Molded rigid polymer monoliths as separation media for capillary electrochromatography.: 1.: Fine control of porous properties and surface chemistry
Molded rigid polymer monoliths as separation media for capillary electrochromatography.: 1.: Fine control of porous properties and surface chemistry
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DOI：
10.1021/ac9713518
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发表时间：
1998-06-01
影响因子：
7.4
通讯作者：
Fréchet, JMJ
中科院分区：
文献类型：
--
作者：
Peters, EC;Petro, M;Fréchet, JMJ
在致孔溶剂存在下，通过甲基丙烯酸丁酯、二甲基丙烯酸乙二酯和 2-丙烯酰氨基-2-甲基-1-丙磺酸 (AMPS) 的混合物的简单共聚，在未经处理的熔融石英毛细管的范围内一步制备了用于毛细管电色谱的整体柱。这些新型大孔整体材料的使用消除了对玻璃料的需求、填充毛细管遇到的困难以及毛细管表面功能化。由于整体材料的多孔特性可以通过改变三元致孔溶剂的组成来轻松调整，因此可以在广泛的范围内独立研究孔径大小和磺酸单体的百分比对毛细管柱的效率和电渗速度的影响。单体内带电功能含量的简单增加会导致当前速度的预期加速。然而，增加孔径会导致分离效率的显着下降。相比之下，随着AMPS水平的增加，由于致孔溶剂的组成的调整，孔径保持固定，显示出效率没有下降，同时保持相同的速度增加，从而导致分离时间显着减少。此外，对具有恒定 AMPS 水平但不同孔径的整料进行的测量表明，当前速度可能受到毛细管柱内当前阻力的影响。
Monolithic columns for capillary electrochromatography have been prepared within the confines of untreated fused-silica capillaries in a single step by a simple copolymerization of mixtures of butyl methacrylate, ethylene dimethacrylate, and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) in the presence of a porogenic solvent. The use of these novel macroporous monoliths eliminates the need for frits, the difficulties encountered with packed capillaries, and capillary surface functionalization. Since the porous properties of the monolithic materials can be easily tailored through changes in the composition of the ternary porogenic solvent, the effects of both pore size and the percentage of sulfonic acid monomer on the efficiency and the electroosmotic now velocity of the capillary columns could be studied independently over a broad range. A simple increase in the content of charged functionalities within the monolith leads to an expected acceleration of the now velocity. However, increasing the pore size leads to a substantial deterioration of the efficiency of the separation. In contrast, monoliths with increasing levels of AMPS in which the pore size remains fixed due to adjustments in the composition of the porogenic solvent show no deterioration in efficiency while maintaining the same increase in now velocity, thus producing a significant reduction in separation time. Additionally, measurements on monoliths with constant levels of AMPS but different pore sizes suggest that now velocity may be affected by the now resistance within the capillary column.