Ying Gong

Super Molecular-polarization Phenomenon of Poly (ethylene glycol) in Deionized Water

A new discovery describing nonionic surfactant poly(ethylene glycol) being added into deionized water, electrical conductivity of the water would show a remarkable increase phenomenon. The mechanism study indicated that the electrical conductivity increase of the water doped some PEG was formed by super-polarization of a PEG molecule on the water molecule. A PEG molecule can form a super polarization body in the water, which will generate a strong polarization effect on the water molecule, thereby increasing water ionization degree and makes the electrical conductivity of water greater.

Influence of the Structure of Comb-Shaped Polymer on the Adsorption between the Polymer and SO42- Ions

Comb-shaped hyper-branched polycarboxylate admixture polymers, both the water-reducing-type JS and slump-retaining-type BT, were prepared, and their adsorption characteristics with SO42- ions were studied by conductivity loss experiments. The results indicated that the adsorptions were related to both the content of carboxylic acid groups in polymers and the concentration of Na2SO4 solution, adsorptive action was formed by the complexation action between the carboxylic acid groups in polymers and SO42- ions, having nothing to do with polyether side chain in polymer. Comb-shaped hyper-branched polymers in aqueous solution would form association super-molecular structure, which could be destroyed by Na2SO4 solution.

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.

Study on the Adsorption Behavior of Ca2+ Ions on Comb-Like Polycarboxylate Polymers in the CaCl2 Solution

Using esterification-polymerization two-steps synthesis method, two kinds of comb-like polycarboxylate agents of BT and JS were synthesized by controlling acid-ester ratio. The adsorption characteristics of Ca2+ ions on comb-like polycarboxylate polymers in the CaCl2 solution were studied. The results indicated that the adsorption behavior was closely related to the structure of polymers, the adsorption power of JS with water-reducing structure was strong, while weak with slump loss resisting polymers BT. The adsorption behavior was also in connection with the acid-ester ratio of polymer structure, the higher the acid-ester ratio is, the greater the absorption power; On the contrary, it will be smaller.

Preparation of a New Kind of Ultra-High Performance Water Reducer and its Application Study

For the first time, a new kind of polycarboxylic acid high-performance water reducer, with ultra-high water reducing performance, was prepared through one-step polymerization, using new type polyether TPEG and acrylic acid as raw materials. Maximum water-reducing ratio of TPC may reach 50%. The most distinguishing characteristic of TPC was its reaction character at normal temperatures (30°C), which was of great practical significance for energy conservation and pollution reduction.

Influence of the PH Value of Comb-Shaped Polymer on the Adsorption between the Polymer and Ca2+ Ions

Comb-shaped hyper-branched polycarboxylate admixture polymers, both the water-reducing-type JS and slump-retaining-type BT, were prepared, and their adsorption characteristics with Ca2+ ions were studied by conductivity loss experiments. The results indicated that, both the water-reducing-type JS and slump-retaining-type BT, would generate certain electrical conductivity loss in CaCl2 aqueous solutions, suggesting that there was some close adsorption between the polymer and Ca2+ ions, the adsorption was closely related with the pH value of the polymers, the neutral and alkaline samples neutralized by NaOH show an higher adsorption than that non-neutralized. The adsorption was achieved by the strong interaction between carboxylic acid groups in the polymer backbones and Ca2+ ions (rather than Cl- ions)

Super Molecular Polarization of Polyoxyethylene-Water Binary Systems

When polyoxyethylene-based non-ionic surfactants were added to deionized water, the electrical conductivity of the water increased. The increase was proportional to the surfactant concentration until a maximum value was reached at concentrations between 20∼25%. As long as the macromolecules contained a polyoxyethylene structure (-C-C-O-) there was noticeable molecular polarization in aqueous solution. The highest polarization capacity was observed at surfactant concentrations of 20∼25%.

Influences of ionic environment on self-assembly behaviour of hyperbranched polymers

Detection of electrical conductivity is carried out to study the characteristics of adsorptive action between several ions such as Ca2+, Cl−, Na+, and hyperbranched comb-like polymers. The results show that the strength of their adsorptions is in the descending order as follows: Ca2+ >   > Cl− (Na+). CaCl2 solution will significantly reduce the electrical conductivity of hyperbranched comb-like polymers, whereas NaCl solution will increase it obviously. Due to association and dispersion of ions in hyperbranched comb-like polymers; all salt ionic solutions can enlarge the critical micelle concentration of hyperbranched comb-like polymers.

Preparation and Physicochemical Properties of Concrete Slump-Loss Resistance Agent for Small Slump

By the application of esterification-polymerization two-step synthesis method, comb-shaped polycarboxylate slump-loss resistance agent XBT for small slump concrete is prepared by controlling ester ratio. The experimental results of concrete and fresh cement paste indicate that XBT has excellent function of plasticity retention in small slump concrete. The experiment of gel permeation liquid chromatogram shows that XBT has wide range of molecular weight distribution, which may be the source of fine plasticity retention performance in the small slump concrete. The combined experiment between ultraviolet and conductivity indicates that there is strong adsorptive action between XBT and Ca2+, and their adsorptive characteristics may be closely related to the plasticity retention properties.