Papers by Keyword: ζ-Potential

Abstract: The stability of silver halide colloids is reported to be important for the toxicological outcome. This study shows a well-suited and cheap condensation reaction to obtain negatively charged silver iodide (AgI) nanoparticles without additional stabilization agents. Charged AgI colloids were synthesized from silver nitrate and potassium iodide solutions. An excess of potassium iodide not only imparted a negative charge, but provided a narrow particle size distribution (50 ± 10 nm). The change of optical properties in the colloid was investigated by UV-VIS spectroscopy. A silver iodide exciton absorption band at peak ~421nm (2.93eV), red-shifted over time. The peak at half maximum intensity increased from 13.3nm to 14.8 nm, characterizing the dispersity of AgI colloidal particles. Colloidal particles stabilized after 33 hours. In-situ real-time UV-VIS measurements provide a tool to adjust the particle characteristics and may serve to further optimize the performance in biological applications.

Abstract: The influence of Al³⁺ ions that had been solid dissolved in C-S-H on the amount of Na⁺ ions adsorbed on C-S-H surface was studied. The experimental results show that the solid dissolution of Al³⁺ ions in C-S-H structure makes the electronegative C-S-H surface increase electronegative amounts, that is the reason why the adsorption ability of C-S-H for Na⁺ ions increase.

Abstract: In this study, by using UV-visible adsorption spectrophotometer, ζ-potential analyzer and X-ray photo spectroscopy, the adsorption characteristics and surface electrochemical properties of WPS were studied in comparison with traditional naphthalene sulfonated formaldehyde condensates (FDN) whose dispersion ability mainly depends on electrostatic repulsive forces. WPS was prepared through free radical copolymerization in self-Single screw reactive extruder and synthesized from waste plexiglas and vinyl monomers by way of special extrusion modification. The results show that the adsorption of WPS and FDN on cement particle surface approximately conforms to Langmuir’s adsorption isotherm. The adsorption of WPS belongs to physical adsorption and its saturated adsorbed quantity was 5.38mg/g. When the dosage of WPS was 1 wt.% of cement, the thickness of the adsorption layer on the surface of cement particles was 61.2 nm. The ζ-potential of cement particle with WPS changed from positive (15 mV) to negative (-64.74mV) with its concentration increasing from 0 to 20 g/L and decreased from -65.19 to-39.82 mV (reducing by 38.9%) with its concentration of 10 g/L within 60 h.