Nematidil Narjes, Sadeghi Mohammad, Nezami Shabnam, Sadeghi Hossein
Young Researchers and Elite Club, Arak Branch, Islamic Azad University, Arak, Iran.
Department of Chemistry, Arak Branch, Islamic Azad University, Arak, Iran.
Carbohydr Polym. 2019 Oct 15;222:114971. doi: 10.1016/j.carbpol.2019.114971. Epub 2019 Jun 6.
In this paper, a new Schiff base based on porous chitosan-glutaraldehyde /montmorrilonite nanoparticles modified with 3-aminopropyl triethoxysilane (PCG/ NaMMTNPs-APTES) nanocomposite was prepared using cationic copolymerization technique. The structure of the biosorbents was characterized using FTIR, SEM, TEM, DSC, TGA/DTG, BET, DLS and Zeta potential analysis. The BET technique is demonstrating the further surface area and porosity of the PCG/NaMMTNPs-APTES in compare to the non-modified porous chitosan-glutaraldehyde, PCG. TGA/DTG and DSC results revealed a clear difference in thermal stability, so that; the nanocomposite exhibited significantly thermal stability in compared to the PCG hydrogel at high temperature. The obtained biosorbent hydrogels were also investigated as the adsorbents for removal of heavy metals and methylene blue dye from the aqueous solution by AAS and UV-vis techniques, respectively. The results showed that the maximum removal percentage of Pb and Hg ions for PCG/NaMMTNPs-APTES and PCG was achieved 94.16, 85.27% and 80.83, 70.27% in pH 6.5 and pH 6.0 for 40 min, respectively. The obtained results are described using the adsorption kinetics and desorption isotherm models. Furthermore, the thermodynamic parameters on the sorption possess was evaluated.
在本文中，采用阳离子共聚技术制备了一种基于多孔壳聚糖 - 戊二醛/蒙脱石纳米粒子（PCG/NaMMTNPs）并经3 - 氨丙基三乙氧基硅烷（APTES）改性的新型席夫碱纳米复合材料。使用傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、差示扫描量热法（DSC）、热重分析/微商热重分析（TGA/DTG）、比表面积分析仪（BET）、动态光散射（DLS）和Zeta电位分析对生物吸附剂的结构进行了表征。BET技术表明，与未改性的多孔壳聚糖 - 戊二醛（PCG）相比，PCG/NaMMTNPs - APTES具有更大的比表面积和孔隙率。TGA/DTG和DSC结果显示出热稳定性存在明显差异，即在高温下，该纳米复合材料相比PCG水凝胶表现出显著的热稳定性。还分别采用原子吸收光谱法（AAS）和紫外可见光谱法（UV - vis）研究了所制备的生物吸附剂水凝胶作为吸附剂从水溶液中去除重金属和亚甲基蓝染料的性能。结果表明，在pH值为6.5、吸附时间40分钟时，PCG/NaMMTNPs - APTES对Pb和Hg离子的最大去除率分别达到94.16%和85.27%；在pH值为6.0、吸附时间40分钟时，PCG对Pb和Hg离子的最大去除率分别为80.83%和70.27%。使用吸附动力学和解吸等温线模型对所得结果进行了描述。此外，还评估了吸附过程的热力学参数。
