Aqueous-based initiator attachment and ATRP grafting of polymer brushes from poly(methyl methacrylate) substrates.

Many polymers, such as PMMA, are very susceptible to swelling or dissolution by organic solvents. Growing covalently attached polymer brushes from these surfaces by atom-transfer radical polymerization (ATRP) is challenging because of the typical requirement of organic solvent for initiator immobilization. We report an unprecedented, aqueous-based route to graft poly(N-isopropylacrylamide), PNIPAAm, from poly(methyl methacrylate), PMMA, surfaces by ATRP, wherein the underlying PMMA is unaffected.

Thermal Response of Poly(N-isopropylacrylamide) Brushes Probed by Surface Plasmon Resonance.

The thermally induced hydration transition of surface-grafted poly(N-isopropyl acrylamide) (PNIPAAm) brushes was probed by surface plasmon resonance spectroscopy (SPR) and contact angle measurements. Data are presented for a PNIPAAm brush film with a dry thickness of ∼50 nm that was synthesized by atom radical transfer polymerization on the surface of a self-assembled monolayer on gold. SPR measurements were taken as a function of temperature in two modes:  the quasi-static mode, in which the sample was equilibrated at each temperature for ∼15 min prior to measurement, and the real-time mode, in which SPR reflectivity data were collected as the sample was heated and cooled at ∼4.