Dynamic Surface Properties of Amino-Terminated Self-Assembled Monolayers Incorporating Reversible CO2 Chemistry

作者：Mohammed Fiaz S; Wuttigul Sirikanya; Kitchens Christopher L^*

来源：Industrial & Engineering Chemistry Research, 2011, 50(13): 8034-8041.

DOI：10.1021/ie102526s

An innovative approach to creating a dynamically controllable smart surface is proposed, incorporating the reversible reaction of CO2 with free primary and secondary amines of amino-terminated self-assembled monolayers (SAMs). Solutions of N-(2-aminoethyl)(3-aminopropyl)methyldimethoxysilane (AEAPMDS),N-(6-aminohexyl)-3-aminopropyltrimethoxysilane (AHAPTS), and trimethoxysilylpropyl(polyethleneimine) (PEI-silane) were exposed to CO2, producing the respective carbamate species. The reacted CO2 was readily released by application of moderate heating and reduced pressure. Thermogravametric analysis (TGA) showed a weight loss percentage corresponding to 1 mol of CO2 per 1 mol of diamine at roughly 50 degrees C, and attenuated total reflectance Fourier transform infrared (ATR FTIR) spectroscopy confirmed the formation of the carbamate species. Well-ordered amino-terminal SAMs of AEAPMDS, AHAPTS, and PEI-silane were prepared on silicon substrates from toluene solutions and were then exposed to CO2. The subsequent changes in the surface structure and wettability were characterized by variable-angle ellipsometry, atomic force microscopy (AFM), and static contact-angle goniometry. The SAMs showed a reversible change in layer thickness coupled with an increase in hydrophilicity upon CO2 exposure.

• 出版日期2011-7-6