聚碳酸酯仿生超疏性自清洁表面的微热压成型
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摘要
荷叶超疏特性自清洁功能的仿生制造是解决传热表面结垢问题的一种有效途径,基于荷叶超疏特性自清洁机制分析,设计出具有仿生自清洁功能的聚碳酸酯微观阵列圆柱和圆锥台形粗糙结构的超疏特性表面形貌,研究了其微热压成型工艺。研究表明:通过仿生表面改形,使聚碳酸酯基片形成微米级阵列圆柱形和圆锥台形粗糙微结构,可使其液珠接触角超过160°,从而使其具有荷叶类似的超疏特性自清洁功能,而低压微热压成型工艺能实现仿生聚碳酸酯微观阵列超疏特性自清洁功能表面成型制造。当热压成型温度跨越Tg+20℃,聚碳酸酯基片可完全演化为黏弹性高弹态,这可使变形充填成型所需的应力突降98%,从而使微观阵列圆柱和圆锥台的热压成型压力分别降低至2.0、2.85 MPa,可有效避免仿生超疏特性自清洁功能表面微热压成型的脱模损伤。
Bionic manufacturing of the lotus leaves,superhydrophobic self cleaning surface is an effective way to solve the problem of fouling in heat transfer surface.Based on analysis of superhydrophobic self cleaning mechanism of lotus leaf,the polycarbonate array micro cylindrical and cylindrical conical superhydrophobic surface with self cleaning function was designed,and its micro hot pressing process was studied.Research shows that the polycarbonate substrate is formed into array cylindrical and cylindrical conical rough microstructures by the bionic modification of surface morphology,which make its contact angle of the liquid droplet is more than 160 degrees,and make it have the superhydrophobic self cleaning function of lotus leaf.The low pressure micro hot embossing process can realize the bionic manufacturing of the polycarbonate superhydrophobicv self cleaning functional surface with array micro cylindrical and cylindrical conical structure characteristics.When the hot embossing temperature is over Tg+20℃,the polycarbonate substrate is completely transformed to the viscoelastic high elastic state,and make the required stress of thermal viscoelastic plastic deformation was reduced suddenly,the range of sudden drop is over 98%,which make the hot embossing pressure of the micro array cylinder and the conical table is respectively reduced to 2.0 MPa and 2.85 MPa,and can effectively avoid the demoulding damage in micro hot embossing process of bionic superhydrophobic self cleaning surface.
Bionic manufacturing of the lotus leaves,superhydrophobic self cleaning surface is an effective way to solve the problem of fouling in heat transfer surface.Based on analysis of superhydrophobic self cleaning mechanism of lotus leaf,the polycarbonate array micro cylindrical and cylindrical conical superhydrophobic surface with self cleaning function was designed,and its micro hot pressing process was studied.Research shows that the polycarbonate substrate is formed into array cylindrical and cylindrical conical rough microstructures by the bionic modification of surface morphology,which make its contact angle of the liquid droplet is more than 160 degrees,and make it have the superhydrophobic self cleaning function of lotus leaf.The low pressure micro hot embossing process can realize the bionic manufacturing of the polycarbonate superhydrophobicv self cleaning functional surface with array micro cylindrical and cylindrical conical structure characteristics.When the hot embossing temperature is over Tg+20℃,the polycarbonate substrate is completely transformed to the viscoelastic high elastic state,and make the required stress of thermal viscoelastic plastic deformation was reduced suddenly,the range of sudden drop is over 98%,which make the hot embossing pressure of the micro array cylinder and the conical table is respectively reduced to 2.0 MPa and 2.85 MPa,and can effectively avoid the demoulding damage in micro hot embossing process of bionic superhydrophobic self cleaning surface.
引文
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[8] LATTHE S S,GURAV A B,MARUTI C S,et al.Recent progress in preparation of superhydrophobic surfaces:a review[J]. Journal of Surface Engineered Materials and Advanced Technology,2012,2:76-94.
[9] LIN M C,YEH J P,CHEN S C,et al.Study on the replication accuracy of polymer hot embossed microchannels[J].International Communications in Heat&Mass Transfer,2013,42(3):55-61.
[10] YEO L P,NG S H,WANG Z,et al.Micro-fabrication of polymeric devices using hot roller embossing[J]. Microelectronic Engineering,2009,86(4/5/6):933-936.
[11] PALACIOS C M,VASIEV I,GADEGAARD N,et al.Direct micrometer patterning and functionalization of polymer blend surfaces by using hot embossing[J]. European Polymer Journal,2014,59:333-340.
[12] CHENG G,SAHLI M,GELIN J C,et al.Physical modelling,numerical simulation and experimental investigation of microfluidic devices with amorphous thermoplastic polymers using a hot embossing process[J].Journal of Materials Processing Technology,2015,229:36-53.
[13]贺永,傅建中,陈子辰.微热压成型脱模缺陷分析及其脱模装置[J].机械工程学报,2008,44(11):53-58.
[2] YU Y,ZHAO Z H,ZHENG Q S.Mechanical and superhydrophobic stabilities of two-scale surfacial structure of lotus leaves[J].Langmuir,2007,23(15):8212-8216.
[3] BARTHLOTT W,NEINHUIS C.Purity of the sacred lotus,or escape from contamination in biological surfaces[J].Planta,1997,202(1):1-8.
[4] KOCH K,BHUSHAN B,BARTHLOTT W. Diversity of structure,morphology and wetting of plant surfaces[J].Soft Matter,2008,4(10):1943-1963.
[5] SOGAARD E. Injection molded self cleaning surfaces[D].Denmark:Technical University of Denmark,2016.
[6] QUAN Y Y,ZHANG L Z.Facile fabrication of superhydrophobic films with fractal structures using epoxy resin microspheres[J]. Applied Surface Science,2014,292:44-54.
[7] HUANG Y H,WU J T,YANG S Y.Direct fabricating patterns using stamping transfer process with PDMS mold of hydrophobic nanostructures on surface of micro cavity[J].Microelectronic Engineering,2011,88(6):849-854.
[8] LATTHE S S,GURAV A B,MARUTI C S,et al.Recent progress in preparation of superhydrophobic surfaces:a review[J]. Journal of Surface Engineered Materials and Advanced Technology,2012,2:76-94.
[9] LIN M C,YEH J P,CHEN S C,et al.Study on the replication accuracy of polymer hot embossed microchannels[J].International Communications in Heat&Mass Transfer,2013,42(3):55-61.
[10] YEO L P,NG S H,WANG Z,et al.Micro-fabrication of polymeric devices using hot roller embossing[J]. Microelectronic Engineering,2009,86(4/5/6):933-936.
[11] PALACIOS C M,VASIEV I,GADEGAARD N,et al.Direct micrometer patterning and functionalization of polymer blend surfaces by using hot embossing[J]. European Polymer Journal,2014,59:333-340.
[12] CHENG G,SAHLI M,GELIN J C,et al.Physical modelling,numerical simulation and experimental investigation of microfluidic devices with amorphous thermoplastic polymers using a hot embossing process[J].Journal of Materials Processing Technology,2015,229:36-53.
[13]贺永,傅建中,陈子辰.微热压成型脱模缺陷分析及其脱模装置[J].机械工程学报,2008,44(11):53-58.