title: [Atomic force microscope analysis of adsorption and flocculation behaviors of polydiallyldimethylammonium salts: influence of counterion].
abstract: High molecular weight polydiallyldimethylammonium nitrate (PDADMANO3) and polydiallyldimethylammonium sulfate (PDADMASO4) were prepared from polydiallyldimethylammonium chloride (PDADMAC). The effects of univalent counterions (Cl-, ON3-) and bivalent counterion (SO4(2-) on solution, absorption and flocculation properties of polydiallyldimethylammonium salts (PDADMAX) were investigated by conductivity, reduced viscosity, atomic force microscopy (AFM), residual turbidity, distributions of zeta potential and flocculation index of kaolin suspension. The results show that different counterions possess significant effects on solution properties, absorption and flocculation behaviors of PDADMAX. PDADMANO3 shows stronger flocculation efficiency and "neutralization action", whereas PDADMASO4 shows the wider optimum dosage and larger floc size, as well as "bridging action". In particular, AFM image of single polyelectrolyte polymer is a valuable tool for the analysis of the absorption and flocculation mechanism of polyelectrolye.
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. tbh_8@163.com
authors.forename: Bing-hui
authors.initials: BH
authors.lastname: Tian
authors.forename: Xiao-qing
authors.initials: XQ
authors.lastname: Wu
authors.forename: Zhao-kun
authors.initials: ZK
authors.lastname: Luan
authors.forename: Xian-jia
authors.initials: XJ
authors.lastname: Peng
mesh_terms: D000327:Adsorption; D005427:Flocculation; D018625:Microscopy, Atomic Force; D011095:Polyethylenes / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride