Intensity of light scattered from polymeric gels: Influence of the structure of the networks

Abstract

The fluctuating part of the intensity of light scattered from polystyrene networks swollen to equilibrium in benzene has been measured by means of a technique using a spectrum analyzer or a rms meter. The scattered intensity is shown to decrease with the equilibrium concentration of the gel, according to a scaling law similar to that predicted from the theory of semidilute solutions. The fluctuating part of the intensity of light scattered from swollen networks containing controlled amounts of pendant chains has been shown to increase with decreasing cross-linking density. These results are in satisfactory agreement with the behavior of the elastic modulus determined from mechanical measurements.