Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290, USA.
J Chromatogr A. 2011 Nov 4;1218(44):7989-95. doi: 10.1016/j.chroma.2011.09.004. Epub 2011 Sep 8.
Superficially porous particles are characterized by a non-porous particle core surrounded by a thin porous layer. Superficially porous particles have been shown to have chromatographic advantages over traditional totally porous particles by reducing the resistance to mass transfer and the eddy diffusion contributions to the theoretical plate height, particularly for biomolecule separations. Currently, 1.7 μm superficially porous particles are commercially available, but a further decrease in the particle diameter and reduction in the porous layer thickness has the potential to further improve the efficiency of the column packing material. In this study, the synthesis of smaller diameter superficially porous particles was investigated. As the particle diameter was decreased, however, synthesis parameters previously reported were rendered unsuitable due to particle agglomeration, non-uniform coating, and porous layer disintegration. Parameters such as colloidal silica size, drying process, and sintering temperature were investigated to improve the structural characteristics of smaller diameter superficially porous particles. Reported is a synthetic route for production of 1.1 μm superficially porous particles having a 0.1 μm porous layer. Based on the revised method, the particles produced have a surface area, pore diameter, and particle size distribution RSD of 52 m(2)/g, 71 Å, and 2.2%, respectively.
表面多孔颗粒的特点是多孔核外包裹着一层很薄的多孔层。与传统的全多孔颗粒相比，表面多孔颗粒在减少传质阻力和涡流扩散对理论塔板高度的贡献方面具有色谱优势，特别是在生物分子分离方面。目前，市场上已有 1.7μm 的表面多孔颗粒，但进一步减小粒径和减少多孔层厚度，有可能进一步提高柱填充材料的效率。在本研究中，考察了更小粒径的表面多孔颗粒的合成。然而，随着粒径的减小，以前报道的合成参数由于颗粒团聚、涂层不均匀和多孔层崩解而变得不合适。考察了胶体二氧化硅粒径、干燥工艺和烧结温度等参数，以改善更小粒径表面多孔颗粒的结构特性。本文报道了一种生产 1.1μm 表面多孔颗粒的合成路线，其多孔层厚度为 0.1μm。根据改进后的方法，所制备的颗粒的比表面积、孔径和粒径分布 RSD 分别为 52m²/g、71Å 和 2.2%。
