An improved model of the layered structure of cellulose microfibrils is proposed, taking into account the presence of slit-like pores between its structural elements. The scheme of the formation of donoracceptor intramolecular, intermolecular and interlayer hydrogen bonds of one glucopyranose unit in the cellulose crystallite is presented. The mechanism of specific adsorption interactions of water molecules in a monolayer with active centers located on the hydrophilic surfaces of elementary fibrils is described. The energy of dipole-dipole interactions was calculated depending on the distance between the active center and the adsorbate water molecule. The thermodynamic parameters characterizing the state of the adsorbate in the adsorption layers are determined by the proton magnetic relaxation method and sorption measurements. The possibility of determining the net heat of adsorption in a bilayer taking into account the Arrhenius nature of the correlation times of the thermal molecular motions of the adsorbate was established. An increase in the entropy of adsorbed water during the adsorption process was revealed. It was found that during adsorption, a part of the inner regions of crystallites transitions to their surface with the participation of cellulose hydroxyl groups, and during desorption, the reverse process is observed.

中文翻译：

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纤维素的结构组织和吸附特性

考虑到纤维素微纤维结构元素之间存在缝隙状孔隙，提出了一种改进的纤维素微纤维分层结构模型。提出了在纤维素微晶中一个葡萄糖吡喃糖单元的供体受体分子内，分子间和层间氢键的形成方案。描述了单分子层中水分子与活性中心位于基本原纤维亲水表面上的特异性吸附相互作用的机理。根据活性中心与被吸附物水分子之间的距离，计算出偶极-偶极相互作用的能量。通过质子磁弛豫法和吸附测量来确定表征吸附层中吸附物状态的热力学参数。建立了考虑到被吸附物的热分子运动的相关时间的阿雷尼乌斯性质来确定双层中的吸附净热的可能性。揭示了在吸附过程中吸附水的熵的增加。发现在吸附过程中，微晶的内部区域的一部分在纤维素羟基的参与下过渡到其表面，并且在解吸过程中，观察到相反的过程。