Abstract

Aqueous suspensions of nanocrystalline cellulose (NCC) were obtained by sulfuric acid hydrolysis using the standard procedure. Suspensions, films, and aerogel of NCC were characterized by various methods: the degree of polymerization was determined, elemental analysis was carried out, the degree of crystallinity and crystallite size were calculated on the basis of X-ray data, and the morphology of NCC aerogels was studied using scanning electron microscopy. The particle size of the NCC was determined using a transmission electron microscope, a scanning atomic force microscope, and the method of dynamic light scattering. NCC hydrosols with different pH were used to prepare lyophilized NCC samples. From NCC hydrosols with pH 2.2, by gradual replacement of water with an organic solvent, NCC organogels with acetone, acetonitrile, and ethanol were obtained. The dispersion of lyophilized NCC and NCC organogels (acetone, acetonitrile, and ethanol) in water and in 11 organic solvents was investigated. The effect of the pH of the initial aqueous suspension of the NCC and the solvent forming the NCC organogel on the repeated dispersibility of the NCC is shown. The optimum pH value of the initial aqueous suspension of NCC was determined, which determines the maximum dispersibility of the lyophilized samples in each specific solvent. Acetone, acetonitrile, and ethanol organogels are dispersed in most of the solvents studied with the formation of particles less than 100 nm in diameter.

中文翻译：

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纳米晶纤维素在有机溶剂中的分散性

摘要

使用标准程序通过硫酸水解获得纳米晶纤维素（NCC）的水悬浮液。用多种方法表征NCC的悬浮液，薄膜和气凝胶：确定聚合度，进行元素分析，根据X射线数据计算结晶度和微晶尺寸以及NCC的形态使用扫描电子显微镜研究气凝胶。使用透射电子显微镜，扫描原子力显微镜和动态光散射法确定NCC的粒径。使用具有不同pH值的NCC水溶胶制备冻干的NCC样品。从pH 2.2的NCC溶胶中，通过逐渐用有机溶剂代替水，将NCC有机凝胶用丙酮，乙腈，得到乙醇。研究了冻干的NCC和NCC有机凝胶（丙酮，乙腈和乙醇）在水和11种有机溶剂中的分散性。示出了NCC的初始水性悬浮液的pH和形成NCC有机凝胶的溶剂对NCC的重复分散性的影响。确定了NCC初始水悬浮液的最佳pH值，该值确定了冻干样品在每种特定溶剂中的最大分散性。丙酮，乙腈和乙醇有机凝胶分散在大多数研究的溶剂中，形成直径小于100 nm的颗粒。示出了NCC的初始水性悬浮液的pH和形成NCC有机凝胶的溶剂对NCC的重复分散性的影响。确定了NCC初始水悬浮液的最佳pH值，该值确定了冻干样品在每种特定溶剂中的最大分散性。丙酮，乙腈和乙醇有机凝胶分散在大多数研究的溶剂中，形成直径小于100 nm的颗粒。示出了NCC的初始水性悬浮液的pH和形成NCC有机凝胶的溶剂对NCC的重复分散性的影响。确定了NCC初始水悬浮液的最佳pH值，该值确定了冻干样品在每种特定溶剂中的最大分散性。丙酮，乙腈和乙醇有机凝胶分散在大多数研究的溶剂中，形成直径小于100 nm的颗粒。