PEG Brushes on Porous, PDMS-Coated Surfaces and Their Interaction with Carbon Dioxide

A porous polymeric substrate covered with a thin polydimethylsiloxane (PDMS) coating is used for the surface-initiated polymerization of polyethylene glycol (PEG)-based polymer brushes. Successful synthesis of the brushes is evidenced by several methods and their impact on the characteristics of the polymeric multilayer substrate is studied. Investigation into the behavior of PEG-based brushes using atomic force microscopy and multiple transmission-reflection infrared (MTR-FTIR) spectroscopy reveals conformational changes of the brush chains upon exposure to carbon dioxide. The results presented here highlight an elegant way to covalently modify porous, PDMS-coated substrates with polymer brushes to alter their characteristics.