Institute of Chemical Sciences, Gomal University, D.I.Khan, 29050, Pakistan.
Faculty of Agriculture, Gomal University, D.I.Khan, 29050, Pakistan.
Chemosphere. 2023 Apr;321:138000. doi: 10.1016/j.chemosphere.2023.138000. Epub 2023 Jan 29.
In this research article, novel starch phosphate grafted polyvinyl imidazole (StP-g-PIMDZs) was synthesized. Firstly, a phosphate group was attached to starch polymer via a phosphorylation reaction. Next, 1-vinyl imidazole (VIMDZ) was grafted on the backbone of starch phosphate (StP) through a free radical polymerization reaction. The synthesis of these modified starches was confirmed by H NMR, P NMR and FT-IR techniques. The grafting of vinyl imidazole onto StP diminished the crystallinity. Due to the insertion of the aromatic imidazole ring, the StP-g-PIMDZs demonstrated greater thermal stability. The StP and StP-g-PIMDZs were used as sorbents for the adsorption of methylene blue dye (MBD) from the model solution. The maximum removal percentage for starch, StP, StP-g-PIMDZ 1, StP-g-PIMDZ 2 and StP-g-PIMDZ 3 was found to be 60.6%, 66.7%, 74.2%, 85.3 and 95.4%, respectively. The Pseudo second order kinetic model and Langmuir adsorption isotherm were best suited to the experimental data with R = 0.999 and 0.99, respectively. Additionally, the thermodynamic parameters showed that the adsorption process was feasible, spontaneous, endothermic and favored chemi-sorption mechanism.
在这篇研究文章中，合成了新型淀粉磷酸酯接枝聚乙烯亚胺（StP-g-PIMDZs）。首先，通过磷酸化反应将磷酸基团接枝到淀粉聚合物上。然后，通过自由基聚合反应将 1-乙烯基咪唑（VIMDZ）接枝到淀粉磷酸酯（StP）的主链上。通过 H NMR、P NMR 和 FT-IR 技术证实了这些改性淀粉的合成。乙烯基咪唑接枝到 StP 上降低了结晶度。由于芳族咪唑环的插入，StP-g-PIMDZs 表现出更高的热稳定性。StP 和 StP-g-PIMDZs 被用作模型溶液中亚甲基蓝染料（MBD）吸附的吸附剂。淀粉、StP、StP-g-PIMDZ1、StP-g-PIMDZ2 和 StP-g-PIMDZ3 的最大去除率分别为 60.6%、66.7%、74.2%、85.3%和 95.4%。准二级动力学模型和 Langmuir 吸附等温线最适合实验数据，R 分别为 0.999 和 0.99。此外，热力学参数表明吸附过程是可行的、自发的、吸热的，并有利于化学吸附机制。
