Papers by Keyword: Cationic Polyelectrolyte

Abstract: This study reports on the modification of natural bentonite by a cationic polyelectrolyte, which is a lignin-based aldehyde-ketone resin, and the application of this modified clay as adsorbent in the removal of reactive dyes from aqueous solution. Modified bentonite was characterized by IR and zeta-potential test, its dye removal performance was evaluated. Results show that intermolecular interaction and electrostatic attraction between dyes and adsorbent are responsible for the adsorption behavior. The removal of reactive dyes increased with increasing temperature and the optimum pH range was 4.0-6.5. The negative values of ΔG reflected the spontaneous adsorption and the values of ΔH showed that it was a combination of chemical and physical adsorption. Equilibrium adsorption data fitted well to Langmuir isotherm and the adsorption capacity for reactive red and reactive blue was 125.0 and 159.2 mg/g, respectively.

Abstract: A cationic polymeric flocculant was synthesized through solution polymerization. The polymerization was initiated by acrylamide and Aacryloxyethyltrimethyl Ammonium Chloride(DAC) monomers, and ammonium persulfate and sodium sulfite as redox initiation system. The copolymer obtained was characterized by Fourier-transform infrared (FTIR) spectroscopy. Its flocculating properties were evaluated by turbidity removal with clay suspensions, turbidity and COD removal with sewage using standard jar tests. The results demonstrate that the copolymer can be used as a kind of cationic polymeric flocculant in water and wastewater treatment.

Abstract: In this paper, the adsorption characteristics of cationic polyelectrolyte PDADMAC on BGF particles and the Zeta potential of BGF particles have been investigated. A new type of composite abrasives slurry was obtained with cationic polyelectrolyte modified BGF particles and its polishing performance was studied. Experimental results showed that the Zeta potential of the modified BGF particles was changed from negative to positive and the maximum value (+35mv) was obtained when the adsorption saturation was achieved, and the adsorption capacity of SiO2 abrasives on BGF particles was improved significantly. The material removal rate was 469nm/min with the modified BGF/SiO2 composite abrasives slurry containing 5% SiO2 and 3% modified BGF particles, increasing by 47% and 89% than those of the unmodified BGF/SiO2 composite abrasives slurry (319nm/min) and the single silica abrasives slurry (248nm/min), respectively.

Abstract: In this paper, the inhibition efficiency of Quaternary Polyethyleneimine (QPEI) self-adsorbed films was studied by polarization curve and weight loss method. We made an intensive study of its anticorrosion mechanism for low carbon steel in different acid baths using Polyethyleneimine(PEI) and QPEI as inhibitor, respectively. Diatomite particles were surface-modified with PEI and QPEI, respectively, and their zeta potentials were measured. The morphologies and compositions of the polymer film on the steel surface were examined with the aids of SEM and XPS, respectively. Compared with PEI, the cationic property is stronger, and it is not influenced by the PH value of mediums. The zeta potential of diatomite particles surface-modified with QPEI remains higher positive in whole PH range. The above facts enough confirm that anticorrosion mechanism of QPEI for low carbon steel attributes to its possessing outstanding cationic property.

Abstract: In this paper, the adsorption characteristics of cationic polyelectrolyte PDADMAC on BGF particles and Zeta potential of BGF particles have been investigated. A new type of composite abrasive slurry was obtained with cationic polyelectrolyte modified BGF particles and its polishing performance was studied. Experimental results showed that the Zeta potential of the modified BGF particles was changed from negative to positive and the maximum value (+35mv) was obtained when the adsorption saturation was achieved, and the adsorption capacity of SiO₂ abrasives on BGF particles was improved significantly as well. The material removal rate was 469nm/min with the modified BGF/ SiO₂ composite abrasives slurry containing 5% SiO₂ and 3% modified BGF particles, increasing by 47% and 89% than those of the unmodified BGF/SiO2 composite abrasives slurry (319nm/min) and the single silica abrasives slurry (248nm/min), respectively.