Organic Polymer Chemistry Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran; Research Institute for Nanotechnology and Advanced Materials, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran; College of Pardis, Chemistry Section, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran.
College of Pardis, Chemistry Section, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran.
Ultrason Sonochem. 2018 Mar;41:572-581. doi: 10.1016/j.ultsonch.2017.10.022. Epub 2017 Oct 23.
This article reports the first incorporation of calcium carbonate nanoparticles (CC NPs) into tragacanth gum (TG) to prepare a new hydrogel nanocomposite (HNC) system using a green, safe, and eco-friendly method, ultrasound irradiation as an efficient biosorbent of heavy metal ions from wastewater. Morphological studies revealed that the surface of obtained HNCs is rough, homogeneous, and porous-like due to the embedding of CC NPs as well as sonication in comparison to the neat TG which has a smooth surface. The particle size reduction was observed for CC NPs in the matrix (from 57 to 10 nm), which is owing to the extraordinary effect of sonication on this process. Thermal stability of HNCs has been increased after using CC NPs from 8.5 wt% for TG to about 22 wt% for HNCs. The optical band gap of TG/CC HNC 5 wt% calculated to be 4.46 eV which is less than that of CC NPs (5.58 eV) and even TG (6.28 eV) and this result indicated that TG/CC HNC 5 wt% is relatively more conductive than CC NPs and TG. The nitrogen adsorption-desorption disclosed an isotherm type III of Brunauer classification for TG/CC HNC 5 wt% and the surface area has been increased from 0.7 m.g for TG to 2.3 m.g for TG/CC HNC 5 wt%. Also, the BET surface area for TG/CC HNC 5 wt% calculated to be 7.8 nm which is classified into mesoporous materials. The Pb ions were significantly removed from water using TG/CC HNC 5 wt% and the removal efficiency was determined as 83% at optimized conditions (pH = 5, adsorbent dosage = 0.015 g, time = 3 h, and Pb concentration = 70 mg.L).
本文首次将碳酸钙纳米粒子（CC NPs）掺入黄蓍胶（TG）中，通过超声辐射这一绿色、安全且环保的方法，制备了一种新型水凝胶纳米复合材料（HNC）系统，该方法可有效从废水中吸附重金属离子。形貌研究表明，与表面光滑的纯 TG 相比，由于 CC NPs 的嵌入以及超声处理，所得 HNC 的表面粗糙、均匀且呈多孔状。CC NPs 在基质中的粒径减小（从 57 纳米减小至 10 纳米），这归因于超声处理对这一过程的非凡影响。在使用 CC NPs 后，HNC 的热稳定性从 TG 的 8.5wt%提高到 HNC 的约 22wt%。计算得出 TG/CC HNC 5wt%的光学带隙为 4.46eV，小于 CC NPs（5.58eV）甚至 TG（6.28eV）的光学带隙，这表明 TG/CC HNC 5wt%的导电性比 CC NPs 和 TG 相对更强。氮气吸附-脱附结果表明，TG/CC HNC 5wt%的等温线属于 Brunauer 分类的 III 型，比表面积从 TG 的 0.7m.g 增加到 TG/CC HNC 5wt%的 2.3m.g。此外，TG/CC HNC 5wt%的 BET 比表面积计算值为 7.8nm，属于中孔材料。在优化条件下（pH=5、吸附剂用量=0.015g、时间=3h、Pb 浓度=70mg.L），使用 TG/CC HNC 5wt%可显著去除水中的 Pb 离子，去除效率为 83%。
