摘要
第二类吸收式热泵(AHT)是一种有效回收利用低品位热能的节能、环保型技术,具有显著的经济效益和社会效益。随着能源紧张及其价格的上涨,日益受到世界各国的重视。然而在高温高浓度下工质溴化锂对设备材料0Cr18Ni9不锈钢等的腐蚀更加严重,已经严重制约了AHT在高温领域的发展和应用。
本文首次在0Cr18Ni9不锈钢表面利用提拉法制备了双功能性硅氧烷BMBSE膜,采用FT-IR、SEM、EPMA、极化曲线、EIS对膜层表面性能、结构等进行表征,并根据第二类吸收式热泵高温下的实际工况进行静态浸泡腐蚀实验,对薄膜在高温下的耐腐蚀能力进行研究。结果表明,双功能性BMBSE硅氧烷与不锈钢基体发生了化学键合,形成-Si-O-Fe键在不锈钢表面成膜。同时由于有机组分甲基和亚甲基的引入,结构均匀致密,并具有一定的疏水性;电化学测试结果表明BMBSE膜的极化阻抗比不锈钢大4个数量级,自腐蚀电流密度也下降低了4个数量级左右,具有良好的耐腐蚀性能;成膜的影响因素优化结果表明BMBSE、EtOH、D.I.water摩尔比为1∶4∶3,热处理温度为200℃时,更有利于制备结构均匀、致密、耐腐蚀性能好的薄膜;静态浸泡腐蚀实验结果说明,在180℃、55%的高温溴化锂溶液中BMBSE膜能起到良好的腐蚀防护作用。
并进一步采用正硅酸乙酯(TEOS)对BMBSE膜的结构进行改进,在不锈钢表面制备了具有一定疏水性的更加致密的BMBSE/TEOS复合膜。研究表明TEOS的加入可以提高BMBSE膜与基底材料的交联点密度,薄膜更致密,腐蚀防护性能更好。实验表明,当TEOS摩尔含量比在2∶1时,BMBSE/TEOS复合膜具有最佳的腐蚀保护能力;在180℃、55%的高温溴化锂溶液中的腐蚀速度为5.64um/a,表现出比BMBSE膜更强的耐腐蚀能力。
采用EIS考察了BMBSE膜及BMBSE/TEOS复合膜不锈钢试样在55%溴化锂溶液中有氧、室温条件下的腐蚀过程。两者都表现出良好的耐腐蚀性能,而BMBSE/TEOS膜具有更加优异的耐腐蚀能力和耐渗水性。
The absorption heat transformer (AHT) is a energy conservation technology which converts low level energy and exhaust heat into high level energy. It has attracted more attention in the world-wide energy crisis recent years. Lithium bromide solutions, the commonly used absorbent solutions in heating and refrigerating absorption systems, can cause serious corrosion problems on metallic component, especially at high temperature, which has seriously restricted the development of AHT at high temperature.
In this paper, functional bis-silanes BMBSE films were successfully prepared on 0Crl8Ni9 stainless steels substrates by Czochralski Method. The surface morphologies and structures of the film were studied by means of scanning electronic micrographs (SEM), contact angle measurement, Fourier transform infrared spectroscopy (FT-IR), and Electron probe x-ray micro analyzer (EPMA). The results showed that a perfect BMBSE film was produced by deposition of molecules attached to the metal surface by chemical bonds of Si-O-Fe between the BMBSE film and the 0Cr18Ni9 stainless steel. Meanwhile, the coated surface was hydrophobic with a contact angle of 107.2°since the introduction of methyl groups and methylene groups. Static immersing corrosion test, potentiodynamically polarization curve and electrochemical impedance spectroscopy (EIS) were conducted to evaluate the film corrosion performances. The results of potentiodynamically polarization curve and EIS in 55wt% LiBr solutions at room temperature in atmospherical pressure indicated that the corrosion current density of BMBSE film coated surface was 4 orders of magnitude smaller than that of bare SUS304 steel, and the impedance was increased by a factor of 10000. Static immersing corrosion test presented that the BMBSE film can significantly increase the corrosion resistance in 55wt%LiBr solution at 180°C compared with stainless steels.
Furthermore, tetraethyl orthosilicate (TEOS) was added to improve the structure of BMBSE film. A hydrophobic composite film of BMBSE/TEOS was successfully prepared on 0Cr18Ni9 stainless steels substrates. The results showed that the introduction of TEOS increased the crosslinkage between composite films and substrates which led to a denser layer and further improved the anti-corrosion property of 0Cr18Ni9 stainless steels. The anti-corrosion property of BMBSE/TEOS composite film tended to peak with the molar ratio of BMBSE to TEOS being 2:1. Corrosion rate of BMBSE/TEOS composite film coated surface was 5.64um/a in 55wt%LiBr solution at 180℃, which was better than of BMBSE film coated one.
EIS was applied to investigate the corrosion process of the BMBSE film and BMBSE/TEOS composite film coated 0Crl8Ni9 stainless steels in 55wt%LiBr solution at room temperature. Both of two films exhibit an excellent corrosion resistant property with the composite film being better.
引文
[1]David Pech,Philippe Steyer,Anne-Spophie Loir,et al.Analysis of the corrosion protective ability of PACVD silica-based coatings deposited on steel[J].Surface and coatings technology 2006,201:347-352.
[2]徐溢,唐守渊,张晓凤.金属表面硅烷试剂膜结构及性能表征方法[J].光谱学与光谱分析,2004,24(4):495-498.
[3]Tammy L.Metroke,Robert L.Parldlill,Edward T.Knobbe.Passivation of metal alloys using sol-gel-derived materiats-a review[J].Progress in Organic Coatings,2001,41(4):233-238.
[4]Directive number 2003/53/CE of the Euro- pean Parliament and Council(September 18,2000)and further modification(June 27,2002).
[5]Arkles B."Silicon Esters" Gelest Catalog,reprinted from Encyclopedia of Chemical Technology,4th Ed,Vol.22.Wiley,1997:69-81.
[6]Stevens M P.Polymer Chemistry:An Introduction,3rd Edition.Oxford University Press,1999.
[7]Owen.M.J,Race.D.J.Biaxial strength behaviour of glass fabric-reinforced polyester resins[J].Composites,1981,12(1):13-25.
[8]Plueddemann E P.J.Adhesion Sci.Technology,1991,5(4):261.
[9]Plueddemann E P.Encyclopedia of Polymer Sci.Eng.,2nd Ed.New York:John Wiley & Sons,1986:284.
[10]Plueddemann E P.Silane Coupling Agents.New York:Plenum Press,1991.
[11]Van Ooij W J,D.Zhu,M.Stacy,et al.Corro- sion Protection Properties of Organo- functional Silanes-an Overview[J].Tsinghua Science and Technology,2005,10(6):639-665.
[12]Van Ooij W J,Song J,Subramanian V.International symposium on aluminum surface and technology.Antwerp,Belgium,1997,May,12.
[13]Vignesh Palanivel,Danqing Zhu,Van Ooij W J.Nanoparticle-filled silane films as chromate replacements for aluminum alloys[J].Progress in Organic Coatings,2003,47:384-392.
[14]Subramanian V,van Ooij W J.Corrosion,1998,54:204.
[15]Subramanian V.Ph.D.Dissertation,Department of Material Science and Engineering,University of Cincinnati,1999.
[16]van Ooij W J,Subramanian Vijay.Method of preventing corrosion of metals using silanes.University of Cincinnati,US Pat.6261638,July 17,2001.
[17]Puomi P.Ph.D.Dissertation,Department of Physical Chemistry,Abo Akademi University,Finland,2000.
[18]van Ooij W J.The potential of organofunctional silanes as chromate replacements on aluminum alloys.The SIP seminar on Chromate Replacements,Oslo,Norway,March 18-19,2002.Published in:http://www.sintef.nDiunttslmateklsip2000/meeting2002-03-18.htm.
[19]van Ooij W J,Zhu D.Progress in Organic Coatings,2004,49:42-53.
[20]Arkles B,Tailoring Surfaces with Silanes[J].ChemTech,1977,7:766.
[21]R.C.Hooper,Proc.SPIConf.Reinforced Plast.,Div.11th Sect8-B(1956)
[22]W.A.Zisman.Surface chemistry of plastics reinforced by strong fibers[J].IEC Product Research and Development,1963,8(2):98-111.
[23]E.P.Plueddeman.Interface on polymer Matrix Composites[J].Academic Press,1974:1-10.
[24]晨光化工研究院有机硅编写组,有机硅单体及聚合物[M],北京:化学工业出版社,1986:430
[25]何敏婷,偶联剂在涂料及复合材料中的应用[J]。现代涂料与涂装,2002,02:32-34
[26]Zhu D,Van Ooij W J,Structural character- rization of bis-[triethoxysilylpropyl]tetrasulfide and bis-[trimethoxysilyl- propyl]amine silanes by Fourier-transform infrared spectroscopy and electrochemical impedance spectroscopy[J].Journal of Adhesion Science and Technology,2002,16(9):1235-1260.
[27]Zhu D,Van Ooij W J.Corrosion protection of AA 2024-T3 by bis-[3-(triethoxysilyl)propyl]tetrasulfide in sodium chloride solution.Part 2:Mechanism for corrosion protection[J].Corrosion Science,2003,45(10):2177-2197.
[28]Danqing Zhu,Van Ooij W J.Enhanced corrosion resistance of AA 2024-T3 and hot-dip galvanized steel using a mixture of bis-[triethoxysilylpropyl]tetrasul- fide and bis-[trimethoxysilylpropyl]amine[J].Electrochimica Acta,2004,49:1113-1125.
[29]Van Ooij W J,Zhu D,Electrochemical impedance spectroscopy of bis-[tri ethoxysilypropyl]tetrasulfide on Al 2024-T3 substrates[J].Corrosion,2001,57(5):413-427.
[30]Gandhi J S,Suky Singh,Van Ooij W J.Evidence for formation of metallosiloxane bonds by comparison of dip-coated and electrode- posited silane films[J].Journal of Adhesion Science and Technology,2006,20(15):1741-1768.
[31]W.J.Van Ooij,A.Sabata.Patent 5,108,793,1992.
[32]W.J.Van Ooij,R.A.Edwards,A.Sabata.Patent 5,292,549,1994.
[33]W.J.Van Ooij,A.Sabata.Patent 5,322,713,1994.
[34]王楠,徐溢,杨立华。硅烷试剂防腐蚀工艺研究[J].材料保护,2001,34(11):32-34.
[35]高红云,张招贵.硅烷偶联剂的偶联机理及研究现状[J]。江西化工,2003,2:30-34.
[36]王雪明,李爱菊,李国丽等.硅烷偶联剂在防腐涂层金属预处理中的应用研究[J].材料科学与工程学报,2005,23(1):146-150.
[37]杜作栋,陈剑华。有机硅化学[M].北京,高等教育出版社,1990:184-206.
[38]黄汉生.硅烷偶联剂及其应用技术动向[J]。化工新型材料,1995,11:23-28.
[39]蒋宪明.硅烷偶联剂在填充复合材料中的应用[J]。国外塑料,1994(2):5-12.
[40]吴纪森.有机硅及其应用[M].北京,科学技术文献出版社,1990:309
[41]G.P.Sundararajan,Van Ooij W J.Silane based pretreatments for automotive steels[J].Surface Engineering,2000,16(4):315-320.
[42]Child T,W.J.Van Ooij.Application of silane technology to prevent corrosion of metals and paint adhesion[J].Trans IMF,1999,77(2):64-70.
[43]W.J.Van Ooij,Child T.Protecting metals with silane coupling agents[J].Chemtech,1998,28(2):26-35.
[43]Plueddemann E.P,Silane Coupling Agents[M],New York:Plenum Press,1991.
[44]Subramanian V,Van Ooij W J.Effect of the amine functional group on corrosion rate of iron coated with firms of organofunc- tional silanes[J].Corrosion,1998,54(3):204-215.
[45]Sheffer M,Groysman A,Mandler D.Electro- deposition of sol-gel films on Al for corrosion protection[J].Corrosion science,2003,45(12):2893-2904.
[46]Underhill P R,Goring G,DuQuesnay D L.A study of the curing of 3-glycidoxyprop- yltrimethoxy silane films on aluminum[J].International Journal of Adhesion and Adhesives,1998,18(5):313-317.
[47]Gandhi.J S,Metroke.T L,Eastman.M A,et al.Effect of the degree of hydrolysis and condensation of bis-[triethoxysilylpro- pyl]tetrasulfide on the corrosion prote- ction of coated aluminum Alloy 2024-T3[J].Corrosion,2006,62(7):612-623.
[48]Van Ooij W J,Zhu D Q,Prasad G,et al.Silane based chromate replacements for corrosion control,paint adhesion,and rubber bonding[J].Surface Engineering,2000,16(5):386-396.
[41]G.P.Sundararajan,Van Ooij W J.Silane based pretreatments for automotive steels[J].Surface Engineering,2000,16(4):315-320.
[49]Guirong Pan,Dale W.Shaefer,Van Ooij W J,et al.Morphology and water resistance of mixed silane films of bis[3-(triethoxy- silyl)propyl]tetrasulfide and bis-[tri- methoxysilylpropyl]amine[J].The solid films,2006,515:2771-2780.
[50]Vignesh Palanivel,Danqing Zhu,Van Ooij W J.Nanoparticle-filled silane films as chromate replacements for aluminum alloys[J].Progress in Organic Coatings,2003,47:384-392.
[51]陆峰,Van Ooij W J.铝合金表面硅烷处理后腐蚀性能的研究[J].材料工程,1999,8:18-20.
[52]郭增昌,王云芳,王汝敏.铝合金表面不同硅烷化预处理的耐蚀性研究[J].中国腐蚀与防护学报,2007,27(3):172-180。
[53]王云芳,郭增昌,王汝敏.铝合金表面硅烷化膜层的表征及电化学分析[J].材料保护,2006,39(12):3-7.
[54]王云芳,郭增昌,王汝敏.铝合金表面复合硅烷化膜层的制备和表征[J].材料保护,2007,40(11):39-41.
[55]Hu J M,Liu L,Zhang J Q.Effects of electrodeposition potential on the corrosion properties of bis-1,2[tri- ethoxysilyl]ethane films on aluminum alloy[J].Electrochimica Acta,2006,51(19):3944-3949.
[56]胡吉明,刘惊,张鉴清等.LY12铝合金表面电化学沉积制备DTMS硅烷膜及其耐蚀性研究[J].高等学校化学学报,2006,27(6):1121-1125.
[57]张为民,胡吉明,硅烷膜的阴极电化学辅助沉积及其防护性能[J].金属学报,2006,42(3):295-298.
[58]顾仁敖,陈惠,刘国坤,过渡金属表面有机官能团硅烷膜的研究-镍电极表面γ-氨丙基三甲氧基硅烷膜的结构[J].化学学报,2003,61(10):1550-1555.
[59]黄令,林克发,杨防祖,铜电极表面硅烷膜的自组装及其性能研究[J].电化学,2005,11(2):188-192.
[60]吴海江,卢锦堂,陈锦虹,热镀锌钢表面硅烷膜耐蚀性能的初步研究[J].腐蚀与防护,2006,27(1):14-17.
[61]Franquet A,Terryn H,Vereecken J.IRSE study on effect of thermal curing on the chemistry and thickness of organosilane films coated on aluminium[J].Applied Surface Science,2003,211(1-4):259-269
[62]Danqing Zhu,Wim J.van Ooij.Corrosion protection of metals by water-based silane mixtures of bis-[trimethoxysilylpropyl]amine and vinyltriacetoxysilane[J].Progress in Organic Coatings,2004,49(1):42-53.
[63]Wei Yuan,W J.van Ooij.Characterization of Organofunctional Silane Films on Zinc Substrates[J].Journal of Colloid and Interface Science,1997,185(1):197-209.
[64]Buchheit,R.G.;Grant,R.P.;Hlava,P.F.;Mckenzie,B.;Zender,G.L.Local dissolution phenomena associated with S phase(Al2CuMg)particles in aluminum alloy 2024-T3[J],Journal of the Electrochemical Society,1997,144(8):2621-2628
[65]丁新更,杨辉,汪铭,银离子掺杂有机硅烷薄膜耐蚀和抗菌性能研究[J].材料保护,2004,37(12):5-20.
[66]丁新更,杨辉,汪铭,不锈钢表面含银有机硅烷偶联剂抗菌耐蚀薄膜制备和性能[J].材料科学与工程学报,2004,22(5):663-665
[67]Palanivel W.M.Dissertation M.S.University of Cincinnati,department of materials science and engineering,2003.
[68]Palanivel,Vignesh;Huang,Y;Van Ooij,W.J.Effects of addition of corrosion inhibitors to silane films on the performance of AA2024-T3 in a 0.5 M NaCl solution[J].Progress in Organic Coatings,2005,53(2):153-168
[69]Wang R,Hashimoto K.Fujishima A.et al.Light induced amphilic surface[J].Nature,1997,388(31):431-432
[70]Jun song,W J.Ooij.Bonding and corrosion protection mechanisms of γ-APS and BTSE silane films on aluminum substrates[J].Journal of Adhesion Science & Technology,2003,17(16):2191-2221.
[71]Pu Zhengcai,Van Ooij W.J,Mark J.E.Hydrolysis kinetics and stability of bis(triethoxysily)ethane in water-ethanol solution by FTIR spectroscopy[J].Journal of Adhesion Science and Technology,1997,11(1):29-47.
[72]J S Gandhi,Suky Singh,W J.Ooij.Evidence for formation of metallo-siloxane bonds by comparison of dip- coated and electrodeposited silane films[J].Journal of Adhesion Science and Technology,2006,20(15):1741-1768.
[73]Anna Maria Beccaria,Laura Chiaruttini,The inhibitive action of metacryloxypropylmethoxy- silane on aluminum corrosion in NaCl solutions[J].Corrosion Science,1999,41(5):885-899.
[74]Yoshimasa Urushihara,Takashi Nishino,Effects of film-forming conditions on surface properties and structures of diblock copolymer with perfulouroalkyl side chains[J].Langmuir,2005,21(6):2614-2618.