• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Applied Polymer Science >Urea-Induced Conformational Changes f Chitosan Molecules and the Shift of Break Point of Mark-Houwink Equation by Increasing Urea Concentration
【24h】

Urea-Induced Conformational Changes f Chitosan Molecules and the Shift of Break Point of Mark-Houwink Equation by Increasing Urea Concentration

机译：尿素引起的壳聚糖分子构象变化和马克-霍温克方程断裂点的位移

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Chitosan solutions of the same 83% degree of deacetylation (DD) but different weight average molecular weights (M_ws)(78-914 kDa) in 0.01 M HCl containing different concentrations of urea(0-6M)were prepared. Intrinsic viscosity ([#eta#])and weight average molecular weight (M_w)of chitosan were measured with a capillary viscometer and light scattering,respectively.Mark-Houwink exponent a was used as the parameter of conformational index. The Mark-Houwink exponent a increased with increasing concentrations of urea. When solutions contained 0,2,3,4,and 6M urea, the value of a increased from 0.715 to 0.839,0.894,1.000,and 1.060,respectively. This indicates the occurrence of urea-induced conformational transitions of chitosans.The break point shifted from 223 kDa in solutions containing no urea to 280 kDa in 2M urea solutions, to 362 kDa in 4M urea solutions and further to 481 kDa in 6M urea solutions.
机译：制备了相同的83％脱乙酰度（DD），但重均分子量（M_ws）（78-914 kDa）不同的壳聚糖溶液，该溶液在0.01 M HCl中含有不同浓度的尿素（0-6M）。用毛细管粘度计和光散射法分别测定壳聚糖的特性粘度（η）和重均分子量（M_w）。Mark-Houwink指数a用作构象指数的参数。 Mark-Houwink指数随尿素浓度的增加而增加。当溶液中包含0、2、3、4和6M尿素时，其值分别从0.715增加到0.839、0.894、1.000和1.060。这表明发生了由尿素引起的壳聚糖构象转变。断点从不含尿素的溶液中的223 kDa变为2M尿素溶液中的280 kDa，在4M尿素溶液中的362 kDa以及在6M尿素溶液中的481 kDa。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号