Development of characterization method for sub-nano scale small voids of amorphous materials by multi probe gas diffusion technique.

基于体积法，以各种气体分子为探针分子，开发了一种表征微孔粉末样品小空隙体积的新设备和新技术。作为微孔材料，制备了无定形二氧化硅和BTESE（双三乙氧基硅基乙烷）二氧化硅多孔粉末样品，并利用多探针气体分子扩散法对其孔隙结构进行了详细评价。这项技术使我们能够估计这些非晶材料的亚纳米尺度空隙结构的差异。通过对微观结构已知的Y型沸石的孔隙体积进行评价，验证了该技术的有效性，并成功得到了理论孔隙体积。通过分子模拟研究了无定形二氧化硅和BTESE二氧化硅在结构上的差异。模拟的气体分子扩散率在这些小孔洞结构中的分子大小依赖性与多探针气体分子扩散法测量的孔洞体积分布具有良好的相关性。

A novel equipment and technique for characterization of small void volume of microporous powder sample were developed based on the volumetric method by using various gas molecules as a probe molecule. As microporous materials, the porous powder sample of amorphous silica and BTESE(bis-triethoxysilyl ethane) silica was prepared, and the detailed void structure was evaluated using the multi-probe gas molecular diffusion method. This technique enables us to estimate the difference in the sub-nano scale void structure of these amorphous materials. The validity of this technique verified by evaluating the void volume of Y type zeolite whose micro structure is well known, and the theoretical pore volume was successfully obtained. The difference in the structure of amorphous silica and BTESE silica was examined also by the molecular simulation. The simulated molecular size dependence of gas diffusivity in these small void structures showed good correlation with the void volume distribution measured with the multi-probe gas molecular diffusion method.