Temperature‐Responsive Glycopolymer Brushes Synthesized via RAFT Polymerization Using the Z‐group Approach

Abstract

AbstractSummary: Stimuli‐responsive glycopolymer brushes composed of N‐acryloyl glucosamine (AGA) and N‐isopropylacrylamide (NIPAAm) were prepared using RAFT polymerization. The RAFT agent was immobilized on the surface of a treated silicon waver via covalent attachment using the Z‐group. PAGA and PNIPAAm brushes showed a linear increase in brush thickness with the consumption of monomer in solution. The polymers generated in solution confirm the living behavior with the molecular weight increasing linearly with monomer conversion while the molecular weight distribution remains narrow. Additionally, the ability of PAGA brushes to grow further in the presence of NIPAAm reveals the presence of an active RAFT end group indicative of a living system. PAGA and PNIPAAm homopolymer brushes up to 30 nm were grown using this technique. PAGA brushes were utilized for further chain extension to generate stimuli‐responsive brushes with block structures of PAGA and PNIPAAm. The PAGA‐block‐PNIPAAm brushes were found to grow in size with the consumption of NIPAAm. Contact angle measurements confirm the suggested mechanism showing that the second monomer is incorporated between the first layer and the silicon surface as expected using the Z‐group approach.Structure of the stimuli‐responsive glycopolymer brushes.magnified imageStructure of the stimuli‐responsive glycopolymer brushes.