Study on the preparation of PAM/MMT W/W emulsion and its application as a flocculant

In this study, the polyacrylamide/montmorillonite water in water (WPAMt) emulsion was prepared through dispersion polymerization in ammonium sulfate (AS) aqueous solution using gelatin as stabilizer. The copolymer was prepared from acrylamide (AM) and diallyl dimethyl ammonium chloride (DMDAAC). Organic montmorillonite (OMMT), prepared by intercalation of AM into the interlayers of sodium montmorillonite (Na-MMT), was added into the system to form a "cross-linking" structure in which PAM molecules were grafted onto MMT. The polymerization was initiated by ammonium persulfate (APS) and sodium hydrogen sulfite (SHS). The droplet formation of the WPAMt emulsion was observed through an optical microscope. The particle size and distribution of the WPAMt emulsion was measured by dynamic light scattering (DLS), and the particle size ranged from 2 to 6 mm. Besides, the influence of various polymerization parameters including OMMT dosage, gelatin concentration, pH value, DMDAAC concentration, and initiator concentration on the apparent viscosity and flocculation ability of the WPAMt emulsion was also investigated.