Superhydrophobicity on Micro-and Nanostructured Polyolefin Surfaces:an Experimental and Theoretical

• 作 者: Tapani A Pakkanen Esa Puukilainen Janne Hirvi Tiina Rasilainen Mika Suvanto
• 机 构: Deparment of Chemistry University of Joensuu Joensuu FI-801018,Finland,Deparment of Chemistry Unive
• 出 处: 复旦学报(自然科学版)
• 发表日期: 2007年05期

1 Results Simultaneous micro-and nanostructuring was prepared on polyolefin surfaces by injection molding.The molds were made of electropolished aluminum foil where the micropatterns were structured with a custom made robot.Nanopatterns were subsequently created on the molds by oxidizing the aluminum surface electrochemically in polyprotic acid.The preparation technique allowed simultaneous control of the dimensions of the micro-and nanostructures.Structuring has a remarkable effect on the contact angle between the polyolefin and water.With optimized microstructure covered with nanostructure the static contact angle between polypropylene and water was found to be 165°.The sliding angle of about 2.5° proved the superhydrophobic state[1]. Molecular dynamics simulations were used to study the effect of periodic roughness of polyethylene on the hydrophobicity.Nanoscale pillars of different lateral dimensions and heights were derived from flat crystalline surfaces,and the results of simulations on the structured surfaces were compared with theoretical predictions of the Wenzel and Cassie equations[2-3].

1 Results Simultaneous micro-and nanostructuring was prepared on polyolefin surfaces by injection molding. Molds were made of electropolished aluminum foil where the micropatterns were structured with a custom made robot. Nanopatterns were subsequently created on the molds by oxidizing the aluminum surface electrochemically in polyprotic acid. The preparation technique allows simultaneous control of the dimensions of the micro-and nanostructures.Structuring has a remarkable effect on the contact angle between the polyolefin and water. With optimized microstructure covered with nanostructure the static contact angle between polypropylene and water was found to be 165 °. The sliding angle of about 2.5 ° proved the superhydrophobic state [1]. Molecular dynamics simulations were used to study the effect of periodic roughness of polyethylene on the hydrophobicity. Nano-scale pillars of different lateral dimensions and heights were derived from the crystalline surfaces, and the results of simu lations on the structured surfaces were compared with theoretical predictions of the Wenzel and Cassie equations [2-3].