Neutron Reflectivity Study of the Density Profile of a Model End-Grafted Polymer Brush: Influence of Solvent Quality

Neutron reflectivity measurements are made on a chemically end-grafted polymer brush swollen over a range of temperatures above and below the theta point. Good agreement between the brush profiles and recent self-consistent field calculations and numerical simulations is obtained for temperatures in the vicinity of the theta point and in a good solvent. The expansion of the main body of the brush resembles a swelling gel, while the brush tail expands similarly to a polymer in solution.