吸水材料的水势及非金属矿物／高分子吸水保水复合材料的水势研穷

Research of water potential of water-retaining agent and attapulgite/poly （sodium acrylate） superabsorbent composite

非金属矿物，高分子吸水保水复合材料（MPSAC）近年来由于其优异的吸水保水性能在节水农业，生态环境建设等领域得到了广泛应用。以植物细胞吸水机理和吸水材料吸水机理对比为基础，以MPSAC中坡缕石粘土，聚丙烯酸（钠）吸水保水复合材料为研究对象，借用植物生理学中水势的概念，采用水凝胶液体交换法测定吸水材料．MPSAC制备条件中不同中和度对水势变化趋势的影响，并且比较了矿物含量为10％（质量分数）时吸水材料水势与空白样吸水树脂水势的差异。通过实验可知：采用水凝胶液体交换法测量吸水材料的水势是科学的、可行的。并且用水势表征吸水材料的吸水能力比用吸水倍率更科学、更客观。此项研究对于研究由土壤-吸水材料-植物根系构成的连续的体系中水分的流动状态，揭示体系水分流动的更深层次的动力具有重要意义。通过空白样与加入10％（质量分数）坡缕石的复合样品水势的对比得知，加入适量坡缕石对于吸水材料的水势具有明显的影响。坡缕石加入后，可以使复合吸水材料的水势值增高．这样更利于水分向土壤中的释放，它所吸收的水分也更容易被植物所吸收利用。

Mineral/polymer-superabsorbent-composite has been used a lot in the field of water saving agriculture and construction of ecological environment because of excellent water absorbing and water retaining performance. In this article, we based on the contrast of mechanism of plant cell and superabsorbent, use the definition from plan physiology, and research the water potential of a kind of MPSAC which compound with attapulgite and poly sodium acrylate. We use hydrogel- liquid- exchange method to test water potential of a series of samples with different degree of neutralization and in the next, comparing the pure sample with the sample which added 10wt% mineral. We can get some conclusions from the experiment. The hydrogel- liquid- exchange method proved to be scientific and available. It＇s much more exactly than using absorbency to measure the capability of superabsorbent. Also, it＇s significant for indicating the direction of water in the system of soil-superabsorbent-plant. Compared the pure sample with the compound sample, we can know, when added attapulgite, water potential of compound sample increased 42.8%, at the meanwhile absorbency decreased 20%, that means add attapulgite to the superabsorbent have obviously effect on water potential of material. When apply in agriculture, it＇s much easier to release water to soil than pure sample, and the water can be used as much as possible.