CHARACTERIZATION OF POLY(STYRENE-CO-DIVINYLBENZENE) MICROGELS

In the reported experiments, tightly crosslinked poly(styrene-co-divinylbenzene) microgels with molecular weights in the range 10**7 to 10**8 g mole** minus **1 were studied in solution in demethylformamide containing 7 g dm** minus **3 LiBr. Laser light scattering photon correlation spectroscopy (PCS) was used to measure z-average translational diffusion coefficients D//z and dilute solution viscometry to measure intrinsic viscosities left bracket eta right bracket ; values of the equivalent hydrodynamic radii left angle bracketR// eta **3right angle bracket//n**1**/**3 and left angle bracketR//D** minus **1right angle bracket//z** minus **1 were derived. Weight-average molecular weights M// omega and z-average mean squre radii of gyration left angle bracketS**2right angle bracket//z were determined by conventional light scattering. The microgels were investigated by gel permeation chromatography, and molecular weight data obtained using the left bracket eta right bracket M calibration procedure were in satisfactory agreement with results obtained by electron microscopy and conventional light scattering.