Search

Bio-based polymer is a promising candidate to substitute conventional petroleum-derived polymer as it is sustainably produced from renewable resources, which helps reduce the production process’ carbon footprint. It also helps reduces humankind’s dependability on fossil fuel-based feedstock. In this work, a sustainable jatropha oil-based polyurethane acrylate (PUA) was successfully prepared and synthesised using a 3-steps process; epoxidation (formation of an epoxy group), hydroxylation (addition of–OH group to opened ring), and acrylation (addition of acrylate group into polyol). The yellowish PUA prepared has a gel consistency, which is sticky and slightly runny. The PUA was characterised by using wet chemical tests such as oxirane oxygen content (OOC), acid value (AV), hydroxyl number (OHV) and iodine value. OOC value for the PUA synthesised was 4.23 % at the 5 hr reaction time. At the same time, the Epoxidised jatropha oil (EJO) used to prepare polyol records a hydroxyl number of hydroxyl 185.81 mg KOH/g and an acid value of 1.06. The polyol prepared was mixed with 2, 4-toluene-diisocyanate (TDI) and Hydroetyhlmethacrylate (HEMA) to produce PUA. The PUA was characterised by thermogravimetry analysis (TGA) and electrochemical impedance spectroscopy (EIS). TGA analysis shows that the polymer is stable up to 373 K, whereas the EIS analysis records an ionic conductivity of (5.60±0.03) × 10-6 S cm-1. This polymer’s great thermal stability properties make it suitable for outdoor application where high temperature due to sun exposure is common. Furthermore, PUA prepared gel-like properties to make it a suitable candidate for preparing a gel polymer electrolyte.

The textile industry is one of the fastest-growing industries that significantly contribute to the economic growth in Malaysia. Dyeing wastewater is one of the more difficult to control in industrial wastewater. Methylene blue is a widely used dye in the textile industry, which cannot be discharged directly into the natural environment without treatment. The present study involves the degradation of methylene blue by a Fenton-like system using calcium peroxide (CaO2, CP). The process of degradation was recorded spectrophotometrically. The field emission scanning electron microscope (FESEM) and energy dispersive X-ray (EDX) were measured for testing the purchased commercial calcium peroxide. The effect of pH, the initial dosage of CaO2, and temperatures were studied with kinetics modeling, respectively. The results indicated that 97.07% removal of methylene blue took place at the optimum condition (pH=3.0, initial CaO2, dosage=3.0 g, 65°C, 150 rpm, contact time=60 minutes). Over four models (zero-order, first-order, second-order, Behnajady, Modirshahla, and Ghanbary (BMG) model) applied in this study, the BMG model with the R2=0.9935 was in accordance with the experimental data.

The effectiveness of chemical steeping was examined as a novel pretreatment prior to hydrolysis to influence the extractable yield of glucose and xylose from oil palm trunk (OPT). The chemical steeping parameters were 0.2% sodium metabisulphite (w/v), 0.5% lactic acid (v/v), 26 ± 2 °C, and 1 h, followed by dilute acid hydrolysis (2%, 4%, and 6% of sulphuric acid (v/v); 115 °C, 120 °C, and 130 °C; 15 min, 30 min, and 60 min). For comparison, the glucose and xylose yield extracted from untreated OPT was also examined. Thermal analysis showed that the lactic acid and sodium metabisulphite successfully degraded the lignocellulose of OPT. The total extracted glucose and xylose yield was improved, and was approximately 2.5% to 28.8% higher than the yield extracted from non-pretreated OPT fines. RSM analysis showed that the 130 °C x 50 min x 2% was predicted as the optimum parameters for the extraction of glucose and xylose through chemically treated OPT, and followed the dilute acid hydrolysis process. Analysis of variance showed that the hydrolysis parameters were significant model terms for the glucose and xylose yield. In conclusion, chemical steeping was successful as a pretreatment to increase the extractable glucose and xylose yield from OPT.

Sichuan Basin (SCB) is a typical basin in southwest China and a traditional smog-prone area. Control of air pollution in this area is particularly critical in achieving China’s carbon emission peak and carbon neutral goals. It is characterized by high population density, heavy transportation, rapid industrialization, complex topography, and meteorological conditions. However, the air pollution studies of SCB remain the sparse and in-depth studies are still warranted. None of the previous research has synthetically reviewed the status of air pollution in this region. This paper comprehensively overviewed the air pollution of SCB from five aspects: air pollution characteristics, sources of air pollutants, driving factors of air pollution, air pollution episodes and health risks. A comparison on the air pollution of typical megacities in the basin was also discussed. The findings and shortcomings of the existing studies were also summarized. Recommendations for future research directions were also proposed.

Glyphosate [N-(phosphonomethyl)-glycine], an organophosphate broad-spectrum herbicide, is a serious environmental contaminant that poses a significant threat to humans. It can be detected as a contaminant in water; thus, effective procedures for its removal are urgently required. The present study investigated the performance of glyphosate removal from aqueous solutions using a Fenton-like system. Calcium peroxide (CaO2) was used as a source of hydroxyl free radicals with Fe2+ as a catalyst to trigger the Fenton reaction. Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and potassium permanganate titration were carried out for characterization of calcium peroxide. The effect of operating parameters such as pH, the molar ratio of Ca2+:Fe2+, the initial dosage of calcium peroxide, and the initial glyphosate concentration on the removal efficiency was studied, respectively. The maximum total phosphorus (TP) and chemical oxygen demand (COD) removal were 94.50% and 68.60%, respectively, within 120 min under optimal conditions (pH = 3.0, initial glyphosate concentration = 50 ppm, initial CaO2 dosage = 0.5 g, molar ratio of Ca2+:Fe2+ = 6, room temperature). Experimental data were analyzed using zero-order, first-order, second-order, and Behnajady, Modirshahla, and Ghanbary (BMG) kinetics models. The degradation kinetics of glyphosate could be mostly fitted with the BMG kinetics model. This study demonstrated that calcium peroxide could be considered an effective oxidant for glyphosate wastewater treatment.

Cosmos caudatus (C. caudatus) is a medicinal plant that is high in bioactive compounds such as phenolics. In this study, an ultrasound extraction method was used to optimise the extraction of bioactive compounds from C. caudatus leaves. Response surface methodology (RSM) based on a Box-Behnken design (BBD) was applied to obtain the optimum extraction parameters which is solid–liquid ratio (10–30 g/mL), particle size (180–850 µm) and extraction time (20–30 min) for maximal quercitrin and total phenolic content (TPC) yields. Analysis of antimicrobial activity was performed against two human pathogenic microbes: Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) by the agar well diffusion method. The optimal ultrasonic extraction condition was as follow: solvent-liquid ratio of 1:28 (g/mL), particle size of 485 µm, and duration of 30 min, respectively. Remarkably, extraction using ultrasonic method had recovered more bioactive content and antioxidant activity than the Soxhlet method. The extract also exhibited good antimicrobial activities. Due to the above findings, the ultrasonic extraction was found to be suitable to improve recovery extraction of quercitrin and TPC from C. caudatus leaves. It also opens the possibility that the plant extract can be used for functional food and antimicrobial agents in various applications.

An approach of green in situ synthesis single-step method was applied to produce antibacterial paper. The objective was to investigate the effect of precursor addition on the formation of zinc oxide particles using an in situ single-step method. Zinc chloride concentrations of 0.1, 0.3, 0.5, and 0.7 M were prepared and added into a solution of algae extract and bamboo pulp. The prepared pulps were tested and made into handsheets using a papermaking machine based on TAPPI T205 (2006). Morphological observation of treated papers was conducted using a field emission scanning electron microscope (FESEM). An average of 400 to 570 nm zinc oxide spherical-shaped particle was observed on the fibers of paper. The percentage of element composition of the treated paper were 15.08% to 34.08% of zinc and 17.45% to 32.59% of oxygen captured via scanning electron microscopy with energy dispersive X-ray (SEM-EDX) analysis. The crystallinity test was performed using X-ray dispersion (XRD). A higher percentage of precursors exhibited a more amorphous structure. A measurement of more than 30% increment of inhibition zone was obtained from 10.00 to 25.00 mm against S. aureus, S. choleraesuis, and E. coli. Precursors addition of more than 0.3 M would have the most potential to enhance the growth of zinc oxide via in situ preparation, hence providing better antibacterial properties of the prepared papers.

In this paper, the adsorptive performance of synthesized thiourea (TU) modified poly(acrylonitrile-co-acrylic acid) (TU-P(AN-co-AA)) polymeric adsorbent for capturing p-nitrophenol (PNP) from aqueous solution was investigated. TU-P(AN-co-AA) was synthesized via the redox polymerization method with acrylonitrile (AN) and acrylic acid (AA) as the monomers, then modified chemically with thiourea (TU). Characterization analysis with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), elemental microanalysis for CHNS, zeta potential measurement, Brunauer–Emmett–Teller (BET) surface analysis and thermal analyses were carried out to determine the morphology and physico-chemical properties of the synthesized polymer. The characterization results indicated successful surface modification of polymer with TU. The performance of TU-P(AN-co-AA) for the removal of PNP was investigated under various experimental parameters (adsorbent dosage, initial adsorbate concentration, contact time and temperature). The results demonstrated that the Freundlich isotherm model and pseudo-second-order kinetic model best described the equilibrium and kinetic data, respectively. Thermodynamic studies showed that the uptake of PNP by TU-P(AN-co-AA) was spontaneous and exothermic in nature. The results of the regeneration studies suggested that the TU-P(AN-co-AA) polymer is a reusable adsorbent with great potential for removing PNP from wastewater. Highlights Poly(AN-co-AA) was synthesized using free radical polymerization and modified with thiourea.; The polymeric adsorbent possessed multi-functional groups with negative surface charge.; PNP sequestration onto TU-P(AN-co-AA) adsorbents was high.; Equilibrium and kinetic models were employed for the experimental data analyses.; The regeneration study indicated the stability and reusability of the thioamide-modified polymer.

Inappropriate discharge of industrial wastewater and household effluent has led to an accumulation of hazardous organic substances, oil and grease, heavy metal ions, dyes, and leftover pharmaceutical products in the aquatic environment. To mitigate the adverse effects of polluted water, various techniques have been implemented for physical, chemical, and biological wastewater treatments. In chemical wastewater treatments, utilizing polymers are among the most common pathways, in which cellulose-derived materials as one of the abundantly available lignocellulosic constituents have gained much interest for the applications. As environmental remediation agents, cellulose derivatives have great potential due to their biocompatibility, excellent mechanical properties, environmental friendliness, economic viability, low toxicity, and robustness. In a chemical wastewater treatment, cellulose derivatives can be valorized to various industrial applications, such as membrane technology, absorption and adsorption process, flocculant, a catalyst for chemical reaction, and disinfecting agent. In this review paper, various types of utilization methods of cellulose derivatives, ranging from nano, micro, and natural form in industrial wastewater and household effluent treatment, are extensively discussed. In addition, the cellulose performance in adsorption, filtration is also briefly elaborated and then compared with those of the conventional polymer-based materials, such as polyether sulfone (PES), Polyvinylidene fluoride (PVDF), and carbon nanofiber (CNF).

This study aims to formulate and fabricate the optimum condition of modified kenaf core (MKC) for the removal of targeted endocrine-disrupting compounds in a batch adsorption system. Kenaf core was chemically modified using phosphoric acid as an activating agent, which involved the pyrolysis step. Results indicated a significant difference (p 0.05) for unmodified and novel modified biochar, observed in characteristic performance analysis via ultimate analysis, Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR) spectrum, and Brunauer-Emmett-teller (BET) surface area. The removal percentage of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) in individual and binary mixture systems was examined in order to ascertain the highest removal percentage for MKC application in an aqueous solution. The main and interaction effects of three prepared variables such as incorporate of impregnation concentration of an acid catalyst (0.1-1.0 M), particle size (45-1,000 µm), and dosage (1.0-20.0 g/L) were examined and statistically analyzed via design of experiment (DoE) through developed quadratic models. The removal efficiency of E2 and EE2 in an individual system leads to T

This study performs an appraisal of the adsorptive capacity of amidoxime-modified poly(acrylonitrile-co-acrylic acid) or abbreviated as (AO-modified poly(AN-co-AA)) for the p-nitrophenol (PNP) adsorption, from aquatic environments via batch system. The AO-modified poly(AN-co-AA) polymer was developed with redox polymerization, and then altered by using hydroxylamine hydrochloride (HH). Tools used to describe the physicochemical and morphological characteristics of the AO-modified poly(AN-co-AA) were Fourier transform infrared (FTIR) spectroscopy, CHN elemental analysis, X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The adsorption kinetics were examined by pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion kinetic models. Meanwhile, the isotherms were investigated by Langmuir, Freundlich, Temkin and Redlich–Peterson models. It was found that the adsorption was best fitted with pseudo-second order, and agreed with both Langmuir and Freundlich isotherm models. It was described best with the Freundlich isotherm due to highest R2 (0.999). The maximum adsorption capacity was 143.06 mg g−1 at 298 K, and thermodynamic functions showed that the adsorption process was exothermic. Also, following five regeneration cycles, the adsorbent recorded 71.7% regeneration efficiency. The finding in this study indicates that the AO-modified poly(AN-co-AA) is an effective adsorbent to remove PNP from an aqueous solution.

Drying kinetic models and energy characteristics are well known tools to evaluate and predict the most suitable drying physiochemical conditions for a particular product. In this study, a thin-layer drying model was developed to best describe the drying kinetic behaviour of Cosmos caudatus. The drying experiments were conducted using a thermal convection oven and C. caudatus leaves were dried at five different temperatures (40, 50, 60, 70, 80?C). Six different thin-layer drying models were proposed and applied to select the best drying model by fitting to the experimental moisture ratio data. The proposed drying models included Page, Modified Page, Lewis, Henderson-Pabis, Two Term and Weibull, and the results were statically compared and evaluated based on their goodness of fit. Among these, the Page model was found to best represent the thin-layer drying behaviour of C. caudatus with 99.76%, 5.93?10-5, 9.68?10-5 for the coefficients determination (R2), reduced chi-square (?2), and root mean square error (RMSE), respectively. The average effective moisture diffusion coefficient (Deff) for the temperature 40 to 80?C ranged from 4.12?10-12 to 24.71?10-12 m2/s, while the activation energy (Ea) was calculated at 39.35 kJ/mol based on the Arrhenius?s equation.

The industrial effluents of heavy metal become a great concern because of their toxicity. The better design of experimental (DOE) should be applied for an efficient treatment process. The statistic...

Poly(acrylonitrile-co-ethylene glycol dimethacrylate-co-vinylbenzyl chloride) (poly(AN-co-EGDMA-co-VBC)) was synthesized by suspension polymerization and further hypercrosslinked by Friedel-Crafts reaction to serve as a sorbent to remove the pharmaceuticals. Energy dispersive X-ray analysis showed decreased chlorine content in the polymers, confirming a successful hypercrosslinking. BET analysis revealed that the hypercrosslinked (HXL) poly(AN-co-EGDMA-co-VBC) had a specific surface area up to 363 m2 g−1 with an average particle size of 77.2–174.1 μm. Hypercrosslinking of the polymer increased the specific surface area up to 42%, even at low VBC content (10%). Pore size distribution showed that the terpolymers were mesoporous. The maximum adsorption capacity of diclofenac (DCF) and metformin (MET) determined by the Langmuir isotherm model were up to 61.0 mg g−1 and 5.1 mg g−1, respectively and the adsorption kinetic followed pseudo-second-order rate equation. The equilibrium capacity of the sorbent decreased to approximately 78% for DCF and 72% for MET after four cycles of adsorption-desorption process, exhibiting good reusability property.

Palm oil mill effluent (POME) is a hazardous wastewater which contains high organic constituents and salt concentrations. The ultrafiltration (UF) process is a promising treatment design used for secondary treatment such as POME. However, membrane fouling is the major problem which limits the performance of the UF. This paper describes a detailed investigation of polyvinylidiene fluoride (PVDF) membrane for the treatment of POME. The fouling behavior was analyzed by water flux, fouling mechanism, scanning electron microscopy (SEM), particle size distribution (PSD) and Energy Dispersive X-ray (EDX). It was found that a significant reduction in the permeate flux was caused by the build up of a fouling layer. Study on the fouling mechanism shows that cake filtration dominated the fouling activities on the membrane surface, compared to standard blocking, intermediate blocking, and complete blocking. This result is supported by membrane autopsy through SEM, PSD and EDX. HIGHLIGHTS The treatment of palm oil mill effluent via PVDF membrane was discussed.; Membrane fouling was investigated by the fouling model, SEM, PSD and EDX.; Cake filtration was the main fouling model compared with standard, intermediate and complete blocking.

Polyurethane acrylate (PUA) gel polymer electrolytes were prepared with tetrabutylammonium iodide (TBAI) as the complex salt. Fourier transform infrared spectroscopy results confirmed that the N H, C O, C N and C O C polar functional groups formed the coordination with TBA+ cations of salt observed from the bands shift. The maximum ionic conductivity of (1.88 ± 0.02) × 10-4 S cm−1 was obtained for the electrolyte with composition of 67.94 wt% PUA–30.00 wt% TBAI–2.06 wt% I2 (S3 electrolyte) which influenced by the highest charge mobility of (6.24 ± 0.12) × 10-7 cm2 V−1 s−1 and number density of (1.93 ± 0.04) × 1021 cm−3 estimated from fitting the Nyquist plots. The S3 electrolyte was electrochemically stable up to 1.64 V and capable of performing up to 2000 cycles steadily. Triiodide ion diffusivity obtained was 1.70 × 10-8 cm2 s−1. The electrolyte performance in dye-sensitized solar cells (DSSCs) was tested and cell with S3 electrolyte showed the highest solar conversion efficiency of (1.97 ± 0.21)% with short-circuit current density ( J sc ) of (7.15 ± 0.74) mA cm−2 and open-circuit voltage ( V oc ) of (0.55 ± 0.01) V when exposed under 1000 W m−2 light illumination. The highest efficiency obtained was influenced by the high electrons driving force in DSSCs. Low reduction resistance ( R pt ) of (2.46 ± 0.08) Ω at the electrolyte/counter electrode interface along with low charge transfer resistance ( R ct ) of (24.97 ± 0.14) Ω at TiO2/dye/electrolyte interface and charge diffusion resistance ( R d ) of (34.14 ± 0.11) Ω in redox electrolyte increase the electrons dynamic, thus resulting high J sc and hence high DSSC efficiency. This work shows that PUA-based electrolytes have potential for DSSC applications.

A copper chloride (CuCl) electrolyzer that constitutes of composite proton exchange membrane (PEM) that functions at medium-temperature (>100 °C) is beneficial for rapid electrochemical kinetics, and better in handling fuel pollutants. A synthesized polybenzimidazole (PBI) composite membrane from the addition of ZrO2 followed with phosphoric acid (PA) is suggested to overcome the main issues in CuCl electrolysis, including the copper diffusion and proton conductivity. PBI/ZrP properties improved significantly with enhanced proton conductivity (3 fold of pristine PBI, 50% of Nafion 117), superior thermal stability (>600 °C), good mechanical strength (85.17 MPa), reasonable Cu permeability (7.9 × 10−7) and high ionic exchange capacity (3.2 × 10−3 mol g−1). Hydrogen produced at 0.5 A cm−2 (115 °C) for PBI/ZrP and Nafion 117 was 3.27 cm3 min−1 and 1.85 cm3 min−1, respectively. The CuCl electrolyzer efficiency was ranging from 91 to 97%, thus proven that the hybrid PBI/ZrP membrane can be a promising and cheaper alternative to Nafion membrane.

Electrolyte is one of the main components of dye sensitized solar cell (DSSC) preparation. Electrolyte is an ionic charge transfer medium between charge and discharge. In order to improve and study the performance of electrolyte in the DSSC, different sized iodide salts have been applied. In this review, the effect of different type of iodide salts in the performance of electrolyte and DSSC were presented. Single and binary salt systems usage in DSSC with iodide salt for solar conversion efficiency, ionic conductivity and properties were presented. Single salt which is in large/bulky sized able to enhance the ionic conductivity while for the small sized iodide salt, it give higher solar conversion efficiency. As both small and large sized iodide salt combine, it will reveal a better result in ionic conductivity and solar conversion efficiency in DSSC. Furthermore, DSSC was discovered by Hermann Wilhelm Vogel in 1873 which related to the color of photography. He found out that addition of green dye will make the photographic films more sensitive to the light at longer wavelength. About 118 years later, DSSC was first carried out by O’regan and Gratzel.

The invention of spindleless lathe technology has enabled veneers to be produced from small logs, such as logs from short rotation Hevea plantations, with low recovery loss. However, for structural laminated products, such as laminated veneer lumber (LVL), manufacturers are highly selective regarding the veneers for their conventional production. During the peeling process of small logs (< 18 cm), deeper and higher frequency of lathe checks were induced on veneer surface compared to the common log size used (> 30 cm). In this study, spindleless rotary-peeled veneers made from small rubber logs were processed into LVL using different lamination pressures: 7, 8, 9, and 10 kgf/cm2. The effects of lamination pressures on the physical and mechanical properties of the produced LVL were evaluated. Based on the findings, the specific gravity increased from 0.73 to 0.83 with increased lamination pressure. In terms of mechanical properties, all the values increased with lamination pressure, but with a sudden drop with 10 kgf/cm2. Understanding the effect of lamination pressure on the physical and mechanical properties can shed light on optimizing the usage of spindleless rotary-peeled veneers from small logs for the production LVL and other lamination products.

Oil palm empty fruit bunch (EFB), an abundant fiber material obtained after extracting the oil from the strands, is classified as short fiber which needs supporting agent in order to enhance its me...

The present work demonstrated an eco-friendly and facile method for the preparation of starch/Fe3O4/zeolite-bionanocomposite (BNC) at moderate temperature. Zeolite and starch were used as solid support and stabilizer, respectively. The analysis of UV–vis showed the appearance of surface plasmon resonance. From PXRD analysis, the incorporation of magnetite nanoparticles (NPs) in zeolite substrate results in reducing of intensities and broadening of the zeolite peaks of BNC. The TEM analysis showed the formation of highly distributed Fe3O4-NPs with an average diameter and standard deviation of 9.24 ± 3.57 nm. The FESEM and EDX analyses imply that Fe3O4-NPs were homogeneously formed on the surface of the zeolite substrate. VSM analysis illustrated the as prepared BNC possessed magnetic behaviour with a saturation magnetization and coercivity of 1.84 emu g−1 and 17.76 G, respectively. The prepared BNC showed potential applicability in energy as low-cost electrode material. The BNC was used as a non-precious catalyst for oxygen reduction reaction (ORR) in the alkaline medium. The presence of starch and zeolite promoted long term stability up to 1000 cycles and avoid the dissolution and agglomeration of iron oxide. The ORR commences at the onset potential of 0 V follows by the two successive reduction peaks at −0.48 V and −1.00 V. Keywords: Green synthesis, Bionanocomposite, Electrocatalytic, Oxygen reduction reaction