of micron-sized silica particles in non-aqueous (i.e. hydrocarbon) media was examined on both the macroscopic and microscopic scales. The silica surfaces were either“clean”(i.e. untreated) or“treated”(i.e. with irreversibly adsorbed materials from Athabasca bitumen); the hydrocarbons were mixtures of toluene and n-heptane at various ratios (to allow for different degrees of“aromaticity”in the solvent). On the macroscopic scale, gravity settling of the silica particles in non-aqueous media was monitored, and particle-particle interactions were characterized semi-empirically by the initial rates of sedimentation. On the microscopic scale, the microscope images of suspensions of bitumen-treated silica in non-aqueous media clear presented that the particles began to manifest themselves as large aggregates, with the floc size increasing seemingly monotonically with decreasing solvent aromaticity. Moreover, the interactions between individual glass spheres (both untreated and bitumen-treated) were directly examined using micropipette technique in non-aqueous media. It was found that there were interactions existed between two untreated glass spheres in toluene and in n-heptane, and also existed between two bitumen-treated glass spheres in n-heptane. However, there were no interactions between two bitumen-treated glass spheres in toluene. The interactions (i.e. adhesive forces) between individual glass spheres were then directly quantified using the microcantilever technique (again, in non-aqueous liquids). It was found that, for untreated silica spheres, the settling rates of the suspensions were relatively insensitive to the interparticle adhesive forces. This is in contrast to the case for treated silica particles, where strong correlation was observed between the settling rate and particle-particle adhesion. The surfaces of both bitumen-treated and untreated silica particles were further investigated by X-ray photoelectron spectroscopic analysis. It was observed that N and S species that coming from bitumen materials existed on the surface of bitumen-treated silica comparing to the untreated silica particles. Supposing these bitumen staff was evenly adsorbed onto the surface of silica (in ideal situation), the thickness of this coating is less than 5 nm. Besides, the preliminary study on the gravity settling of the bitumen-treated silica particles in non-aqueous media (toluene-heptane mixture with bitumen) was also conducted. And it was found that silica settled slower when bitumen exists. These findings may have important relevance to the commercial“paraffinic froth treatment”process.
沥青是重质原油,其密度比传统原油高很多;在浅部地层中的沥青粘度相当高,流动性很小甚至几乎不流动,一般不能以打井开采原油、稠油的方法来提取油砂中的沥青。目前开采油砂的方式一般分为露天开采法与井下开采法两种。加拿大的油砂开采中,大约有20%使用露天开采法,80%使用井下开采法。露天开采仅用于埋深小于75米的油砂矿,这个方法实际上就是将地表的土壤,植被等用卡车和铲子除去,露出油砂直接开采,具有资源回收率高、可用大型自动化机械设备、生产安全等特点。井下开采方式适用于埋深大于75米的油砂矿,主要技术有:蒸汽吞吐(CSS)、蒸汽辅助重力驱油(SAGD)和汽化萃取(VAPEX)等。
目前,露天开采在技术上较为成熟,加拿大及委内瑞拉等都已形成大规模的工业开采。其主要过程是:油砂被挖掘后由装载量达数百吨的巨型卡车运到粉碎系统,被粉碎机粉碎到颗粒粒度为30～40cm左右,再传送到下一级滚筒粉碎系统,在这个系统中,没有利用价值的岩石先从油砂中分离出来,剩下的油砂再与40°C左右的大量热水充分混合、粉碎,得到颗粒粒度大约5cm左右的浆状油砂。浆状油砂被泵送到下游的萃取分离装置,在输送的过程中,油砂在管道中进一步得到混合。在主分离器中,油砂被初步分离成粗沥青、水和沙子。接下来,粗沥青被送入重力分离容器中,通入工业风,沥青随工业风鼓泡而出,形成飘在表面的泡沫沥青。沙砾、泥浆、水等残留物沉入容器底部,并被泵送到残渣处理系统。生成的泡沫沥青(沥青含量为60%,水含量为30%,固体颗粒为10%)被送入泡沫沥青处理系统(froth treatment),在该系统中加入石脑油做溶剂,降低沥青的粘度,并进一步将水、固体颗粒与沥青分离,得到较高纯度、粘度适中并便于管道输送的沥青。当这种稀释了的沥青被送到改质装置后,石脑油则从沥青中被分离出来,并被送回到froth treatment系统循环利用,沥青则被送入到下一道工序生产合成原油。
当前有利的高油价形势和丰富的油砂资源储量,为加拿大油砂工业带来了广阔的发展前景。目前加拿大的油砂开采工艺主要是依靠使用大量热(温)水来进行沥青的提纯(water-based extraction)。然而大规模油砂的开发与开采,对环境造成了极大的危害。大量热(温)水的耗用,对水资源与能源是极大的浪费与污染。首先大量的水资源从Athabasca河抽提,造成河周围城市的用水紧张,同时加热用水,耗费大量的能源,尤其在冬季更加速了温室气体的排放(以油砂为原料制造一桶原油所释放的二氧化碳是传统油井制造同样原油的三倍,虽然其排放二氧化碳的总量在全球比例很小,但是燃料资源已经成为加拿大最快速增长的温室气体排放物)。其次这些过程用水在提纯沥青过程中受到污染,夹带有固体颗粒以及沥青,不能排放回Athabasca河,并被放置在尾矿池中。这些尾矿会污染地下水,随地下水的流动而污染更多区域,并有从尾矿池大坝泄漏到周边土壤和地表水中的巨大风险。此外,加拿大能源署还指出,油砂开采导致土地破坏,复垦的土地产量和土壤稳定性均发生退化。然而除此之外,这种基于以水为主的沥青提纯方式仍不能达到工业上的期望。提纯后的沥青中仍存在2～5%的水,以及0.5～1%的固体微细颗粒(这些水以乳化水的形式存在,并且水的表面富集微细颗粒,使得这些乳化水及微细固体颗粒能够稳定地存在于沥青中;同时沥青中的两性分子asphaltene具有表面活性,也能够稳定水的存在,使之成为稳定的油包水乳液),这些微量存在的物质在接下来沥青的炼制过程中将造成严重的危害。乳化水中存在的氯离子会腐蚀下游装置,微细颗粒则会结焦并使催化剂失活。另外,这种基于以水为主的沥青提纯方式不能全部将附着在砂石表面的沥青提取干净,造成沥青的回收率降低。因此,在近年来油砂大量开采的情况下,更加迫切地需要找到可以更好地提纯沥青并解决油砂开采中对水资源以及其他能源浪费与污染问题的方法。
近来,提出了采用非水(即使用溶剂)的方式进行沥青的提纯(non-aqueous extraction),此方法避免了使用大量的水资源,转而使用少量的溶剂,希望可以从根本上解决以上因使用大量的水而产生的各种问题。这种方式简单上说,是将溶剂与油砂混合,然后使用常规的分离手段(过滤,沉降等)除去水以及固体杂质从而得到“洁净”的沥青。但是此方法目前仍没有进行工业化生产。其主要原因是不能彻底去除沥青中的微细颗粒(<0.3μm)。最近发现在泡沫沥青的处理上(即froth treatment),如果加入直链正构烷烃(如正戊烷,正己烷或正庚烷)来代替石脑油(此过程为Paraffinic Froth Treatment,或称PFT过程),可彻底除去沥青中的杂质水以及固体颗粒,就连沥青中的asphaltene也会絮凝沉淀析出,得到满足工业要求的“洁净”沥青。从使用非水溶剂,彻底除去杂质,提纯“洁净”的沥青角度,PFT过程与理想中的采用非水方式提纯沥青如出一辙,因此可以借鉴PFT过程,进一步完善非水提纯沥青的方式。然而,有关PFT过程的机理至今没有达成共识。目前被广泛认可的PFT机理认为:正构烷烃的加入,使得沥青中的asphaltene絮凝并沉降析出,沥青中存在的乳化水以及微细颗粒会陷于asphaltene的絮凝团中并伴随着asphaltene的沉降而沉降。但是乳化水以及微细颗粒沉降析出是否一定与asphaltene的絮凝沉降有关,还未有相应的文献报道。如果能够了解PFT过程的机理,将对非水提纯沥青的方式起到重要的推动作用,更是对目前油砂开采业的一场革命性变革。本文意在研究PFT过程的机理,主要考察微细颗粒在纯有机溶剂中(即没有水,没有沥青,没有asphaltene絮凝沉淀的情况下)二氧化硅微球的分散状态及原因。
本文分别在宏观与微观的条件下研究了微米级二氧化硅微球(0.25μm)在非水(有机溶液)溶剂中的团聚。非水溶剂为甲苯-正庚烷按照不同体积配比得到的混合溶液,溶液通过改变甲苯的体积分数来改变溶液的芳香度。二氧化硅通过表面改性,分别使用未改性的(即干净的)以及沥青改性的(即沥青分子不可逆地吸附于二氧化硅表面)微球作为研究对象。在宏观的条件下考察了二氧化硅微球(表面未改性的以及沥青改性的)在非水溶剂中的自由沉降,沉降速度通过焙烧法由沉降曲线获得(使用超声振荡的方法均匀分散含有一定质量分数的二氧化硅微球的有机溶剂,停止超声,并开始计时,在零时刻,二氧化硅微球开始自由沉降,然后在相同的取样位置,不同的时间点,选取同样体积的样品,经过焙烧,采用差重法得到不同时间点固体颗粒的质量,然后用固体的质量对时间作图,得到一条近似幂函数的曲线,曲线的最初斜率则被认为是颗粒的沉降速度)。实验结果表明,沥青改性的二氧化硅微球在甲苯-正庚烷混合液中的自由沉降速度受混合溶液中甲苯体积分数的影响较大,即受溶液芳香度的影响较大。颗粒在100%甲苯中的自由沉降速度接近斯托克斯自由沉降速度(0.25μm单个二氧化硅微球在甲苯溶液中的自由沉降速度)。相反,在0%甲苯(100%正庚烷)中沥青改性的二氧化硅微球的自由沉降速度则远远大于其斯托克斯自由沉降速度。未改性的二氧化硅微球的沉降速度则受溶液芳香度的影响较小,并远远大于沥青改性的二氧化硅微球的沉降速度。
在微观实验中,首先通过显微镜观察了沥青改性的二氧化硅微球在甲苯-正庚烷的混合溶液中的分散状态。观察结果表明:二氧化硅微球在100%甲苯溶液中分散均匀,没有团聚现象发生。在含有50%的甲苯混合液中二氧化硅微球则形成了较小的团聚体,但是在0%甲苯(即100%正庚烷)溶液中则形成了较大的团聚体。正是这种在溶液中的不同分散状态,导致了宏观实验中二氧化硅微球在甲苯-正庚烷混合溶液中表现出不同的沉降速度。颗粒分散较均匀,则沉降速度较慢,颗粒易于团聚则沉降速度较快。然而颗粒的团聚与否与颗粒之间的相互作用密切相关,因此接下来,同样在微观的条件下,使用了micropipette技术更深一层研究玻璃(与二氧化硅性质相似)微球之间在甲苯或者正庚烷溶液中的作用。Micropipette是用毛细玻璃管在显微镜下研究微米级物质的状态及行为的一种技术。最初应用于医学和生物学领域,近年来被应用在工程领域以及油砂的研究当中。研究中将经过实验室锻造的市售毛细玻璃管放置在可三维调控的操作平台(micromanipulator)上,并将毛细管的顶端插入操作器皿中(器皿中已盛放有被研究的物质,由于本实验所有的操作必须都在有机溶剂的环境下进行,因此操作器皿也是特殊制造的,可操作的范围为0.5cm宽×2cm长×0.1cm高,有机溶剂由毛细力被限制在操作范围内,并全部由水覆盖,确保了操作环境的安全及结果的准确)在显微镜下对研究对象进行测试,实验的结果可以由连接的电脑进行实时监控。本实验的关键是毛细玻璃管的锻造,以及操作者对整套流程的熟练把握。使用的毛细玻璃管规格为外径1mm,内径0.7mm,首先使用市售拉伸仪器,加热毛细玻璃管的中间部分并轴向拉伸,制作成两段顶端成锥体形状并密闭的玻璃管,然后将密闭的玻璃管顶端在自行设计的仪器上锻造,将锥体的端部整齐平滑的切断,形成内径约为10μm的平整切口,毛细玻璃管的尾部则与针管相连接,依靠吸力来捕捉被研究的玻璃微球。玻璃微球也经过相同的表面改性,分为未改性的以及沥青改性的两种。实验中,由抽气针管控制,用开口的毛细玻璃管去捕捉被研究的玻璃微球,然后通过控制三维操作平台来移动毛细玻璃管,在有机溶剂中用被捕捉到的玻璃微球去触碰其它玻璃微球(测试包括能否在剪切力存在的情况下带动其他玻璃微球),来测试玻璃微球之间在不同有机溶液中作用力的大小。实验结果表明,未改性的玻璃微球之间在甲苯或正庚烷溶液中,以及沥青改性的玻璃微球之间在正庚烷溶液中都存在着较大的吸引力,被捕捉的玻璃微球即使在剪切力的存在下也可带动其他玻璃微球。然而经沥青改性的玻璃微球在甲苯溶液中未发现任何吸引力的存在。
颗粒之间的这种相互吸引力随后利用microcantilever技术进行了定量的测定。Microcantilever技术是micropipette技术的延伸,是将用于micropipette技术的毛细玻璃管制作成“潜望镜”的形状,即将毛细玻璃管锻造成带有两个直角弯并保持在同一水平面上。这种带有两个直角弯的micropipette即称为microcantilever。(直角弯均在自行设计的仪器上锻造完成,本实验中microcantilever的第一个直角弯距离micropipette的顶端约0.5mm,第二个直角弯折向相反方向,并距离第一个直角弯约5～6mm。)如果固定microcantilever的末端,并在microcantilever的前端施加一定的作用力,则必使悬臂产生形变,根据形变的大小以及microcantilever的弹性指数(根据玻璃的杨氏模量,由线性梁理论计算得到,每一个microcantilever的弹性指数根据其特有的尺寸都有所不同)即可计算得出作用力的数值,测量误差为±1mN/m。本实验首先将拉伸成锥形并前端密闭的毛细玻璃管顶部的玻璃融化成玻璃微球(直径约为30μm)作为考察对象(与micropipette实验中的玻璃微球相对应),然后再锻造成microcantilever,并放置在三维可操控平台的右侧。为完成玻璃微球之间作用力的测定,还需要另外一个玻璃微球,因此接下来,制作一个前端玻璃融化成微球的直的micropipette并放置在三维可操控平台的左侧。通过控制操作平台,将左右两侧的玻璃微球均放置在操作器皿中(与micropipette实验相同,均在有机溶剂中进行,并由水覆盖)使得两个微球的中心处于同一水平面,固定右侧的microcantilever,缓慢移动左侧的micropipette,使得micropipette顶端的玻璃微球接触到microcantilever顶端的微球,并缓慢往回拉动micropipette直到两个微球分开,此时microcantilever顶端的微球回复到初始位置。记录microcantilever顶端微球的变化位置,根据已经计算得到的该microcantilever的弹性指数即可计算出这两个玻璃微球在此有机溶剂中的吸引力。为确保实验的准确度,microcantilever以及micropipette不重复使用。玻璃微球也按照同样的方式分别进行表面改性。实验结果与宏观颗粒沉降实验结果相比较得到:未改性的玻璃微球在甲苯-正庚烷混合溶液中的吸引力较大,并且随着溶液中甲苯体积分数的增加而减少,颗粒的沉降速度与其相互作用力没有明显的关联。这是因为即使在玻璃微球之间作用力最小的情况下(即在100%甲苯溶液中),颗粒之间的作用力也足够使得颗粒团聚并快速地沉降。经沥青改性的玻璃微球在甲苯-正庚烷混合溶液中的吸引力与颗粒的沉降速度有明显的关联,作用力越大则颗粒的沉降速度越快,颗粒之间作用力的大小也随着溶液中甲苯体积分数的增加而减少,在100%甲苯溶液中,颗粒之间未发现有吸引力的存在。
不同表面改性的二氧化硅微球经由X射线光电子能谱分析与比较后发现,在未改性的二氧化硅微球表面探测到强烈的氧,硅元素信号;在沥青改性的二氧化硅表面除了发现以上元素信号外,还发现了硫和氮的信号(可以用来评估沥青是否吸附在二氧化硅的表面),分析结果还表明沥青改性的二氧化硅表面吸附的沥青层厚度小于5nm。
沥青改性的二氧化硅微球在含有沥青的有机溶液中的团聚也进行了探索性的研究。宏观的颗粒沉降实验表明,溶液中沥青的含量越高,二氧化硅微球分散的越好,沉降速度越低。同时,经asphaltene改性,以及经不含asphaltene的沥青改性的二氧化硅微球在甲苯-正庚烷混合溶液中的沉降速度也进行了测定,结果发现与沥青改性的二氧化硅微球的沉降速度相类似。由于沥青中的asphaltene组分会在正庚烷溶剂的作用下絮凝,从而影响颗粒之间作用力的测定,因此沥青改性的二氧化硅微球之间在沥青-甲苯-正庚烷混合溶液中的作用力在本论文中没有进行论述。
The aggregation of micron-sized silica particles in non-aqueous (i.e. hydrocarbon) media was examined on both the macroscopic and microscopic scales. The silica surfaces were either“clean”(i.e. untreated) or“treated”(i.e. with irreversibly adsorbed materials from Athabasca bitumen); the hydrocarbons were mixtures of toluene and n-heptane at various ratios (to allow for different degrees of“aromaticity”in the solvent). On the macroscopic scale, gravity settling of the silica particles in non-aqueous media was monitored, and particle-particle interactions were characterized semi-empirically by the initial rates of sedimentation. On the microscopic scale, the microscope images of suspensions of bitumen-treated silica in non-aqueous media clear presented that the particles began to manifest themselves as large aggregates, with the floc size increasing seemingly monotonically with decreasing solvent aromaticity. Moreover, the interactions between individual glass spheres (both untreated and bitumen-treated) were directly examined using micropipette technique in non-aqueous media. It was found that there were interactions existed between two untreated glass spheres in toluene and in n-heptane, and also existed between two bitumen-treated glass spheres in n-heptane. However, there were no interactions between two bitumen-treated glass spheres in toluene. The interactions (i.e. adhesive forces) between individual glass spheres were then directly quantified using the microcantilever technique (again, in non-aqueous liquids). It was found that, for untreated silica spheres, the settling rates of the suspensions were relatively insensitive to the interparticle adhesive forces. This is in contrast to the case for treated silica particles, where strong correlation was observed between the settling rate and particle-particle adhesion. The surfaces of both bitumen-treated and untreated silica particles were further investigated by X-ray photoelectron spectroscopic analysis. It was observed that N and S species that coming from bitumen materials existed on the surface of bitumen-treated silica comparing to the untreated silica particles. Supposing these bitumen staff was evenly adsorbed onto the surface of silica (in ideal situation), the thickness of this coating is less than 5 nm. Besides, the preliminary study on the gravity settling of the bitumen-treated silica particles in non-aqueous media (toluene-heptane mixture with bitumen) was also conducted. And it was found that silica settled slower when bitumen exists. These findings may have important relevance to the commercial“paraffinic froth treatment”process.
引文
[1]. Liu JJ, Xu ZH, Masliyah J. Role of fine clays in bitumen extraction from oil sands. Aiche Journal, 2004. 50(8): 1917-1927.
[2]. Greene DL, Hopson JL, Li J. Have we run out of oil yet? Oil peaking analysis from an optimist's perspective. Energy Policy, 2006. 34(5): 515-531.
[3]. Clark KA, Pasternack DS. Hot water separation of bitumen from Alberta bituminous sand. Industrial and Engineering Chemistry, 1932. 24: 1410-1416.
[4]. Tipman R, Long YC, Shelfantook WE. Solvent process for bitumen separation from oil sands froth. 2001. United States Patent, Patent No. 6214213 B1.
[5]. Romanova UG, Yarranton HW, Schramm LL, Shelfantook WE. Investigation of oil sands froth treatment. Canadian Journal of Chemical Engineering, 2004. 82(4): 710-721.
[6]. Xu YM, Dabros T, Hamza H. Study on the mechanism of foaming from bitumen froth treatment tailings. Journal of Dispersion Science and Technology, 2007. 28: 413-418.
[7]. Long YC, Dabros T, Hamza H. Stability and settling characteristics of solvent-diluted bitumen emulsions. Fuel, 2002. 81(15): 1945-1952.
[8]. Romanova UG, Valinasab M, Stasiuk EN, Yarranton HW. The effect of oil sands bitumen extraction conditions on froth treatment performance. Canadian Inst Mining Metallurgy Petroleum, 2006: 36-45.
[9]. Masliyah J, Zhou ZJ, Xu ZH, Czarnecki J, Hamza H. Understanding water-based bitumen extraction from athabasca oil sands. Canadian Journal of Chemical Engineering, 2004. 82(4): 628-654.
[10]. Woynillowicz D, Baker CS, Raynolds M. Oil Sands Fever: The Environmental Implications of Canada's Oil Sands Rush, 2005.
[11]. Butts KH. The strategic importance of water. Parameters, US Army War College Quarterly Spring. 1997. XXVII: 66-83.
[12]. Yang XL, Czarnecki J. The effect of naphtha to bitumen ratio on properties of water in diluted bitumen emulsions. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 2002. 211(2-3): 213-222.
[13]. Kotlyar LS, Deslands Y, Sparks BD, Kodama H, Schutte R. Characterization of colloidal solids from athabasca fine tails. Clays and Clay Minerals, 1993. 41(3): 341-345.
[14]. Gu GX, Zhang LY, Wu XA, Xu ZH, Masliyah J. Isolation and characterization of interfacial materials in bitumen emulsions. Energy & Fuels, 2006. 20(2): 673-681.
[15]. Yan NX, Gray MR, Masliyah JH. On water-in-oil emulsions stabilized by fine solids. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 2001. 193(1-3): 97-107.
[16]. Yan NX, Masliyah JH. Adsorption and desorption of clay particles at the oil-water interface. Journal of Colloid and Interface Science, 1994. 168(2): 386-392.
[17]. Saukowski DM, Yarranton HW. Oilfield solids and water-in-oil emulsion stability. Journal of Colloid and Interface Science, 2005. 285(2): 821-833.
[18]. Gu G, Xu Z, Nandakumar K, Masliyah JH. Influence of water-soluble and water-insoluble natural surface active components on the stability of water-in-toluene-diluted bitumen emulsion. Fuel, 2002. 81(14): 1859-1869.
[19]. Bensebaa F, Kotlyar LS, Sparks BD, Chung KH. Organic coated solids in athabasca bitumen: Characterization and process implications. Canadian Soc Chemical Engineering, 2000: 610-616.
[20]. Zhao SQ, Kotlyar LS, Sparks BD, Woods JR, Gao JS, Chung KH. Solids contents, properties and molecular structures of asphaltenes from different oilsands. Fuel, 2001. 80(13): 1907-1914.
[21]. Tu Y, Li ZF, Pleizier G, Ng S, Chung KH. Separation and characterisation of problematic solids from athabasca oil sands and waste unit samples. Canadian Journal of Chemical Engineering, 2004. 82(4): 678-686.
[22]. Kotlyar LS, Sparks BD, Woods JR, Chung KH. Solids associated with the asphaltene fraction of oil sands bitumen. Energy & Fuels, 1999. 13: 346-350.
[23]. Liu JJ, Xu ZH, Masliyah J. Interaction between bitumen and fines in oil sands extraction system: Implication to bitumen recovery. Canadian Journal of Chemical Engineering, 2004. 82(4): 655-666.
[24]. Wallace D, Tipman R, Komishke B, Wallwork V, Perkins E. Fines/water interactions and consequences of the presence of degraded illite on oil sands extractability. Canadian Journal of Chemical Engineering, 2004. 82(4): 667-677.
[25]. Dai Q, Chung KH. Bitumen-sand interaction in oil sand processing. Fuel, 1995. 74(12): 1858-1864.
[26]. Tu Y, O' Carroll JB, Kotlyar LS, Sparks BD, Ng BD, Chung KH, Cuddy G. Recovery of bitumen from oilsands: gelation of ultra-fine clay in the primary separation vessel. Fuel, 2005. 84(6): 653-660.
[27]. Sparks BD, Kotlyar LS, O'Carroll JB, Chung KH. Athabasca oil sands: effect of organic coated solids on bitumen recovery and quality. Journal of Petroleum and Engineering, 2003. 39: 417-430.
[28]. Sparks BD, Meadus FW. A study of some factors affecting solvent losses in the solvent-extraction-spherical agglomeration of oil sands. Fuel Processing Technology, 1981. 4(4): 251-264.
[29]. Meadus FW, Chevrier PJ, Sparks BD. Solvent-extraction of athabasca oil-sand in a rotating mill. 1. Dissolution of bitumen. Fuel Processing Technology, 1982. 6(3): 277-287.
[30]. Meadus FW. Bassaw BP, Sparks BD. Solvent-extraction of athabasca oil-sand in a rotating mill. 2. Solids-liquid separation and bitumen quality. Fuel Processing Technology, 1982. 6(3): 289-300.
[31]. Sparks BD, Meadus FW, Hoefele E. Solvent extraction spherical agglomeration of oil sands. Environment International, 1988. 14(4): VIII-VIII.
[32]. Oyler JF, Brand JD, Zavada R. Circular solvent extractor. 1987. United States Patent, Patent No. 4683029.
[33]. Karnofsky GB. Process for solvent extraction of bitumen from oil sand. 1984. United States Patent, Patent No. 4448667.
[34]. Johnson CB. Thin layer solvent extraction. 1999. United States Patent, Patent No.5911541.
[35]. Rosenbloom WJ. Recovery of oil from tar sand by an improved extraction process. 1975. United States Patent, Patent No. 3875046.
[36]. Benson AM. Filtration of solvent-water extraction tar sand. 1969. United States Patent, Patent No. 3459653.
[37]. Savage WE, Cheney HA. Process of extracting tar from tar sand. 1971. United States Patent, Patent No. 3553099.
[38]. Hsieh RC, Clifford RK. Solvent extraction process for recovering bitumen from tar sand. 1987. United States Patent, Patent No. 4676889.
[39]. Farnand JR, Meadus FW, Sparks BD. Removal of intractable fine solids from bitumen solutions obtained by solvent extraction of oil sands. Fuel Processing Technology, 1985. 10(2): 131-144.
[40]. Sparks BD, Meadus FW. Combined solvent extraction and agglomeration technique for the recovery of bitumen from tar sands. Energy Processing/Canada, 1979. 72(1): 55-61.
[41]. Sparks BD, Meadus FW, Kumar A, Woods JR. The effect of asphaltene content on solvent selection for bitumen extraction by the sesa process. Fuel, 1992. 71(12): 1349-1353.
[42]. Chia J, Yeung A. Strength of asphaltene clusters in heptane-diluted bitumen. Fuel, 2004. 83(4-5): 619-621.
[43]. Madge DN, Garner WN. Theory of asphaltene precipitation in a hydrocarbon cyclone. Minerals Engineering, 2007. 20(4): 387-394.
[44]. Anonymous. Worldwide look at reserves and production. Oil and Gas Journal, 2004. 102(47): 22-23.
[45]. Darcovich K, Kotlyar LS, Tse WC, Ripmeester JA, Capes CE, Sparks BD. Wettability of organic-rich solids separated from athabasca oil sands. Energy & Fuels, 1989. 3(3): 386-391.
[46]. Anonymous. Canada's oilsands resource has become the world's hottest hydrocarbon play. Oil & Gas Journal, 2006. 104(22): 4-11.
[47]. Mossop GD. Geology of the athabasca oil sands. Science, 1980. 207(4427): 145-152.
[48]. Czarnecka E, Gillott JE. Formation and characterization of clay complexes with bitumen from athabasca oil sand. Clays and Clay Minerals, 1980. 28(3): 197-203.
[49]. Peramanu S, Pruden BB, Rahimi P. Molecular weight and specific gravity distributions for athabasca and cold lake bitumens and their saturate, aromatic, resin, and asphaltene fractions. Industrial & Engineering Chemistry Research, 1999. 38(8): 3121-3130.
[50]. Fuhr BJ, Hawrelechko C, Holloway LR, Huang HB. Comparison of bitumen fractionation methods. Energy & Fuels, 2005. 19(4): 1327-1329.
[51]. Woods J, Kung J, Kingston D, Kotlyar L, Sparks B, McCracken T. Canadian crudes: A comparative study of SARA fractions from a modified HPLC separation technique. Oil & Gas Science and Technology-Revue De L Institut Francais Du Petrole, 2008. 63(1): 151-163.
[52]. Aske N, Kallevik H, Sjoblom J. Determination of saturate, aromatic, resin, and asphaltenic (SARA) components in crude oils by means of infrared and near-infrared spectroscopy. Energy & Fuels, 2001. 15(5): 1304-1312.
[53]. Ignasiak T, Kempjones AV, Strausz OP. Molecular-structure of athabasca asphaltene-clevage of carbon-sulfur bonds by radical ion electron-transfer reactions. Journal of Organic Chemistry, 1977. 42(2): 312-320.
[54]. Trejo F, Centeno G, Ancheyta J. Precipitation, fractionation and characterization of asphaltenes from heavy and light crude oils. Fuel, 2004. 83(16): 2169-2175.
[55]. Dickie JP, Yen TF. Macrostructures of asphaltic fractions by various instrumental methods. Analytical Chemistry, 1967. 39(14): 1847-1852.
[56]. Sztukowski DM, Jafari M, Alboudwarej H, Yarranton HW. Asphaltene self-association and water-in-hydrocarbon emulsions. Journal of Colloid and Interface Science, 2003. 265(1): 179-186.
[57]. Mitchell DL, Speight JG. Solubility of asphaltenes in hydrocarbon solvents. Fuel, 1973. 52(2): 149-152.
[58]. Angle CW, Long YC, Hamza H, Lue L. Precipitation of asphaltenes from solvent-diluted heavy oil and thermodynamic properties of solvent-diluted heavy oil solutions. Fuel, 2006. 85(4): 492-506.
[59]. Sabbagh O, Akbarzadeh K, Badamchi-Zadeh A, Svrcek WY, Yarranton HW. Applying the PR-EoS to asphaltene precipitation from n-alkane diluted heavy oils and bitumens. Energy & Fuels, 2006. 20(2): 625-634.
[60]. Andersen SI, Birdi KS. Influence of temperature and solvent on the precipitation of asphaltenes. Fuel Science and Technology International, 1990. 8(6): 593-615.
[61]. Mitchell DL, Speight JG. The solubility of asphaltenes in hydrocarbon solvents. Fuel, 1973. 52(2): 149-152.
[62]. Victorov AI, Firoozabadi A. Thermodynamic micellization model of asphaltene precipitation from petroleum fluids. Aiche Journal, 1996. 42(6): 1753-1764.
[63]. Hu YF, Guo TM. Effect of temperature and molecular weight of n-alkane precipi tation. Fluid Phase Equilibria, 2001. 192(1-2): 13-25.
[64]. Alboudwarej H, Beck J, Svrcek WY, Yarranton HW, Akbarzadeh K. Sensitivity of asphaltene properties to separation techniques. Energy & Fuels, 2002. 16(2): 462-469.
[65]. Hu YF, Guo TM. Effect of temperature and molecular weight of n-alkane precipitants on asphaltene precipitation. Fluid Phase Equilibria, 2001. 192(1-2): 13-25.
[66]. Pillon L.Z. Effect of experimental conditions and solvents on the precipitation and composition of asphaltenes. Petroleum Science and Technology, 2001. 19(5-6): 673-683.
[67]. Ancheyta J, Centeno G, Trejo F, Marroquin G, Garcia JA, Tenorio E, Torres A. Extraction and characterization of asphaltenes from different crude oils and solvents. Energy & Fuels, 2002. 16(5): 1121-1127.
[68]. Oliensis GL. A qualitative test for determining the degree of heterogeneity of asphalts. ASTM proc of the 36th Ann Meeting Chicago, 1933. (33): 715-728.
[69]. Fossen M, Kallevik H, Knudsen KD, Sjoblom J. Asphaltenes precipitated by a two-step precipitation procedure. 1. Interfacial tension and solvent properties. Energy & Fuels, 2007. 21(2): 1030-1037.
[70]. Fossen M, Sj?blom J, Kallevik H, Jakobsson J. A new Procedure for direct precipitation and fractionation of asphaltenes from crude oil. Journal of Dispersion Science and Technology, 2007. 28(1): 193-197.
[71]. Yang XL, Hamza H, Czarnecki J. Investigation of subfractions of athabasca asphaltenes and their role in emulsion stability. Energy & Fuels, 2004. 18(3): 770-777.
[72]. Zhang LY, Lawrence S, Xu ZH, Masliyah JH. Studies of Athabasca asphaltene Langmuir films at air-water interface. Journal of Colloid and Interface Science, 2003. 264(1): 128-140.
[73]. Strausz OP, Mojelsky TW, Lown EM. The molecular-structure of asphaltene-an unfolding story. Butterworth-Heinemann Ltd, 1992: 1355-1363.
[74]. Lawrence S, Zhang LY, Xu ZH, Masliyah J. Langmuir and Langmuir-Blodgett asphaltene films at heptane-water interface. Canadian Journal of Chemical Engineering, 2004. 82(4): 821-828.
[75]. Mojelsky TW, Ignasiak TM, Frakman Z, Mclntyre DD, Lown EM, Montgomery DS, Strausz OP. Structural features of alberta oil sand bitumen and heavy oil asphaltenes. Energy & Fuels, 1992. 6(1): 83-96.
[76]. McLean JD, Kilpatrick PK. Effects of asphaltene aggregation in model heptane-toluene mixtures on stability of water-in-oil emulsions. Journal of Colloid and Interface Science, 1997. 196(1): 23-34.
[77]. Li J, Huang XS, Zhang YZ, Xu M. Bitumen Colloidal and Structural Stability Characterization. Road Materials and Pavement Design, 2009. 10: 45-59.
[78]. Jada A, Salou A. Effects of the asphaltene and resin contents of the bitumens on the water-bitumen interface properties. Journal of Petroleum Science and Engineering, 2002. 33(1-3): 185-193.
[79]. Zhao B, Becerra M, Shaw JM. On Asphaltene and Resin Association in Athabasca Bitumen and Maya Crude Oil. Energy & Fuels, 2009. 23: 4431-4437.
[80]. Carty WM. The colloidal nature of kaolinite. American Ceramic Society Bulletin, 1999. 78(8): 72-76.
[81]. Mitchell JK. Fundamentals of soil behavior. New York: John Wiley and Sons, Inc. 2nd ed. 1993: 32.
[82]. Madge DN, Romero J, Strand WL. Hydrocarbon cyclones in hydrophilic oil sand environments. Minerals Engineering, 2004. 17:625-636.
[83]. Li ZF, Kung J, Tu Y, Kotlyar LS, Chung KH. Characterization of ultra fine solids (BS) in athabasca bitumen. Chinese Journal of Structural Chemistry, 2004. 23(7): 751-754.
[84]. Takamura K. Microscopic structure of athabasca oil sand. Canadian Journal of Chemical Engineering, 1982. 60(4): 538-545.
[85]. Yarranton HW, Hussein H, Masliyah JH. Water-in-hydrocarbon emulsions stabilized by asphaltenes at low concentrations. Journal of Colloid and Interface Science, 2000. 228(1): 52-63.
[86]. Henry JD, Prudich ME, Lau C. Liquid, liquid, solid systems: role of water in particle removal from hydrocarbon suspension. Colloids and Surfaces, 1980. 1( 3-4): 335- 348.
[87]. Hsu EC, Merchant P, Smith DL, Kelly KP, Lacy SM. Process for the removal of solids from an oil. 1987. United States Patent No: 4692237.
[88]. Zhou ZA, Hussein H, Xu ZH, Czarnecki J, Masliyah JH. Interaction of ionic species and fine solids with a low energy hydrophobic surface from contact angle measurement. Journal of Colloid and Interface Science, 1998. 204(2): 342-349.
[89]. Li H, Zhou ZA, Xu Z, Masliyah JH. Role of acidified sodium silicate in low temperature bitumen extraction from poor-processing oil sand ores. Industrial & Engineering Chemistry Research, 2005. 44(13): 4753-4761.
[90]. Wang SY, Chung KH, Masliyah JH, Gray MR. Deposition of fine particles in packed beds at hydrotreating conditions: Role of surface chemistry. Industrial & Engineering Chemistry Research, 1999. 38(12): 4878-4888.
[91]. Ding XL, Repka C, Xu ZH, Masliyah J. Effect of illite clay and divalent cations on bitumen recovery. Canadian Journal of Chemical Engineering, 2006. 84(6): 643-650.
[92]. Sheu EY. Petroleum asphaltene-properties, characterization, and issues. Energy & Fuels, 2002. 16: 74-82.
[93]. Seki H, Kumata F. Structural change of petroleum asphaltenes and resins by hydrodemetallization. Energy & Fuels, 2000. 14(5): 980-985.
[94]. Groenzin H, Mullins OC. Molecular size and structure of asphaltenes from various sources. Energy & Fuels, 2000. 14(3): 677-684.
[95]. Long J, Xu ZH, Masliyah JH. Single molecule force spectroscopy of asphaltene aggregates. Langmuir, 2007. 23(11): 6182-6190.
[96]. Barre L, Simon S, Palermo T. Solution properties of asphaltenes. Langmuir, 2008. 24(8): 3709-3717.
[97]. Akbarzadeh K, Alboudwarej H, Svrcek WY, Yarranton HW. A generalized regular solution model for asphaltene precipitation from n-alkane diluted heavy oils and bitumens. Fluid Phase Equilibria, 2005. 232(1-2): 159-170.
[98]. Cook DLM. Another notch in the oilsands technology belt. Oilsands Review, March 2007: 43-45.
[99]. Rao BML, Serrano JE. Viscometric study of aggregation interactions in heavy oil. Petroleum Science and Technology, 1986. 4(4): 483-500.
[100]. Kotlyar LS, Sparks BD, Woods JR, Raymond S, LePage Y, Shelfantook W. Distribution and types of solids associated with bitumen. Petroleum Science and Technology, 1998. 16(1-2): 1-19.
[101]. Ferworn KA, Mehrotra AK, Svrcek WY. Measurement of asphaltene agglomeration from cold lake bitumen diluted with n-alkanes. Canadian Journal of Chemical Engineering, 1993. 71(5): 699-703.
[102]. Akbarzadeh KH, Svrcek AWK, Yarranton HW. Regular solution model for asphaltene precipitation from bitumen-alkane systems, Proceedings of the Can. Intern. Pet. Conf., Calgary, 2003: 023.
[103]. Rastegari K, Beck J, Svrcek W, Yarranton H. Measurement and modelling of asphaltene flocculation from Athabasca bitumen. Proceedings of the Can. Intern. Pet. Conf., Calgary, 2003: 059.
[104]. Rahmani NHG, Dabros T, Masliyah JH. Online optical monitoring of asphaltene aggregation. Industrial & Engineering Chemistry Research, 2005. 44(1): 75-84.
[105]. Fenistein D, Barre L, Broseta D, Espinat D, Livet A, Roux JN, Scarsella M. Viscosimetric and neutron scattering study of asphaltene aggregates in mixed toluene/heptane solvents. Langmuir, 1998. 14(5): 1013-1020.
[106]. Oliver DR. The sedimentation of suspensions of closely-sized spherical particles. Chemical Engineering Science, 1961. 15(3-4): 230-242.
[107]. Whitmore RL. The sedimentation of suspensions of spheres. British Journal of Applied Physics, 1955. 6(7): 239-245.
[108]. Coe HB, Clevenger GH. Methods for determining the capacities of slime-settling tanks. Transactions of the American Institute of Mining and Metallurgical Engineers, 1916. 55: 356-384.
[109]. Richardson JF, Harker JH, Backhurst JR. Coulson and Richardson's Chemical Engineering fifth ed. Particle technology and separation process. Butterworth-Heinemann, 2002. 2.
[110]. Gregory J. Fundamentals of flocculation. Critical Reviews in Environmental Control, 1989. 19(3): 185-230.
[111]. Michaels AS, Bolger JC. Settling Rates and Sediment Volumes of Flocculated Kaolin Suspensions. Industrial & Engineering Chemistry Fundamentals, 1962. 1(1): 24-33.
[112]. Henry DC. The Cataphoresis of Suspended Particles. Part I. The Equation of Cataphoresis. Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, 1931. 133(821): 106-129.
[113]. Lyklema J. Principles of the stability of lyophobic colloidal dispersions in non-aqueous media. Advances in Colloid and Interface Science, 1968. 2(2): 67-114.
[114]. Van Der Hoeven PC, Lyklema J. Electrostatic stabilization in non-aqueous media. Advances in Colloid and Interface Science, 1992. 42: 205-277.
[115]. Widegren J, Bergstr?m L. The effect of acids and bases on the dispersion and stabilization of ceramic particles in ethanol. Journal of the European Ceramic Society, 2000. 20(6): 659-665.
[116]. Israelachvili JN. Intermolecular and surface forces. 2 nd. London: Academic Press, 1991.
[117]. Biggs S. Steric and bridging forces between surfaces fearing adsorbed polymer-an atomic force microscopy study. Langmuir, 1995. 11(1): 156-162.
[118]. Butt HJ, Kappl M, Mueller H, Raiteri R, Meyer W, Ruhe J. Steric forces measured with the atomic force microscope at various temperatures. Langmuir, 1999. 15(7): 2559-2565.
[119]. Uchikawa H, Hanehara S, Sawaki D. The role of steric repulsive force in the dispersion of cement particles in fresh paste prepared with organic admixture. Cement and Concrete Research, 1997. 27(1): 37-50.
[120]. Plunkett MA, Rodner S, Bergstrom L, Rutland MW. Surface forces and characterization of glass surfaces bearing grafted polymers: solvent dependence. Journal of Adhesion Science and Technology, 2002. 16(7): 965-981.
[121]. Radford SJ, Dickinson E, Golding M. Stability and rheology of emulsions containing sodium caseinate: combined effects of ionic calcium and alcohol. Journal of Colloid and Interface Science, 2004. 274(2): 673-686.
[122]. De Gennes PG. Polymers at an interface; a simplified view. Advances in Colloid and Interface Science, 1987. 27(3-4): 189-209.
[123]. Alexander S. Adsorption of chain molecules with a polar head a-scaling description. Journal De Physique, 1977. 38(8): 983-987.
[124]. Wang SQ, Liu JJ, Zhang LY, Masliyah J, Xu ZH. Interaction Forces between Asphaltene Surfaces in Organic Solvents. Langmuir, 2010 26(1): 183-190.
[125]. Wang SQ, Liu JJ, Zhang LY, Xu ZH, Masliyah J. Colloidal Interactions between Asphaltene Surfaces in Toluene. Energy & Fuels, 2009. 23(1): 862-869.
[126]. Butt HJ, Kappl M, Mueller H, Raiteri R. Steric Forces Measured with the Atomic Force Microscope at Various Temperatures. Langmuir, 1999. 15(7): 2559-2565.
[127]. Hiemenz PC, Rajagopalan R. Principles of colloid and surface chemistry. 3 rd ed. Marcel Dekker Inc. New York, 1997: 528.
[128]. Israelachvili JN. Intermolecular and surface forces. 2 nd ed. Academic press: London, 1992.
[129]. Dzyaloshinskii IE, Lifshitz EM, Pitaevskii LP. General theory of Van Der Waals forces. Advances in Physics, 1961. 10(38): 165-209.
[130]. Weir S, Moody GM. The importance of flocculant choice with consideration to mixing energy to achieve efficient solid/liquid separation. Minerals Engineering, 2003. 16: 109-113.
[131]. Benbouzid M, Hafsi S. Thermal and kinetic analyses of pure and oxidized bitumens. Fuel, 2008. 87(8-9): 1585-1590.
[132]. Richardson JF, Zaki WN. The sedimentation of a suspension of uniform spheres under conditions of viscous flow. Chemical Engineering Science, 1954. 3(2): 65-73.
[133]. Marlow BJ, Sresty GC, Hughes RD, Mahajan OP. Colloidal stabilization of clays by asphaltenes in hydrocarbon media. Colloids and Surfaces, 1987. 24(4): 283-297.
[134]. Evans EA, Skalak R, Hochmuth RM. Mechanics and thermodynamics of biomembranes. 1. Crc Critical Reviews in Bioengineering, 1979. 3(3): 181-330.
[135]. Evans E, Needham D. Physical-properties of surfactant bilayer-membranes-thermal transitions, elasticity, rigidity, cohsion, and colloidal interations. Journal of Physical Chemistry, 1987. 91(16): 4219-4228.
[136]. Yeung A, Dabros T, Masliyah J. Does equilibrium interfacial tension depend on method of measurement? Journal of Colloid and Interface Science, 1998. 208(1): 241-247.
[137]. Moran K, Yeung A, Masliyah J. Factors affecting the aeration of small bitumen droplets. Canadian Soc Chemical Engineering, 2000: 625-634.
[138]. Yeung A, Dabros T, Masliyah J, Czarnecki J. Micropipette: a new technique in emulsion research. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 2000. 174(1-2): 169-181.
[139]. Moran K, Yeung A, Masliyah J. Shape relaxation of an elongated viscous drop. Journal of Colloid and Interface Science, 2003. 267(2): 483-493.
[140]. Yeung A, Moran K, Masliyah J, Czarnecki J. Shear-induced coalescence of emulsified oil drops. Journal of Colloid and Interface Science, 2003. 265(2): 439-443.
[141]. Moran K, Yeung A. Determining bitumen viscosity through drop shape recovery. Canadian Journal of Chemical Engineering, 2004. 82(4): 813-820.
[142]. Tsamantakis C, Masliyah J, Yeung A, Gentzis T. Investigation of the interfacial properties of water-in-diluted-bitumen emulsions using micropipette techniques. Journal of Colloid and Interface Science, 2005. 284(1): 176-183.
[143]. Tsamantakis C, Masliyah J, Yeung A, Gentzis T. The behaviour of micro-bitumen drops in aqueous clay environments. Journal of Colloid and Interface Science, 2005. 288(1): 129-139.
[144]. Moran K, Czarnecki J. Competitive adsorption of sodium naphthenates and naturally occurring species at water-in-crude oil emulsion droplet surfaces. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 2007. 292(2-3): 87-98.
[145]. Kang ZW, Yeung A, Foght JM, Gray MR. Hydrophobic bacteria at the hexadecane-water interface: Examination of micrometre-scale interfacial properties. Colloids and Surfaces B-Biointerfaces, 2008. 67(1): 59-66.
[146]. Yeung A, Dabros T, Czarnecki J, Masliyah J. On the interfacial properties of micrometre-sized water droplets in crude oil. Proceedings of the Royal Society of London Series a-Mathematical Physical and Engineering Sciences, 1999. 455(1990): 3709-3723.
[147]. Moran K, Yeung A, Masliyah J. Measuring interfacial tensions of micrometer-sized droplets: A novel micromechanical technique. Langmuir, 1999. 15(24): 8497-8504.
[148]. Moran K, Yeung A, Masliyah J. The viscoplastic properties of crude oil-water interfaces. Chemical Engineering Science, 2006. 61(18): 6016-6028.
[149]. Moran K, Yeung A, Czarnecki J, Masliyah J. Micron-scale tensiometry for studying density-matched and highly viscous fluids - with application to bitumen-in-water emulsions. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 2000. 174(1-2): 147-157.
[150]. Yeung AKC, Pelton R. Micromechanics: A new approach to studying the strength and breakup of flocs. Journal of Colloid and Interface Science, 1996. 184(2): 579-585.
[151]. Crandall SH, Dahl NC, Lardner TJ. An introduction to the mechanics of solids. 2 nd ed. ed. 1972, New York: McGraw-Hill.
[152]. Schramm LL, Stasuik EN, Turner D. The influence of interfacial tension in the recovery of bitumen by water-based conditioning and flotation of Athabasca oil sands. Fuel Processing Technology, 2003. 80(2): 101-118.
[153]. Drummond C, Israelachvili J. Surface forces and wettability. Journal of Petroleum Science and Engineering, 2002. 33(1-3): 123-133.
[154]. Vralstad T, Fossen M, Sjoblom J, Randhol P. Influence of interfacial tension on seeded calcium carbonate scale precipitation: Effect of adsorbed asphaltenes. Journal of Dispersion Science and Technology, 2008. 29(3): 440-446.
[155]. Nordling C, Sokolowski E, Siegbahn K. Precision method for obtaining absolute values of atomic binding energies. Physical Review, 1957. 105(5): 1676-1677.
[156]. Sokolowski E, Nordling C, Siegbahn K. Magnetic analysis of X-ray produced photo and auger electrons. Arkiv for Fysik, 1957. 12(4): 301-318.
[157]. Epling WS, Mount CK, Hoflund GB. Surface characterization study of the chemical alteration of an air-exposed polycrystalline tin foil during H-atom exposures. Applied Surface Science, 1998. 134(1-4): 187-193.
[158]. Tabbal M, Merel P, Moisa S, Chaker M, Ricard A, Moisan M. X-ray photoelectron spectroscopy of carbon nitride films deposited by graphite laser ablation in a nitrogen postdischarge. Applied Physics Letters, 1996. 69(12): 1698-1700.
[159]. Zhang X, Zhang F, Chan KY. Synthesis of titania-silica mixed oxide mesoporous materials, characterization and photocatalytic properties. Applied Catalysis A: General, 2005. 284(1-2): 193-198.
[160]. Gupta JA, Landheer D, Sproule GI, McCaffrey JP, Graham MJ, Yang KC, Lu ZH, Lennard WN. Interfacial layer formation in Gd2O3 films deposited directly on Si(0 0 1). Applied Surface Science, 2001. 173(3-4): 318-326.
[161]. Czuprynski P, Joubert O. X-ray photoelectron spectroscopy analyses of silicon dioxide contact holes etched in a magnetically enhanced reactive ion etching reactor. Journal of Vacuum Science & Technology B, 1998. 16(3): 1051-1058.
[162]. Opitz A, Ahmed SIU, Schaefer JA, Scherge M. Nanofriction of silicon oxide surfaces covered with thin water films. Wear, 2003. 254(9): 924-929.
[163]. Wen JM, Somorjai G, Lim F, Ward R. XPS study of surface composition of a segmented polyurethane block copolymer modified by PDMS end groups and its blends with phenoxy. Macromolecules, 1997. 30(23): 7206-7213.
[164]. Park JH, Moon JS, Han JH, Berdinskiy AS, Kuvshinov DG, Yoo JB, Park CY, Nam JW, Lee CG, Choe DH. Effects of binders and organic vehicles on the emission properties of carbon nanotube paste. Diamond and Related Materials, 2005. 14(9): 1463-1468.
[165]. Song HJ, Shin HJ, Chung Yongsu, Lee JC, Lee MK. X-ray absorption and photoelectron spectroscopic study of plasma-nitrided SiO2 film. Journal of Applied Physics, 2005. 97(11): 113711(1-7).
[166]. Siriwardane RV, Cook JM. Interactions of NO and SO2 with iron deposited on silica. Journal of Colloid and Interface Science, 1985. 104(1): 250-257.
[167]. Jung AS, Navamthavan R, Lee KM, Choi CK. Plasma characteristics of low-k SiOC(-H) films prepared by using plasma enhanced chemical vapor deposition from DMDMS/O2 precursors. Surface and Coatings Technology, 2008. 202(22-23): 5693-5696.
[168]. Peuckert M, Greil P. Oxygen distribution in silicon nitride powders. Journal of Materials Science, 1987. 22(10): 3717-3720.
[169]. Mérel P, Tabbal M, Chaker M, Moisa S, Margot J. Direct evaluation of the sp3 content in diamond-like-carbon films by XPS. Applied Surface Science, 1998. 136(1-2): 105-110.
[170]. Jin Z, Bhat GA, Yeung M, Kwok HS, Wong M. Nickel induced crystallization of amorphous silicon thin films. Journal of Applied Physics, 1998. 84(1): 194-200.
[171]. Johansson LS, Campbell JM, Koljonen K, Stenius P. Evaluation of surface lignin on cellulose fibers with XPS. Applied Surface Science, 1999. 144-145: 92-95.
[172]. So SK, Choi WK, Cheng CH, Leung LM, Kwong CF. Surface preparation and characterization of indium tin oxide substrates for organic electroluminescent devices. Applied Physics A: Materials Science & Processing, 1999. 68(4): 447-450.
[173]. Holgado JP, Munuera G, Espinós JP, González-Elipe AR. XPS study of oxidation processes of CeOx defective layers. Applied Surface Science, 2000. 158(1-2): 164-171.
[174]. Abdallah WA, Taylor SD. Surface characterization of adsorbed asphaltene on a stainless steel surface. Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms, 2007. 258(1): 213-217.
[175]. Moulder JF, Stickle WF, Sobol PE, Bomben KD. Handbook of X-ray Photoelectron Spectroscopy. 1995, Eden Prairie, MN: Physical Electronics Inc.
[176]. Delpeux S, Beguin F, Benoit R, Erre R, Manolova N, Rashkov I. Fullerene core star-like polymers - 1. Preparation from fullerenes and monoazidopolyethers. European Polymer Journal, 1998. 34(7): 905-915.
[177]. Ou GP, Gui WM, Jin SC, Zhang FJ. Surface analysis for LiBq4 growing on ITO and CuPc film using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Applied Surface Science, 2006. 252(10): 3417-3427.
[178]. Ignatova VA, Van DBS, Van DS, Popok VN. Quantification problems in depth profiling of PWR steels using Ar+ ion sputtering and XPS analysis. Microscopy and Microanalysis, 2006. 12(5): 432-437.
[179]. B?cking T, Salomon A, Cahen D, Gooding JJ. Thiol-terminated monolayers on oxide-free Si: assembly of semiconductor-alkyl-S-metal junctions. Langmuir, 2007. 23(6): 3236-3241.
[180]. Kelemen SR, George GN, Gorbaty ML. Direct determination and quantification of organic sulfur forms by X-ray photoelectron spectroscopy (XPS) and sulfur k-edge absorption spectroscopy. Fuel Processing Technology, 1990. 24: 425-429.
[181]. Siskin M, Kelemen SR, Eppig CP, Brown LD, Afeworki M. Asphaltene Molecular Structure and Chemical Influences on the Morphology of Coke Produced in Delayed Coking. Energy & Fuels, 2006. 20(3): 1227-1234.
[182]. Rudrake A, Karan K, Horton JH. A combined QCM and XPS investigation of asphaltene adsorption on metal surfaces. Journal of Colloid and Interface Science, 2009. 332(1): 22-31.
[183]. Gorbaty ML, George GN, Kelemen SR. Direct Determination and Quantification of Sulfur Forms in Heavy Petroleum and Coal, in Coal Science II. 1991, American Chemical Society: Washington, DC. 127-136.
[184]. Kelemen SR, Gorbaty ML, Kwiatek PJ. Quantification of nitrogen forms in argonne premium coals. Energy & Fuels, 1994. 8(4): 896-906.
[185]. Ma YW, Jiang SJ, Jian GQ, Tao HS, Yu LS, Wang XB, Wang XZ, Zhu JM, Hu Z, Chen Y. CNx nanofibers converted from polypyrrole nanowires as platinum support for methanol oxidation. Energy & Environmental Science, 2009. 2(2): 224-229.
[186]. Stanczyk K. Temperature?àíTime SieveA Case of Nitrogen in Coal. Energy & Fuels, 2004. 18(2): 405-409.
[187]. Kelemen SR, Freund H, Gorbaty ML, Kwiatek PJ. Thermal Chemistry of Nitrogen in Kerogen and Low-Rank Coal. Energy & Fuels, 1999. 13(2): 529-538.
[188]. Kelemen SR, Gorbaty ML, Kwiatek PJ, Fletcher TH, Watt M, Solum MS, Pugmire RJ. Nitrogen Transformations in Coal during Pyrolysis. Energy & Fuels, 1998. 12(1): 159-173.
[189]. Ghosh K, Kumar M, Maruyama T, Ando Y. Tailoring the field emission property of nitrogen-doped carbon nanotubes by controlling the graphitic/pyridinic substitution. Carbon, 2010. 48(1): 191-200.
[190]. Tu Y, Kingston D, Kung J, Kotlyar LS, Sparks BD, Chung KH. Adsorption of pentane insoluble organic matter from oilsands bitumen onto clay surfaces. Petroleum Science and Technology, 2006. 24: 327-338.
[191]. Khristov K, Taylor SD, Czarnecki J, Masliyah J. Thin liquid film technique - application to water-oil-water bitumen emulsion films. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 2000. 174(1-2): 183-196.
[192]. Liu J, Zhang L, Xu Z, Masliyah J. Colloidal interactions between asphaltene surfaces in aqueous solutions. Langmuir, 2006. 22(4): 1485-1492.
[193]. Zhang LY, Lopetinsky R, Xu Z, Masliyah JH. Asphaltene monolayers at a toluene/water interface. Energy and Fuels, 2005. 19(4): 1330-1336.
[194]. Fordedal H, Midttun O, Sjoblom J, Kvalheim OM, Schildberg Y, Volle JL. A multivariate screening analysis of w/o emulsions in high external electric fields as studied by means of dielectric time domain spectroscopy .2. Model emulsions stabilized by interfacially active fractions from crude oils. Journal of Colloid and Interface Science, 1996. 182(1): 117-125.
[195]. Schorling PC, Kessel DG, Rahimian I. Influence of the crude oil resin asphaltene ratio on the stability of oil water emulsions. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 1999. 152(1-2): 95-102.
[196]. Li MY, Xu MJ, Ma Y, Wu ZL, Christy AA. Interfacial film properties of asphaltenes and resins. Fuel, 2002. 81(14): 1847-1853.
[197]. Yarranton HW, Alboudwarej H, Jakher R. Investigation of asphaltene association with vapor pressure osmometry and interfacial tension measurements. Industrial & Engineering Chemistry Research, 2000. 39(8): 2916-2924.
[198]. Agrawala M, Yarranton HW. An asphaltene association model analogous to linear polymerization. Industrial & Engineering Chemistry Research, 2001. 40(21): 4664-4672.
[2]. Greene DL, Hopson JL, Li J. Have we run out of oil yet? Oil peaking analysis from an optimist's perspective. Energy Policy, 2006. 34(5): 515-531.
[3]. Clark KA, Pasternack DS. Hot water separation of bitumen from Alberta bituminous sand. Industrial and Engineering Chemistry, 1932. 24: 1410-1416.
[4]. Tipman R, Long YC, Shelfantook WE. Solvent process for bitumen separation from oil sands froth. 2001. United States Patent, Patent No. 6214213 B1.
[5]. Romanova UG, Yarranton HW, Schramm LL, Shelfantook WE. Investigation of oil sands froth treatment. Canadian Journal of Chemical Engineering, 2004. 82(4): 710-721.
[6]. Xu YM, Dabros T, Hamza H. Study on the mechanism of foaming from bitumen froth treatment tailings. Journal of Dispersion Science and Technology, 2007. 28: 413-418.
[7]. Long YC, Dabros T, Hamza H. Stability and settling characteristics of solvent-diluted bitumen emulsions. Fuel, 2002. 81(15): 1945-1952.
[8]. Romanova UG, Valinasab M, Stasiuk EN, Yarranton HW. The effect of oil sands bitumen extraction conditions on froth treatment performance. Canadian Inst Mining Metallurgy Petroleum, 2006: 36-45.
[9]. Masliyah J, Zhou ZJ, Xu ZH, Czarnecki J, Hamza H. Understanding water-based bitumen extraction from athabasca oil sands. Canadian Journal of Chemical Engineering, 2004. 82(4): 628-654.
[10]. Woynillowicz D, Baker CS, Raynolds M. Oil Sands Fever: The Environmental Implications of Canada's Oil Sands Rush, 2005.
[11]. Butts KH. The strategic importance of water. Parameters, US Army War College Quarterly Spring. 1997. XXVII: 66-83.
[12]. Yang XL, Czarnecki J. The effect of naphtha to bitumen ratio on properties of water in diluted bitumen emulsions. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 2002. 211(2-3): 213-222.
[13]. Kotlyar LS, Deslands Y, Sparks BD, Kodama H, Schutte R. Characterization of colloidal solids from athabasca fine tails. Clays and Clay Minerals, 1993. 41(3): 341-345.
[14]. Gu GX, Zhang LY, Wu XA, Xu ZH, Masliyah J. Isolation and characterization of interfacial materials in bitumen emulsions. Energy & Fuels, 2006. 20(2): 673-681.
[15]. Yan NX, Gray MR, Masliyah JH. On water-in-oil emulsions stabilized by fine solids. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 2001. 193(1-3): 97-107.
[16]. Yan NX, Masliyah JH. Adsorption and desorption of clay particles at the oil-water interface. Journal of Colloid and Interface Science, 1994. 168(2): 386-392.
[17]. Saukowski DM, Yarranton HW. Oilfield solids and water-in-oil emulsion stability. Journal of Colloid and Interface Science, 2005. 285(2): 821-833.
[18]. Gu G, Xu Z, Nandakumar K, Masliyah JH. Influence of water-soluble and water-insoluble natural surface active components on the stability of water-in-toluene-diluted bitumen emulsion. Fuel, 2002. 81(14): 1859-1869.
[19]. Bensebaa F, Kotlyar LS, Sparks BD, Chung KH. Organic coated solids in athabasca bitumen: Characterization and process implications. Canadian Soc Chemical Engineering, 2000: 610-616.
[20]. Zhao SQ, Kotlyar LS, Sparks BD, Woods JR, Gao JS, Chung KH. Solids contents, properties and molecular structures of asphaltenes from different oilsands. Fuel, 2001. 80(13): 1907-1914.
[21]. Tu Y, Li ZF, Pleizier G, Ng S, Chung KH. Separation and characterisation of problematic solids from athabasca oil sands and waste unit samples. Canadian Journal of Chemical Engineering, 2004. 82(4): 678-686.
[22]. Kotlyar LS, Sparks BD, Woods JR, Chung KH. Solids associated with the asphaltene fraction of oil sands bitumen. Energy & Fuels, 1999. 13: 346-350.
[23]. Liu JJ, Xu ZH, Masliyah J. Interaction between bitumen and fines in oil sands extraction system: Implication to bitumen recovery. Canadian Journal of Chemical Engineering, 2004. 82(4): 655-666.
[24]. Wallace D, Tipman R, Komishke B, Wallwork V, Perkins E. Fines/water interactions and consequences of the presence of degraded illite on oil sands extractability. Canadian Journal of Chemical Engineering, 2004. 82(4): 667-677.
[25]. Dai Q, Chung KH. Bitumen-sand interaction in oil sand processing. Fuel, 1995. 74(12): 1858-1864.
[26]. Tu Y, O' Carroll JB, Kotlyar LS, Sparks BD, Ng BD, Chung KH, Cuddy G. Recovery of bitumen from oilsands: gelation of ultra-fine clay in the primary separation vessel. Fuel, 2005. 84(6): 653-660.
[27]. Sparks BD, Kotlyar LS, O'Carroll JB, Chung KH. Athabasca oil sands: effect of organic coated solids on bitumen recovery and quality. Journal of Petroleum and Engineering, 2003. 39: 417-430.
[28]. Sparks BD, Meadus FW. A study of some factors affecting solvent losses in the solvent-extraction-spherical agglomeration of oil sands. Fuel Processing Technology, 1981. 4(4): 251-264.
[29]. Meadus FW, Chevrier PJ, Sparks BD. Solvent-extraction of athabasca oil-sand in a rotating mill. 1. Dissolution of bitumen. Fuel Processing Technology, 1982. 6(3): 277-287.
[30]. Meadus FW. Bassaw BP, Sparks BD. Solvent-extraction of athabasca oil-sand in a rotating mill. 2. Solids-liquid separation and bitumen quality. Fuel Processing Technology, 1982. 6(3): 289-300.
[31]. Sparks BD, Meadus FW, Hoefele E. Solvent extraction spherical agglomeration of oil sands. Environment International, 1988. 14(4): VIII-VIII.
[32]. Oyler JF, Brand JD, Zavada R. Circular solvent extractor. 1987. United States Patent, Patent No. 4683029.
[33]. Karnofsky GB. Process for solvent extraction of bitumen from oil sand. 1984. United States Patent, Patent No. 4448667.
[34]. Johnson CB. Thin layer solvent extraction. 1999. United States Patent, Patent No.5911541.
[35]. Rosenbloom WJ. Recovery of oil from tar sand by an improved extraction process. 1975. United States Patent, Patent No. 3875046.
[36]. Benson AM. Filtration of solvent-water extraction tar sand. 1969. United States Patent, Patent No. 3459653.
[37]. Savage WE, Cheney HA. Process of extracting tar from tar sand. 1971. United States Patent, Patent No. 3553099.
[38]. Hsieh RC, Clifford RK. Solvent extraction process for recovering bitumen from tar sand. 1987. United States Patent, Patent No. 4676889.
[39]. Farnand JR, Meadus FW, Sparks BD. Removal of intractable fine solids from bitumen solutions obtained by solvent extraction of oil sands. Fuel Processing Technology, 1985. 10(2): 131-144.
[40]. Sparks BD, Meadus FW. Combined solvent extraction and agglomeration technique for the recovery of bitumen from tar sands. Energy Processing/Canada, 1979. 72(1): 55-61.
[41]. Sparks BD, Meadus FW, Kumar A, Woods JR. The effect of asphaltene content on solvent selection for bitumen extraction by the sesa process. Fuel, 1992. 71(12): 1349-1353.
[42]. Chia J, Yeung A. Strength of asphaltene clusters in heptane-diluted bitumen. Fuel, 2004. 83(4-5): 619-621.
[43]. Madge DN, Garner WN. Theory of asphaltene precipitation in a hydrocarbon cyclone. Minerals Engineering, 2007. 20(4): 387-394.
[44]. Anonymous. Worldwide look at reserves and production. Oil and Gas Journal, 2004. 102(47): 22-23.
[45]. Darcovich K, Kotlyar LS, Tse WC, Ripmeester JA, Capes CE, Sparks BD. Wettability of organic-rich solids separated from athabasca oil sands. Energy & Fuels, 1989. 3(3): 386-391.
[46]. Anonymous. Canada's oilsands resource has become the world's hottest hydrocarbon play. Oil & Gas Journal, 2006. 104(22): 4-11.
[47]. Mossop GD. Geology of the athabasca oil sands. Science, 1980. 207(4427): 145-152.
[48]. Czarnecka E, Gillott JE. Formation and characterization of clay complexes with bitumen from athabasca oil sand. Clays and Clay Minerals, 1980. 28(3): 197-203.
[49]. Peramanu S, Pruden BB, Rahimi P. Molecular weight and specific gravity distributions for athabasca and cold lake bitumens and their saturate, aromatic, resin, and asphaltene fractions. Industrial & Engineering Chemistry Research, 1999. 38(8): 3121-3130.
[50]. Fuhr BJ, Hawrelechko C, Holloway LR, Huang HB. Comparison of bitumen fractionation methods. Energy & Fuels, 2005. 19(4): 1327-1329.
[51]. Woods J, Kung J, Kingston D, Kotlyar L, Sparks B, McCracken T. Canadian crudes: A comparative study of SARA fractions from a modified HPLC separation technique. Oil & Gas Science and Technology-Revue De L Institut Francais Du Petrole, 2008. 63(1): 151-163.
[52]. Aske N, Kallevik H, Sjoblom J. Determination of saturate, aromatic, resin, and asphaltenic (SARA) components in crude oils by means of infrared and near-infrared spectroscopy. Energy & Fuels, 2001. 15(5): 1304-1312.
[53]. Ignasiak T, Kempjones AV, Strausz OP. Molecular-structure of athabasca asphaltene-clevage of carbon-sulfur bonds by radical ion electron-transfer reactions. Journal of Organic Chemistry, 1977. 42(2): 312-320.
[54]. Trejo F, Centeno G, Ancheyta J. Precipitation, fractionation and characterization of asphaltenes from heavy and light crude oils. Fuel, 2004. 83(16): 2169-2175.
[55]. Dickie JP, Yen TF. Macrostructures of asphaltic fractions by various instrumental methods. Analytical Chemistry, 1967. 39(14): 1847-1852.
[56]. Sztukowski DM, Jafari M, Alboudwarej H, Yarranton HW. Asphaltene self-association and water-in-hydrocarbon emulsions. Journal of Colloid and Interface Science, 2003. 265(1): 179-186.
[57]. Mitchell DL, Speight JG. Solubility of asphaltenes in hydrocarbon solvents. Fuel, 1973. 52(2): 149-152.
[58]. Angle CW, Long YC, Hamza H, Lue L. Precipitation of asphaltenes from solvent-diluted heavy oil and thermodynamic properties of solvent-diluted heavy oil solutions. Fuel, 2006. 85(4): 492-506.
[59]. Sabbagh O, Akbarzadeh K, Badamchi-Zadeh A, Svrcek WY, Yarranton HW. Applying the PR-EoS to asphaltene precipitation from n-alkane diluted heavy oils and bitumens. Energy & Fuels, 2006. 20(2): 625-634.
[60]. Andersen SI, Birdi KS. Influence of temperature and solvent on the precipitation of asphaltenes. Fuel Science and Technology International, 1990. 8(6): 593-615.
[61]. Mitchell DL, Speight JG. The solubility of asphaltenes in hydrocarbon solvents. Fuel, 1973. 52(2): 149-152.
[62]. Victorov AI, Firoozabadi A. Thermodynamic micellization model of asphaltene precipitation from petroleum fluids. Aiche Journal, 1996. 42(6): 1753-1764.
[63]. Hu YF, Guo TM. Effect of temperature and molecular weight of n-alkane precipi tation. Fluid Phase Equilibria, 2001. 192(1-2): 13-25.
[64]. Alboudwarej H, Beck J, Svrcek WY, Yarranton HW, Akbarzadeh K. Sensitivity of asphaltene properties to separation techniques. Energy & Fuels, 2002. 16(2): 462-469.
[65]. Hu YF, Guo TM. Effect of temperature and molecular weight of n-alkane precipitants on asphaltene precipitation. Fluid Phase Equilibria, 2001. 192(1-2): 13-25.
[66]. Pillon L.Z. Effect of experimental conditions and solvents on the precipitation and composition of asphaltenes. Petroleum Science and Technology, 2001. 19(5-6): 673-683.
[67]. Ancheyta J, Centeno G, Trejo F, Marroquin G, Garcia JA, Tenorio E, Torres A. Extraction and characterization of asphaltenes from different crude oils and solvents. Energy & Fuels, 2002. 16(5): 1121-1127.
[68]. Oliensis GL. A qualitative test for determining the degree of heterogeneity of asphalts. ASTM proc of the 36th Ann Meeting Chicago, 1933. (33): 715-728.
[69]. Fossen M, Kallevik H, Knudsen KD, Sjoblom J. Asphaltenes precipitated by a two-step precipitation procedure. 1. Interfacial tension and solvent properties. Energy & Fuels, 2007. 21(2): 1030-1037.
[70]. Fossen M, Sj?blom J, Kallevik H, Jakobsson J. A new Procedure for direct precipitation and fractionation of asphaltenes from crude oil. Journal of Dispersion Science and Technology, 2007. 28(1): 193-197.
[71]. Yang XL, Hamza H, Czarnecki J. Investigation of subfractions of athabasca asphaltenes and their role in emulsion stability. Energy & Fuels, 2004. 18(3): 770-777.
[72]. Zhang LY, Lawrence S, Xu ZH, Masliyah JH. Studies of Athabasca asphaltene Langmuir films at air-water interface. Journal of Colloid and Interface Science, 2003. 264(1): 128-140.
[73]. Strausz OP, Mojelsky TW, Lown EM. The molecular-structure of asphaltene-an unfolding story. Butterworth-Heinemann Ltd, 1992: 1355-1363.
[74]. Lawrence S, Zhang LY, Xu ZH, Masliyah J. Langmuir and Langmuir-Blodgett asphaltene films at heptane-water interface. Canadian Journal of Chemical Engineering, 2004. 82(4): 821-828.
[75]. Mojelsky TW, Ignasiak TM, Frakman Z, Mclntyre DD, Lown EM, Montgomery DS, Strausz OP. Structural features of alberta oil sand bitumen and heavy oil asphaltenes. Energy & Fuels, 1992. 6(1): 83-96.
[76]. McLean JD, Kilpatrick PK. Effects of asphaltene aggregation in model heptane-toluene mixtures on stability of water-in-oil emulsions. Journal of Colloid and Interface Science, 1997. 196(1): 23-34.
[77]. Li J, Huang XS, Zhang YZ, Xu M. Bitumen Colloidal and Structural Stability Characterization. Road Materials and Pavement Design, 2009. 10: 45-59.
[78]. Jada A, Salou A. Effects of the asphaltene and resin contents of the bitumens on the water-bitumen interface properties. Journal of Petroleum Science and Engineering, 2002. 33(1-3): 185-193.
[79]. Zhao B, Becerra M, Shaw JM. On Asphaltene and Resin Association in Athabasca Bitumen and Maya Crude Oil. Energy & Fuels, 2009. 23: 4431-4437.
[80]. Carty WM. The colloidal nature of kaolinite. American Ceramic Society Bulletin, 1999. 78(8): 72-76.
[81]. Mitchell JK. Fundamentals of soil behavior. New York: John Wiley and Sons, Inc. 2nd ed. 1993: 32.
[82]. Madge DN, Romero J, Strand WL. Hydrocarbon cyclones in hydrophilic oil sand environments. Minerals Engineering, 2004. 17:625-636.
[83]. Li ZF, Kung J, Tu Y, Kotlyar LS, Chung KH. Characterization of ultra fine solids (BS) in athabasca bitumen. Chinese Journal of Structural Chemistry, 2004. 23(7): 751-754.
[84]. Takamura K. Microscopic structure of athabasca oil sand. Canadian Journal of Chemical Engineering, 1982. 60(4): 538-545.
[85]. Yarranton HW, Hussein H, Masliyah JH. Water-in-hydrocarbon emulsions stabilized by asphaltenes at low concentrations. Journal of Colloid and Interface Science, 2000. 228(1): 52-63.
[86]. Henry JD, Prudich ME, Lau C. Liquid, liquid, solid systems: role of water in particle removal from hydrocarbon suspension. Colloids and Surfaces, 1980. 1( 3-4): 335- 348.
[87]. Hsu EC, Merchant P, Smith DL, Kelly KP, Lacy SM. Process for the removal of solids from an oil. 1987. United States Patent No: 4692237.
[88]. Zhou ZA, Hussein H, Xu ZH, Czarnecki J, Masliyah JH. Interaction of ionic species and fine solids with a low energy hydrophobic surface from contact angle measurement. Journal of Colloid and Interface Science, 1998. 204(2): 342-349.
[89]. Li H, Zhou ZA, Xu Z, Masliyah JH. Role of acidified sodium silicate in low temperature bitumen extraction from poor-processing oil sand ores. Industrial & Engineering Chemistry Research, 2005. 44(13): 4753-4761.
[90]. Wang SY, Chung KH, Masliyah JH, Gray MR. Deposition of fine particles in packed beds at hydrotreating conditions: Role of surface chemistry. Industrial & Engineering Chemistry Research, 1999. 38(12): 4878-4888.
[91]. Ding XL, Repka C, Xu ZH, Masliyah J. Effect of illite clay and divalent cations on bitumen recovery. Canadian Journal of Chemical Engineering, 2006. 84(6): 643-650.
[92]. Sheu EY. Petroleum asphaltene-properties, characterization, and issues. Energy & Fuels, 2002. 16: 74-82.
[93]. Seki H, Kumata F. Structural change of petroleum asphaltenes and resins by hydrodemetallization. Energy & Fuels, 2000. 14(5): 980-985.
[94]. Groenzin H, Mullins OC. Molecular size and structure of asphaltenes from various sources. Energy & Fuels, 2000. 14(3): 677-684.
[95]. Long J, Xu ZH, Masliyah JH. Single molecule force spectroscopy of asphaltene aggregates. Langmuir, 2007. 23(11): 6182-6190.
[96]. Barre L, Simon S, Palermo T. Solution properties of asphaltenes. Langmuir, 2008. 24(8): 3709-3717.
[97]. Akbarzadeh K, Alboudwarej H, Svrcek WY, Yarranton HW. A generalized regular solution model for asphaltene precipitation from n-alkane diluted heavy oils and bitumens. Fluid Phase Equilibria, 2005. 232(1-2): 159-170.
[98]. Cook DLM. Another notch in the oilsands technology belt. Oilsands Review, March 2007: 43-45.
[99]. Rao BML, Serrano JE. Viscometric study of aggregation interactions in heavy oil. Petroleum Science and Technology, 1986. 4(4): 483-500.
[100]. Kotlyar LS, Sparks BD, Woods JR, Raymond S, LePage Y, Shelfantook W. Distribution and types of solids associated with bitumen. Petroleum Science and Technology, 1998. 16(1-2): 1-19.
[101]. Ferworn KA, Mehrotra AK, Svrcek WY. Measurement of asphaltene agglomeration from cold lake bitumen diluted with n-alkanes. Canadian Journal of Chemical Engineering, 1993. 71(5): 699-703.
[102]. Akbarzadeh KH, Svrcek AWK, Yarranton HW. Regular solution model for asphaltene precipitation from bitumen-alkane systems, Proceedings of the Can. Intern. Pet. Conf., Calgary, 2003: 023.
[103]. Rastegari K, Beck J, Svrcek W, Yarranton H. Measurement and modelling of asphaltene flocculation from Athabasca bitumen. Proceedings of the Can. Intern. Pet. Conf., Calgary, 2003: 059.
[104]. Rahmani NHG, Dabros T, Masliyah JH. Online optical monitoring of asphaltene aggregation. Industrial & Engineering Chemistry Research, 2005. 44(1): 75-84.
[105]. Fenistein D, Barre L, Broseta D, Espinat D, Livet A, Roux JN, Scarsella M. Viscosimetric and neutron scattering study of asphaltene aggregates in mixed toluene/heptane solvents. Langmuir, 1998. 14(5): 1013-1020.
[106]. Oliver DR. The sedimentation of suspensions of closely-sized spherical particles. Chemical Engineering Science, 1961. 15(3-4): 230-242.
[107]. Whitmore RL. The sedimentation of suspensions of spheres. British Journal of Applied Physics, 1955. 6(7): 239-245.
[108]. Coe HB, Clevenger GH. Methods for determining the capacities of slime-settling tanks. Transactions of the American Institute of Mining and Metallurgical Engineers, 1916. 55: 356-384.
[109]. Richardson JF, Harker JH, Backhurst JR. Coulson and Richardson's Chemical Engineering fifth ed. Particle technology and separation process. Butterworth-Heinemann, 2002. 2.
[110]. Gregory J. Fundamentals of flocculation. Critical Reviews in Environmental Control, 1989. 19(3): 185-230.
[111]. Michaels AS, Bolger JC. Settling Rates and Sediment Volumes of Flocculated Kaolin Suspensions. Industrial & Engineering Chemistry Fundamentals, 1962. 1(1): 24-33.
[112]. Henry DC. The Cataphoresis of Suspended Particles. Part I. The Equation of Cataphoresis. Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, 1931. 133(821): 106-129.
[113]. Lyklema J. Principles of the stability of lyophobic colloidal dispersions in non-aqueous media. Advances in Colloid and Interface Science, 1968. 2(2): 67-114.
[114]. Van Der Hoeven PC, Lyklema J. Electrostatic stabilization in non-aqueous media. Advances in Colloid and Interface Science, 1992. 42: 205-277.
[115]. Widegren J, Bergstr?m L. The effect of acids and bases on the dispersion and stabilization of ceramic particles in ethanol. Journal of the European Ceramic Society, 2000. 20(6): 659-665.
[116]. Israelachvili JN. Intermolecular and surface forces. 2 nd. London: Academic Press, 1991.
[117]. Biggs S. Steric and bridging forces between surfaces fearing adsorbed polymer-an atomic force microscopy study. Langmuir, 1995. 11(1): 156-162.
[118]. Butt HJ, Kappl M, Mueller H, Raiteri R, Meyer W, Ruhe J. Steric forces measured with the atomic force microscope at various temperatures. Langmuir, 1999. 15(7): 2559-2565.
[119]. Uchikawa H, Hanehara S, Sawaki D. The role of steric repulsive force in the dispersion of cement particles in fresh paste prepared with organic admixture. Cement and Concrete Research, 1997. 27(1): 37-50.
[120]. Plunkett MA, Rodner S, Bergstrom L, Rutland MW. Surface forces and characterization of glass surfaces bearing grafted polymers: solvent dependence. Journal of Adhesion Science and Technology, 2002. 16(7): 965-981.
[121]. Radford SJ, Dickinson E, Golding M. Stability and rheology of emulsions containing sodium caseinate: combined effects of ionic calcium and alcohol. Journal of Colloid and Interface Science, 2004. 274(2): 673-686.
[122]. De Gennes PG. Polymers at an interface; a simplified view. Advances in Colloid and Interface Science, 1987. 27(3-4): 189-209.
[123]. Alexander S. Adsorption of chain molecules with a polar head a-scaling description. Journal De Physique, 1977. 38(8): 983-987.
[124]. Wang SQ, Liu JJ, Zhang LY, Masliyah J, Xu ZH. Interaction Forces between Asphaltene Surfaces in Organic Solvents. Langmuir, 2010 26(1): 183-190.
[125]. Wang SQ, Liu JJ, Zhang LY, Xu ZH, Masliyah J. Colloidal Interactions between Asphaltene Surfaces in Toluene. Energy & Fuels, 2009. 23(1): 862-869.
[126]. Butt HJ, Kappl M, Mueller H, Raiteri R. Steric Forces Measured with the Atomic Force Microscope at Various Temperatures. Langmuir, 1999. 15(7): 2559-2565.
[127]. Hiemenz PC, Rajagopalan R. Principles of colloid and surface chemistry. 3 rd ed. Marcel Dekker Inc. New York, 1997: 528.
[128]. Israelachvili JN. Intermolecular and surface forces. 2 nd ed. Academic press: London, 1992.
[129]. Dzyaloshinskii IE, Lifshitz EM, Pitaevskii LP. General theory of Van Der Waals forces. Advances in Physics, 1961. 10(38): 165-209.
[130]. Weir S, Moody GM. The importance of flocculant choice with consideration to mixing energy to achieve efficient solid/liquid separation. Minerals Engineering, 2003. 16: 109-113.
[131]. Benbouzid M, Hafsi S. Thermal and kinetic analyses of pure and oxidized bitumens. Fuel, 2008. 87(8-9): 1585-1590.
[132]. Richardson JF, Zaki WN. The sedimentation of a suspension of uniform spheres under conditions of viscous flow. Chemical Engineering Science, 1954. 3(2): 65-73.
[133]. Marlow BJ, Sresty GC, Hughes RD, Mahajan OP. Colloidal stabilization of clays by asphaltenes in hydrocarbon media. Colloids and Surfaces, 1987. 24(4): 283-297.
[134]. Evans EA, Skalak R, Hochmuth RM. Mechanics and thermodynamics of biomembranes. 1. Crc Critical Reviews in Bioengineering, 1979. 3(3): 181-330.
[135]. Evans E, Needham D. Physical-properties of surfactant bilayer-membranes-thermal transitions, elasticity, rigidity, cohsion, and colloidal interations. Journal of Physical Chemistry, 1987. 91(16): 4219-4228.
[136]. Yeung A, Dabros T, Masliyah J. Does equilibrium interfacial tension depend on method of measurement? Journal of Colloid and Interface Science, 1998. 208(1): 241-247.
[137]. Moran K, Yeung A, Masliyah J. Factors affecting the aeration of small bitumen droplets. Canadian Soc Chemical Engineering, 2000: 625-634.
[138]. Yeung A, Dabros T, Masliyah J, Czarnecki J. Micropipette: a new technique in emulsion research. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 2000. 174(1-2): 169-181.
[139]. Moran K, Yeung A, Masliyah J. Shape relaxation of an elongated viscous drop. Journal of Colloid and Interface Science, 2003. 267(2): 483-493.
[140]. Yeung A, Moran K, Masliyah J, Czarnecki J. Shear-induced coalescence of emulsified oil drops. Journal of Colloid and Interface Science, 2003. 265(2): 439-443.
[141]. Moran K, Yeung A. Determining bitumen viscosity through drop shape recovery. Canadian Journal of Chemical Engineering, 2004. 82(4): 813-820.
[142]. Tsamantakis C, Masliyah J, Yeung A, Gentzis T. Investigation of the interfacial properties of water-in-diluted-bitumen emulsions using micropipette techniques. Journal of Colloid and Interface Science, 2005. 284(1): 176-183.
[143]. Tsamantakis C, Masliyah J, Yeung A, Gentzis T. The behaviour of micro-bitumen drops in aqueous clay environments. Journal of Colloid and Interface Science, 2005. 288(1): 129-139.
[144]. Moran K, Czarnecki J. Competitive adsorption of sodium naphthenates and naturally occurring species at water-in-crude oil emulsion droplet surfaces. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 2007. 292(2-3): 87-98.
[145]. Kang ZW, Yeung A, Foght JM, Gray MR. Hydrophobic bacteria at the hexadecane-water interface: Examination of micrometre-scale interfacial properties. Colloids and Surfaces B-Biointerfaces, 2008. 67(1): 59-66.
[146]. Yeung A, Dabros T, Czarnecki J, Masliyah J. On the interfacial properties of micrometre-sized water droplets in crude oil. Proceedings of the Royal Society of London Series a-Mathematical Physical and Engineering Sciences, 1999. 455(1990): 3709-3723.
[147]. Moran K, Yeung A, Masliyah J. Measuring interfacial tensions of micrometer-sized droplets: A novel micromechanical technique. Langmuir, 1999. 15(24): 8497-8504.
[148]. Moran K, Yeung A, Masliyah J. The viscoplastic properties of crude oil-water interfaces. Chemical Engineering Science, 2006. 61(18): 6016-6028.
[149]. Moran K, Yeung A, Czarnecki J, Masliyah J. Micron-scale tensiometry for studying density-matched and highly viscous fluids - with application to bitumen-in-water emulsions. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 2000. 174(1-2): 147-157.
[150]. Yeung AKC, Pelton R. Micromechanics: A new approach to studying the strength and breakup of flocs. Journal of Colloid and Interface Science, 1996. 184(2): 579-585.
[151]. Crandall SH, Dahl NC, Lardner TJ. An introduction to the mechanics of solids. 2 nd ed. ed. 1972, New York: McGraw-Hill.
[152]. Schramm LL, Stasuik EN, Turner D. The influence of interfacial tension in the recovery of bitumen by water-based conditioning and flotation of Athabasca oil sands. Fuel Processing Technology, 2003. 80(2): 101-118.
[153]. Drummond C, Israelachvili J. Surface forces and wettability. Journal of Petroleum Science and Engineering, 2002. 33(1-3): 123-133.
[154]. Vralstad T, Fossen M, Sjoblom J, Randhol P. Influence of interfacial tension on seeded calcium carbonate scale precipitation: Effect of adsorbed asphaltenes. Journal of Dispersion Science and Technology, 2008. 29(3): 440-446.
[155]. Nordling C, Sokolowski E, Siegbahn K. Precision method for obtaining absolute values of atomic binding energies. Physical Review, 1957. 105(5): 1676-1677.
[156]. Sokolowski E, Nordling C, Siegbahn K. Magnetic analysis of X-ray produced photo and auger electrons. Arkiv for Fysik, 1957. 12(4): 301-318.
[157]. Epling WS, Mount CK, Hoflund GB. Surface characterization study of the chemical alteration of an air-exposed polycrystalline tin foil during H-atom exposures. Applied Surface Science, 1998. 134(1-4): 187-193.
[158]. Tabbal M, Merel P, Moisa S, Chaker M, Ricard A, Moisan M. X-ray photoelectron spectroscopy of carbon nitride films deposited by graphite laser ablation in a nitrogen postdischarge. Applied Physics Letters, 1996. 69(12): 1698-1700.
[159]. Zhang X, Zhang F, Chan KY. Synthesis of titania-silica mixed oxide mesoporous materials, characterization and photocatalytic properties. Applied Catalysis A: General, 2005. 284(1-2): 193-198.
[160]. Gupta JA, Landheer D, Sproule GI, McCaffrey JP, Graham MJ, Yang KC, Lu ZH, Lennard WN. Interfacial layer formation in Gd2O3 films deposited directly on Si(0 0 1). Applied Surface Science, 2001. 173(3-4): 318-326.
[161]. Czuprynski P, Joubert O. X-ray photoelectron spectroscopy analyses of silicon dioxide contact holes etched in a magnetically enhanced reactive ion etching reactor. Journal of Vacuum Science & Technology B, 1998. 16(3): 1051-1058.
[162]. Opitz A, Ahmed SIU, Schaefer JA, Scherge M. Nanofriction of silicon oxide surfaces covered with thin water films. Wear, 2003. 254(9): 924-929.
[163]. Wen JM, Somorjai G, Lim F, Ward R. XPS study of surface composition of a segmented polyurethane block copolymer modified by PDMS end groups and its blends with phenoxy. Macromolecules, 1997. 30(23): 7206-7213.
[164]. Park JH, Moon JS, Han JH, Berdinskiy AS, Kuvshinov DG, Yoo JB, Park CY, Nam JW, Lee CG, Choe DH. Effects of binders and organic vehicles on the emission properties of carbon nanotube paste. Diamond and Related Materials, 2005. 14(9): 1463-1468.
[165]. Song HJ, Shin HJ, Chung Yongsu, Lee JC, Lee MK. X-ray absorption and photoelectron spectroscopic study of plasma-nitrided SiO2 film. Journal of Applied Physics, 2005. 97(11): 113711(1-7).
[166]. Siriwardane RV, Cook JM. Interactions of NO and SO2 with iron deposited on silica. Journal of Colloid and Interface Science, 1985. 104(1): 250-257.
[167]. Jung AS, Navamthavan R, Lee KM, Choi CK. Plasma characteristics of low-k SiOC(-H) films prepared by using plasma enhanced chemical vapor deposition from DMDMS/O2 precursors. Surface and Coatings Technology, 2008. 202(22-23): 5693-5696.
[168]. Peuckert M, Greil P. Oxygen distribution in silicon nitride powders. Journal of Materials Science, 1987. 22(10): 3717-3720.
[169]. Mérel P, Tabbal M, Chaker M, Moisa S, Margot J. Direct evaluation of the sp3 content in diamond-like-carbon films by XPS. Applied Surface Science, 1998. 136(1-2): 105-110.
[170]. Jin Z, Bhat GA, Yeung M, Kwok HS, Wong M. Nickel induced crystallization of amorphous silicon thin films. Journal of Applied Physics, 1998. 84(1): 194-200.
[171]. Johansson LS, Campbell JM, Koljonen K, Stenius P. Evaluation of surface lignin on cellulose fibers with XPS. Applied Surface Science, 1999. 144-145: 92-95.
[172]. So SK, Choi WK, Cheng CH, Leung LM, Kwong CF. Surface preparation and characterization of indium tin oxide substrates for organic electroluminescent devices. Applied Physics A: Materials Science & Processing, 1999. 68(4): 447-450.
[173]. Holgado JP, Munuera G, Espinós JP, González-Elipe AR. XPS study of oxidation processes of CeOx defective layers. Applied Surface Science, 2000. 158(1-2): 164-171.
[174]. Abdallah WA, Taylor SD. Surface characterization of adsorbed asphaltene on a stainless steel surface. Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms, 2007. 258(1): 213-217.
[175]. Moulder JF, Stickle WF, Sobol PE, Bomben KD. Handbook of X-ray Photoelectron Spectroscopy. 1995, Eden Prairie, MN: Physical Electronics Inc.
[176]. Delpeux S, Beguin F, Benoit R, Erre R, Manolova N, Rashkov I. Fullerene core star-like polymers - 1. Preparation from fullerenes and monoazidopolyethers. European Polymer Journal, 1998. 34(7): 905-915.
[177]. Ou GP, Gui WM, Jin SC, Zhang FJ. Surface analysis for LiBq4 growing on ITO and CuPc film using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Applied Surface Science, 2006. 252(10): 3417-3427.
[178]. Ignatova VA, Van DBS, Van DS, Popok VN. Quantification problems in depth profiling of PWR steels using Ar+ ion sputtering and XPS analysis. Microscopy and Microanalysis, 2006. 12(5): 432-437.
[179]. B?cking T, Salomon A, Cahen D, Gooding JJ. Thiol-terminated monolayers on oxide-free Si: assembly of semiconductor-alkyl-S-metal junctions. Langmuir, 2007. 23(6): 3236-3241.
[180]. Kelemen SR, George GN, Gorbaty ML. Direct determination and quantification of organic sulfur forms by X-ray photoelectron spectroscopy (XPS) and sulfur k-edge absorption spectroscopy. Fuel Processing Technology, 1990. 24: 425-429.
[181]. Siskin M, Kelemen SR, Eppig CP, Brown LD, Afeworki M. Asphaltene Molecular Structure and Chemical Influences on the Morphology of Coke Produced in Delayed Coking. Energy & Fuels, 2006. 20(3): 1227-1234.
[182]. Rudrake A, Karan K, Horton JH. A combined QCM and XPS investigation of asphaltene adsorption on metal surfaces. Journal of Colloid and Interface Science, 2009. 332(1): 22-31.
[183]. Gorbaty ML, George GN, Kelemen SR. Direct Determination and Quantification of Sulfur Forms in Heavy Petroleum and Coal, in Coal Science II. 1991, American Chemical Society: Washington, DC. 127-136.
[184]. Kelemen SR, Gorbaty ML, Kwiatek PJ. Quantification of nitrogen forms in argonne premium coals. Energy & Fuels, 1994. 8(4): 896-906.
[185]. Ma YW, Jiang SJ, Jian GQ, Tao HS, Yu LS, Wang XB, Wang XZ, Zhu JM, Hu Z, Chen Y. CNx nanofibers converted from polypyrrole nanowires as platinum support for methanol oxidation. Energy & Environmental Science, 2009. 2(2): 224-229.
[186]. Stanczyk K. Temperature?àíTime SieveA Case of Nitrogen in Coal. Energy & Fuels, 2004. 18(2): 405-409.
[187]. Kelemen SR, Freund H, Gorbaty ML, Kwiatek PJ. Thermal Chemistry of Nitrogen in Kerogen and Low-Rank Coal. Energy & Fuels, 1999. 13(2): 529-538.
[188]. Kelemen SR, Gorbaty ML, Kwiatek PJ, Fletcher TH, Watt M, Solum MS, Pugmire RJ. Nitrogen Transformations in Coal during Pyrolysis. Energy & Fuels, 1998. 12(1): 159-173.
[189]. Ghosh K, Kumar M, Maruyama T, Ando Y. Tailoring the field emission property of nitrogen-doped carbon nanotubes by controlling the graphitic/pyridinic substitution. Carbon, 2010. 48(1): 191-200.
[190]. Tu Y, Kingston D, Kung J, Kotlyar LS, Sparks BD, Chung KH. Adsorption of pentane insoluble organic matter from oilsands bitumen onto clay surfaces. Petroleum Science and Technology, 2006. 24: 327-338.
[191]. Khristov K, Taylor SD, Czarnecki J, Masliyah J. Thin liquid film technique - application to water-oil-water bitumen emulsion films. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 2000. 174(1-2): 183-196.
[192]. Liu J, Zhang L, Xu Z, Masliyah J. Colloidal interactions between asphaltene surfaces in aqueous solutions. Langmuir, 2006. 22(4): 1485-1492.
[193]. Zhang LY, Lopetinsky R, Xu Z, Masliyah JH. Asphaltene monolayers at a toluene/water interface. Energy and Fuels, 2005. 19(4): 1330-1336.
[194]. Fordedal H, Midttun O, Sjoblom J, Kvalheim OM, Schildberg Y, Volle JL. A multivariate screening analysis of w/o emulsions in high external electric fields as studied by means of dielectric time domain spectroscopy .2. Model emulsions stabilized by interfacially active fractions from crude oils. Journal of Colloid and Interface Science, 1996. 182(1): 117-125.
[195]. Schorling PC, Kessel DG, Rahimian I. Influence of the crude oil resin asphaltene ratio on the stability of oil water emulsions. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 1999. 152(1-2): 95-102.
[196]. Li MY, Xu MJ, Ma Y, Wu ZL, Christy AA. Interfacial film properties of asphaltenes and resins. Fuel, 2002. 81(14): 1847-1853.
[197]. Yarranton HW, Alboudwarej H, Jakher R. Investigation of asphaltene association with vapor pressure osmometry and interfacial tension measurements. Industrial & Engineering Chemistry Research, 2000. 39(8): 2916-2924.
[198]. Agrawala M, Yarranton HW. An asphaltene association model analogous to linear polymerization. Industrial & Engineering Chemistry Research, 2001. 40(21): 4664-4672.