Chemoresponsive surface-tethered polypeptide brushes based on switchable secondary conformations

摘要: Surface-tethered chemoresponsive polypeptides prepared by surface-initiated vapor deposition polymerization (SI-VDP) were used to investigate the conversion efficiency between α-helical and β-sheet conformations of poly(γ-methyl-L-glutamate) (PMLG) homopolypeptide PMLG-b-poly(β-benzyl-L-glutamate) (PBLG) copolypeptide brushes. The end-grafted PMLG brush predominantly adopted a conformation after exposure formic acid vapor, it was converted back treatment with mixture dichloroacetic (DCA) chloroform (CHCl3). This conformational inter-conversion process reversible repeatable for number cycles. Factors that affected α-helix studied, including chain mobility, concentration DCA, temperature vapor. For brushes one end restriction, 60% from α β achieved 40 °C 2 days, while in PMLG-b-PBLG brushes, 40% 9 which slower than due additional restriction PBLG block. In comparison, spin-coated films chains had no restrictions, 80% within days same condition. effects solvent on morphologies surface-grafted also observed. changes properties these films, surface wettability, thickness, morphologies, characterized contact angle measurement, ellipsometry, atomic force microscopy, respectively.