An experimental and theoretical analysis of molecular separations by diffusion through ultrathin nanoporous membranes.
An experimental and theoretical analysis of molecular separations by diffusion through ultrathin nanoporous membranes.
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DOI：
10.1016/j.memsci.2010.11.056
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发表时间：
2011-03-01
影响因子：
9.5
通讯作者：
McGrath, J. L.
中科院分区：
文献类型：
--
作者：
Snyder, J. L.;Clark, A., Jr.;Fang, D. Z.;Gaborski, T. R.;Striemer, C. C.;Fauchet, P. M.;McGrath, J. L.
基于扩散的分离对于实验室和临床透析过程是必不可少的。新的分子薄纳米孔膜可能会提高通过这些过程实现的分离的速度和质量。在这项工作中，我们用15 nm厚的多孔纳米晶硅(PNC-Si)膜进行了蛋白质和小分子的分离，并将结果与超薄膜中的一维和三维扩散模型进行了比较。该模型通过直接检测PNC-Si膜的透射式电子显微镜中的孔特征来预测膜的阻抗量。理论结果表明，与具有相同孔径和孔隙率的较厚膜相比，分子薄膜有望在平衡前的时间实现更高的分辨率分离。探讨了孔隙率、孔分布、扩散时间、腔体尺寸等实验参数对筛分特性的影响。实验结果与理论符合得很好，超薄薄膜对小于物理孔径截止值的分子的扩散几乎没有总的阻力。被测试的最大分子在模拟中遇到的阻碍比预期的要大，这表明模型中没有考虑的因素，如分子形状、静电斥力和对孔壁的吸附，可能是重要的。
Diffusion based separations are essential for laboratory and clinical dialysis processes. New molecularly thin nanoporous membranes may improve the rate and quality of separations achievable by these processes. In this work we have performed protein and small molecule separations with 15 nm thick porous nanocrystalline silicon (pnc-Si) membranes and compared the results to 1- and 3- dimensional models of diffusion through ultrathin membranes. The models predict the amount of resistance contributed by the membrane by using pore characteristics obtained by direct inspection of pnc-Si membranes in transmission electron micrographs. The theoretical results indicate that molecularly thin membranes are expected to enable higher resolution separations at times before equilibrium compared to thicker membranes with the same pore diameters and porosities. We also explored the impact of experimental parameters such as porosity, pore distribution, diffusion time, and chamber size on the sieving characteristics. Experimental results are found to be in good agreement with the theory, and ultrathin membranes are shown to impart little overall resistance to the diffusion of molecules smaller than the physical pore size cutoff. The largest molecules tested experience more hindrance than expected from simulations indicating that factors not incorporated in the models, such as molecule shape, electrostatic repulsion, and adsorption to pore walls, are likely important.
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影响因子：
17.1
作者：
Gaborski TR;Snyder JL;Striemer CC;Fang DZ;Hoffman M;Fauchet PM;McGrath JL
通讯作者：
McGrath JL
影响因子：
9.5
作者：
Latulippe, David R.;Ager, Kimberly;Zydney, Andrew L.
通讯作者：
Zydney, Andrew L.
影响因子：
4.4
作者：
Makhnovskii, YA;Berezhkovskii, AM;Zitserman, VY
通讯作者：
Zitserman, VY
影响因子：
3
作者：
Fissell, W. H.;Humes, H. D.;Roy, S.
通讯作者：
Roy, S.
影响因子：
56.9
作者：
Holt, JK;Park, HG;Bakajin, O
通讯作者：
Bakajin, O