In order to explore the nature of the hydration and swelling of superabsorbent resin, a theoretical investigation into the cooperativity effect of the H-bonding interactions in the hydrates of four model compounds that can be regarded as the units of hydroquinone formaldehyde resin (HFR) (i.e., O-hydroxymethyl-1,4-dihydroxybenzene, methylene di-O-hydroxymethyl-1,4-dihydroxybenzene, p-hydroxy hydroxymethyl calix[4]arene and p-hydroxy hydroxymethyl calix[5]arene) was carried out by many-body interaction and density functional reactivity theory. The HFR···H₂O···H₂O complexes, in which the H₂O···H₂O moieties are bound with both the hydroxyl groups of HFR, are the most stable. For the HFR(H₂O)_n clusters, the interaction energy per building block is increased as the number of the size n increases, indicating the cooperativity effect. Therefore, a deduction is given that the cooperativity effects of the H-bonding interactions play an important role in the process of the hydration and swelling of HFR, and the swelling behavior is mainly attributed to the cooperativity effects which arised from the interactions between the H₂O molecules. The origin of the cooperativity effect was examined employing several information-theoretic quantities in the density functional reactivity theory. The degree of swelling of HFR was quantitated using a measure of volume.

Graphical abstract

中文翻译：

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水合和溶胀：通过多体相互作用和密度泛函反应理论研究对羟基羟甲基杯[4] / [5]芳烃与H 2 O之间H键相互作用的协同作用。

为了探索高吸收性树脂的水合和溶胀的性质，对四种模型化合物的水合物中H键相互作用的协同作用效应进行了理论研究，这些化合物可以被视为对苯二酚甲醛树脂（HFR）的单位（即，通过许多方法进行了O-羟甲基-1,4-二羟基苯，亚甲基二-O-羟甲基-1,4-二羟基苯，对羟基羟甲基杯[4]芳烃和对羟基羟甲基杯[5]芳烃的合成。体相互作用和密度泛函反应理论。HFR··H ₂ O··H ₂ O络合物，其中H ₂ O···H ₂O部分与HFR的两个羟基结合，是最稳定的。对于HFR（H ₂ O）_n簇，每个构造块的交互作用能量随大小n的数量增加而增加，表明了协同作用。因此，可以推论H键结合相互作用的协同作用在HFR的水合作用和溶胀过程中起重要作用，而溶胀行为主要归因于H之间相互作用产生的协同作用。₂O分子。在密度泛函反应性理论中，利用几个信息理论量检验了协同作用的起源。HFR的溶胀度通过体积测量来定量。

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