High-resolution, submicron particle size distribution analysis using gravitational-sweep sedimentation
High-resolution, submicron particle size distribution analysis using gravitational-sweep sedimentation
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DOI：
10.1016/s0006-3495(99)77273-5
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发表时间：
1999-02-01
影响因子：
3.4
通讯作者：
Mächtle, W
中科院分区：
文献类型：
--
作者：
Mächtle, W
沉降速度是分析大分子复杂溶液的有力工具。然而，样品的混浊度对目前适用于此类分析的分子络合物的大小施加了上限。此外，颗粒大小分布的广度，再加上不同颗粒密度的可能变化，使得分析极其复杂的混合物变得困难。聚合物行业也面临着同样的问题。在乳胶、颜料、漆和乳液的分散体必须进行表征的地方，为聚合物工业开发的用于生化科学的方法有着丰富的历史。提出了两种这样的方法。它们使用分析超速离心法来确定亚微米级颗粒的密度和尺寸分布。这两种方法都依赖于斯托克斯方程来估计颗粒的大小和密度，而浊度通过米氏理论进行了修正，提供了浓度测量。第一种方法利用不同密度的分散介质中的沉降时间来评价颗粒的密度和粒度分布。如果样品在化学上是均匀的，这种方法就可以工作，第二种方法将在不同样品浓度下收集的数据拼接在一起，从而能够高分辨率地确定颗粒直径从10到3000 nm的尺寸分布。通过在1小时内将转子转速从0指数增加到40,000 rpm，可以测量到非常广泛分布的分散体的尺寸分布。本文简要介绍了使用超速离心机进行粒度分布分析的历史，并对最新的实验方法进行了描述。提供了几个方法的应用，展示了其用途的广度，包括扩展到含有非球形和发色粒子的样品。
Sedimentation velocity is a powerful tool for the analysis of complex solutions of macromolecules. However, sample turbidity imposes an upper limit to the size of molecular complexes currently amenable to such analysis. Furthermore, the breadth of the particle size distribution, combined with possible Variations in the density of different particles, makes it difficult to analyze extremely complex mixtures. These same problems are faced in the polymer industry. where dispersions of latices, pigments, lacquers, and emulsions must be characterized, There is a rich history of methods developed for the polymer industry finding use in the biochemical sciences. Two such methods are presented. These use analytical ultracentrifugation to determine the density and size distributions for submicron-sized particles. Both methods rely on Stokes' equations to estimate particle size and density, whereas turbidity, corrected using Mie's theory, provides the concentration measurement. The first method uses the sedimentation time in dispersion media of different densities to evaluate the particle density and size distribution. This method works provided the sample is chemically homogeneous, The second method splices together data gathered at different sample concentrations, thus permitting the high-resolution determination of the size distribution of particle diameters ranging from 10 to 3000 nm. By increasing the rotor speed exponentially from 0 to 40,000 rpm over a 1-h period, size distributions may be measured for extremely broadly distributed dispersions. Presented here is a short history of particle size distribution analysis using the ultracentrifuge, along with a description of the newest experimental methods. Several applications of the methods are provided that demonstrate the breadth of its utility, including extensions to samples containing nonspherical and chromophoric particles.