Abstract

Composite filamentary hydrogels based on cross-linked polyacrylamide, filled with TiO₂ particles, were synthesized. The degree of crosslinking of the hydrogel matrix was set by the molar ratio of the cross-linking agent and monomer: 1 : 50, 1 : 100, 1 : 200, or 1 : 300. The diffusion of Methyl Orange dye in the polymer matrix as a function of the degree of crosslinking was studied by spectrophotometry, and the diffusion coefficient was calculated: 1.4 × 10^–6, 1.8 × 10^–6, 3.4 × 10^–6, and 4.8 × 10^–6 cm² s^–1, respectively. The photocatalytic activity of the composite hydrogels toward UV-induced degradation of a model dye, Methyl Orange, was studied. The effective rate constants of the photocatalytic degradation of the dye under the action of polyacrylamide/TiO₂ composite hydrogels and aqueous TiO₂ suspensions were determined. The presence of the hydrogel polymer matrix reduces the photocatalytic activity of TiO₂ particles compared to the aqueous suspension containing the same amount of the particles. The photocatalytic activity of both aqueous TiO₂ suspension and polyacrylamide/TiO₂ composite hydrogel linearly depends on the total amount of TiO₂ particles in the system.

中文翻译：

---

不同交联度聚丙烯酰胺水凝胶中固定化二氧化钛的光催化活性

摘要

合成了基于交联聚丙烯酰胺的复合丝状水凝胶，填充有 TiO ₂颗粒。水凝胶基质的交联度由交联剂与单体的摩尔比设定：1:50、1:100、1:200或1:300。 甲基橙染料在聚合物基质中的扩散通过分光光度法研究作为交联度的函数，并计算扩散系数：1.4 × 10 ^–6、1.8 × 10 ^–6、3.4 × 10 ^–6和 4.8 × 10 ^–6 cm ² s ^–1， 分别。研究了复合水凝胶对紫外线诱导的模型染料甲基橙降解的光催化活性。测定了聚丙烯酰胺/TiO ₂复合水凝胶和TiO ₂水悬浮液作用下光催化降解染料的有效速率常数。与含有等量粒子的水性悬浮液相比，水凝胶聚合物基质的存在降低了TiO ₂粒子的光催化活性。TiO ₂水悬浮液和聚丙烯酰胺/TiO ₂复合水凝胶的光催化活性线性取决于体系中TiO ₂颗粒的总量。