Asian Journal of Green Chemistry

Abstract The world will produce 90 million tons of chicken eggs in 2030. As eggshell represents 11%, about 10 million tons of waste shells accumulate in the environment, which causes a hazard to human health. Recycling this waste into value-added products requires adequate strategies. Herein, amorphous calcium silicate hydrate (ECSH) has been synthesized via sol-gel method by utilizing chicken eggshells as an alternative source of calcium. ECSH was characterized using the wide-angle X-ray diffraction (XRD) pattern, Fourier transform-infrared spectroscopy (FT-IR), N2 adsorption/desorption isotherms, and field-emission scanning electron microscopy (FE-SEM). The insecticidal activity of ECSH and nervous system insecticides (methomyl and chlorpyrifos) was evaluated against Spodoptera littoralis. Methomyl and chlorpyrifos displayed high acute toxic effects with LC₂₅ of 158.0 and 98.14 ppm and LC₅₀ of 438.25 and 256.68 ppm, respectively. The combination of ECSH with methomyl and chlorpyrifos increased the insecticidal activity and reduced the applied amount of such toxic insecticides.

Abstract The expansion and development of bioplastics and their products would increase environmental sustainability and reduce greenhouse gas emissions. A game-changer and a critical component of a long-term plastic pollution solution, bioplastics would be a game-changer. However, extensive public awareness is required to achieve long-term change in the fight against plastic pollution. This response could aid in addressing environmental threats. Plastic particles and waste and biodegradable plastics, make up a small part of the worldwide plastics industry, needing further research and development. This work provides a comprehensive analysis of the advances in biodegradable plastics through the challenges of the plastic industry and the vast market potential for biodegradable plastics. Government policy, and the socioeconomic and environmental consequences of plastics. Physio-chemical characteristics, standards, certifications, and analytical methods are discussed. It was found that bioplastics outperform petroleum-based plastics in terms of energy consumption, petroleum use, and carbon dioxide emissions. However, they fall short in terms of cost and application. Pollution and safety differ from one plastic to the next; although, bioplastics are generally safer. Hence, bioplastics are believed to be unviable in their existing state for the wide-scale application.

Abstract A fast and sensitive method for detecting resorcinol by producing yellowish-green color species using the reaction of potassium dichromate with resorcinol in a sulfuric acid medium. NAG-4SX3-3D analyzer was used to evaluate the transducer energy response. To improve the sensitivity of the newly developed approach, the relevant parameter was explored. The linear range (0.05-32) mmol.L^-1 for resorcinol measurement and RSD percent for the repetition (n=6) was significantly lower than 0.3% for (0.7, 23 millimol.L^-1) with L.O.D.=48.1687 ng/sample from the progressive dilution across the calibration graph's lowest concentration linear dynamic range (r=0.9997), (correlation coefficient), percentage linearity (R² %=99.95). The proposed approach was compared to the previous technique (UV-spectrophotometric at λ_max=273 nm). It can be concluded that, in addition to the technique's sensitivity (developed) and the use of a few chemicals, it outperforms the 10 mm irradiation of the classic reference method. Furthermore, continual dilution in CFIA enables the handling of high or low concentrations, opening up a larger range of applications. Based on the foregoing, the developed methodology is judged to be the most suited for resorcinol molecules compared to the reference techniques.

Abstract Rigid aromatic backbone in high-performance polymers such as Kevlar has been known to be effective in their remarkable properties. Four new polyureas were synthesized based on the 2, 3-Dihydro-1, 4-phthalazinedione with various aromatic and aliphatic diisocyanates to mimic the properties of high-performance polymers with accessible monomers, facile synthesis procedures, and more economic. The chemical structure of polyureas was validated using Infrared spectroscopy (IR) and elemental analysis. Molecular weight was determined using the Mark-Houwink equation. Weight losses of these polyureas with temperature were determined by thermal gravimetric analysis (TGA). Depending on the structure of polyureas, that had an average melting temperature of 153-290 °C, Solubility parameters were calculated using the group molar attraction constants of Hoy. Polymers were almost insoluble in different solvents, as demonstrated by attempts to solubilize in several solvents at 40 °C.

Abstract Many novel mesogenic azo-Schiff base compounds have been produced successfully. An azo compound was obtained by a reaction of p-nitroaniline and hydrochloric acid with NaNO₂ to prepare diazonium salt, this was followed by a coupling reaction with aniline to produce the final azo dye (II). While alkoxybenzaldehyde was prepared by reacting benzaldehyde with an alkyl halide (III). Finally, azo-Schiff bases were prepared by reacting azo dye with alkoxybenzaldehyde. The prepared compounds were diagnosed using FT-IR and ¹H NMR spectrometers. A polarizing optical microscope (POM) and a differential scanning calorimeter (DSC) were used to study liquid crystalline properties. It was observed that the thermal stability of the liquid crystalline phases of the prepared compounds increased with the length of the aliphatic chain. In addition, most of the compounds gave liquid crystalline properties and more than one transition, and the reason for this is the molecular structure of the compounds. Likewise, increasing the length of the terminal groups decreased the melting points of the products.

Abstract Due to various biological and pharmaceutical applications, derivations of Dihydropyrano[c]chromene have received great attention from researchers. Because of the considerable significance of these compounds, various methods with different conditions and catalysts have been used to synthesize them. However, some of these methods have disadvantages such as low efficiency, prolonged reaction time, toxic solvents. In this research, the performance of Cerium oxide/aluminum oxide for synthesizing the derivatives of dihydropyrano (c) chromene as an effective and nonhomogeneous catalyst has been investigated. This method contains numerous advantages, which are discussed in the following.

Abstract In this research study, we report the characteristics of Sn-doped In₂O₃ (ITO) films intended for use as transparent conducting electrodes. The ITO thin films were deposited using spin coating method in the frame of a sol-gel process in the presence of polyvinyl alcohol (PVA) as a binder. After using the sol-gel spin coating method, Indium tin oxide thin films were annealed at 550 °C under different argon rates (from 50 to 150 mL/min) and pressures (from 10 to 650 torr) for 45 min. The influence of different rates of argon pressure on the microstructure, and electrical and optical properties of ITO surfaces were evaluated using XRD, EDX, SEM, UV–Vis, and four-point probe. Wettability of the ITO surface was indicated in hydrophobicity with a contact angle (CA) of 0º before annealing. XRD patterns illustrated that all the films are polycrystalline of Cbb structure with preferentially oriented along (222) plane. The SEM images showed that the grain size of ITO nanoparticles and the thickness of the films were obtained at about 70-150 nm and 400-450 nm, respectively. The analyses were mainly proven here to highlight the role of the rate of argon atmosphere and pressure on the microstructure and the optical and electrical properties of the films. Increasing argon atmosphere and decreasing pressure increase the conductivity and crystallization of samples. The obtained results indicated that minimum sheet resistance (82 Ω/Square and resistivity and or 3.69×10⁴ Ω.cm) were achieved for thin films annealed under pressure of 10 torr and argon rate of 150 mL/min So that its transmission range was above 81% and its band gap about 3.73 eV. This sample has better results than the other samples in different conditions and has the best results compared to similar cheap methods. The process was tested repeatedly in data measurement and manufacturing to ensure its repeatability.