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Outstanding biodegradability and biocompatibility are attributes associated with particular polyester substances that make this group useful in specific biomedical fields. To assess the potential as a biomaterial, a novel composite consisting of hydroxyapatite (HAp) and unsaturated polyester resin (UPR) was developed in this work. Using a hand-lay-up technique, various percentages (50, 40, 30, 20, and 10%) of HAp were reinforced into the UPR matrix to fabricate composite materials out of glass sheets. Prior to processing of the composite samples, hydroxyapatite was chemically synthesized in a wet chemical manner. Using a universal testing machine (UTM), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and thermo-gravimetric analysis (TGA), the fabricated samples were characterized. The crystallographic parameters of synthesized hydroxyapatite (HAp) were also estimated through a range of formulas. The optimal amount for hydroxyapatite was 40% according to the findings of the tensile strength (TS), tensile modulus (TM), percentage of elongation at break (EB), bending strength (BS), and bending modulus (BM). Improvements in TS, TM, BS, and BM for the ideal combination were 39.39, 9.21, 912.05, and 259.96%, in each case, over the controlled one. Thermogravimetric analysis (TGA) has been implemented to determine the degradation temperature of the fabricated composites up to 600 °C., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Green synthesis of silver nanoparticles (AgNPs) using a plant extract has attracted significant attention in recent years. It is found as an alternative for other physicochemical approaches because of its simplicity, low cost, and eco-friendly rapid steps. In the present study, Ophiorrhiza mungos ( Om )-mediated AgNPs have been shown to be effective bioadsorbents for methylene blue (MB) dye removal (88.1 ± 1.74%) just after 1 h at room temperature in the dark from an aqueous medium for the first time. Langmuir and Freundlich isotherms fit the experimental results having the correlation coefficient constants R 2 = 0.9956 and R 2 = 0.9838, respectively. From the Langmuir fittings, the maximum adsorption capacity and adsorption intensity were found to be 80.451 mg/g and 0.041, respectively, indicating the excellent performance and spontaneity of the process. Taking both models under consideration, interestingly, our findings indicated a fairly cooperative multilayer adsorption that might have been governed by chemisorption and physisorption, whereas the adsorption kinetics followed the pseudo-second-order kinetics mechanism. The positive and low values of enthalpy (Δ H 0 = 4.91 kJ/mol) confirmed that adsorption is endothermic and physical in nature; however, the negative free energy and positive entropy value (Δ S 0 = 53.69 J/mol K) suggested that the adsorption is spontaneous. The biosynthesized adsorbent was successfully reused up to the fifth cycle. A proposed reaction mechanism for the adsorption process of MB dye onto Om -AgNPs is suggested. The present study may offer a novel finding such as an effective and sustainable approach for the removal of MB dye from water using biosynthesized Om -AgNPs as reusable adsorbents at a comparatively faster rate at a low dose for industrial applications., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

This study provides an efficient and straightforward approach to eliminate carbon dioxide (CO 2 ) by absorption using a calcium oxide (CaO) sorbent derived from chicken eggshells. The sorbent concentration, stirring speed, and contact time were varied. The optimal condition for CO 2 removal was a 10% calcium hydroxide (Ca(OH) 2 ) suspension at 600 rpm with 20 min interaction. This optimum condition conferred the ever-highest absorption (98.71%) of CO 2 through Ca(OH) 2 suspensions from eggshell-derived CaO. X-ray diffraction was used to identify crystallographic phases and optimum conditions revealed calcium carbonate (CaCO 3 ) formation with the highest intensity, Fourier transform infrared spectroscopy revealed peaks for the carbonate (CO 3 2- ) group, field emission scanning electron microscopy was used to investigate the morphological and structural properties of the sorbent before and after CO 2 absorption, and thermogravimetric analysis was performed to understand the reaction mechanism. According to the kinetic analysis, the sorbent can be fully decomposed with a minimum activation energy ( E a ) of 89.09 kJ/mol., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

With an ever-increasing population and unpredictable climate changes, meeting energy demands and maintaining a sustainable environment on Earth are two of the greatest challenges of the future. Biogas can be a very significant renewable source of energy that can be used worldwide. However, to make it usable, upgrading the gas by removing the unwanted components is a very crucial step. CO 2 being one of the major unwanted components and also being a major greenhouse gas must be removed efficiently. Different methods such as physical adsorption, cryogenic separation, membrane separation, and chemical absorption have been discussed in detail in this review because of their availability, economic value, and lower environmental footprint. Three chemical absorption methods, including alkanolamines, alkali solvents, and amino acid salt solutions, are discussed. Their primary works with simple chemicals along with the latest works with more complex chemicals and different mechanical processes, such as the DECAB process, are discussed and compared. These discussions provide valuable insights into how different processes vary and how one is more advantageous or disadvantageous than the others. However, the best method is yet to be found with further research. Overall, this review emphasizes the need for biogas upgrading, and it discusses different methods of carbon capture while doing that. Methods discussed here can be a basic foundation for future research in carbon capture and green chemistry. This review will enlighten the readers about scientific and technological challenges regarding carbon dioxide minimization in biogas technology., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)