Solvent-responsiveness of PS–PEO binary mixed polymer brushes: a coarse-grained molecular dynamics study

Abstract

Systems of mixed polymer brushes (polystyrene–polyethylene oxide, PS–PEO) uniformly grafted on solid substrate were investigated by coarse-grained molecular dynamics simulations. The effects of grafting density and relatively degree of polymerisation of PS and PEO on the switching property of PS–PEO mixed polymer brushes in water and solvent are explored and discussed. Simulation results indicate that PS dominated the thickness of PS–PEO mixed polymer brushes in different solvents, which can be controlled by adjusting the grafting density. Brush heights of mixed PS–PEO polymer brushes fluctuate in different solvents when grafting density varies. The chemical composition of the very top surface of these mixed polymer brushes are largely determined by the relative polymerisation degree of PS and PEO.

Keywords:

• Polymer brushes
• solvent responsiveness
• coarse-grained
• molecular simulation
• molecular dynamics simulation

Acknowledgements

The authors thank the financial supports from National Natural Science Foundation of China (Nos. 91334202, 21376089), the National Key Basic Research Program of China (No. 2013CB733500), Guangdong Science Foundation (2014A030312007) and the Fundamental Research Funds for the Central Universities (SCUT-2015ZP033). CPU hours allocated by the SCUTGrid at South China University of Technology and the ScGrid of Supercomputing Centre, Computer Network Information Centre of Chinese Academy of Sciences are also gratefully acknowledged.