In this study, SnO2 nanoparticles with controlled morphologies were synthesized by varying the precursor concentration (0.08 and 0.12 M) using a hydrothermal route and embedded in a PMMA matrix to investigate their third-order nonlinear optical (NLO) properties. X-ray diffraction and Raman spectroscopy confirm the formation of phase-pure tetragonal rutile SnO2. Morphological analysis reveals nanorod-like structures for the 0.08 M sample and spherical to quasi-spherical nanoparticles for the 0.12 M sample. UV-Visible spectroscopy shows a slight increase in optical band gap with increasing precursor concentration. The NLO properties were evaluated using the open and closed aperture Z-scan technique using a linearly polarized He-Ne laser operating at a wavelength of 632.8 nm with an output power of 10 mW. The 0.12 M SnO2-PMMA nanocomposite exhibits enhanced nonlinear absorption (beta = 3.42 & times; 10(-6 )cm/W) and nonlinear refractive index (n2 = 3.54 & times; 10(-4) cm(2)/W) compared to the 0.08 M sample (beta = 2.14 & times; 10(-6 )cm/W, n2 = 3.00 & times; 10(-4) cm(2)/W). These results demonstrate the effectiveness of precursor concentration in tailoring NLO performance for photonic applications.
Flexible wearable strain sensors that accurately capture joint motion are essential for rehabilitation assessment, motion monitoring, and human-machine interaction. However, conventional hydrogel sensors often suffer from limited mechanical robustness, poor durability, insufficient conductivity, or biocompatibility concerns caused by conductive fillers and chemical crosslinkers. Here, we report a multifunctional biocompatible hydrogel strain sensor, PCH, constructed from a polyvinyl alcohol/chitosan (PVA/CS) double-network matrix, hydroxyl ethylidene diphosphonic acid (HEDP)-mediated dynamic coordination crosslinking, and potassium chloride (KCl)-based ion conduction. FTIR analysis confirms the formation of a hybrid PVA/CS-HEDP network stabilized by hydrogen bonding and phosphonate-associated interactions, contributing to enhanced mechanical integrity. The PCH hydrogel exhibits favorable tensile properties, stable cyclic loading-unloading behavior, and reliable durability. Electromechanical tests show a linear and sensitive strain response with a gauge factor of 0.84 and high linearity (R2 = 0.9976). In joint mobility monitoring, PCH generates precise angle-dependent signals during +/- 90 degrees wrist bending and maintains stable output under continuous bidirectional motion. It also shows repeatable finger-joint sensing performance and favorable cytocompatibility, hemocompatibility, and skin compatibility, demonstrating strong potential for real-time wearable joint monitoring.
Gastroretentive drug delivery systems (GRDDS) enhance therapeutic efficacy for drugs with narrow upper gastrointestinal absorption windows. In the present study, dual-mechanism floating mucoadhesive microbeads of amoxicillin trihydrate (AMX) were developed by ionotropic gelation using low-methoxy pectin (LM-pectin) and Moringa oleifera gum (MOG). Utilizing a randomized 3(2) full factorial design, the optimized formulation exhibited high entrapment efficiency (83.75 +/- 1.23%), prolonged buoyancy (>8 h), and controlled AMX release (similar to 65% over 8 h). Solid state (FT-IR, DSC, and XRD) analyses confirmed successful drug incorporation and partial amorphization of AMX within the polymer matrix, whereas SEM revealed heterogeneous surface characteristics typical of dehydrated polymeric networks. Release kinetics followed the Korsmeyer-Peppas model (n = 0.734), indicating anomalous transport arising from the combined contributions of drug diffusion and polymer relaxation. Mechanistically, the calcium-mediated interpenetrating polymer network between LM-pectin and MOG enhanced matrix integrity, regulated swelling behavior, and minimized burst release. By synergistically combining floating and mucoadhesive mechanisms, the developed system is expected to prolong gastric residence and sustain local AMX delivery. Overall, the LM-pectin-MOG composites represent promising GRDDS carriers for localized H. pylori eradication and warrant further in vivo investigations.
The development of lightweight and lead-free radiation shielding materials has attracted considerable attention for medical, industrial, and nuclear applications. In this study, the photon attenuation characteristics of theoretically modeled polycarbonate/poly(methyl methacrylate) (PC/PMMA) composites reinforced with zinc cobalt oxide (ZnCo2O4), titanium silicon carbide (Ti3SiC2), and molybdenum gallium carbide (Mo2GaC) were investigated within the photon energy range 0.01 MeV-15 MeV. The mass and linear attenuation coefficients of the prepared composites were evaluated using the Phy-X software. Based on the obtained attenuation parameters, the half and tenth value layers, mean free path, effective atomic number, equivalent atomic number, and effective electron density were determined. Furthermore, the exposure buildup factor and energy absorption buildup factor were analyzed to assess the photon interaction behavior at different penetration depths and energies. The results demonstrated that the incorporation of high-density ceramic and carbide fillers significantly improved the radiation shielding capability of the PC/PMMA matrix, particularly at low and intermediate photon energies where photoelectric absorption and Compton scattering dominate. Among the investigated composites, the sample containing Mo2GaC exhibited superior attenuation performance due to their relatively higher atomic numbers and electron densities. The findings indicate that the developed composites are promising candidates for environmentally friendly gamma-ray shielding applications.
A novel polymer based on the ethylene-vinyl acetate copolymer (EVA)/butadiene rubber (BR) thermoplastic vulcanizate (TPV) with adjustable heat-triggered shape memory property was prepared by dynamic vulcanization. The morphology structure of the EVA/BR TPV was a sea-island structure with the crosslinked BR particle sizes ranging from 3 mu m to 6 mu m. The melting and crystallization behavior of the EVA/BR TPV was tested by differential scanning calorimetry (DSC), and the result showed that the melting points of the EVA and the EVA/BR TPV were about 86 degrees C. The shape memory results showed that the excellent shape memory property of the EVA/BR TPV could be adjusted effectively by changing the weight ratio of EVA/BR, shape deformation temperature (T d) and shape recovery temperature (T r), with both the shape fixation ratio (SF %) and shape recovery ratio (SR %) of the EVA/BR TPV exceeding 95% at the certain condition (T d = 85 degrees C, T r = 85 degrees C, the weight ratio of EVA/BR = 80/20). It should be noticed that the shape recovery time could be reduced obviously with the decreasing weight ratio of the EVA/BR.
Solid polymer electrolytes based on methyl cellulose/polyethylene oxide (MC:PEO) blends are promising for electrochemical and optoelectronic applications; however, balancing ionic transport and optical performance remains challenging. This work investigates the effect of Melaleuca viminalis extract on the structural, electrical, dielectric, and optoelectronic properties of MC:PEO-LiNO3 polymer electrolytes. Films containing 15-25 wt.% LiNO3 and 0-30 wt.% extract were prepared by solution casting and characterized using XRD, FTIR, EIS, and UV-Vis spectroscopy. XRD confirmed semi-crystalline structures with crystallinity ranging from 28.13% to 41.33%, where 10 wt.% extract enhanced amorphization, while higher loading promoted partial recrystallization. FTIR analysis revealed intermolecular interactions involving O-H, C-O, and C=O groups and modifications in Li+ coordination. EIS results showed optimum conductivity at 10 wt.% extract, reaching 2.97 mu S cm(-1) (IKZ6) compared to 2.31 mu S cm(-1) for the undoped sample, whereas excessive extract increased bulk resistance up to 10,405 Omega and suppressed ion transport. Optical analysis demonstrated tunable bandgap behavior (4.95-2.90 eV), high transparency (88-99%), and epsilon ' > epsilon '', indicating stable dielectric characteristics. These findings demonstrate the concentration-dependent role of Melaleuca viminalis extract in tuning multifunctional polymer electrolyte properties.
In this study, high-performance hybrid composites were fabricated by incorporating MXene, carbon nanotubes (CNTs), and hexagonal boron nitride (h-BN) into a poly(butylene succinate) (PBS) matrix. The synergistic interaction between two-dimensional MXene sheets, one-dimensional CNT networks, and insulating h-BN platelets enabled the formation of a controlled percolative structure with enhanced interfacial polarization and charge transport. Among all compositions, the PBS/MXene/CNT/h-BN hybrid composite (S10, total filler fraction = 0.20) exhibited the optimum multifunctional performance. As a result, the dielectric constant increased from 3.2 (pure PBS) to 110 at 1 kHz, while maintaining a dielectric loss of 0.31. The AC conductivity improved significantly, reaching 1.6 & times; 10-3 S/m, indicating efficient charge transport pathways. The composites exhibited a maximum energy density of 0.04868 J/cm & sup3; with an efficiency of 85%, demonstrating improved energy storage capability. Notably, the EMI shielding effectiveness increased from 1.5 to 52 dB, with absorption-dominated shielding (96.8%), highlighting superior electromagnetic attenuation performance. Despite increased conductivity, the incorporation of h-BN preserved dielectric stability and improved breakdown strength up to 17 kV/mm. Percolation analysis confirmed a three-dimensional conductive network with a critical exponent of t = 1.9 and a percolation threshold of pc = 0.12, confirming the establishment of an interconnected conductive structure.
