Influence of surface charge on viscosity behavior of cellulose microcrystal suspension
Influence of surface charge on viscosity behavior of cellulose microcrystal suspension
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DOI：
10.1007/bf01177736
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发表时间：
1999-01-01
影响因子：
2.9
通讯作者：
Okana, T
中科院分区：
文献类型：
--
作者：
Araki, J;Wada, M;Okana, T
以针叶木牛皮纸浆为原料，用4N盐酸代替硫酸水解，制备出表面电荷最小的微晶纤维素。通过用 55% (w/w) 硫酸处理，向该材料引入硫酸酯基团作为表面电荷。在 60 摄氏度下处理 2 小时，得到的表面电荷水平与 H2SO4 水解微晶的表面电荷水平几乎相同。通过改变H2SO4处理条件来控制硫酸基团的数量。尽管无论制备方法如何，微晶颗粒的微观尺寸和形状都是相同的，但表面电荷的引入大大降低了粘度并消除了其时间依赖性。这些粘度行为的变化被认为是由 HCl 水解制备的初始无电荷微晶中存在的松散聚集体的电荷诱导分散造成的。
Microcrystalline cellulose with minimal surface charge was prepared from softwood kraft pulp via hydrolysis by 4N hydrochloric acid instead of sulfuric acid. To this material, sulfate ester groups as surface charge were introduced by treating with 55 % (w/w) sulfuric acid. A treatment at 60 degrees C for 2h gave nearly the same level of surface charge as that of the H2SO4-hydrolyzed microcrystal. The number of sulfate groups were controlled by changing the H2SO4 treatment conditions. Although the microscopic size and shape of the microcrystalline particles were the same irrespective of the preparation method, the introduction of surface charge drastically reduced the viscosity and removed its time dependence. These changes in viscosity behavior are considered to result from charge-induced dispersion of loose aggregates existing in the initial charge-free microcrystals prepared by HCl hydrolysis.