首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Control of surface properties of self-assembled monolayers by tuning the degree of molecular asymmetry
Authors:Susana Moreno Flores  Andrey Shaporenko
Institution:a Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
b Applied Physical Chemistry Department, University of Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
c Center of Micro and Nanochemistry and Engineering, Organic Chemistry I, University of Siegen, Adolf-Reichwein-Str. 3, 57068 Siegen, Germany
Abstract:We have studied self-assembled monolayers (SAMs) of asymmetric dialkyldisulfide derivatives of the form CH3-(CH2)11+m-S-S-(CH2)11-OH with m = −4, −3, 0, +2 and +4 on gold. Sub-nanoscale changes in the length of the CH3-terminated alkylchain have been used to selectively protrude one particular end group in the resulting film. The alteration of the chain length in only two methylene units already results in changes of surface properties, which have been detected with local (chemical force microscopy) and macroscopic (contact angle) techniques. In particular, advancing contact angles can be adjusted between 40° and 80°. The adhesion between a hydrophobic tip and these SAMs in water is determined by the chemical nature of the protruding end group. Chemical force microscopy, X-ray photoelectron spectroscopy and infrared reflection absorption spectroscopy have shown that these SAMs are composed of mixed, well-packed CH3- and OH-alkylthiolate branches. The surface composition ratio is close to 1:1 for all investigated SAMs.
Keywords:Self-assembly  Asymmetric dialkyldisulfide derivatives  Scanning probe techniques  Chemical force microscopy  Wetting  X-ray photoelectron spectroscopy  Infrared reflection absorption spectroscopy
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号