Simultaneous SAXS and WAXS investigations of changes in native cellulose fiber microstructure on swelling in aqueous sodium hydroxide
Simultaneous SAXS and WAXS investigations of changes in native cellulose fiber microstructure on swelling in aqueous sodium hydroxide
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DOI：
10.1002/app.2287
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发表时间：
2002-02-07
影响因子：
3
通讯作者：
Cameron, RE
中科院分区：
文献类型：
--
作者：
Crawshaw, J;Bras, W;Cameron, RE
采用小角和广角x射线同时散射技术，研究了天然纤维素（cellulose I）纤维在氢氧化钠转化为钠纤维素（Na-cellulose I）过程中的微观结构变化。广角x射线散射用于监测转换的程度，而小角x射线散射用于探索初级原纤维、微原纤维和纤维间空隙的较高结构水平。天然纤维素纤维在水或氢氧化钠水溶液中膨胀后，由于膨胀剂分离了基本纤维，打开了结构，产生了许多小空隙，因此空隙体积分数增加，空隙横截面尺寸减小。膨胀的天然纤维素转化为钠纤维素后，空隙体积分数和平均空隙截面尺寸均增加。在从干燥的纤维素I纤维到膨胀的na -纤维素I纤维的转化过程中，空隙的横截面尺寸经历了一个最小值，这表明空隙结构可能经过一个类似于纤维素I的水膨胀结构的中间物。应用化学学报（英文版），2002。
Simultaneous small- and wide-angle X-ray scattering was used to follow changes in the microstructure of native cellulose (cellulose I) fibers during conversion to sodium cellulose I (Na-cellulose I) by aqueous sodium hydroxide. Wide-angle X-ray scattering was used to monitor the extent of conversion, while small-angle X-ray scattering was used to explore what occurs at the higher structural levels of the elementary fibrils, microfibrils, and interfibrillar voids. Native cellulose fibers, swollen in either water or aqueous sodium hydroxide, exhibited an increase in the void volume fraction and a decrease in the void cross-section size, as the swelling agent separated elementary fibrils, opening up the structure, and creating many small voids. After conversion of swollen native cellulose to sodium cellulose I, the void volume fraction and average void cross-section dimensions both increased. During conversion from dry cellulose I fibers to swollen Na-cellulose I fibers, the void cross-section dimensions went through a minimum, suggesting that the void structure may go via an intermediate similar to the water swollen structure of cellulose I. (C) 2002 John Wiley & Sons, Inc. J Appl Polym Sci 83: 1209-1218, 2002.