Gwak Gyeong-Hyeon, Kim Min-Kyu, Oh Jae-Min
Department of Chemistry and Medical Chemistry, College of Science and Technology, Yonsei University, Wonju, Gangwondo 26493, Korea.
Nanomaterials (Basel). 2016 Jan 26;6(2):25. doi: 10.3390/nano6020025.
Composite hydrogels were prepared that consisted of quasi-colloidal layered double hydroxide (LDH) nanoparticles and agarose via the electrophoretic method, starting from three different agarose concentrations of 0.5, 1, and 2 wt/v%. The composite hydrogel was identified to have a uniform distribution of LDH nanoparticles in agarose matrix. Microscopic studies revealed that the composite hydrogel had a homogeneous quasi-colloidal state of LDHs, while the simple mixture of LDH powder and agarose hydrogels did not. It was determined that agarose concentration of the starting hydrogel did not significantly influence the amount of LDH that developed in the composite. The chromate scavenging efficiency of the composite hydrogel and corresponding agarose or mixture hydrogel was evaluated with respect to time, and chromate concentration. In general, the composite hydrogels exhibited much higher chromate removal efficacy compared with agarose or mixture hydrogels. Through estimating chromate adsorption by LDH moiety in the composite or mixture hydrogel, it was suggested that the agarose component facilitated the stability and dispersibility of the quasi-colloidal state of LDH nanoparticles in the composite resulting in high adsorption efficacy. From Freundlich isotherm adsorption fitting, composites were determined to possess beneficial cooperative adsorption behavior with a high adsorption coefficient.
通过电泳法，从三种不同浓度（0.5、1和2 wt/v%）的琼脂糖开始，制备了由准胶体层状双氢氧化物（LDH）纳米颗粒和琼脂糖组成的复合水凝胶。经鉴定，复合水凝胶中的LDH纳米颗粒在琼脂糖基质中分布均匀。微观研究表明，复合水凝胶具有均匀的LDH准胶体状态，而LDH粉末与琼脂糖水凝胶的简单混合物则没有。结果表明，起始水凝胶的琼脂糖浓度对复合水凝胶中生成的LDH量没有显著影响。针对时间和铬酸盐浓度，评估了复合水凝胶以及相应的琼脂糖或混合水凝胶对铬酸盐的清除效率。总体而言，与琼脂糖或混合水凝胶相比，复合水凝胶表现出更高的铬酸盐去除效果。通过估算复合水凝胶或混合水凝胶中LDH部分对铬酸盐的吸附，表明琼脂糖成分促进了复合水凝胶中LDH纳米颗粒准胶体状态的稳定性和分散性，从而导致高吸附效果。通过弗伦德利希等温吸附拟合，确定复合材料具有有益的协同吸附行为和高吸附系数。
