Journal of Composites and Biodegradable Polymers

Performance Recovery of Phase Change Materials (PCMs)-Modified Limestone Calcined Clay Cement (LC3) Composite Through Air-Void Control Using a Silicone-Based Defoamer

Yoon Tung Chan — 2026-02-12

Limestone calcined clay cement (LC³) has emerged as a promising low-carbon alternative to ordinary Portland cement (OPC) due to its reduced clinker content and associated carbon footprint. In parallel, integrating phase change materials (PCMs) into cementitious composites offers a pathway to enhance building thermal regulation through latent heat storage. However, hydrophobic PCMs may adversely affect fresh workability and hardened performance, particularly by promoting entrapped air and increasing porosity. This study investigates the incorporation of capric acid (CA) as an organic PCMs through partial cement replacement (0%, 1%, 5%, and 10% by mass) in OPC and LC³ mortars. In this context, the mortar is a functional organic–inorganic composite, where the organic PCMs phase contributes thermal energy storage functionality. Unlike most PCMs studies focused on OPC systems, this work emphasises LC³ and identifies air-void control as a critical mechanism for performance recovery in LC³–PCMs composites. It also evaluates the effectiveness of a silicone-based defoamer (0.15% by mass of the total mixture) in mitigating air-related performance losses. Fresh flowability, hardened density, ultrasonic pulse velocity, and compressive strength were determined up to 28 days. Results showed that increasing CA content reduced flowability, density, UPV, and compressive strength in both OPC and LC³ systems, indicating that hydrophobic PCMs inclusion adversely affected matrix continuity. However, the incorporation of a silicone-based defoamer enabled performance recovery in both OPC and LC³ composites by improving matrix compactness through air-void control. Overall, the results demonstrate that air-void control is critical for PCMs-modified mortars, and that defoamer addition provides a practical approach to improve the performance of LC³–PCMs systems while maintaining their sustainability benefits.

Synthesis and Physicochemical Characterization of Chitosan- Derived Prodrug Polymers with Antioxidant Activity

Wisam Abdul Jaleel Jawad — 2026-03-28

Prodrug design is a good way for drug targeting through changing the physiochemical, biopharmaceutical and pharmacokinetics properties, so prodrugs are active chemical agent undergo conversion in vivo to release the active drugs. The research apply it's lighting toward an important functional groups to permit the synthesis of prodrug polymers through a chemical reaction between chitosan and succinic anhydride by using suitable conditions (thionyl chloride as drops and 5ml of sulpheric acid (IN)) by way for one hour and at (60 Celsius) the reflux process was done for each amoxicillin and cephalexin as drugs and their detailed molecular structures of both prodrug polymers were characterized by FT-IR, ¹H-NMR spectrums. XRD analysis of prodrug polymer P5 appears a sharp peak at (28.07 degree) with high intensity that matched it's crystalline nature of polymer (P6) (607) while thermal analyses (TG, DTG, DTA, DSC), TG curve show's one decomposition stage (35 Celsius) and DTG appears three stages of mass losing at three temperatures degrees (36,50,85 Celsius) while DTA curve clear's three decomposition stages. On the other hand TG curve of prodrug polymer (P6) reflect's two decomposition stages at (50,73 Celsius) DTG curve appears three temperatures (36,70,85 Celsius) and with three weight losing percentage (94.5%, 99.1%, 98.75%), so DTA curve reflects one decomposition stage at (70celsius), DSC thermogram of prodrug polymer reaction at (54.9celsius) as (P5) show's an endothermic compared with the other polymer (P6) to fix same fact of an endothermic reaction at (51celsius), while swelling ratio percentage of prodrug polymer (P6) is (217%) on the time (72 hour) as compared with the other swelling ratio polymer of prodrug (P5) is (197%) at same time (72 hour). Controlled drug release results explain the suitable time (72 hour) to achieve an increasing of controlled drug release at (PH=7.4). For prodrug polymer (P5) as (0.265 nm) as absorbance Lastly, antioxidant activity of prodrug polymer (P5) appears highly DPPH scavenged percent (97.74%) at (2.5mg/ml)as a concentration.

Investigation on Amino-Induced In-Situ Interfacial Copolymeri-zation Nanofiltration Membranes for Dye-Containing Wastewater Separation

Si Zhang — 2026-04-02

To address the demand for efficient dye separation and salt recovery in textile wastewater treatment, this study proposes a fabrication strategy for composite nanofiltration (NF) membranes modified with UiO-66-NH₂. This approach involves introducing varying proportions of UiO-66-NH₂ into the aqueous phase solution during interfacial polymerization. By leveraging the abundant amino active sites on the UiO-66-NH₂ to undergo covalent reactions with acyl chloride monomers in the organic phase, in-situ chemical bonding between the MOF material and the polyamide (PA) separation layer was achieved concurrently with the interfacial polymerization of piperazine (PIP) and trimesoyl chloride (TMC). This method significantly enhanced the interfacial compatibility between the MOF nanoparticles and the polymer matrix, successfully yielding a series of thin-film nanocomposite (TFN) membranes with robust interfacial bonding characteristics. The incorporation of UiO-66-NH₂ markedly improved membrane permeability and optimized its rejection performance toward various dyes. At an optimal loading of 0.15 wt%, the pure water flux of the composite membrane reached 45.77 L·m^-2·h^-1, representing an increase of more than 80% compared with the pristine membrane (24.65 L·m^-2·h^-1). Meanwhile, rejection efficiencies for methyl blue (MeB) and congo red (CR) were as high as 98.0%, while methyl orange (MO) and methylene blue (MB) achieved rejections exceeding 75.0% (75.6% and 83%, respectively). The membrane also exhibited good operational stability during a 12 h continuous filtration test, maintaining a flux decline of less than 8.5% and dye rejection rates stably maintained above 98% (for CR) and 75% (for MO), respectively. UiO-66-NH₂ was uniformly incorporated into the PA network and formed stable covalent bonds, which effectively regulated the physicochemical properties of the membrane surface and separation channels, thereby simultaneously enhancing the water flux and dye rejection efficiency. This study provided an effective approach for developing NF membranes with high water permeability, high retention rate, and good stability for dye wastewater treatment.

Interface Mechanical Behavior of Unstabilized Earth Block–Palm Fiber Composites: Experimental and Analytical Pull-Out Analysis

Enzo Candelot-Hours — 2026-04-03

The development of sustainable construction materials has renewed interest in bio-based fiber-reinforced earthen composites; however, the mechanical performance of these materials is governed by the fiber–matrix interface, which remains poorly quantified. This study presents an integrated experimental–numerical investigation of the interface behavior between date palm fibers (DPFs) and unstabilized earth blocks.

The experimental program combined tensile testing of DPFs using Digital Image Correlation, compression tests on raw earth, and single-fiber pull-out tests to characterize interfacial behavior from adhesion to frictional sliding. The results show an average Young’s modulus of 7.42 GPa for DPFs, 38.09 MPa for raw earth, and an interface stiffness of 487.17 MPa/m. Pull-out tests enabled identification of key interfacial parameters governing load transfer mechanisms.

A numerical model adapted from Gontero’s formulation was developed using an equivalent diameter approach to represent the flat geometry of palm fibers while preserving the contact surface. The model successfully reproduces the experimental pull-out response and captures the transition from adhesion to friction-dominated behavior.

This work provides an experimentally calibrated micromechanical framework for predicting the behavior of palm fiber–reinforced earthen composites and contributes to the performance-based design of sustainable bio-reinforced construction materials.

Biogenic Synthesis of Potassium-Doped Cobalt Oxide Nanoparticles and Tailoring the Effect on Structural, Optical, Electrical and Antimicrobial Properties

A. Ajitha — 2026-07-02

Limited size effects and a high surface to volume ratio cause the features of nanoparticles to differ from those of the comparable bulk material. Alkali metal substitution has been found to improve the optical and electrical properties of pure Co₃O₄. Utilizing non-toxic, affordable, and environmentally favourable compounds is crucial for the production of nanoparticles. In order to create nanoparticles, a variety of metabolites from plant materials and animal products can be used. These metabolites can serve as fuel, capping agents, reducing agents, stabilizing or chelating agents for collecting metal ions. Thus Pure Co₃O₄ and K doped Co₃O₄ nanoparticles are created in the current study using an egg white-based microwave assisted hydrothermal method. Since egg albumen is an emerging biopolymer for creating biodegradable composites. By using different molar amounts of potassium [1, 3, and 5 mole%] as a dopant, we tried to improve the optical and electrical conductivity of cobalt oxide nanoparticles made from egg albumen, the natural biopolymer with green credentials using a microwave-assisted hydrothermal method. X-ray diffraction, energy dispersive X-ray spectroscopy, SEM analysis and dielectric studies were used to evaluate bare and doped samples. The found topology and small average crystallite size emphasize egg albumin's role as a stabilizer and size controller. Reduced optical band gap recommends using K doped samples for UV light absorption, which favours for optoelectronic device fabrication. Thus, by regulating K concentration, we may improve electrical conductivity and optical property of Co₃O₄ nanoparticles for device fabrication. The use of egg albumen and metal oxide (i.e., cobalt oxide nanoparticles) in antibacterial applications are the primary focus.

Assessment of the Mechanical Integrity and Feasibility of Hyper PLA-CF for High-Speed FDM Manufacturing of Functional Components

Roaa H. Ibrahim — 2026-07-22

Fused Filament Fabrication (FFF), also known as Fused Deposition Modeling (FDM), has attracted considerable attention over the past decade due to rapid technological advancements that have enabled a transition from prototyping to the production of functional components. This research investigates the viability of next-generation composite materials for high-speed printing, a topic that is seldom studied. It emphasizes Hyper Polylactic Acid reinforced with Carbon Fiber (Hyper PLA-CF), engineered for high-speed printing, wherein increased printing speeds, accelerated cooling, and reduced polymer chain diffusion modify thermal and bonding properties beyond the capabilities of conventional PLA-CF. The study evaluates mechanical performance, including tensile, compressive, bending, and impact properties, in relation to printing parameters such as layer thickness, nozzle temperature, build plate temperature, and printing speed, utilizing Taguchi design, Multiple Linear Regression (MLR), and Analysis of Variance (ANOVA). Scanning Electron Microscope (SEM) analysis was employed to investigate the microstructural characteristics. The results demonstrate that Hyper PLA-CF maintains high strength at elevated speeds, with strength influenced by the interaction between thermal parameters and layer geometry. Layer thickness notably influences tensile, bending, and impact properties, whereas build plate temperature primarily affects compression strength. SEM observations confirmed the influence of layer thickness and nozzle temperature on interlayer bonding and failure modes. These findings establish design parameters for reliable high-speed FFF utilizing Hyper PLA-CF on the CREALITY K1C, thereby addressing a critical gap in industrial implementation.