Influence of the pH of Comb-Shaped Polymer Solutions on the Adsorption Between the Polymer and SO42- Ions
Comb-shaped hyper-branched polycarboxylate polymers, both water-reducing-type admixtures (applied in cement, symbol of JS) and slump-retaining-type admixtures (applied in cement, symbol of BT), were prepared, and their adsorption characteristics with SO42- ions were studied by conductivity loss experiments. The results indicated that both JS and BT generate electrical conductivity losses in Na2SO4 aqueous solutions, suggesting that there was some interaction adsorption between the SO42- ions and the polymer. The adsorption was closely related to the pH of the sample solutions and occurred due to the strong interactions between the carboxylic acid groups in the polymer backbones and SO42- ions (rather than Na+ ions). However, there was an extremely weak electrostatic adsorptive interaction between the SO42- ions and the long polyether side-chain.
G. R. Duan et al., "Influence of the pH of Comb-Shaped Polymer Solutions on the Adsorption Between the Polymer and SO42- Ions", Applied Mechanics and Materials, Vols. 99-100, pp. 928-933, 2011