The development of eco-friendly composites using recycled high-density polyethylene (rHDPE) and date palm leaf (DPL) fibers is often hindered by poor interfacial bonding. This incompatibility arises from the hydrophobic nature of the polymer matrix versus the hydrophilic nature of the natural fibers. The aim of this study is to investigate the effects of fiber treatment and nanoparticle modification on the microstructure and performance of rHDPE/DPL/ZnO composites, prioritizing efficient fiber-side treatments over matrix processing. This study was carried out by chemically treating DPL fibers with sodium hydroxide (NaOH) and stearic acid, followed by modification with zinc oxide (ZnO) nanoparticles to improve adhesion. The composites were then subjected to a comprehensive suite of characterization tests, including tensile testing for mechanical strength, thermogravimetric analysis (TGA) for thermal stability, differential scanning calorimetry (DSC) for thermal transitions, X-ray diffraction (XRD) for crystalline structure, and optical microscopy for morphological evaluation. The findings show that the treatments significantly enhanced the material properties across all metrics. Tensile testing revealed that the A5 composite achieved the highest mechanical performance, with a Young's modulus of approximately 1.2 GPa and an elongation at break of roughly 9%. TGA results indicated improved thermal stability; specifically, sample A4 showed a degradation temperature (Td) increase of 8.7 degrees C (+1.83%) over A3, while sample A6 showed a gain of 5.1 degrees C (+1.07%) over A5. XRD analysis confirmed an efficient structural reinforcement, reaching a maximum crystallinity of 74.06%. Furthermore, melt flow index (MFI) analysis demonstrated that while fiber reinforcement naturally increases viscosity, stearic acid treatment provides a lubricating effect that maintains MFI values between 6 and 7 g/10 min, ensuring excellent processability for injection molding and 3D printing. Finally, optical microscopy and morphological studies observed superior fiber dispersion and cleaner interfaces, indicating that the fibers were evenly spread and well-separated within the rHDPE structure. It was concluded that the combination of chemical treatments and ZnO nanoparticle modification effectively bridges the compatibility gap between rHDPE and DPL fibers. These findings underscore the viability of these modified composites for high-performance structural and industrial applications.
The aim of this study is to investigate the manufacturability of Melilotus officinalis (L.) reinforced epoxy biocomposites as a renewable biofiller and to characterize the mechanical, thermal, and dielectric properties of these materials. For this purpose, composites containing biomass at 0, 3, 6, and 9 wt.% were prepared; the samples were examined by tensile testing, FTIR, SEM, EDX, XRD, Shore D hardness, thermal conductivity, and dielectric analysis. The findings showed that with increasing M. officinalis content, tensile strength, hardness, and density decreased, while ductility and elongation at break improved. The significant decrease in thermal conductivity revealed an increase in heat insulation efficiency. Dielectric analyses showed that strong interfacial polarization occurred at low frequencies, and the dielectric constant and loss values decreased as the frequency increased. SEM examinations confirmed that the plant-derived filler was homogeneously distributed and formed acceptable interfacial adhesion with the matrix. In conclusion, although the use of synthetic epoxy matrix and the decrease in mechanical strength limit load-bearing structural applications, M. officinalis is a promising biofiller for lightweight and partially bio-based epoxy composites thanks to its increased ductility and improved thermal insulation properties.
Despite that artificial nerve guide conduits (NGC) have been widely applied in nerve tissue repair for treating peripheral nerve injury (PNI), those apparatuses face great challenges in repairing long-gap nerve defects due to their non-conductive nature. Herein, we report that such clinical issue can be addressed by a bio-mimic polycaprolactone (PCL)-based nerve conduit doped with conductive mixtures (denoted as PP) of polyethylene dioxythiophene (PEDOT) and polystyrene sulfonate (PSS). The PCL-PP nerve conduits demonstrated porous reticular fibrous networks with biocompatible and physicochemical properties. The structure novelty endows the material with a robust mechanical character with a Young's modulus of 0.32 MPa and a tensile strength of 2.9 MPa. Benefited from the capability of conducting endogenous electrical stimulation due to the high conductivity of 5.8 & times; 10(-3) S/m, the PCL-PP nerve conduits can regulate the biological behavior of Schwann cells (SCs), and remarkably promote the myelin sheath growth and regeneration of nerve tissues in a 10 mm sciatic nerve defect SD rat model. Compared to the contrast nerve conduits without PP compositions, the PCL-PP nerve conduits accelerated the recovery rate of extremity motor function of SD rats by a factor of 1.25-fold. These findings prove that our reported novel PCL-PP composite nerve conduit with functional integration of bioelectrical stimulation is a promising therapeutic approach toward PNI therapy.
The extensive use of petroleum-based polymers has exacerbated environmental pollution and fossil fuel depletion, spurring global interest in eco-friendly alternatives. Biodegradable materials serve as a potential replacement for non-biodegradable polymers. Among them, Cellulose, a prevalent natural biopolymer, having emerged as a promising material due to its affordability, biocompatibility, and biodegradability. However, cellulose alone have poor properties, therefore modification may be reequired. Recent research investigated the preparation of cellulose and Montmorillonite (MMT) clay films using the ionic liquid 1-ethyl-3-methylimidazolium acetate as a solvent. The study is aimed to evaluate the impact of MMT on the mechanical, absorption, and thermal properties of cellulose films. The results indicated that incorporating MMT significantly improved the films' moisture and water absorption properties. Moisture absorption decreased from 15.73 wt% to 8.55 wt%, and water absorption reduced from 22.68 wt% to 9.15 wt% as MMT content increased from 0% to 3%. Additionally, the water contact angle increased by approximately 54%, suggesting reduced hydrophilicity due to enhanced interaction between cellulose and clay particles. Differential scanning calorimetry (DSC) revealed that the glass transition temperature of the cellulose films increased with MMT loading, peaking at 89.447 ℃ with 3% MMT. While crystallization temperature remained unchanged or decreased, tensile stress and modulus improved with increased MMT content, achieving a maximum tensile strength of 32.06 MPa and modulus of 1.53 GPa at 3% MMT. The thermal stability of the films also enhanced, with a maximum improvement of 35.6% in thermal stability at 3% MMT loading. In conclusion, the research demonstrated that cellulose/MMT nanocomposite films, produced via solvent casting with EMIMAc, exhibited notable improvements in mechanical, absorption, and thermal properties due to effective cellulose-MMT interactions.
This study introduces a novel polyaniline–chitosan/nano TiO 2 composite (PAn-CS) synthesized through nanoparticle-incorporating to modify surface features, thereby improving its ability to adsorb and remove anionic rose Bengal (RB) dye. The composite was produced by incorporating TiO 2 , SiO 2 , or ZrO 2 nanoparticles into the PAn-CS composite using chemical oxidation via a single-stage precipitation procedure. Analysis of the structural and morphological characteristics was carried out with X-ray diffraction, Fourier-transform infrared and scanning electron microscopy. The composites’ thermal stability, surface properties, and surface charge of composites were also evaluated. The adsorption process was investigated through kinetics, isotherms, thermodynamics, and mechanistic insights. Results indicated that adding nano-oxides enhanced the PAn-CS composite’s affinity for RB removal. Optimal TiO 2 -content at 10% wt. howed a maximum adsorption efficiency of 96% within 60 minutes at 25 o C and pH 4, with a 0.025 g adsorbent dose and an initial dye concentration of 25 mg/L. Notably, the PAn-CS/TiO 2 composite demonstrated the highest RB adsorption capacity of 643.62 mgg -1 . The adsorption data were well fitted by the pseudo-second-order kinetic model, suggesting chemisorptions as the primary mechanism. The adsorption involved electrostatic, hydrogen bonds, and π-π interactions. The composite also showed excellent stability and reusability over five cycles, highlighting its potential for practical and sustainable dye-removal applications.
