Although chitosan (CS) is used in many industries because of its low cost, biodegradability, nontoxic, antibacterial, and antioxidant qualities, it lacks sufficient mechanical and barrier properties. Biodegradable polymers based on CS, polyvinyl alcohol (PVA), and starch (S) were prepared at various ratios (1/3/6 and 1/5/4) via a blending polymerization process in the presence of water as the solvent and glacial acetic acid as the catalyst. The obtained biodegradable polymers were characterized via FTIR, TGA, SEM, and mechanical tests. The biodegradable polymers were mixed with rice straw and carbon black to study the effects of rice straw and carbon black on the physicomechanical properties of the biodegradable polymer films, including viscosity, tensile strength, elongation, and contact angle. The incorporation of rice straw and carbon black into a polymer blend significantly enhanced the physical and mechanical properties while also boosting their biodegradability by 36% and 15%, respectively, due to their biological activity. Notably, the CS/PVA/S blend with a ratio of 1/5/4, combined with rice straw, emerged as the standout performer. It exhibited superior mechanical strength and the shortest degradation time, outperforming the CS/PVA/S blended with a ratio of 1/3/6 mixed with carbon black. According to these findings, the biodegradable polymers became more soluble as the temperature increased from 30 to 45 °C.

Citrate-EDTA-H ₂ O ₂ buffering system recovers Li/Co/Ni/Mn from battery black mass at pH 5.0 using a dual chelation mechanism.

Despite its broad application due to its affordability, biodegradability, and natural antimicrobial and antioxidant activities, chitosan (CS) still exhibits limitations in mechanical strength and barrier effectiveness. Owing to its unique chemical characteristics, itaconic acid (IT) presents potential as a compatibilizing agent in polymeric blend formulations. Biodegradable polymers composed of chitosan (CS), itaconic acid (IT), and starch (S) were synthesized using two polymerization methods. The first method involved grafting IT onto CS at varying ratios of IT (4%, 6%, and 8% wt.), using 1% v/v acetic acid/water as the solvent and potassium persulfate as the initiator. In the second approach, starch (S) was blended with the copolymer P(CS-g-IT) at concentrations of 1%, 3%, and 5%, utilizing water as the solvent and glacial acetic acid as a catalyst. The resulting biodegradable films underwent characterization through FTIR, TGA, SEM, and mechanical property analysis. To further explore the effects of combining IT, starch, and carbon black, the blends, referred to as P[(CS-g-IT)-b-S], were also loaded with carbon black. This allowed for the evaluation of the materials’ physicomechanical properties, such as viscosity, tensile strength, elongation, and contact angle. The findings demonstrated that the presence of IT, starch, and carbon black collectively improved the films’ mechanical performance, physical traits, and biodegradability. Among the samples, the blended copolymer with 1% starch exhibited the highest mechanical properties, followed by the grafted copolymer with 8% IT and the blended copolymer mixed with carbon black at 7%. In contrast, the blended copolymer with 5% starch showed the highest hydrophilicity and the shortest degradation time compared to the grafted copolymer with 8% IT and the blended copolymer mixed with 7% carbon black.

Physico-chemical characteristics of shugite rocks of Kazakhstan (Bakyrchik deposit) were studied usingthe methods of elementary analysis, IR-spectroscopy, scanning electron microscopy, Raman spectroscopyand X-ray phase analysis. The content of carbon in shungite rock was determined to be from 3% to 19 %.The flotation technology for shungite rocks of Kazakhstan was developed, the content of carbon in theconcentrate reaching 40.0%. When studying the elemental composition, the mineral part of shungite rockswas stated to be presented, mainly, by silicon, aluminium, calcium, magnesium, potassium, sodium, ironand titanium oxides. IR-spectroscopic investigations showed that in the concentrate, apart from polycyclichydrocarbons containing methylene groups, there appeared carboxyl groups. The results of scanningelectron microscopy (SEM) showed that flotation and thermal activation of shungite rocks on carbon allowobtaining a more developed surface structure and porosity. The structure of shungite carbon was shown bythe method of Raman scattering to be close to that of glassy carbon. The results of X-ray diffraction analysis(XRD) of natural shungite rocks showed that the samples under study contained a carbonaceous substanceand a number of mineral components: quartz, illite, bassanite, burgerite, muscovite. It is shown that shungitecarbon of “Bakyrchik” deposit is identical to shungite of Zazhogino deposit in Russia. The stated physicochemical characteristics allow to determine the directions of the use of carbon concentrate for solution of ecological and technological problems.

Electrode materials were prepared from activated carbonizates of walnut shell, apricot pits and shungite rock from “Bakyrchik” deposit, East Kazakhstan. Physicochemical characteristics of the obtained samples were studied by the Brunauer-EmettTaylor method, scanning electron microscopy, Raman spectroscopy and other methods. Electrochemical properties of the obtained materials were studied by the method of cyclic voltammetry. It was found that the samples have an amorphous structure. Samples based on plant raw materials after hydrothermal carbonization at 240 °С during 24 h, have more homogeneous and developed surface. Specific surface area of carbon containing materials based on apricot pits is 1300 m2/g, for those on the based on mineral raw material, it is 153 m2/g. It was shown that materials after hydrothermal carbonization can be used for catalytic purposes and electrodes after thermal carbonization for analytical and electrocatalytic purposes.Electrode obtained by HTC have electrocatalytic activity. CSC 240 has high background current (slope i/Е is 43 mА V–1 cm–2), low potential of the hydrogen electroreduction (more positive by ~ 0.5 V than samples based on plant raw materials). The reaction of DA determination is more pronounced on the electrodes obtained by HTC 240 °C, 24 h, due to the nature, carbon structure and high specific surface area of obtained samples.