Effect of biocidal additives on the mesostructure of epoxy–siloxane bioactive coatings

Abstract

We investigate the structure formation of sol–gel synthesized epoxy–siloxane compositions with a ratio of the main precursors of R_{TEOS/EPONEX 1510} = 27/27 wt %, modified with biocidal additives of detonation nanodiamonds (c_DND = 0.13, 0.27, and 0.58 wt %), titanium dioxide (\(^cTi{O_2}\) = 0.1, 0.3, and 0.5 wt %), and Photosens (c_Ph = 0.04, 0.1, and 0.27 wt %), by small-angle X-ray scattering. Based on small-angle X-ray scattering (SAXS) data, it is revealed that the synthesized epoxy–siloxane xerogels are systems with a twolevel fractal structure, in the formation of which the siloxane component plays the dominant role. It is found that the introduction of small additions of detonation synthesis, titanium dioxide, or Photosens (less than 1 wt %) into the epoxy–siloxane compositions affects both the fractal dimension D_S of the surface and the size d_c1 of primary particles, and the fractal dimension D_M and sizes d_c2 of mass fractal clusters formed from them.