Zurina Mohamad

This study explores the valorisation of post-industrial recycled polyethylene terephthalate (rPET) via incorporation of sepiolite clay to develop a composite adsorbent for methylene blue (MB) dye removal. The composite formulation was evaluated by varying the rPET concentration, TFA:DCM solvent ratio, sepiolite content, and blending time. The selected formulation had an average particle size of 267.10 nm, a specific surface area of 0.67 m²/g, and a pore volume of 0.003925 cm³/g. Adsorption conditions were then optimised using a five-factor, three-level Box–Behnken design, considering contact time, MB concentration, adsorbent dosage, pH, and temperature. The resulting quadratic model was statistically significant (F = 114.18, p < 0.0001), with R² = 0.9892, adjusted R² = 0.9805, and predicted R² = 0.9568; however, the lack-of-fit was also significant (F = 90.90, p < 0.0001), indicating that model predictions should be interpreted within the investigated factor ranges. At the selected conditions of 62.5 min, 25.5 mg/L MB, 2.55 g/50 mL adsorbent, pH 7, and 55 °C, the model predicted an MB removal efficiency of 99.03%. The adsorbent retained at least 93% reusability efficiency after six adsorption–washing–reuse cycles. The kinetic data were described more closely by the pseudo-second-order model, whereas the Freundlich model provided a better representation of the equilibrium data (R² = 0.9976). Thermodynamic results indicated that adsorption was favourable and exothermic within the investigated temperature range. Overall, the results show that post-industrial PET can be converted into a value-added sepiolite-containing adsorbent for MB removal.

Blending recycled poly(ethylene terephthalate) (RPET) with biobased polyamide 11 (PA‐11) offers a promising route toward sustainable engineering plastics; however, its broader application is limited by inherent immiscibility and reduced toughness. In this study, a hybrid reinforcement strategy employing one‐dimensional halloysite nanotubes (HNTs) and two‐dimensional graphene nanoplatelets (GNPs) was investigated in a Joncryl®‐compatibilized RPET/PA‐11 matrix to enhance both mechanical and thermal performance. By maintaining a constant total nanofiller loading of 2 phr and systematically varying the HNT‐to‐GNP ratio, the individual and synergistic effects of the hybrid fillers were isolated. The optimized hybrid composition (1.4 phr HNTs/0.6 phr GNPs) exhibited a balanced enhancement of properties, achieving a tensile strength of 63.5 MPa, flexural strength of 113.6 MPa, Young's modulus of 1414 MPa, and a markedly improved impact resistance of 732 J m ⁻¹ . Spectroscopic and morphological analyses indicated that this performance arises from strengthened interfacial interactions and uniform hybrid filler dispersion at intermediate GNP contents, whereas higher GNP loadings led to agglomeration and diminished effectiveness. Thermal analyses further revealed increased glass transition and crystallization temperatures, along with a delayed onset of thermal degradation from 370 to 412 °C, consistent with the formation of an effective hybrid barrier network. Overall, the results demonstrate that geometry‐complementary hybrid nanofillers provide an effective pathway for upcycling RPET/PA‐11 blends into mechanically robust and thermally stable materials suitable for demanding engineering applications. © 2026 Society of Chemical Industry.

In the pursuit of sustainable packaging to combat plastic pollution, sodium alginate, a renewable biopolymer, holds promise but demands enhancements for brittleness and moisture sensitivity. This study compares ionic crosslinking and polymer blending to develop high‐performance films from a tensile strength‐optimized formulation. Ionic crosslinking with CaCl ₂ boosts tensile strength to 41 MPa but induces brittleness (co ‐terephthalate] (PBAT) yields better films with 47 MPa tensile strength, 852 g m ⁻² day ⁻¹ water vapor transmission rate and improved thermal stability, driven by hydrogen bonding and ‘sea–island’ morphology. Based on published literature on PBAT compostability and reported degradation behavior of PBAT/alginate‐type systems, the blend films are expected to be compatible with industrial composting end‐of‐life routes; however, biodegradation was not measured in this study. Polymer blending emerges as a superior strategy, decoupling trade‐offs for multifunctional, ecofriendly packaging films. © 2026 Society of Chemical Industry.

The mechanical characteristics of the biodegradable polymer are crucial to determine the application of the materials, especially as the packaging materials. This work reports the optimisation of the biodegradable polymer film formulation based on fish gelatin and glycerol on the tensile strength (Ts) and elongation at break (EB) of biopolymer film. The gelatin from the skin of tilapia fish is dissolved in 100 millilitres (ml) of distilled water and mixed with glycerol as a hydrophilic plasticiser, then cast and dried to produce films. The range contents of fish gelatin and glycerol used are 5.0 to 9.0 grams (g) and 10 to 20 % (w/w), respectively. This optimisation is done with central composite design (CCD) using response surface methodology (RSM). The maximum Ts of 27.625 MPa was found at formulation with 9.0 grams of gelatin and 10% glycerol, and the optimum EB of 44.578% was recorded at 9.0 grams of gelatin with 20% glycerol. These formulations exhibited only 5.12% and 0.60% error between actual and predicted values. Otherwise, Fourier transform infrared spectroscopy (FTIR) also demonstrated the achievable glycerol incorporated in fish gelatin film at 20% glycerol by hydrogen bonding in Amides A, I, II, and III mostly shifted to the higher wavenumber. This success can be seen from the aliphatic alcohol (C-O molecules derived from glycerol) peak around 1035 cm-1 and 1029 cm-1. The peaks shifted from 1029.99 cm-1 to 1035.77 cm-1 at 10% to 20% of glycerol. Otherwise, the successful incorporation of glycerol by decreasing intermolecular forces of films where peaks of Amide A became more intense, wider and sharper.

The rapid advancement of sustainable materials has driven the need for high-performance polymer nanocomposites with superior mechanical, thermal, and structural properties. In this study, a novel RPET/PA-11/Joncryl^® nanocomposite reinforced with halloysite nanotubes (HNTs) is developed for the first time, marking a significant breakthrough in polymer engineering. Six different proportions of HNT (0, 1, 2, 3, 4, and 5 phr) are introduced to the blend of rPET/PA-11/Joncryl^® through a twin-screw extruder and injection moulding machine. The incorporation of HNTs into the RPET/PA-11 matrix, coupled with Joncryl^® as a compatibilizer, results in a synergistic enhancement of material properties through improved interfacial adhesion, load transfer efficiency, and nanoscale reinforcement. Comprehensive characterization reveals that the optimal formulation with 2 phr HNT (NCS-H2) achieves remarkable improvements in tensile strength (56.14 MPa), flexural strength (68.34 MPa), and Young’s modulus (895 MPa), far exceeding conventional polymer blends. Impact resistance reaches 243.46 J/m, demonstrating exceptional energy absorption and fracture toughness. Thermal analysis confirms enhanced stability, with an onset degradation temperature of 370 °C, attributing the improvement to effective matrix–filler interactions and restricted chain mobility. Morphological analysis through FESEM validates uniform HNT dispersion at optimal loading, eliminating agglomeration-induced stress concentrators and reinforcing the polymer network. The pioneering integration of HNT into RPET/PA-11/Joncryl^® nanocomposites not only bridges a critical gap in sustainable polymers but also establishes a new benchmark for polymer nanocomposites. This work presents an eco-friendly solution for engineering applications, offering mechanical robustness, thermal stability, and recyclability. The results form the basis for next-generation high-performance materials for industrial use in automotive, aerospace, and high-strength structural applications.

This study investigates the development of sustainable nanocomposites using recycled polyethylene terephthalate (RPET) and polyamide 11 (PA-11) blends reinforced with graphene nanoplatelets (GNPs). RPET/PA-11 blends were compatibilized with 2 phr Joncryl^® and processed using melt blending followed by injection moulding. The effects of varying GNP contents (1–4 phr) on mechanical, thermal, and flame-retardant properties were analysed. The nanocomposite with 1 phr GNPs exhibited an optimal balance of mechanical, flame-retardant, and thermal properties, along with improved dispersion compared to higher GNP loadings. Higher GNP concentrations led to increased stiffness but also promoted agglomeration, which negatively impacted tensile and impact strength. Thermal analysis revealed that GNPs influenced the cold crystallization behaviour of RPET, while the TGA results indicated a moderate enhancement in thermal stability. The maximum degradation temperature (T_max) increased from 410.38 °C to 430.06 °C with 1 phr GNPs but declined at higher loadings. Similarly, flammability tests showed an improvement in the limiting oxygen index (LOI) from 19 to 24. Morphological analysis confirmed that GNPs facilitated PA-11 dispersion within the RPET matrix, particularly at lower GNP concentrations (1 phr). These findings highlight the potential of RPET/PA-11/GNP nanocomposites for multifunctional applications, providing an optimal balance between mechanical performance, thermal stability, and flame resistance. This research highlights the synergistic effect of GNPs in achieving sustainable, high-performance materials, addressing the challenges of plastic waste management and the need for eco-friendly engineering solutions for industries such as automotive, packaging, and construction.

This study examines the influence of nanofillers on the ultraviolet (UV) penetration depth of photopolymer resins used in stereolithography (SLA) 3D printing, and their impact on printability. Three nanofillers, multiwalled carbon nanotubes (MWCNT), graphene nanoplatelets (xGNP), and boron nitride nanoparticles (BNNP), were incorporated into a commercially available photopolymer resin to prepare nanocomposite formulations. The UV penetration depth (Dp) was assessed using the Windowpane method, revealing a significant reduction with the addition of nanofillers. At a concentration of 0.25 wt.%, MWCNT showed the highest reduction in Dp (90%), followed by xGNP (65%) and BNNP (33%). SLA 3D printing was performed at varying nanofiller concentrations to evaluate printability. The findings highlight a strong correlation between Dp and the maximum printable nanofiller concentration, with MWCNT limiting printability to 0.05 wt.% due to its low Dp, while BNNP allowed printing up to 1.5 wt.%. Mechanical testing showed substantial improvements in hardness and elastic modulus, even at low nanofiller concentrations, with BNNP outperforming other fillers. Compared to a clear photopolymer, the elastic modulus for 3D printed nanocomposite samples with 0.05 wt.% nanofiller compositions showed an improvement of 43% for MWCNT, 63% for xGNP, and 104% for BNNP. The hardness results showed an improvement of 86% for MWCNT, 103% for xGNP, and 179% for BNNP. These results underscore the importance of Dp in determining the layer thickness and print success in SLA 3D printing. Practical applications include the design of advanced photopolymer nanocomposites for biomedical devices, electronics, and lightweight structural components. This research provides valuable insights for tailoring material properties to meet the demands of high-performance additive manufacturing.

This study investigates the impact of Niax^TM Silicone L-5440, a silicon-based surfactant, on the foaming behaviors of rigid polyurethane foam (RPUF) filled with aluminium hydroxide (ATH). The aim is to understand the effect of the surfactant on the compression strength, morphology, and flammability of the foam. Various concentrations of the surfactant, ranging from 0.5 to 3 pphp, were incorporated into the RPUF/ATH blend. Five key parameters were examined, including density, closed-cell content, structural characterization using scanning electron microscopy (SEM), compressive strength, and UL-94 rating. The results revealed that adding the silicon surfactant significantly influenced the foam properties. Foam formulations with lower surfactant concentrations resulted in denser foam with a higher percentage of closed cells (86.24%). The morphology of the foams exhibited variation in average pore sizes, initially decreasing and subsequently increasing with increasing surfactant concentration. Notably, the compressive strength of the foam increased when the surfactant concentration reached 1 pphp. Moreover, the inclusion of the surfactant improved the flammability characteristics, as evidenced by a UL-94 rating of V-1 without dripping.

This study presents an innovative approach to improving the mechanical and viscoelastic properties of 3D-printed stereolithography (SLA) nanocomposites by incorporating graphene nanoplatelets (xGNP) into photopolymer matrices. Utilizing an SLA 3D printer, photopolymer formulations with xGNP concentrations of up to 0.25 wt% were successfully produced. Post-print curing was carried out using two different methods: ultraviolet (UV) curing and high-temperature curing at 160 °C. Mechanical characterization using nanoindentation showed a significant increase in elastic modulus by 104% and an increase in hardness by 85% for nanocomposites containing 0.25 wt% xGNP. Furthermore, dynamic mechanical analysis (DMA) revealed a 39% improvement in storage modulus for samples without post-curing and an improvement of approximately 30% for samples subjected to high-temperature curing. These significant improvements highlight xGNP’s potential to not only increase the performance of SLA 3D-printed components but also streamline the manufacturing process by reducing or eliminating energy-intensive post-curing steps. This innovative integration of graphene nanoplatelets paves the way for the production of high-performance, functional 3D-printed products and offers significant advances for various industries with a high impact. The results highlight the transformative role of nanomaterials in additive manufacturing and position this work at the forefront of materials science and 3D printing technology.

In this study, rigid polyurethane foams (RPUF) were successfully modified using 30 wt.% aluminium hydroxides (ATH), 1.0 pphp silicone surfactant, and different concentrations of graphene, using a one-shot one-step foaming method. This study aims to improve the compressive strength, flame retardancy, and thermal properties of RPUF by creating a synergistic effect between ATH and graphene in fire-retardant RPUF hybrid composites. The effects of a fixed amount of ATH and silicone surfactant and various loadings of graphene on RPUF were investigated. The results show that 0.5 wt.% graphene loading confers the best compression performance on the hybrid composite. Their compressive strength value of 12.58 KPa was higher than virgin RPUF (4.07 KPa) and RPUF/ATH (9.89 KPa). FTIR confirmed the functional groups in the virgin RPUF but could not identify new functional groups in most modified composites. The smallest amount of graphene addition (0.5 wt.%) produced a more stable hybrid composite structure. At 3.0 wt.% graphene addition, the maximum decomposition temperature of the RPUF/ATH hybrid composite was recorded (539oC), which was enhanced by 50% compared to virgin RPUF (296oC), and the highest char residue of 17.46% was observed. The incorporation of graphene enhanced the thermal firmness of the hybrid composite. The study also revealed an enhancement in the fire resistance of the hybrid composite. The LOI and UL-94 results showed that incorporating 3.0 wt.% enables increased LOI value and V-0 classification compared to virgin samples. This hybrid composite can be used in high-performance building insulation applications.