Zhang Huaibin, Huang Wenyan, Komarneni Sridhar
Department of Ecosystem Science and Management and Materials Research Institute, 204 Energy and the Environment Laboratory, The Pennsylvania State University, University Park, PA 16802, USA.
Jiangsu Key Laboratory of Environmentally Friendly Polymeric Materials, School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China.
Nanomaterials (Basel). 2024 Mar 4;14(5):467. doi: 10.3390/nano14050467.
Polymer intercalated clay nanocomposites were prepared from various montmorillonites (Mt) and a polymer, polydiallyldimethylammonim (PDDA) chloride. X-ray diffraction (XRD) analysis of the above polymer intercalated nanocomposites showed either no crystalline peaks or very broad peaks with the intercalation of PDDA polymer in the interlayers, probably as a result of exfoliation of the clay layers. Infrared spectroscopy revealed the presence of PDDA in all the clay nanocomposite materials. The maximum adsorption capacities of nitrate, perchlorate, and chromate by one of the polymer intercalated nanocomposite materials prepared from montmorillonite, Kunipea were 0.40 mmol·g-1, 0.44 mmol·g-1 and 0.299 mmol·g-1, respectively. The other two polymer intercalated nanocomposites prepared with montmorillonites from Wyoming and China showed very good adsorption capacities for perchlorate but somewhat lower uptake capacities for chromate and nitrate compared to the nanocomposite prepared from montmorillonite from Kunipea. The uptake of nitrate, perchlorate and chromate by the polymer intercalated nanocomposites could be well described using the Freundlich isotherm while their uptake kinetics fitted well to the pseudo-second-order model. The uptake kinetics of nitrate, perchlorate, and chromate were found to be fast as equilibrium was reached within 4 h. Moreover, the uptakes of chromate by polymer intercalated nanocomposites were found to be highly selective in the presence of Cl-, SO42- and CO32-, the most abundant naturally occurring anions.
聚合物插层黏土纳米复合材料是由各种蒙脱石（Mt）和一种聚合物聚二烯丙基二甲基氯化铵（PDDA）制备而成。对上述聚合物插层纳米复合材料进行X射线衍射（XRD）分析发现，随着PDDA聚合物插入层间，要么没有结晶峰，要么只有非常宽的峰，这可能是黏土层剥落的结果。红外光谱显示所有黏土纳米复合材料中都存在PDDA。由蒙脱石Kunipea制备的一种聚合物插层纳米复合材料对硝酸盐、高氯酸盐和铬酸盐的最大吸附容量分别为0.40 mmol·g-1、0.44 mmol·g-1和0.299 mmol·g-1。用怀俄明州和中国的蒙脱石制备的另外两种聚合物插层纳米复合材料对高氯酸盐显示出非常好的吸附容量，但与由Kunipea蒙脱石制备的纳米复合材料相比，对铬酸盐和硝酸盐的吸附容量略低。聚合物插层纳米复合材料对硝酸盐、高氯酸盐和铬酸盐的吸附可以用Freundlich等温线很好地描述，而它们的吸附动力学很好地符合准二级模型。发现硝酸盐、高氯酸盐和铬酸盐的吸附动力学很快，在4小时内达到平衡。此外，发现在Cl-、SO42-和CO32-（自然界中最丰富的阴离子）存在的情况下，聚合物插层纳米复合材料对铬酸盐的吸附具有高度选择性。
