Surface photo-anchored PNIPAM crosslinked membrane on glass substrate by covalent bonds

Abstract

• PNIPAM covalently fixed on the glass surface to increase its adhesion. • The existence of TMPTA resulted a higher LCST value compared with PNIPAM alone. • PNIPAM still showed good thermo-sensitivity after fixed on the surface of glass. • Due to the property of discoloration with different temperature, PNIPAM membrane grafted on the surface of glass substrate had potential applications as temperature control switch device. In this study a hydroxylated glass surface was functionalized by 3-methacryloxypropyltrimethoxysilane (MPS) monolayer followed by the photoinitiated radical polymerization graft of N-isopropylacrylamide (NIPAM) chemical bonded to the C C groups of MPS and used trimethylolpropane triacrylate (TMPTA) as cross-linking agent. Composition of the PNIPAM membrane grafted on the glass substrate was investigated by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscope (XPS). UV–vis transmittance and water contact angle were used to examine the thermo-sensitivity. The results indicated that the PNIPAM reticulate membrane which was successfully grafted on the surface of glass by covalent bonds performed good adhesive strength and stability. Due to the property of discoloration with different temperature, PNIPAM membrane grafted on the surface of glass substrate had potential applications as temperature control switch device.