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

2026-04-03T08:07:35+00:00

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

2026-03-29T18:28:21+00:00

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

2026-03-17T08:13:47+00:00

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.