DIRECT MEASUREMENTS OF POLYMER DEPLETION LAYERS BY NEUTRON REFLECTIVITY

被引：34

作者：

LEE, LT ^{[1
]}

GUISELIN, O ^{[1
]}

LAPP, A ^{[1
]}

FARNOUX, B ^{[1
]}

PENFOLD, J ^{[1
]}

机构：

[1] RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND

来源：

PHYSICAL REVIEW LETTERS | 1991年 / 67卷 / 20期

关键词：

D O I：

10.1103/PhysRevLett.67.2838

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We present results of direct measurements of polymer depletion layers at the liquid/air interface using neutron reflectivity. The systems studied are semidilute solutions of polystyrene in toluene using polymers of different molecular weights, The thickness of the depletion layer d is found to be of the order of the correlation length-xi of the polymer in the bulk solution. We show, for the first time, the existence of a depletion layer at the free surface of a polymer solution when gamma-p > gamma-s, where gamma-p and gamma-s are surface tensions of pure polymer and pure solvent, respectively. We show also that the thickness of the depletion layer scales with the bulk concentration phi-b as d approximately phi-b-0.75.

引用

页码：2838 / 2841

页数：4

共 24 条

[1] DIRECT OPTICAL OBSERVATION OF INTERFACIAL DEPLETION LAYERS IN POLYMER-SOLUTIONS [J].