模芯钴含量对仿荷叶PDMS制件表面疏水性的影响
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摘要
目的在采用电铸镍钴合金提高模芯硬度的基础上,研究模芯钴含量对仿荷叶PDMS制件表面质量与疏水性的影响,探明镍钴合金模芯用于模板法制备仿荷叶超疏水表面的可行性。方法采用电铸-聚二甲基硅氧烷(PDMS)二次复制模板法先后制备荷叶母模、镍钴合金电铸模芯与仿荷叶疏水表面PDMS制件。采用数字式显微硬度仪、超景深三维显微镜、Image-Pro Plus图像处理软件、激光共聚焦显微镜等分析模芯钴含量对模芯硬度与PDMS制件表面微结构、粗糙度及疏水性的影响。最后采用接触角测量仪进一步测量与分析PDMS制件表面的疏水性能。结果当镍钴合金模芯钴含量(质量分数计)达到22.4%以上时,模芯硬度较纯镍模芯由244.1HV提升至450HV以上。当模芯钴含量从0增加到51.5%时,仿荷叶PDMS制件表面微结构深宽比先从2.12减小至1.72,再增加至2.38;微结构面积占比从19.15%减小至15.03%;表面粗糙度Ra值从59.01μm增加至74.93μm;静态接触角从166.22°线性减小至149°左右,疏水性降低。结论相比微结构深宽比与面积占比,表面粗糙度对PDMS制件疏水性的影响占主导作用。镍钴合金模芯硬度显著提高的同时,随钴含量的增大,仿荷叶PDMS制件的静态接触角从166.22°减小至149°左右,但仍具有良好的疏水性。
The work aims to study the influence of mass fraction of cobalt in mold inserts on the surface quality and hydrophobicity of the mimic lotus leaf PDMS parts and ascertain the feasibility of achieving the super-hydrophobicity of mimic lotus leaf PDMS parts with mold inserts electroformed with Ni-Co alloy on the basis of improving the hardness of mold inserts with electroformed Ni-Co alloy. Firstly, the electroforming and PDMS secondary template method was used to fabricate lotus leaf mold, mold inserts electroformed with Ni-Co alloy and PDMS parts with mimic lotus leaf hydrophobic surfaces. Then, the effect of cobalt content on the hardness of mold inserts and the microstructure, roughness and hydrophobicity of PDMS parts was analyzed by digital microhardness tester, super depth of field 3 D microscope, Image-Pro Plus, laser confocal microscope, etc. Finally, hydrophobicity was further measured and analyzed by contact angle measuring instrument. The hardness of mold inserts increased from 244.1 HV to above 450 HV when mass fraction of cobalt reached above 22.4%. With the increase of mass fraction of cobalt from 0 to 51.5%, the microstructure aspect ratio of the mimic lotus leaf PDMS parts tended to decrease from 2.12 to1.72 and then increase to 2.38. The surface microstructure area ratio decreased from 19.15% to 15.03%. The surface roughness Ra increased from 59.01 μm to 74.93 μm. The static contact angle decreased from 166.22° to 149° linearly, Which means the hydrophobicity was reduced. Compared with the microstructure aspect ratio and the area ratio, the surface roughness plays a major role in hydrophobicity of PDMS parts. While the hardness of mold inserts is improved significantly, the static contact angle of PDMS parts decreases from 166.22° to about 149° with the increase of mass fraction of cobalt, but PDMS parts still has good hydrophobicity.
The work aims to study the influence of mass fraction of cobalt in mold inserts on the surface quality and hydrophobicity of the mimic lotus leaf PDMS parts and ascertain the feasibility of achieving the super-hydrophobicity of mimic lotus leaf PDMS parts with mold inserts electroformed with Ni-Co alloy on the basis of improving the hardness of mold inserts with electroformed Ni-Co alloy. Firstly, the electroforming and PDMS secondary template method was used to fabricate lotus leaf mold, mold inserts electroformed with Ni-Co alloy and PDMS parts with mimic lotus leaf hydrophobic surfaces. Then, the effect of cobalt content on the hardness of mold inserts and the microstructure, roughness and hydrophobicity of PDMS parts was analyzed by digital microhardness tester, super depth of field 3 D microscope, Image-Pro Plus, laser confocal microscope, etc. Finally, hydrophobicity was further measured and analyzed by contact angle measuring instrument. The hardness of mold inserts increased from 244.1 HV to above 450 HV when mass fraction of cobalt reached above 22.4%. With the increase of mass fraction of cobalt from 0 to 51.5%, the microstructure aspect ratio of the mimic lotus leaf PDMS parts tended to decrease from 2.12 to1.72 and then increase to 2.38. The surface microstructure area ratio decreased from 19.15% to 15.03%. The surface roughness Ra increased from 59.01 μm to 74.93 μm. The static contact angle decreased from 166.22° to 149° linearly, Which means the hydrophobicity was reduced. Compared with the microstructure aspect ratio and the area ratio, the surface roughness plays a major role in hydrophobicity of PDMS parts. While the hardness of mold inserts is improved significantly, the static contact angle of PDMS parts decreases from 166.22° to about 149° with the increase of mass fraction of cobalt, but PDMS parts still has good hydrophobicity.
引文
[1]BHUSHAN B,HER E K.Fabrication of superhydrophobic surfaces with high and low adhesion inspired from rose petal[J].Langmuir the ACS journal of surfaces&colloids,2010,26(11):8207-8217.
[2]GUO S C,WU F,FANG L,et al.Controllable preparation of transparent superhydrophobic TiO2 nanoarrays[J].Materials&processing report,2015,30(1):43-49.
[3]OU J,PEROT B,ROTHSTEIN J P.Laminar drag reduction in microchannels using ultrahydrophobic surfaces[J].Physics of fluids,2004,16(12):4635-4643.
[4]崔日俊,秦静,屈钧娥,等.彩色超疏水不锈钢表面的制备[J].表面技术,2018(2):30-35.CUI Ri-jun,QIN Jing,QU Jun-e,et al.Preparation of super-hydrophobic colored surface on a stainless steel matrix[J].Surface technology,2018(2):30-35.
[5]黎醒,蒋炳炎,吕辉,等.疏水植物表面微纳复合结构电铸模芯的制备[J].材料工程,2018,46(2):66-72.LI Xing,JIANG Bing-yan,LYU Hui,et al.Fabrication of electroformed mold inserts with micro-nano structures from hydrophobic plant surfaces[J].Journal of materials engineering,2018,46(2):66-72.
[6]WENG C,WANG F,ZHOU M Y,et al.Fabrication of hierarchical polymer surfaces with superhydrophobicity by injection molding from nature and function-oriented design[J].Applied surface science,2018,436:224-233.
[7]ZHOU M Y,XIONG X,JIANG B Y,et al.Fabrication of high aspect ratio nanopillars and micro/nano combined structures with hydrophobic surface characteristics by injection molding[J].Applied surface science,2018,427:854-860.
[8]翁灿,周宏慧,王飞,等.高聚物超疏水表面制备技术研究进展[J].工程塑料应用,2014(6):122-125.WENG Can,ZHOU Hong-hui,WANG Fei,et al.Research progress in preparation technologies for ploymer superhydrophobic surfaces[J].Engineering plastics application,2014(6):122-125.
[9]LEE S M,KWON T H.Replication of highly-hydrophobic surface with micro/nano combined structures from nature[J].Nanoscale fabrication,2006,3:247-250.
[10]LEE S M,KWON T H.Mass-producible replication of highly hydrophobic surfaces from plant leaves[J].Nanotechnology,2006,17(13):3189-3196.
[11]汪哲能,邱锡荣,杨博伟.电铸液中钴含量对镍钴合金电铸模芯性能的影响[J].材料保护,2016,49(1):59-62.WANG Zhe-neng,QIU Xi-rong,YANG Bo-wei.Effects of cobalt content in electrolytic bath on properties of Ni-Co alloy for electroforming core[J].Materials protection,2016,49(1):59-62.
[12]刘霁云,赵阳,董世运,等.脉冲电刷镀Ni-Co镀层及其硬度的研究[J].表面技术,2018(1):218-223.LIU Ji-yun,ZHAO Yang,DONG Shi-yun,et al.Ni-Co alloy coatings prepared by pulse brush electroplating and their microhardness[J].Surface technology,2018(1):218-223.
[13]赵祖欣.镍钴合金电铸模具的研究[J].精密成形工程,1992(1):13-18.ZHAO Zu-xin.Study on electroforming mold of Ni-Co alloy[J].Journal of netshape forming engineering,1992(1):13-18.
[14]SHAFIEL M,ALPAS A T.Nanocrystalline nickel films with lotus leaf texture for superhydrophobic and low friction surfaces[J].Applied surface science,2009,256(3):710-719.
[15]WENZEL R N.Resistence of solid surfaces to wetting by water[J].Transactions of the faraday society,1936,28(8):988-994.
[16]CASSIE A B D,BAXTERS S.Wettability of porous surfaces[J].Transactions of the faraday society,1944,40(1):546-551.
[17]周蕊,金海云,高乃奎,等.表面粗糙度对硅橡胶材料表面超疏水性的影响[J].中国表面工程,2009,22(6):30-35.ZHOU Rui,JIN Hai-yun,GAO Nai-kui,et al.Influence of surface roughness on superhydrophobicity of silicone rubber surface[J].China surface engineering,2009,22(6):30-35.
[2]GUO S C,WU F,FANG L,et al.Controllable preparation of transparent superhydrophobic TiO2 nanoarrays[J].Materials&processing report,2015,30(1):43-49.
[3]OU J,PEROT B,ROTHSTEIN J P.Laminar drag reduction in microchannels using ultrahydrophobic surfaces[J].Physics of fluids,2004,16(12):4635-4643.
[4]崔日俊,秦静,屈钧娥,等.彩色超疏水不锈钢表面的制备[J].表面技术,2018(2):30-35.CUI Ri-jun,QIN Jing,QU Jun-e,et al.Preparation of super-hydrophobic colored surface on a stainless steel matrix[J].Surface technology,2018(2):30-35.
[5]黎醒,蒋炳炎,吕辉,等.疏水植物表面微纳复合结构电铸模芯的制备[J].材料工程,2018,46(2):66-72.LI Xing,JIANG Bing-yan,LYU Hui,et al.Fabrication of electroformed mold inserts with micro-nano structures from hydrophobic plant surfaces[J].Journal of materials engineering,2018,46(2):66-72.
[6]WENG C,WANG F,ZHOU M Y,et al.Fabrication of hierarchical polymer surfaces with superhydrophobicity by injection molding from nature and function-oriented design[J].Applied surface science,2018,436:224-233.
[7]ZHOU M Y,XIONG X,JIANG B Y,et al.Fabrication of high aspect ratio nanopillars and micro/nano combined structures with hydrophobic surface characteristics by injection molding[J].Applied surface science,2018,427:854-860.
[8]翁灿,周宏慧,王飞,等.高聚物超疏水表面制备技术研究进展[J].工程塑料应用,2014(6):122-125.WENG Can,ZHOU Hong-hui,WANG Fei,et al.Research progress in preparation technologies for ploymer superhydrophobic surfaces[J].Engineering plastics application,2014(6):122-125.
[9]LEE S M,KWON T H.Replication of highly-hydrophobic surface with micro/nano combined structures from nature[J].Nanoscale fabrication,2006,3:247-250.
[10]LEE S M,KWON T H.Mass-producible replication of highly hydrophobic surfaces from plant leaves[J].Nanotechnology,2006,17(13):3189-3196.
[11]汪哲能,邱锡荣,杨博伟.电铸液中钴含量对镍钴合金电铸模芯性能的影响[J].材料保护,2016,49(1):59-62.WANG Zhe-neng,QIU Xi-rong,YANG Bo-wei.Effects of cobalt content in electrolytic bath on properties of Ni-Co alloy for electroforming core[J].Materials protection,2016,49(1):59-62.
[12]刘霁云,赵阳,董世运,等.脉冲电刷镀Ni-Co镀层及其硬度的研究[J].表面技术,2018(1):218-223.LIU Ji-yun,ZHAO Yang,DONG Shi-yun,et al.Ni-Co alloy coatings prepared by pulse brush electroplating and their microhardness[J].Surface technology,2018(1):218-223.
[13]赵祖欣.镍钴合金电铸模具的研究[J].精密成形工程,1992(1):13-18.ZHAO Zu-xin.Study on electroforming mold of Ni-Co alloy[J].Journal of netshape forming engineering,1992(1):13-18.
[14]SHAFIEL M,ALPAS A T.Nanocrystalline nickel films with lotus leaf texture for superhydrophobic and low friction surfaces[J].Applied surface science,2009,256(3):710-719.
[15]WENZEL R N.Resistence of solid surfaces to wetting by water[J].Transactions of the faraday society,1936,28(8):988-994.
[16]CASSIE A B D,BAXTERS S.Wettability of porous surfaces[J].Transactions of the faraday society,1944,40(1):546-551.
[17]周蕊,金海云,高乃奎,等.表面粗糙度对硅橡胶材料表面超疏水性的影响[J].中国表面工程,2009,22(6):30-35.ZHOU Rui,JIN Hai-yun,GAO Nai-kui,et al.Influence of surface roughness on superhydrophobicity of silicone rubber surface[J].China surface engineering,2009,22(6):30-35.