Dynamic and reversible electrowetting with low voltage on the dimethicone infused carbon nanotube array in air  

作　　者：Miao Wang Lei Zhou Yaqi Hou Wen He Wei Liu Feng Wu Xu Hou 

机构地区：[1]Research Institute for Biomimetics and Soft Matter,Fujian Provincial Key Laboratory for Soft Functional Materials Research,Jiujiang Research Institute,College of Physical Science and Technology,Xiamen University,Xiamen 361005,China [2]State Key Laboratory of Physical Chemistry of Solid Surfaces,Collaborative Innovation Center of Chemistry for Energy Materials,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China

出　　处：《Chinese Chemical Letters》2020年第7期1914-1918,共5页中国化学快报（英文版）

基　　金：the National Natural Science Foundation of China(Nos.51706191,21673197,21621091,21975209);the National Key R&D Program of China(No.2018YFA0209500);the Fundamental Research Funds for the Central Universities(No.20720190037);the Natural Science Foundation of Fujian Province of China(No.2018J06003)。

摘　　要：Unremitting efforts have been intensively making for pursuing the goal of the reversible transition of electrowetting owing to its vital importance to many practical applications,but which remains a major challenge for carbon nanotubes due to the irreversible electrochemical damage.Herein,we proposed a subtly method to prevent the CNT array from electrochemical damage by using liquid medium instead of air medium to form a liquid/liquid/solid triphase system.The dimethicone dynamically refills in CNT arrays after removing of voltage that makes the surface back to hydrophobic,which is an elegant way to not only decrease energy dissipation in electrowetting process but also obtain extra energy in reversible dewetting process.Repeated cycles of in situ experiments showed that more than four reversible electrowetting cycles could be achieved in air.It wo rth mention that the in situ reve rsible electro wetting voltage of the dimethicone infused CNT array has been lowered to 2 V from 7 V which is the electrowetting voltage for the pure CNT array.The surface of the dimethicone infused CNT array can maintain hydrophobicity with a contact angle of 145.6°after four cycles,compared with 148.1°of the initial state.Moreover,a novel perspective of theoretical simulations through the binding energy has been provided which proved that the charged CNTs preferred binding with water molecules thereby replacing the dimethicone molecules adsorbed on the CNTs,whereas reconnected with dimethicone after removing the charges.Our study provides distinct insight into dynamic reversible electrowetting on the nanostructured surface in air and supplies a way for precise control of wettability in surface chemistry,smart phase-change heat transfer enhancement,liquid lenses,microfluidics,and other chemical engineering applications.

关 键 词：Carbon nanotube array ELECTROWETTING REVERSIBLE DYNAMIC Low voltage 

分 类 号：O647.5[理学—物理化学]