MOF-5掺杂改性对纤维素水凝胶保水性能的影响

Effect on water retention performance of MOF-5 doping modified cellulose hydrogel composite materials

以MOF-5为改性剂对纤维素水凝胶进行掺杂改性,通过FT-IR、XRD和SEM对其结构进行了表征,并研究了掺杂量、pH、盐溶液浓度、温度对复合纤维素水凝胶保水性能的影响及其可循环利用特性。结果表明,纤维素水凝胶表面的活性基团,有利于MOF-5与其结合,与纯纤维素水凝胶相比,吸水率最高达4294.94%,提高了1725.63%。保水性实验发现,复合水凝胶在NaCl、AlCl3盐溶液中的保水效果随着浓度增大而减小;当MOF-5掺杂量为20%、pH=12、盐溶液浓度为4 m mol/L时具有最佳的保水效果,且在40℃,放置175 min,最佳掺杂量的复合纤维素水凝胶保水率仍在50%以上。可循环利用性实验证实,复合纤维素水凝胶循环使用3次时,其保有率仍高于50%。实验结果表明该复合水凝胶在高温农业生产领域有潜在应用价值。

In this work,cellulose hydrogel was modified with MOF-5.The chemical structure was characterized by FT-IR,XRD and SEM.The effects of contents,pH,salt solution concentration,and temperature on the water retention properties and recyclable properties of composite cellulose hydrogels were studied.The results showed that the active groups on the surface of cellulose hydrogel were beneficial to the binding of MOF-5,and the binding effect became more obvious as the doping amount increasing.Compared with traditional cellulose hydrogel,the water absorption rate was up to 4294.94%,which was an increase of 1725.63%.The water retention experiment found that the best water retention effect was obtained when the MOF-5 doped amount was 20%,pH=12,and 4 m mol/L salt solution.The water retention effect of the composite hydrogel in NaCl and AlCl3 solutions decreased with increasing concentration.The composite cellulose hydrogel with the optimal doped amount still retained more than 50%of water when left at 40℃for 175 min.Recyclability experiments showed that the retention rate of the composite cellulose hydrogel was still higher than 50%when it was used 3 times.Thus composite hydrogel had potential application value in the field of high-temperature agricultural production.