The kinetics of adsorption binding of Ba²⁺ ions by trimethylsilylated silica

• Main Authors: I. F. Myronyuk, H. V. Vasylyeva, V. I. Mandzyuk, N. A. Bezruka, T. V. Dmytrotsa
• Format: Article
• Language: English
• Published: Vasyl Stefanyk Precarpathian National University 2018-04-01
• Series: Фізика і хімія твердого тіла
• Online Access: http://journals.pu.if.ua/index.php/pcss/article/view/2379

<p>It was established that incomplete substitution of free silanols of fumed silica surface on (CH₃)₃Si-groups leads to an increase in the ability of modified SiO₂ to adsorb Ba²⁺ cations from an electrolyte solution. Silica with 48.3% of trimethylsilyl (TMS) groups adsorbs 1.8 mmol·g^-1 of Ba²⁺ cations from 0.01 M BaCl₂ solution, that in 3 times more than the adsorption of these cations by unmodified silica. It was found that the adsorption of cations by basic and modified silica is well described by the pseudo-second order Lagergren equation. The high adsorption activity of silica with chemisorbed TMS-groups is due to the formation of local regions with relatively large values of negative and positive electrostatic potentials in the vicinity of grafted TMS-groups.</p>