Master thesis defense by Xiangyin Tan

Towards improvements in small-angle X-ray scatter- ing data modeling of mesoporous SBA-15

This project aims to use Monte Carlo (MC) method to improve the model proposed originally by Sundblom et al [1] for quantitative analysis of small-angle X-ray scattering (SAXS) data from the ordered mesoporous silica (OMS) material named SBA-15. The nanostructured mesoporous silica SBA-15, formed by around 20m particles with hexagonal ordered mesopores with a diameter of 10 nm and macropores larger than 50 nm, has the ability to protect antigens from the harsh stomach environment, improve the immune response, and in the future allow for the use of needless vaccines. Depending on their
size, the antigens can be located in the macropores (HBsAg, with a radius around 22 nm, used in the Hepatitis B vaccine) or in the mesopores (dANA, with a ra- dius around 4 nm, used in Diphtheria vaccine). Thus, it is essential to know the size distribution of the mesopores in the SBA-15, and SAXS is a experimental technique that allows us answering this question. However, more advanced models to analyse the experimental data are needed, and MC is a good alternative.