Tunable friction by employment of co-non-solvency of PNIPAM brushes

POLYMER

卷:102

Article

Yu, Yunlong¹  Cirelli, Marco¹  Kieviet, Bernard D.¹  Kooij, E. Stefan²  Vancso, G. Julius¹  de Beer, Sissi¹ 

[1] Univ Twente, MESA Inst Nanotechnol, Mat Sci & Technol Polymers, POB 217, NL-7500 AE Enschede, Netherlands

[2] Univ Twente, MESA Inst Nanotechnol, Phys Interfaces & Nanomat, POB 217, NL-7500 AE Enschede, Netherlands

关键词: Poly(N-isopropyl acrylamide);    Polymer;    Tribology;    Friction;    Atomic force microscopy;    Brush;    Co-non-solvency;   

DOI  :  10.1016/j.polymer.2016.08.029

来源: Elsevier

【 摘 要 】

We present a simple method to control the tribological properties of contacts between polymer brushes and a solid counter surface. We show, using atomic force microscopy (AFM) experiments, that the friction force, upon relative sliding of a poly(N-isopropyl acrylamide) (PNIPAM) brush and a gold colloid on an AFM cantilever, varies over two orders of magnitude when changing the composition of an ethanol-water mixture that solvates the brush. We achieve this large variation in friction via a co-non-solvency effect: In pure water or ethanol, the PNIPAM brush is swollen and the friction is low, while in a 10-90 vol % ethanol-water mixture, the brush is partly collapsed and polymer-stretching causes the friction to be high. (C) 2016 Elsevier Ltd. All rights reserved.

【 授权许可】

Free