SANS OBSERVATIONS ON WEAKLY FLOCCULATED DISPERSIONS

Structural changes occurring in colloidal dispersions of poly-(methyl metacrylate) (PMMA) particles, sterically stabilized with poly-(12-hyd roxystearic acid) (PHSA), while varying the solvent quality, temperatu re and shear rate, are investigated by small-angle neutron scattering (SANS). For a moderately concentrated dispersion in a marginal solvent the transition on cooling from the effective stability to a weak attr action is monitored, The degree of attraction is determined in the fra mework of the sticky spheres model (SSM), SANS and rheological results are correlated.