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充电型体在离子表面活性剂梯度完全低于或完全高于临界微粒度的扩散性传输
Angela Yang1, Brian E McKenzie1, Benjamin Pavlat1
1Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States.
概括
带电的合体在表面活性剂梯度中移动,这一过程称为扩散泳. 这项研究发现,与理论预测相反,在临界微粒度 (CMC) 以上的二甲基硫酸盐 (SDS) 梯度中的合物运动比以下更广泛.
科学领域:
- 体科学 体科学 体科学
- 物理化学 物理化学
- 软物质物理学 软物质物理学
背景情况:
- 带电的体在离子表面活性剂梯度中表现出扩散性,其速度取决于扩散性移动性 (M_DP) 和表面活性剂度梯度.
- 化会改变表面活性剂的扩散性和电荷分布,可能会影响M_DP超过临界菌度 (CMC).
- 之前的模型表明M_DP在CMC以上的信号可能发生变化,但实验证据有限.
研究的目的:
- 研究化对有电荷的合体在离子表面活性剂梯度中的扩散性运动的作用.
- 将合体运输的实验测量与整个CMC的理论预测进行比较.
- 阐明微粒在驱动扩散论中的作用.
主要方法:
- 利用微流体通道,在CMC上方和下方创建二甲基硫酸盐 (SDS) 表面活性剂梯度.
- 在这些梯度内测量了负电荷的聚乙烯合体的运输速度.
- 作为SDS度的函数,确定了合体电泳流动性,并使用了数值传输模型进行比较.
主要成果:
- 实验结果始终显示负电荷的合体具有负的扩散性运动性,在CMC上方或下方没有观察到标志变化.
- 对于CMC以下的移动性的理论预测对合物和表面活性剂性质的不确定性敏感.
- 在CMC上方,实验揭示了与CMC下方相比,合物扩散性传输更广泛,尽管理论上预测了积极的移动性.
结论:
- 实验发现与理论预测相矛盾,关于CMC以上的扩散性运动的迹象.
- 结合体扩散性传输在状SDS溶液中明显增强,相比于同等表面活性剂度梯度的非状溶液.
- 这项研究强调了微粒在扩散论中的复杂作用,并表明了当前理论模型的局限性.
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