Current Research in Green and Sustainable Chemistry最新文献

A new environmentally friendly plan was created to make dihydropyrano [2,3-c]pyrazole structures without using metals. This plan involves combining ethyl acetoacetate, hydrazine hydrate, aldehyde derivatives, and malononitrile in a radical tandem Knoevenagel-Michael cyclocondensation reaction. We used metal-free methylene blue (MB⁺) to create special functions that respond to light. These functions can transfer electrons and energy in water at room temperature using light as a source of energy in the air. The amount of product made is pretty consistent (between 81 and 98 %, with an average of 91.8 %), and it gets made quickly (between 3 and 7 min, with an average of 5.3 min). The important thing mentioned in the conversation is that the process can handle different types of chemicals while still being fast and giving good results. The results show that this special technique is a successful and easy way to get good results in just one step. Methylene blue is used with very little amount to make a chemical reaction happen. This leads to high amounts of product, saves energy, and is good for the environment. It helps use up all the starting materials efficiently, saves time by not needing to separate chromatography, and reduces waste. This photocatalyst is easy to use. This creates many different types of characteristics in the environment and chemicals that last a long time. The turnover number (TON) and turnover frequency (TOF) of dihydropyrano [2,3-c]pyrazole scaffolds were calculated. It is interesting that cyclization on a gram scale can be achieved, showing that this technique can be used in industries.

Hydrogels are desirable biomaterials because of their innovative organization structure, which allows them to function with a wide range of hydrophilicity and biocompatibility. Hydrogels, on the other hand, possess sensitive physical characteristics when coupled with live tissue. In the current work, metformin hydrogen chloride (metformin HCl)- loaded the original [Gum ghatti-cl-Poly(N-isopropyl acrylamide-co-acrylic corrosive)/CoFe₂O₄] nanocomposite hydrogel were orchestrated through the free extreme polymerization strategy utilizing ammonium persulfate (APS) as initiator and N, N′-methylene bis-acrylamide (MBA) as a cross-connecting specialist to eliminate the metformin hydrochloride drug from watery arrangements. The influence of numerous parameters on the amount of adsorbate, including pH, temperature, equilibrium time, and adsorbate weight, was investigated, and the ideal conditions for preparing adsorbate were determined. The hydrogel was characterized using FTIR, XRD, AFM, FESEM, and TGA methods. Three powerful models viz. pseudo-first order, pseudo-second order, and intraparticle scattering model, were used and fitted to the equilibrium data to choose the adsorption part of metformin adsorption onto Gg-cl-poly(NIPA-co-AA)/CoFe₂O₄ nanocomposite hydrogel. The adsorption isotherm information was explored with the assistance of four isotherm models viz. Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (DRK) isotherms. The metformin adsorption process followed the pseudo-second-order model and Langmuir adsorption isotherm with a most extreme adsorption limit of 151.07 ​mg/g. To investigate the adsorption nature and promptness metformin, a couple of thermodynamic limits were estimated and observed that the adsorption system is exothermic and unconstrained.

Phenol is one of the most prevalent contaminants discovered in water bodies. The adsorption process is gaining popularity as a viable method of removing phenolic chemicals from contaminated aquatic resources. The elimination of phenolic chemicals using Palmyra kernel shell activated charcoal has been extensively investigated. The removal effectiveness of Palmyra kernel shell charcoal was calculated using physically, chemically ($H_{3}P{O}_4$ and $NaOH$) and magnetically activated Palmyra kernel shell charcoal for various amounts of phenolic components and varying adsorption durations. According to this research study, physically activated charcoal has a much higher removal efficiency than other activated charcoal. These findings show that physically activated charcoal is easily used to remove phenolic compounds from polluted water resources. Adsorption kinetics were discovered to follow a pseudo-second-order kinetic model. Freundlich, Langmuir, and Temkin isotherm models were used to interpret the experimental results. Several kinetic formulas were utilized to evaluate the adsorption kinetics of phenolic compounds using various activated charcoals derived from Palmyra kernel shells. The experimental results are consistent with the Freundlich isotherm model. All of the activated and non-activated Palmyra kernel shells absorbed the phenolic chemicals, and the value of $1/n$ was found to be between $0.692$ to $0.869$. Scanning Electron Microscopy (SEM) is a technique used to characterize the surface morphology of adsorbents before and after adsorption. FTIR analyses confirmed the presence of phenolic compound functional groups on the adsorbents.

Synthetic plastic sheets are mainly composed of long-chain petrochemical-predicated derivatives, and their pollution is now generally acknowledged as a massive environmental burden, both in the aquatic and terrestrial environments, where this type of plastic takes longer to degrade biophysically, has negative impacts on human lives, and has inhibited disposal alternatives. This work aims at the characterization and performance analysis of biodegradable sheets made by using natural ingredients to reduce the dependency on synthetic plastics and thus culminate in plastic pollution. The multifunctional properties of the prepared sheet from raw jute were quite decent; the tensile strength of the biodegradable sheet was increased to around 22 ​MPa, whereas the tensile strength of the synthetic plastic sheet is around 15 ​MPa. Moreover, the elongation rate also decreased to around 53%. The biodegradability test ascertained the prepared sheet's degradability; the biodegradability rate of the prepared sheet was higher than the synthetic plastic sheet, and also had a nice color appearance due to the colorization with natural dye (turmeric). The outstanding physico-mechanical qualities, satisfactory color durability, and biodegradability of the prepared colored sheet obtained from raw jute could make it an attractive choice for the synthetic plastic sheet and the engendered green polymer nanocomposites. It was the first, and unique endeavor to produce natural colorful biodegradable sheets by utilizing natural ingredients: nanocellulose from raw jute and natural coloring material. It could be recommended that the acquired biodegradables have a prosperous future as a replacement for non-biodegradable traditional plastics.

Petrochemical-based plastics are posing a threat to human existence because of their toxic nature and slow biodegradation rate. However, biodegradable plastics manufactured from natural ingredients are showing hope. The current work deals with developing and characterising starch-based bio-plastic where white vinegar and glycerol have been used as matrix materials and tea has been used as filler material. The developed bio-plastic samples were characterized by soil biodegradation test, Mechanical test, Fourier Transformed Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC) analyses. More than 60% of degradation occurred within 28 days. The results proved that the bio-plastic synthesized using used tea has higher tensile strength than those synthesized using black tea. Higher melting point and glass transition temperature were also obtained from the sample synthesized using used tea, confirmed by TGA and DSC analysis. The FTIR analysis confirmed the presence of various organic functional groups. The obtained results were compared with the results available in the literature. Based on the results, the developed bio-plastic samples can be successfully used in packaging applications.

In this study, artificial neural networks (ANN) and response surface methodology (RSM) were used for the modeling and optimization of CO₂ adsorption in polyethylenimine (PEI)-functionalized halloysite adsorbents. Five-level four-factor central composite design (CCD) using RSM was used to optimize adsorption operational conditions, namely temperature of 20–50 °C and pressure of 1–9 bar, and PEI concentration of 10–40 wt%. The optimum temperature, pressure, and PEI wt% values are 20 °C, 9.00 bar, 29.49 wt% for the input variables, and the adsorption capacity value of 8 mmol/g for the response parameter, respectively. The Bayesian Regularization algorithm optimization technique was used as a learning algorithm. The accuracy of the optimized model was calculated using the mean squared error (MSE) and R². The MLP and RBF models best MSE validation performances at 100 and 30 epochs, respectively, were 0.00011 and 0.00055. After using the experimental data as training data with the ANNs and RSM approach, the resulting model can yield satisfactory results by considering the effects of independent variables and their interactions on the objective function. The correlation coefficient (R²) and the adjusted R-squared (Adj-R²) are 0.9868 and 0.9846, respectively. Additionally, the CO₂ adsorption performances are modeled using ANN for the optimization purpose. Due to the appropriateness of the adequate precision or ratio values of more than 4, the model presented for the system is valid. The S_BET and the total pore volume of IMSiNTs/PEI nanocomposites (IMP-30) were 33.62 m²/g and 0.312 cm³/g, respectively. The mass flux, diffusion coefficient, and mass transfer coefficient for carbon dioxide gas in the single system have measured 4.44⨯10⁻²⁴ mol/m².s, 3.93⨯10⁻²⁰ m²/s, and 2.58⨯10⁻¹⁶ m/s in 14 min, respectively.