School of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China; Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031, China.
Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031, China.
J Colloid Interface Sci. 2019 Jan 1;533:416-427. doi: 10.1016/j.jcis.2018.08.064. Epub 2018 Aug 25.
A novel ternary composite consisting of Mg/Al layered double hydroxides (LDH), polydopamine (PDA) and poly(methyl vinyl ether-alt-maleic anhydride) (PMVE-MA) was fabricated by a facile combination of mussel-inspired chemistry and a ring-opening reaction. Dopamine can serve as a "minimalist mimic" of mussel adhesive protein to form a layer of polydopamine (PDA) on the LDH surface under rather mild conditions (including air atmosphere, aqueous solution, and catalyst free). Subsequently, the PMVE-MA brushes were immobilized onto the PDA modified LDH via a ring-opening reaction. The morphology and chemical compositions of the as-prepared samples were characterized by SEM, TEM, FT-IR, TGA, and XPS. To evaluate the adsorption performance of the PMVE-MA modified LDH (LDH@PDA@PMVE-MA) composites, the obtained samples were used as adsorbents for the removal of copper ions (Cu) from an aqueous solution. The results demonstrated that the LDH@PDA@PMVE-MA composites showed a significant improvement in the adsorption efficiency towards Cu, and the adsorption capacity of the LDH@PDA@PMVE-MA composites was found to be 2 times higher than that of pristine LDH. Adsorption kinetics showed that the experimental data were fitted well by the pseudo-second-order kinetic model. Equilibrium data could be best described by the Langmuir isotherm model, with the maximum monolayer adsorption capacity of 193.78 mg/g. Thermodynamic studies indicated that the adsorption of Cu onto the LDH@PDA@PMVE-MA composites is an endothermic and spontaneous process. Importantly, it can be easily regenerated by low-cost reagents, and exhibited high removal efficiencies after four cycles of adsorption-desorption. These results suggest that the LDH@PDA@PMVE-MA nanocomposites are good candidate for Cu removal from aqueous solutions.
一种新型的三元复合由镁/铝层状双氢氧化物（LDH）、聚多巴胺（PDA）和聚（甲基乙烯基醚-alt-马来酸酐）（PMVE-MA）组成，通过贻贝启发化学和开环反应的简单组合制备而成。多巴胺可以作为贻贝粘蛋白的“简约模拟物”，在相当温和的条件下（包括空气气氛、水溶液和无催化剂）在 LDH 表面形成一层聚多巴胺（PDA）。随后，通过开环反应将 PMVE-MA 刷固定在 PDA 改性的 LDH 上。通过 SEM、TEM、FT-IR、TGA 和 XPS 对所制备样品的形貌和化学成分进行了表征。为了评估 PMVE-MA 改性 LDH（LDH@PDA@PMVE-MA）复合材料的吸附性能，将所得样品用作从水溶液中去除铜离子（Cu）的吸附剂。结果表明，LDH@PDA@PMVE-MA 复合材料对 Cu 的吸附效率有显著提高，并且 LDH@PDA@PMVE-MA 复合材料的吸附容量比原始 LDH 高 2 倍。吸附动力学表明，实验数据拟合良好的准二级动力学模型。平衡数据可以通过 Langmuir 等温模型得到很好的描述，单层最大吸附容量为 193.78mg/g。热力学研究表明，Cu 吸附到 LDH@PDA@PMVE-MA 复合材料上是一个吸热和自发的过程。重要的是，它可以很容易地用低成本试剂再生，并在吸附-解吸四个循环后表现出高的去除效率。这些结果表明，LDH@PDA@PMVE-MA 纳米复合材料是从水溶液中去除 Cu 的良好候选材料。
