International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

In this study, gelatin-SiO2 hybrid coatings were prepared on glass substrates using an acid-catalyzed sol-gel method. The deposited layers were subjected to thermal treatment at 50°C, 150°C, and 250°C to evaluate the effect of temperature on their structure and optical properties. Spectroscopic investigations in the UV-VIS-NIR range show that the hybrid coatings enhance optical transmittance and reduce reflective losses compared to uncoated glass. The best optical performance was observed for the sample thermally treated at 150 °C (GS 150), where an optimal balance between the organic (gelatin) and inorganic (SiO2) phases was achieved, resulting in maximum transmittance and minimal light reflection. At lower treatment temperatures (50°C), the coating exhibited higher porosity but lower structural stability, whereas at higher temperatures (250°C), partial thermal degradation of the gelatin phase led to layer densification and a slight reduction in the antireflective effect. These results demonstrate that gelatin can be successfully used as a biopolymer component to control the microstructure and optical properties of sol-gel hybrid coatings. Improving optical transmittance and reducing reflective losses of glass surfaces is crucial for enhancing photovoltaic module efficiency, as it allows a greater amount of solar radiation to reach the active layer of solar cells.

The amount of paper dyed is increasing each of the last few years, mainly because the increasing consumption of corrugated board papers. Paper is colored by dyes of different chemical nature – inorganic pigments; synthetic organic pigments; basic, acid, direct dyes and others. The reactive dyes are capable of forming covalent dye-polymers bonds, for instance, with the hydroxyl groups of cellulose. In this experiment are being used two laboratory synthesized reactive dyes, derivatives of chlorotriazine and one of them contains a stabilizer fragment. Dyes are used in the composition of offset printing paper with a fiber content of bleached softwood and hardwood pulp in a ratio of 1:1. The paper is sized with alkyl ketene dimer and as filler is used natural calcium carbonate. The strength and hydrophobic properties are being examined. The optical properties are also been examined before and after accelerated thermal ageing of the resulting paper samples and it is being found out that the examined dyes can be of an interest for an industrial production.

The present work is motivated by the tremendous interest in the semiconductor nanostructures. The study of the quantum confined Stark effect (QCSE) in semiconductor superlattices and semiconductor quantum wells has attracted a lot of attention, as it is important both for fundamental physics and in devices for optoelectronic applications. The present paper is a brief review of the main electronic properties, which are the basis for the QCSE device applications of semiconductor superlattices and semiconductor quantum wells.