Impact of electric field on Hofmeister effects in aggregation of negatively charged colloidal minerals

Abstract

Abstract. In this study, the aggregation kinetics of negatively charged colloidal minerals in Na2+ , Ca 2+ and Cu 2+ solutions were measured and Hofmeister effects therein were estimated through total average aggregation (TAA) rates and critical coagulation concentration (CCC). Hofmeister effects of TAA rates increased exponentially with the increase in electric field strength, which cannot be explained by the classical theories (i.e., ionic size, hydration and dispersion forces), indicating strong electric field at colloidal surface was an indispensable factor in studying Hofmeister effects. Meanwhile, Hofmeister series of CCC values Nashow fine correlation with the polarization of various cations, implying that onic polarization in strong electric field would be responsible for Hofmeister effects in aggregation of colloidal minerals, and the deduction was confirmed by the calculated results of electrostatic interactions between colloidal minerals.

Simple Regulation of the Self-Assembling Ability by Multimerization of Elastin-Derived Peptide (FPGVG)n Using Nitrilotriacetic Acid as a Building Block

“…The T t value of NTA-F5 increased regardless of the metal salt being bound to NTA, suggesting that the increment in T t was probably caused by the salting-in effect of metal cations. The ability of salts to influence the solubility of proteins in aqueous solution is classified as the Hofmeister series. − Although the Hofmeister series for cations is less obvious than anions as the position of cation in the Hofmeister series could change in different phenomena, it was reported that the divalent cations can increase the solubility of proteins or colloids. , Therefore, copper ion (Cu 2+ ) strongly enhanced the solubility of NTA-F5. However, the results of DLS measurement revealed that the self-assembling ability of NTA-F5 associated with temperature increment was retained.…”

“…60−62 Although the Hofmeister series for cations is less obvious than anions as the position of cation in the Hofmeister series could change in different phenomena, 62 it was reported that the divalent cations can increase the solubility of proteins or colloids. 62,63 Therefore, copper ion (Cu 2+ ) strongly enhanced the solubility of NTA-F5. However, the results of DLS measurement revealed that the self-assembling ability of NTA-F5 associated with temperature increment was retained.…”

Electrochemically assisted photocatalytic removal of m-cresol using TiO2 thin film-modified carbon sheet photoelectrode

“…Traditional physical techniques, such as flocculation, adsorption on activated carbon and ultra-filtration may be employed efficiently to remove such recalcitrant pollutants. However, they are non-destructive, because they just transfer the dye compounds from water to another phase which would cause a secondary environmental pollution [1][2][3][4][5][6]. This has led to the requirement of regeneration of the adsorbent materials and post-treatment of solid wastes and both of them are expensive [7].…”