Repulsive forces and relaxation on compression of entangled, polydisperse polystyrene brushes

被引：64

作者：

Ruths, M ^{[1
]}

Johannsmann, D ^{[1
]}

Rühe, J ^{[1
]}

Knoll, W ^{[1
]}

机构：

[1] Max Planck Inst Polymer Res, D-55128 Mainz, Germany

来源：

MACROMOLECULES | 2000年 / 33卷 / 10期

关键词：

D O I：

10.1021/ma9920994

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

The interaction forces between high molecular weight polystyrene brushes (M-n = (0.7-1.2) x 10(6) g/mol), formed by radical chain polymerization from an initiator chemically bound to silica (quartz-glass) substrates, were measured with a surface forces apparatus. Because of the high grafting densities obtained (7-10 nm between attachment points), the polymer chains were strongly stretched and extended several hundred nanometers from each surface in a goad solvent. The extension and magnitude of the purely repulsive force measured over the whole interaction range were compared to theoretical predictions. taking into account the polydispersity of the polymer. The differences in range and magnitude between forces measured on approach and on separation of the surfaces increased after long compression times and were attributed to entanglements within each compressed layer.

引用

页码：3860 / 3870

页数：11

共 55 条

[1] ADSORPTION OF CHAIN MOLECULES WITH A POLAR HEAD A-SCALING DESCRIPTION [J].