All publications

A study of developing the structural, thermal, and electrochemical properties of plasticized chitosan/ZnO-based nanocomposite polymer electrolyte membranes

Qamber Ali, Taweesak Boonsod, Kanoktip Boonkerd, Rojana Pornprasertsuk, Wanwisa Limphirat, Wirach Taweepreda

Next Materials · 2026

This work presents the development of sustainable, cost-effective, and high-performance plasticized chitosan/ZnO-based nanocomposite polymer electrolyte membranes (NC-PEMs), using a solution casting technique. Results demonstrate that new hydrogen bonds between the chitosan (CS) matrix, zinc oxide nanoparticles (ZnO-NPs), and ethylene carbonate (EC) are confirmed via Fourier transform infrared (FTIR) spectroscopy. Scanning electron microscopy/energy dispersive X-ray spectrometry (SEM-EDS) reveals uniform dispersion of additives in the CS matrix. X-ray diffraction (XRD) spectra verify the impact of ZnO-NPs and EC on the crystallinity of the CS matrix. The water uptake capacity (WUC) increased from 125 % (for pristine CS) to 378 % with the addition of nanoparticles and plasticizer. Similarly, the ion exchange capacity (IEC) improved from 0.77 to 4.3 meq.g −1 , oxidation stability increased from 28 to 92 h, and proton conductivity enhanced from 3.04 × 10 −3 to 98.53 × 10 −3 S.cm −1 . These findings suggest that such NC-PEMs show strong potential for use in polymer electrolyte membrane fuel cells (PEMFCs). As such, the membrane containing CS (2 wt%), and ZnO and EC at 1 wt% (CS/ZnO1/EC1) is seen to achieve the highest IEC and proton conductivity of 4.3 meq.g −1 and 82–98.53 × 10 −3 S.cm −1 , respectively. This approach paves the way for high-conductivity polymer electrolytes for the practical application of PEMFCs. • Sustainable plasticized chitosan (CS)/ZnO-NP nanocomposite membranes are developed. • New hydrogen bonds between CS, ZnO-NP, and ethylene carbonate (EC) enhanced proton conductivity. • Additives improved tensile strength and elongation at break of nanocomposites. • XRD showed reduced CS crystallinity, improving water uptake and ion exchange. • CS/ZnO-NP/EC membranes exhibited the highest proton conductivity for PEMFCs.

Eco-Functional PVDF Mixed Matrix Membranes: Characterization and Regeneration in Natural Rubber Skim Latex Purification

Rianyza Gayatri, Rendy Muhamad Iqbal, Wirach Taweepreda, Muzafar Zulkifli, Ahmad Naim Ahmad Yahaya

Polymers · 2026

Concentrated natural rubber skim latex is a sustainable, value-added product derived from natural rubber latex processing, offering high rubber content, fine particle size, and shorter polymer chains compared to pure latex, making it suitable for diverse industrial applications. This study employed an environmentally friendly ultrafiltration method using composite membranes composed of polyvinylidene fluoride (PVDF), titanium dioxide (TiO2), and polyvinylpyrrolidone (PVP) to concentrate skim latex without hazardous chemicals. The process generated two fractions: concentrated skim latex and skim serum. Membrane performance and fouling behavior were evaluated using FESEM-EDX and FTIR. Post-filtration analysis revealed significant latex particle deposition on the membrane surface, with elemental mapping confirming the presence of organic and inorganic residues. FTIR spectra indicated interaction between latex components and membrane functional groups, though the membrane’s structural integrity remained intact. Sodium dodecyl sulfate (SDS) was assessed as a cleaning agent and demonstrated the effective partial restoration of membrane performance, as confirmed by flux recovery (PVDF-PVP-TiO2 membrane recovered to a slightly higher flux of 7.35 L/m2h). These results highlight the membrane’s durability, fouling characteristics, and cleaning potential, supporting its reusability in latex processing. This study contributes to the development of sustainable separation technologies in the rubber industry, promoting circular economy and zero-discharge practices.

Investment in research and development for AMR solutions: A comprehensive review

Wirach Taweepreda, Kyu Kyu Tin, Yein Oul, Hnin Wutyi Phoo

Elsevier eBooks · 2026

Unraveling the Chemical Transformation Pathway of Palm Oil Mill Effluent in Removing Sulfate via Synthesized Natural Earth‐Compound Coagulant

Nurul Afifah Md Shukri, N. A. Lutpi, Y. K. Wong, Soon An Ong, Farrah Aini Dahalan, Naimah Ibrahim, Norashikin Ahmad Kamal, Wirach Taweepreda

Water Environment Research · 2026

ABSTRACT This study unravels the intermolecular mechanistic degradation of palm oil mill effluent (POME) in sulfate removal, utilizing a distinctive coagulant derived from naturally abundant limestone (CaCO 3 ), which was activated into calcium hydroxide [Ca(OH) 2 ] through calcination and exothermic reactions. Sulfate was reduced from POME by 88.76% with the optimal conditions (pH 5, 200 g/L Ca(OH) 2 dosage, and 135 min settling time) with strong correlation ( r = 0.8237) and statistically significant ( p = 0.0064) of Pearson's correlation. Scanning electron microscopy (SEM) and energy‐dispersive X‐ray spectroscopy (EDX) revealed an ideal morphology and elemental composition with reduction of 4.4753 m 2 /g surface area in Ca(OH) 2 to slurry. Kinetic studies evaluated that sulfate removal at 4400 mg/L strongly followed the second‐order model with a high coefficient of determination ( R 2 = 0.9883). Analysis using Fourier‐transform infrared spectroscopy (FTIR) and gas chromatography–mass spectrometry (GC–MS) detected the formation of 2‐isopropyl‐5‐methyl‐1‐heptanol (C 11 H 24 O). Overall, this study demonstrates the potential of Ca(OH) 2 from CaCO 3 as an efficient material for POME additional treatment, helping reduce VOCs and improve the value of industrial wastewater.

From Deforestation to Resilience: Pathways for Sustainable Community Development in Ratuwa River Basin Nepal

Sita Ram Kandel, Wirach Taweepreda, Kuaanan Techato, Hari Prashad Joshi

International Journal of Advances in Signal and Image Sciences · 2026

The Churia region of Nepal represents one of the most ecologically fragile landscapes in the Himalayan foothills, providing critical ecosystem services including water regulation, soil conservation, carbon sequestration, and biodiversity habitat. This study examined land cover alterations and their effects on ecosystem services in the Ratuwa River System from 1990 to 2025, employing an integrated approach combining remote sensing analysis, ecosystem service modeling using InVEST and RUSLE, hydrological modeling with SWAT, and socio-economic surveys with 300 households. Findings reveal significant land cover transformations: forest cover declined by 35%, wetlands by 20%, while agricultural land expanded by 25% and settlements more than doubled. These changes severely degraded water regulation services with a 40% increase in surface runoff, 30% reduction in groundwater recharge, and 50% rise in flood frequency. Soil erosion increased from 18.7 to 32.4 t ha⁻¹ year⁻¹, with agriculture contributing 76.5% of total soil loss. Carbon storage declined by 30.5% from 12.8 to 8.9 million tons, and habitat quality decreased from 0.72 to 0.51. Communities face declining agricultural yields, water scarcity, and heightened flood vulnerability, with marginalized households disproportionately affected. While community-led restoration demonstrates promise, long-term sustainability requires sustained institutional support. The study concludes that an integrated landscape governance framework prioritizing forest restoration, sustainable agriculture, and community engagement is essential for building resilience and achieving sustainable development in Nepal's Churia region.

Role of hygroscopic nanofillers and plasticizer in enhancing ionic transport and structural stability of plasticized chitosan-based nanocomposite polymer electrolyte membranes for fuel cells

Qamber Ali, Taweesak Boonsod, Rojana Pornprasertsuk, Wanwisa Limphirat, Wirach Taweepreda, Kanoktip Boonkerd

Materials Chemistry and Physics · 2026

Evaluation of integrated polysaccharide, biopolymers and clay composite membranes for clarification process of citrus fruit (sweet lime) juice

G. Arthanareeswaran, Karthikumar Sankar, U Shameera Parvin, Wirach Taweepreda, Ahmad Fauzi Ismail

International Journal of Biological Macromolecules · 2025

Potential of Lipids from Polymer-Based Dewatered Sewage Sludge as Feedstock for Biodiesel Production

Nor Afifah Khalil, Mohd Faizar Banjar, Fatin Najwa Joynal Abedin, Ahmad Noor Syimir Fizal, Norkhairi Ahmad, Muzafar Zulkifli, Wirach Taweepreda, Md. Sohrab Hossain, Ahmad Naim Ahmad Yahaya

Sustainability · 2025

Municipal wastewater treatment plants produce vast amounts of sewage sludge as waste, with more than 80% dewatered sludge (DS). DS is a polymer-based sludge containing flocculant and extracellular polymeric substances, including lipids. Lipids can be converted into biodiesel as an alternative energy that reduces dependency on fossil fuels while helping cities manage waste more sustainably. Past studies explored the potential of lipids from various sewage sludges in biodiesel production. However, the potential of DS remains largely unexplored. This study evaluates the lipid extracted from DS and the potential of its fatty acid methyl ester (FAME) to be used as biodiesel. Lipid extraction was conducted under varying parameters, including temperatures of 70, 80, and 90 °C, extraction time of 2, 4, 6, and 8 h, and sludge-to-solvent (S/L) ratios of 0.05, 0.075, 0.1, 0.125, 0.15, and 0.175 g/mL. The optimal extraction conditions of 70 °C for 4 h at S/L of 0.175 g/mL yielded 1.71 ± 0.10% lipid. FTIR and TGA revealed that the DS lipids contain triglycerides, fatty acids, glycerol, and proteins. Transesterification of DS lipids produced DS FAME with a fatty acid profile ranging from C4:0 to C22:0. The evaluation of DS FAME revealed a high ester content (94.7%) of fatty acids ranging from C14:0 to C24:1, surpassing the minimum standard of 90% for biodiesel. The elevated proportion of unsaturated fatty acids in DS FAME is expected to result in a low melting point, reducing the solidifying effect and enhancing its performance as biodiesel.

Calamity and Treatment Approach of Sulfate in Palm Oil Mill Effluent: A Mini Review

Nurul Afifah Md Shukri, Nabilah Aminah Lutpi, Yee‐Shian Wong, Soon‐An Ong, Farrah Aini Dahalan, Wirach Taweepreda, Nur Izzati Iberahim, Abdul Haqi Ibrahim, N R Rahmat

Environmental Quality Management · 2025

ABSTRACT The palm oil industry is booming, with a projected market valuation of $100 billion by 2030, driven by its diverse applications in food, cosmetics, and biofuels. However, the industry's rapid growth is accompanied by a significant environmental concern: the presence of sulfate in palm oil mill effluent (POME). Sulfate in POME poses a calamity to the ecosystem, leading to eutrophication and toxicity to aquatic life, also contributing to acid rain formation and higher hydrogen sulfide biogas formation. This mini‐review highlights the severity of sulfate pollution in POME, its environmental implications, and the challenges associated with its treatment. Various treatment approaches, including chemical, biological, and integrated methods, are discussed, focusing on their efficacy, feasibility, and scalability. On top of that, to guarantee total pollution removal, prevent treated effluents from contaminating the environment, and design more efficient treatment techniques, it is essential to analyze the intermolecular breakdown of compounds during wastewater treatment. Thus, this review intends to comprehend the significance of performing and analyzing intermolecular breakdown, as a promising validation for the end‐product of wastewater treatment. The review underscores the need for sustainable and efficient treatment technologies to mitigate the environmental impacts by sulfate in POME, ensuring a systematic pretreatment of POME toward a safe final discharge from excessive sulfate.

A high-performance nanofiltration membrane synthesized by embedding amino acids and ionic liquids in cellulose acetate for heavy metal separation

Debasis Nayak, Vinoth Kumar Raja, G. Arthanareeswaran, Tran Dang Khoa, Wirach Taweepreda

RSC Sustainability · 2025

Cellulose acetate (CA) membranes incorporated with amino acids (AAs) and ionic liquids (ILs) fabricated using phase inversion technique have been proven to be efficient and effective for nanofiltration to treat heavy metal ion solutions.