The effect of fiber activation on the surface properties of a photocatalytic composite material based on it

Introduction. The active development of construction technologies entails the need to improve the properties of traditional materials, including giving them specific functional characteristics such as photocatalytic activity. One of the promising methods for solving this problem is the introduction of specialized additives into standard building mixes, which include photocatalytic composite materials. Within the framework of this article, the influence of various methods of fiber activation on the surface properties of a photocatalytic composite material created on its basis is considered. Materials and research methods. The effect of pre-activation of basalt (BF), glass (GF) and glass alkali-resistant (GAF) fibers on the surface properties of photocatalytic composite materials (PCM) based on them has been studied. The activation of the fiber surface consisted in thermal (T) and chemical (AA) treatment. The research methodology included: analysis of changes in the concentration of active centers of Brensted acids on the fiber surface before and after activation of their surface, after direct deposition of titanium dioxide on the obtained samples of various types of fibers, followed by an assessment of morphological changes. Results and discussions. The following growth trend has been established for the total number of active centers for PCM: PCM(BF+Т) → PCM(GF+AA) → PCM(BF+AA) → PCM(GAF+AA) →PCM(GF) → PCM(GAF+Т) → PCM(GAF) → PCM(GF+Т) → PCM(BF). According to the results of scanning electron microscopy, it was found that PCM(GF) and PCM(GAF+T) are characterized by a more uniform distribution of titanium dioxide particles over the entire surface of the fiber, creating a film-like appearance, unlike samples of PCM(BF) and PCM(GF), as well as PCM(GAF+AA), on which titanium dioxide particles are unevenly distributed, forming growths or aggregates. The analysis showed that sol-gel deposition of titanium dioxide has a significant effect on the properties of the fiber surface, which may affect the physical and mechanical characteristics of composites and their ability to self-clean, and should be taken into account when developing new functional materials with photocatalytic properties. Conclusion. The results obtained made it possible to evaluate the effectiveness of activation of the fiber surface for subsequent use as a substrate in the composition of photocatalytic composite materials