We investigated the influence of two anionic surfactants, namely, sodium dodecyl sulfate and sodium decyl sulfate, on acrylamide-based microgels consisting of --propylacrylamide. In this context, the main focus was on the influence of surfactant addition on the size of the microgels. The surfactant was added to the reaction mixture before or during the polymerization at different points in time.
View Article and Find Full Text PDFIn this work, we compare the properties of smart homopolymer microgels based on -propylacrylamide (NNPAM), -isopropylacrylamide (NIPAM) and -isopropylmethacrylamide (NIPMAM) synthesized under identical conditions. The particles are studied with respect to size, morphology, and swelling behavior using scanning electron and scanning force microscopy. In addition, light scattering techniques and fluorescent probes are employed to follow the swelling/de-swelling of the particles.
View Article and Find Full Text PDFWe consider the interaction of colloidal spheres in the presence of mono-, di-, and trivalent ions. The colloids are stabilized by electrostatic repulsion due to surface charges. The repulsive part of the interaction potential Ψ(d) is deduced from precise measurements of the rate of slow coagulation.
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