Stimuli-responsive composite hydrogels with three-dimensional stability prepared using oxidized cellulose nanofibers and chitosan
Stimuli-responsive composite hydrogels with three-dimensional stability prepared using oxidized cellulose nanofibers and chitosan
复制标题
氧化纤维素纳米纤维与壳聚糖制备三维稳定性刺激响应性复合水凝胶
DOI：
10.1016/j.carbpol.2021.118907
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发表时间：
2022-02-15
影响因子：
11.2
通讯作者：
Uyama, Hiroshi
中科院分区：
文献类型：
--
作者：
Pedige, Madhurangika Panchabashini Horathal;Asoh, Taka-Aki;Uyama, Hiroshi
刺激响应性水凝胶引起了水凝胶行业的关注，因为它们能够根据pH、温度、离子强度、电磁场和光等外部刺激的变化来改变其物理和化学性质。然而，刺激响应性水凝胶的应用由于其不可避免的膨胀和收缩而受到阻碍。细菌纤维素（BC）是一种紧密堆积的纤维素纳米纤维（CNF）的天然水凝胶，被氧化成二醛BC（DABC），并与容易获得的天然聚合物壳聚糖（CS）复合，开发出一种在不同pH条件下具有机械适应性的水凝胶复合材料。由于壳聚糖链氨基的质子化，复合材料在酸性条件下表现出较高的机械性能，而在碱性条件下表现出较低的机械性能，从而表现出 pH 敏感性。在酸性条件下会增加渗透压，从而提高复合材料的机械强度。复合材料良好的三维稳定性使它们在暴露于酸性或碱性条件下时能够始终保持其体积。
Stimuli-responsive hydrogels have garnered the attention of the hydrogel industry, as they are able to change their physical and chemical properties based on changing external stimuli such as pH, temperature, ionic strength, electromagnetic fields, and light. However, stimuli-responsive hydrogel applications are hindered due to their inevitable swelling and shrinkage. Bacterial cellulose (BC), a natural hydrogel with tightly packed cellulose nanofibers (CNFs) was oxidized into dialdehyde BC (DABC) and was composited with chitosan (CS), a readily available natural polymer, to develop a mechanically adaptive hydrogel composite under different pH conditions. Composites exhibit pH sensitivity by presenting higher mechanical properties under acidic conditions and lower mechanical properties under basic conditions owing to the protonation of amino groups of the chitosan chains. Osmotic pressure is built up under acidic conditions, increasing the mechanical strength of the composites. The good three-dimensional stability of composites enables them to consistently maintain their volume when exposed to acidic or basic conditions.