Loghin Diana Felicia, Bazarghideanu Melinda Maria, Vasiliu Silvia, Racovita Stefania, Zaharia Marius-Mihai, Vasiliu Tudor, Mihai Marcela
Petru Poni Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi, Romania.
Gels. 2022 Aug 30;8(9):549. doi: 10.3390/gels8090549.
The synthesis of hydrogel beads involving natural polymers is, nowadays, a leading research area. Among natural polymers, starch and chitosan represent two biomolecules with proof of efficiency and low economic impact in various utilization fields. Therefore, herein, the features of hydrogel beads obtained from chitosan and three sorts of starch (potato, wheat and rise starches), grafted with acrylonitrile and then amidoximated, were deeply investigated for their use as sorbents for heavy metal ions and dyes. The hydrogel beads were prepared by ionotropic gelation/covalent cross-linking of chitosan and functionalized starches. The chemical structure of the hydrogel beads was analyzed by FT-IR spectroscopy; their morphology was revealed by optical and scanning electron microscopies, while the influence of the starch functionalization strategies on the crystallinity changes was evaluated by X-ray diffraction. Molecular dynamics simulations were used to reveal the influence of the grafting reactions and grafted structure on the starch conformation in solution and their interactions with chitosan. The sorption capacity of the hydrogel beads was tested in batch experiments, as a function of the beads' features (synthesis protocol, starch sort) and simulated polluted water, which included heavy metal ions (Cu, Co, Ni and Zn) and small organic molecules (Direct Blue 15 and Congo red).
如今，涉及天然聚合物的水凝胶珠的合成是一个前沿研究领域。在天然聚合物中，淀粉和壳聚糖是两种生物分子，在各个应用领域都证明了其有效性且经济影响较小。因此，本文深入研究了由壳聚糖和三种淀粉（马铃薯淀粉、小麦淀粉和大米淀粉）制得的水凝胶珠的特性，这些淀粉先接枝丙烯腈然后进行偕胺肟化，用作重金属离子和染料的吸附剂。水凝胶珠通过壳聚糖和功能化淀粉的离子凝胶化/共价交联制备。通过傅里叶变换红外光谱对水凝胶珠的化学结构进行分析；通过光学显微镜和扫描电子显微镜揭示其形态，同时通过X射线衍射评估淀粉功能化策略对结晶度变化的影响。分子动力学模拟用于揭示接枝反应和接枝结构对溶液中淀粉构象及其与壳聚糖相互作用的影响。在批量实验中测试了水凝胶珠的吸附容量，该容量是珠子特性（合成方案、淀粉种类）和模拟污染水的函数，模拟污染水包括重金属离子（铜、钴、镍和锌）和小分子有机物（直接蓝15和刚果红）。
