Sörensen Malin H, Valle-Delgado Juan J, Corkery Robert W, Rutland Mark W, Alberius Peter C
YKI, Institute for Surface Chemistry, Stockholm, Sweden.
Langmuir. 2008 Jun 1;24(13):7024-30. doi: 10.1021/la800260h. Epub 2008 May 27.
We introduced the novel technique of AFM-porosimetry and applied it to measure the total pore volume of porous particles with a spherical geometry. The methodology is based on using an atomic force microscope as a balance to measure masses of individual particles. Several particles within the same batch were measured, and by plotting particle mass versus particle volume, the bulk density of the sample can be extracted from the slope of the linear fit. The pore volume is then calculated from the densities of the bulk and matrix materials, respectively. In contrast to nitrogen sorption and mercury porosimetry, this method is capable of measuring the total pore volume regardless of pore size distribution and pore connectivity. In this study, three porous samples were investigated by AFM-porosimetry: one ordered mesoporous sample and two disordered foam structures. All samples were based on a matrix of amorphous silica templated by a block copolymer, Pluronic F127, swollen to various degrees with poly(propylene glycol). In addition, the density of silica spheres without a template was measured by two independent techniques: AFM and the Archimedes principle.
我们引入了原子力显微镜孔隙率测定新技术，并将其应用于测量具有球形几何形状的多孔颗粒的总孔体积。该方法基于使用原子力显微镜作为天平来测量单个颗粒的质量。对同一批次中的几个颗粒进行了测量，通过绘制颗粒质量与颗粒体积的关系图，可以从线性拟合的斜率中提取样品的堆积密度。然后分别根据块状材料和基体材料的密度计算孔体积。与氮气吸附和压汞法不同，该方法能够测量总孔体积，而与孔径分布和孔连通性无关。在本研究中，通过原子力显微镜孔隙率测定法研究了三个多孔样品：一个有序介孔样品和两个无序泡沫结构。所有样品均基于由嵌段共聚物Pluronic F127模板化的无定形二氧化硅基体，并被聚丙二醇不同程度地溶胀。此外，通过两种独立技术：原子力显微镜和阿基米德原理测量了没有模板的二氧化硅球的密度。
