Polymer Composite Research Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
Polymer Composite Research Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
Carbohydr Polym. 2017 Jul 15;168:1-13. doi: 10.1016/j.carbpol.2017.03.047. Epub 2017 Mar 16.
The sodium alginate-g-poly(acrylic acid-co-acrylamide)/rice husk ash (NaAlg-g-P(AA-co-AAm)/RHA) superabsorbent nanocomposite was synthesized by the free-radical graft copolymerization of alginate (NaAlg), acrylic acid (AA), acrylamide (AAm), and RHA in aqueous solution. FTIR spectra revealed that the monomers were grafted onto NaAlg chains, and the nanocomposite was formed successfully. Incorporation of RHA into hydrogel matrix formed porous interlinked channels within hydrogel network. Superabsorbent nanocomposite showed greater equilibrium swelling capacity (1070g/g) compared with neat hydrogel (830g/g). Moreover, water transport mechanism of all hydrogels was non-Fickian diffusion type. Rheological measurements confirmed effective role of RHA in improving gel strength of superabsorbent nanocomposite. The influence of various factors, such as different loads (0.3, 0.6, 0.9 psi), solution pH, saline solution, and temperature on the swelling behavior of hydrogels was also assessed. Superabsorbent nanocomposite exhibited good pH-dependent swelling reversibility and high water retention capability, making it more efficient water-saving material for agricultural and horticultural applications.
由 Alginate (NaAlg)、丙烯酸 (AA)、丙烯酰胺 (AAm) 和稻壳灰 (RHA) 在水溶液中的自由基接枝共聚合成了海藻酸钠-g-聚(丙烯酸-co-丙烯酰胺)/稻壳灰 (NaAlg-g-P(AA-co-AAm)/RHA) 超吸收纳米复合材料。FTIR 光谱表明单体接枝到 NaAlg 链上，成功地形成了纳米复合材料。RHA 掺入水凝胶基质中，在水凝胶网络内形成多孔互穿通道。与纯水凝胶 (830g/g) 相比，超吸收纳米复合材料显示出更大的平衡溶胀能力 (1070g/g)。此外，所有水凝胶的水传输机制均为非菲克扩散型。流变学测量证实了 RHA 在提高超吸收纳米复合材料凝胶强度方面的有效作用。还评估了各种因素，如不同负载 (0.3、0.6、0.9 psi)、溶液 pH 值、盐水溶液和温度对水凝胶溶胀行为的影响。超吸收纳米复合材料表现出良好的 pH 依赖性溶胀可逆性和高保水能力，使其成为农业和园艺应用中更高效的节水材料。
