Related Experiment Video
Updated: Jun 11, 2026
Preparation and Friction Force Microscopy Measurements of Immiscible, Opposing Polymer Brushes
Published on: December 24, 2014
Neutron reflectivity study of the structure of pH-responsive polymer brushes grown from a macroinitiator at the
Mauro Moglianetti1, John R P Webster, Steve Edmondson
1Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK.
Abstract:
Poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) brushes have been grown by surface-initiated atom transfer radical polymerization (SI-ATRP) from a polyanionic macroinitiator adsorbed at the sapphire-water interface, and neutron reflectivity has been used to characterize the structures and pH response of the brushes. The polymer brushes are well-described by Gaussian density profiles with an additional thin, dense layer close to the solid-liquid interface for the thicker brushes at pH 7 and 9, which produces a spike in the density profile. The spike in the distribution accounts for less than 5% of the polymer and disappears as the brushes swell at pH 3. The observed swelling behavior has been used in combination with the predictions of scaling theory and previous experimental measurements to determine the grafted density of PDMAEMA chains.
