Downscaling limits and confinement effects in the miniaturization of porous polymer monoliths in narrow bore capillaries.
Downscaling limits and confinement effects in the miniaturization of porous polymer monoliths in narrow bore capillaries.
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DOI：
10.1021/ac901162x
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发表时间：
2009-09-01
影响因子：
7.4
通讯作者：
Frechet, Jean M. J.
中科院分区：
文献类型：
--
作者：
Nischang, Ivo;Svec, Frantisek;Frechet, Jean M. J.
以甲基丙烯酸丁酯、二甲基丙烯酸乙二酯和致孔剂的混合物为原料，在不同温度下，采用热引发自由基聚合法，在内径为5~75μm的毛细管中制备了聚甲基丙烯酸丁酯-二甲基丙烯酸乙酯共聚物整体柱。扫描电子显微镜和流体力学性质的测量表明，随着毛细管直径的减小，毛细管壁的限制效应导致体积表面积比减小，对整体柱向下伸缩性的影响很大。聚合温度、扩散基团的扩散以及可聚合基团在毛细管内壁上的覆盖密度对缩聚过程影响最大。所有这些因素的优化使得能够在内径低至5μm的毛细管中制备整体结构，同时保持在大得多的毛细管中制备的整体结构的理想特性。在这些条件下，附着在毛细管壁上的不需要的致密聚合物层的形成被最小化。在3种蛋白质的反相梯度分离中，10、25和50μm毛细管的层析性能表明，在相同的流速和梯度时间下，洗脱时间没有变化，但峰宽最小，毛细管最窄。
Monolithic poly(butyl methacrylate-co-ethylene dimethacrylate) columns have been prepared in capillaries ranging in inner diameter from 5 to 75 μm using thermally initiated free-radical polymerization of a mixture of butyl methacrylate, ethylene dimethacrylate and porogens at different temperatures. Scanning electron microscopy and the measurement of hydrodynamic properties reveal that the downward scalability of the monolithic columns is greatly affected by the confinement effect of the capillary wall resulting from the decreased volume-to-surface ratio as the capillary diameter is decreased. The downscaling process is affected most by the polymerization temperature, the diffusion of the propagating radicals, and the density of coverage of polymerizable groups on the inner walls of the capillary. Optimization of all these factors enables the preparation of monolithic structures in capillaries with inner diameters as low as 5 μm while retaining the desirable properties of monoliths prepared in much larger capillaries. Under these conditions, the formation of undesired dense polymer layers attached to the capillary wall was minimized. The chromatographic performance of 10, 25 and 50 μm capillaries evaluated in the reversed phase gradient separation of three proteins showed no change in elution times at identical flow velocities and gradient times while peak elution width was the smallest with the narrowest capillary.
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DOI：
10.1016/j.chroma.2008.09.105
发表时间：
2009-02-20
期刊：
Journal of chromatography. A
影响因子：
--
作者：
Luo Q;Rejtar T;Wu SL;Karger BL
通讯作者：
Karger BL
影响因子：
4.1
作者：
Gusev, I;Huang, X;Horváth, C
通讯作者：
Horváth, C
影响因子：
7.4
作者：
Luo, Quanzhou;Yue, Guihua;Karger, Barry L.
通讯作者：
Karger, Barry L.
影响因子：
7.4
作者：
Ivanov, AR;Zang, L;Karger, BL
通讯作者：
Karger, BL
影响因子：
7.4
作者：
Liao, JL;Chen, N;Hjerten, S
通讯作者：
Hjerten, S