Csiszár Emília, Herceg Imola, Fekete Erika
Department of Physical Chemistry and Materials Science, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary.
Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2., H-1117 Budapest, Hungary.
Polymers (Basel). 2023 Mar 29;15(7):1698. doi: 10.3390/polym15071698.
Cellulose nanocrystals (CNCs) were extracted from bleached cotton by sulfuric acid hydrolysis. Thin films were prepared from the aqueous suspension of CNCs by casting and evaporation with 15% glycerol as a plasticizer. Our research aimed to create stable films resistant to water. The structure and the interactions of the films were modified by short (10 min) heating at different temperatures (100, 140, and 160 °C) and by adding different amounts of citric acid (0, 10, 20, and 30%). Various analytical methods were used to determine the structure, surface properties, and mechanical properties. The interaction of composite films with water and water vapor was also investigated. Heat treatment did not significantly affect the film properties. Citric acid, without heat treatment, acted as a plasticizer. It promoted the disintegration of films in water, increased water vapor sorption, and reduced tensile strength, resulting in flexible and easy-to-handle films. The combination of heat treatment and citric acid resulted in stable liquid-water-resistant films with excellent mechanical properties. A minimum heating temperature of 120 °C and a citric acid concentration of 20% were required to obtain a stable CNC film structure resistant to liquid water.
通过硫酸水解从漂白棉中提取纤维素纳米晶体（CNCs）。以15%甘油作为增塑剂，通过流延和蒸发从CNCs水悬浮液中制备薄膜。我们的研究旨在制备耐水的稳定薄膜。通过在不同温度（100、140和160℃）下短时间（10分钟）加热以及添加不同量的柠檬酸（0、10、20和30%）来改变薄膜的结构和相互作用。使用各种分析方法来测定结构、表面性质和机械性能。还研究了复合薄膜与水和水蒸气的相互作用。热处理对薄膜性能没有显著影响。未经热处理的柠檬酸起到增塑剂的作用。它促进薄膜在水中分解，增加水蒸气吸附，并降低拉伸强度，从而得到柔韧性好且易于处理的薄膜。热处理和柠檬酸的组合产生了具有优异机械性能的耐液态水的稳定薄膜。要获得耐液态水的稳定CNC薄膜结构，最低加热温度为120℃，柠檬酸浓度为20%。
