Silicon oxycarbide coatings are the subject of research due to their exceptional optical, electronic, anti-corrosion, etc., properties, which make them attractive for a number of applications. In this article, we present a study on the synthesis and characterization of thin SiOC:H silicon oxycarbide films with the given composition and properties from a new organosilicon precursor octamethyl-1,4-dioxatetrasilacyclohexane (²D₂) and its macromolecular equivalent—poly(oxybisdimethylsily1ene) (POBDMS). Layers from ²D₂ precursor with different SiOC:H structure, from polymeric to ceramic-like, were produced in the remote microwave hydrogen plasma by CVD method (RHP-CVD) on a heated substrate in the temperature range of 30–400 °C. SiOC:H polymer layers from POEDMS were deposited from solution by spin coating and then crosslinked in RHP via the breaking of the Si-Si silyl bonds initiated by hydrogen radicals. The properties of SiOC:H layers obtained by both methods were compared. The density of the cross-linked materials was determined by the gravimetric method, elemental composition by means of XPS, chemical structure by FTIR spectroscopy, and NMR spectroscopy (¹³C, ²⁹Si). Photoluminescence analyses and ellipsometric measurements were also performed. Surface morphology was characterized by AFM. Based on the obtained results, a mechanism of initiation, growth, and cross-linking of the CVD layers under the influence of hydrogen radicals was proposed.

The development of high-speed computers and electronic memories, high-frequency communication networks, electroluminescent and photovoltaic devices, flexible displays, and more requires new materials with unique properties, such as a low dielectric constant, an adjustable refractive index, high hardness, thermal resistance, and processability. SiOC coatings possess a number of desirable properties required by modern technologies, including good heat and UV resistance, transparency, high electrical insulation, flexibility, and solubility in commonly used organic solvents. Chemical vapor deposition (CVD) is a very useful and convenient method to produce this type of layer. In this article we present the results of studies on SiOC coatings obtained from tetramethylcyclotetrasiloxane in a remote hydrogen plasma CVD process. The elemental composition (XPS, EDS) and chemical structure (FTIR and NMR spectroscopy-¹³C, ²⁹Si) of the obtained coatings were investigated. Photoluminescence analyses and ellipsometric and thermogravimetric measurements were also performed. The surface morphology was characterized using AFM and SEM. The obtained results allowed us to propose a mechanism for the initiation and growth of the SiOC layer.

β-Glucan and cellulose macromolecules represent promising biopolymeric matrices for antimicrobial applications. We present a novel strategy for functionalizing these natural polysaccharides with fluorescent amino-functionalized silica nanoparticles (SiNPs) to create photoactive biohybrid materials. The SiNPs, synthesized via UV-assisted reaction of alkoxysilanes in aqueous media, with well-defined cage-and ladder-like silsesquioxane architectures, were employed to modify yeast β-glucan capsules and cellulose sheets through layer-by-layer deposition and sol-gel techniques. Structural characterization of the glucan-silica and cellulose-silica composites revealed successful integration while preserving the native macromolecular architecture. Encapsulation of photosensitizer phenosafranin (PSF) enabled evaluation of photodynamic activity, with cellulose-based hybrids showing efficient singlet oxygen generation and antibacterial efficacy against E. coli. This work demonstrates the potential of polysaccharide-based biohybrid materials for advanced antimicrobial applications.