The discovery of different aspects of polymer brush synthesis, properties, and applications have resulted in a rapidly developing interest in the field, namely switchable systems. So far, researchers have been able to fabricate triggered switching with the use of common transition selective solvents which have brought about advances in responsive systems like self-cleaning devices. Although these systems have immense potential, the use of a selective solvent restricts further growth as only limited sets of polymers have common selective solvents. The objective of our work is to investigate hydrophilic-to-hydrophobic switching behavior of mixed polystyrene-block-poly(4-vinylpyridine) (PS-P4VP) and polyacrylamide (PAAm) mosaic systems using a common nonselective solvent. The PS-P4VP mosaic brush is prepared by incorporating supramolecular block copolymer assemblies (SMA) onto (p-bromophenyl)-trimethoxysilane modified Si-wafers. SMAs are hybrid materials which are characterized by the ability of one block selectively interacting with a low molecular additive; in our case, 2-(4'-hydroxybenzeneazo) benzoic acid additive (HABA) H-bonding with P4VP block of PS-P4VP, or PS as additive being miscible with the PS block of PS-P4VP. The SMA can form well-ordered arrays of nanoscopic pores upon selective extraction of the HABA or PS additive, which allows for the �grafting to� of PS-P4VP mosaic brush. PAAm is then �grafted through� via photoinitiation in between the PS-P4VP mosaic brush. The systems are characterized via atomic force microscopy (AFM), null ellipsometry and contact angle measurements. Surface adhesion properties are investigated via colloidal probe AFM measurements and biological cell adhesion response is measured by bioluminescence of Escherichia coli and Samonella typhimurium cells.

Mixed polystyrene-block-poly(4-vinylpyridine) and polyacrylamide brush for triggered hydrophobic-to-hydrophilic switching

248th National Meeting (2014)

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