Organic Polymer Chemistry Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran.
Organic Polymer Chemistry Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran.
Int J Biol Macromol. 2021 Jan 1;166:722-729. doi: 10.1016/j.ijbiomac.2020.10.229. Epub 2020 Nov 1.
This study aims to prepare a hydrogel bionanocomposite (HBNC) as an efficient adsorbent and introduce it as a suitable replacement for petroleum-based adsorbents. Thus, tragacanth gum (TG), and carboxyl-functionalized carbon nanotube (CFCNT) were used as raw materials. HBNCs were prepared with the aid of ultrasonication, and different methods were employed to characterize them. The surface structures of the HBNCs were altered after the addition CFCNT into TG and exposure to ultrasound, as well. Transmission electron microscopy images showed CFCNTs were well dispersed in TG. Then, the adsorption of methylene blue (MB) was performed using these HBNCs. The removal efficiency was over 80% at optimized conditions. Nonlinear and linear forms of Langmuir, Freundlich, Dubinin-Radushkevich, Sips, and Redlich-Peterson (R-P) were applied to find the proper arrangement of MB onto the adsorbent. Using statistical equations, it was revealed that the process obeyed the linear R-P model, indicating a mixture of mono- and multilayer adsorption (but mostly monolayer). Also, pseudo-second-order was the appropriate kinetic model and suggested chemical adsorption. According to the thermodynamic calculations, this process was exothermic and spontaneous, and the type of interactions between HBNC and MB was physicochemical. Also, the diffusion study indicated that film diffusion is the primary mechanism.
本研究旨在制备水凝胶生物纳米复合材料（HBNC）作为一种高效吸附剂，并将其作为石油基吸附剂的合适替代品。因此，使用黄原胶（TG）和羧基功能化碳纳米管（CFCNT）作为原料。在超声的辅助下制备 HBNC，并采用不同的方法对其进行表征。在向 TG 中添加 CFCNT 并暴露于超声下后，HBNC 的表面结构也发生了变化。透射电子显微镜图像显示 CFCNT 在 TG 中得到了很好的分散。然后，使用这些 HBNC 进行亚甲基蓝（MB）的吸附。在优化条件下，去除效率超过 80%。采用非线性和线性形式的朗缪尔、弗伦德利希、杜比宁-拉道舍维奇、Sips 和 Redlich-Peterson（R-P）模型，以确定 MB 在吸附剂上的适当排列方式。通过统计方程表明，该过程符合线性 R-P 模型，表明存在单分子层和多分子层吸附的混合（但主要是单分子层）。此外，准二级动力学模型是合适的，表明这是化学吸附。根据热力学计算，该过程是放热和自发的，HBNC 和 MB 之间的相互作用类型是物理化学的。此外，扩散研究表明，膜扩散是主要的机制。
