Compression of Polymer Brushes: Quantitative Comparison of Self-Consistent Field Theory with Experiment

摘要

Polymeric brushes, formed by densely grafting polymer chains to a surface, have become a convenient means of modifying surface properties.1 Of particular interest is the steric repulsion created between opposing brushes, which can, for example, be used to stabilize colloidal particles against flocculation caused by attractive van der Waals forces. Taunton et al.2 were the first to measure the repulsion on a sufficiently well characterized system to allow quantitative comparison with theory. Their experiment measured the force as a function of separation, D, between two crossed cylindrical surfaces of radius, R ≈ 1 cm, covered by 3.0 ( 0.5 mg/m2 of tethered polystyrene chains of molecular weight, 141 kg/mol, immersed in toluene solvent.