X-ray diffraction as a tool of ORMOSIL gels' structure's investigation

摘要

In the paper the results of ORMOSIL gels' structures' investigation were presented. As a method XRD (X-ray diffraction) was applied. ORMOSIL gels comprising phenyl and methyl groups may be used as matrices for active layers in optical fibre sensors because an organic dye acting as a transducer may be easily introduced into their network during a so-called sol-gel process. Moreover, the refractive index of such layers may be modified by changing a molar ratio of different alkoxysilanes in a sol. As a signal of an UV optical fibre sensor strongly depends on sols' composition and ageing time it could be suggested that the structure of the gel may influence the behaviour of the dye. XRD method enables determining positions and distances between molecules, positions of atoms, angles' and bonds' lengths between atoms, distribution of electron's cloud's density on atoms, dipole moment of bonds and molecules as well as the nature of bonds, therefore it may be useful in examination of the structure of partially ordered elementary cell of the gel. The results may help to understand dependence between the structure of the gel and sensor's signal's value and lead to achieve a better performance of the optical fibre UV sensor.