Asian Journal of Green Chemistry
Volume:8 Issue: 2, Spring 2024

Vinyl acetate (VAc) based terpolymers exhibit some outstanding properties. In this review, we report different types of vinyl acetate (VAc) based terpolymers, their preparation via emulsion polymerization, properties, and applications. Emulsion is an environment-friendly industrial polymerization technique. Latex, the end product of emulsion polymerization can be used directly for certain applications. This draws the interest of the researcher to use it for co- and ter polymerization. Terpolymerization of vinyl acetate with different monomers leads to the preparation of terpolymers with some excellent properties. Various types of processes used for the preparation of such terpolymer were reviewed and discussed in this report. This review also focuses on the morphological and thermal behavior of VAc-based terpolymers for understanding the polymerization chemistry and also the progress in this field.

This research investigated heavy metals content and their potential health problems in some rivers across Nasarawa west, Nigeria. The mean concentration of Zn was recorded as 0.32 mg/L which was lower than the limits set by the World Health Organization (WHO), USEPA, and EU. Cu with mean of 0.03 mg/L was also lower than limits set by the WHO, USEPA, and EU. Fe with mean of 1.25 mg/L are found higher than limits prescribed by the WHO, USEPA, and EU. Cd with mean of 0.01 mg/L are lower than limits set by the WHO, USEPA, and EU. Pb with mean of 0.01 mg/L are lower than limits set by the WHO, USEPA, and EU. Lastly as with mean of 0.01 mg/L are equal to limits set by the WHO, USEPA, and EU. The values for validation parameters are low indicating minimal variability and uncertainty in our measurements, signifying high precision in measuring instruments and the tested samples. The pH measurement of all the samples proved acidic. Based on the elevated values of iron (Fe) and arsenic (As) recorded in this study, regular monitoring and treatment of drinking water sources are essential to ensure compliance with regulatory limits and to provide iron and arsenic-free as well as other metal-free drinking water to the public within the investigated location.

The research presents the synthesis and fabrication of dye-sensitized solar cells (DSSCs) on the influence of sodium arsenic on the enhancement of TiO2/dye as photosensitizers, where Hibiscus sabdariffa (roselle) and Vernonia amygdalina (bitter leaf) were used as a source of the chlorophyll, sodium arsenic (NaAs) material of different concentration (0.1-0.4 mol), was synthesized as a layer on top of TiO2. The surface morphology study of TiO2/NaAs0.1, TiO2/NaAs0.2/ bitter leaf dye, TiO2/NaAs0.3/ roselle dye, and TiO2/NaAs0.4/the mixture of bitter leaf dye and roselle dye revealed that the micrograph is usually defined with the granular shape of nanotubes. The grain size of TiO2/NaAs0.1 is not too large and delineated by an immense sum of aggregated nanoparticles. The cells structure is polycrystalline with a most outstanding peak at 2 theta angles of 26.73° and 51.84o corresponding to hkl index numbers (111) and (202). The films have a very high absorbance from the plot, and the absorbance of the films increases as the dye molecules vary. The high absorbance of the films shows that the DSSCs will be a good material for photovoltaic applications. The fill factor of the films is 0.54, 1.24, 1.23, and 0.99 respectively while the conversion efficiency of 0.86%, 4.48%, 3.44%, and 1.81% was recorded.

Multiwall carbon nanotubes (MWCNTs) treated and oxidized with sulfuric acid were utilized as a higher adsorbent for fast removal of sulfadiazine hydrochloride (SFD) drug from aqueous solutions. The effect of different important parameters like equilibrium time (5-60 min), temperature 10-40 oC, pH (3-10), adsorbent dosage (0.001-0.05 g), and concentration of drug (10-100 mg/L) were well studied and optimized. As a result of the value optimization of different factors such as equilibrium time 30 min, temperature 30 ᵒC, solution pH 3, concentration of drug 50 mg/L, and weight of MWCNT 0.03 g. The adsorbent MWCNT was characterized via FE-SEM, TEM, and EDX analyses. The development of MWCNT shows a better potential (removal percentage 97.29% and adsorption capacity Qe 162.15 mg/g) within 1 hr for best drug removal from aqueous solution. The isotherm result was found fitted and in best agreement with the isotherm Freundlich model. The higher and fast removal of drugs was done using MWCNTs in a very short period of time, and the best adsorption efficacy of the developed adsorbent in comparison with developed adsorbent establishes the importance of this research.

In this work, a coal fly ash (CFA) as a waste generated from chimney furnaces was tested as a low-cost adsorbent to streptomycin (SPM) drug removal from aqueous solution. Treatment of the samples coal fly ash was performed to reduce cost the of end use. CFA composition depends on the kind of coal utilized and has crystalline and no crystalline character. CFA is a valuable material and extensively utilized in cement production and as a higher adsorbent for water treatment. The physical properties like surface area, morphology, porosity, and chemical composition (alumina, iron oxide, silica, and titania) make CFA efficient material for wastewater treatment. The CFA was characterized via chemical and physical techniques, like FE-SEM, TEM, and EDX. The best optimum condition of adsorption method for SPM drug removal onto CFA, several factors were studied like, effect of contact time solution pH, concentration of drug, adsorbent dosage, and solution temperature. The percentage removal of SPM drug increased while the modified CFA dosage increased. The removal percentage % of drug increased with decreased drug concentration, also increased with increase quantity of CFA. The best of SPM drug removal found 91.76 % at concentration of drug 10 g/mL, adsorbent dosage 0.05 g, temperature 25 oC, and solution pH of 6.6. The adsorption models were tested with two isotherms like isotherm Langmuir, and isotherm Freundlich, the adsorption model was found to follow the model Freundlich.

In the wake of growing concerns regarding the safety of our ecosystems, environmentally sustainable protocols for natural antioxidant extraction from plants are highly desirable. The current article is the outcome of the realization of this compelling need. Adiantum capillus-veneris L. is a widely found fern species known for its several ethnomedicinal uses. It is rich in phytochemicals such as phenolics of different types. In the current study, isopropanol-propylene glycol binary solvent was used as an extractant for bioactive compounds from this plant. The input factors used for optimization were time, temperature, solvent-to-solid ratio (SSR), selected responses were total phenolic content (TPC), total flavonoid content (TFC), and radical scavenging activity (RSA). The optimum conditions found by numerical optimization were SSR 30 mL/g, time 2.62 h, and temperature 60 °C with predicted TPC, TFC, and RSA as 16.14 mg gallic acid equivalents/g dry weight (DW), 57.64 mg rutin equivalents/g DW, and 94.63 %, respectively. The validation study strongly supported the suggested model with only a small % error. Based on these findings, a procedure may be developed for the safe and sustainable extraction of antioxidants from A. capillus-veneris for industrial application using isopropanol-propylene glycol binary solvent.

This study demonstrates peanut shells as a potential inexpensive and ecofriendly adsorbent for adsorption of streptomycin drug from aqueous solution via batch adsorption method. Reaction isotherm studies were carried out at several experimental conditions of concentration of streptomycin drug (10-100 mg/g), adsorbent dosage (0.1-2 g), equilibrium time (5-60 min), and solution pH (3-10). The adsorbent surface was characterized via field emission scanning electron microscopes (FE-SEM) and transmission electron microscopy (TEM). The best adsorption efficiency of drug on to peanut shells was observed as high as 1.677 mg/g. The removal percentage % of streptomycin drug rise with increasing weight of peanut shells as well as solution of pH. Equilibrium of streptomycin drug on to peanut shells rind is found to be quick, and equilibrium to reached in 60 min. Langmuir isotherm and Freundlich isotherm models were useful to fit the result of equilibrium peanut shells, and it was noticed that isotherm Freundlich fits the multilayer peanut shells ability for drug was 1.455 mg/g. These data demonstrated that peanut shells are locally available, ecologically, effective and inexpensive adsorbent for the adsorption of Streptomycin drug from aqueous solution.

This systematic review critically examines recent advancements in electrochemical materials and methodologies for enhancing stability and performance in energy storage and analytical applications. The review encompasses a diverse range of topics, including the thermodynamic analysis of cathode-contacting material stability, nanostructure-modified electrodes for detecting emerging contaminants, electrochemical stability of Zn anodes, long-term cycling of inorganic Ca(NO3)2 salt electrodes, chemically modified electrode interactions for signal transduction, self-assembled iron oxide nanoparticle-modified electrodes for simultaneous Cd(II) and Pb(II) ion stripping analysis, molecularly imprinted polymers-based electrochemical sensors for catecholamine neurotransmitter determination, amino acid-fabricated glassy carbon electrodes for simultaneous sensing of heavy metal ions, and silver nanoparticles coupled with graphene nanoplatelets for detecting Rhodamine B in food products. By systematically analyzing these advancements, this review offers insights into the diverse strategies employed to enhance electrochemical system stability and sensitivity, serving as a valuable reference for researchers and engineers working in energy storage and analytical electrochemistry fields.