Journal of Inorganic and Organometallic Polymers and Materials最新文献

This study investigates the enhancement of mechanical and wear properties of polylactic acid (PLA) reinforced with graphene nanoparticles (GNPs) to address PLA’s limitations in wear-intensive environments. By incorporating varying concentrations of GNPs (0.5–2 wt%), significant improvements were observed, with the PLA + 1.5 wt% GNP composite achieving optimal performance. Key findings include a 68.9% increase in hardness and a 67.4% reduction in wear rate compared to pure PLA, attributed to effective nanoparticle dispersion and interfacial bonding. Surface morphology and elemental analysis validated the reinforcement effects, although higher GNP concentrations led to agglomeration, reducing efficiency. These results highlight the potential of GNP-reinforced PLA composites for applications requiring high mechanical strength and wear resistance, particularly in sustainable 3D-printed products. Future research should focus on improving nanoparticle dispersion techniques and exploring dynamic operational conditions to further optimize material performance.

A rare-earth based novel perovskite solid solution 0.5(Na_0.5La_0.5)TiO₃–0.5(BaTiO₃) is synthesized via high temperature reaction–diffusion route and its functional properties are analyzed through comprehensive characterization of data extracted following different experimental techniques. Quantitative analysis of room temperature X-ray diffraction and Raman spectroscopic data suggest formation of solid solution in tetragonal phase with p4mm symmetry. Field emission scanning electron micrograph (FESEM) illustrates polyhedral shaped grains with sizes varying between 100 nm and 800 nm. Fourier Transform Infrared (FTIR) and photoluminescence (PL) spectra study give insight to the molecular and recombination dynamics in the compound. Detail optical characterization of the solid solution via UV–Visible spectroscopy reveals optical band-gap (~ 3.13 eV), Urbach energy (~ 0.116 eV), as well as frequency dependent skin depth, extinction coefficient and optical dielectric properties. These all observations evaluate the compound as a possible future candidate for photovoltaic and optoelectronic applications in near UV region. Complex impedance spectroscopy (CIS) technique is adopted as a probe to get insight into the dielectric polarization, electrical properties and associated relaxation phenomena in the compound. High dielectric constant, low dielectric loss and near stable dielectric behavior in high frequency region up to temperature 600 K suggest materials use in high frequency capacitor applications. The ferroelectric nature of compound is established through observation of diffused dielectric anomaly at 610 K and room temperature hysteresis loop. The predominance of bulk contribution towards overall electrical/transport properties is observed from Nyquist plot study. A strong temperature dependence of bulk dc resistance is suggestive for possible thermistor applications and hence the thermistor parameters are evaluated. The alternating current (AC) conduction spectra at different temperatures are examined through Jonscher’s power law which supports overlapping large polaron tunneling (OLPT) model conduction mechanism in the compound. The thermally activated conduction process follows Arrhenius equation and activation energies over different range of temperatures have been estimated to have knowledge on the charge species involved.

Using first-principles density functional theory (DFT), this study explores the structural, electronic, optical, mechanical, magnetic, vibrational, charge distribution, and anisotropic properties of lead-free halide perovskites LiBX₃ (B = Ca, Ba; X = Cl, Br, I). All compounds crystallize in the cubic Pm3̅m phase, with lattice constants and unit cell volumes increasing as heavier halides are substituted. Tolerance factor analysis confirms the structural stability of these compounds, particularly for Ca-based systems. Electronic structure calculations reveal direct band gaps ranging from 3.75 eV for LiCaCl₃ to 2.33 eV for LiBaI₃, with the gaps decreasing from Cl to I. The partial density of states (PDOS) shows significant hybridization between halide p-states and cation d-states, allowing for the tuning of band dispersions. Optical analyses reveal high absorption coefficients (> 10⁵ cm⁻¹), with iodide compounds exhibiting enhanced dielectric constants, strong reflectivity, and broad optical conductivity spectra, making them suitable for light-harvesting and UV–visible optoelectronic applications. Mechanical stability is confirmed via elastic constants, with Ca-based systems showing higher stiffness and Ba-based iodides demonstrating improved ductility, flexibility, and machinability. Spin-polarized calculations indicate minimal magnetic splitting, confirming non-magnetic ground states. Charge density, Mulliken, and Hirshfeld analyses reveal an increasing covalent character and polarizability from Cl to I, which impacts bonding and charge transport. Anisotropy in elastic moduli further supports their use in flexible devices. Phonon dispersion indicates that Ba-based compounds are dynamically stable, while Ca-based materials exhibit soft modes, suggesting potential lattice instabilities.

Carbon Dots (CDs) are a class of zero-dimensional materials that are considered as the latest addition to the fluorescent family with potential applications in various fields owing to their immense chemical, biological, and physical properties. Although there is increasing interest in the synthesis of highly luminous CDs from biomass and fruits, the use of dangerous chemicals raises severe concerns. Therefore, our goal is to create CDs utilising Moringa leaves without the use of any dangerous chemicals. CDs can be used as reducing agents with good results, however, there aren’t many studies on the subject, which is a major drawback. To verify the reducing power of CDs (MCDs) generated from Moringa leaves, we have carried out the reduction of graphene oxide with the synthesized MCDs. Fluorescent gels based on CDs have emerged as a new class of material with potential applications in bioimaging, photonics, and sensing. CD-based fluorescent gels are made by simply adding CDs into the pre-synthesized gels; hence, we have tried the fabrication of fluorescent gels using MCDs and the triblock copolymer. Thus, prepared gels are added into the polyvinylidene difluoride (PVDF) matrix as a filler to make smart composite films with shape memory characteristics. Hence, this study also intends to create shape memory fluorescent films using CDs for the first time, which will be useful in the domains of biomedicine and anti-counterfeiting.

In this work, we report the facile aqueous synthesis of graphene oxide-FeZnCuInS/ZnS (GO-FeZCIS/ZnS) nanocomposite as a potential dual phototherapeutic agent. The as-synthesised nanocomposite showed a photoluminescence quantum yield (PLQY) higher than that of the undoped QDs and a superior average lifetime. The structural characterisations showed that the nanocomposite was negatively charged (− 40.40 mV) and quasi-spherical, with an average diameter of 33.09 nm. The XRD results revealed that the nanocomposite exhibits a zinc blend structure. The cytotoxicity assay against KM-Luc /GFP malignant fibrous histiocytoma-like cells stably expressing the firefly luciferase gene (KM-Luc) and Breast carcinoma cells (FM3A-Luc) showed that the materials are biocompatible, while the photothermal profiling analysis showed that the material was able to generate a lot of heat with a temperature change of about 45.2 °C which was higher than that of ZnCuInS/ZnS (ZCIS/ZnS) (35.5 °C) and FeZnCuInS/ZnS (FeZCIS/ZnS) (39.3 °C) QDs with singlet oxygen quantum yield of 0.27. The results showed the as-synthesised nanocomposite as a promising therapeutic agent for dual cancer phototherapy.

A medium-entropy spinel ferrite, Zn_0.2Cd_0.2Mn_0.6Fe₂O₄, was synthesized via the sol-gel method using polyvinyl alcohol (PVA) as a surfactant. The resulting material was thoroughly characterized using XRD, ATR-FTIR, XPS, HRTEM, FESEM, EDS, and BET analyses. XRD analysis confirmed the successful synthesis of single-phase nanocrystalline powders exhibiting a cubic spinel structure (Fd-3 m), with an observed increase in the lattice parameter. XPS analysis reveals the incorporation of Zn²⁺ and Cd²⁺ into the Zn_0.2Cd_0.2Mn_0.6Fe₂O₄ lattice, along with the coexistence of Mn²⁺/Mn³⁺ and Fe²⁺/Fe³⁺ redox species. These mixed-valence states contribute to the formation of heterojunctions, which enhance the hydrogen evolution reaction (HER) activity and stability. FESEM imaging revealed granular and uneven surface morphology, while HRTEM analysis confirmed the presence of compact, irregularly shaped nanogranules. Zn_0.2Cd_0.2Mn_0.6Fe₂O₄ exhibited a mesoporous structure, characterized by a surface area of 36.63 m²/g and a pore volume of 0.088 cm³/g. The HER performance of the Zn_0.2Cd_0.2Mn_0.6Fe₂O₄/NF electrode was evaluated in 1 M KOH at 25 °C using cathodic polarization and electrochemical impedance spectroscopy (EIS). The Zn_0.2Cd_0.2Mn_0.6Fe₂O₄/NF electrode exhibited superior HER performance, delivering 58.53 mA cm^− 2 at − 1.4 V with a low overpotential of 210.1 mV at 10 mA cm^− 2. Its high catalytic efficiency was supported by low charge transfer resistance (R_ct), indicating efficient interfacial charge transport. The enhanced double-layer capacitance (C_dl = 4.02 mF cm^− 2) for Zn_0.2Cd_0.2Mn_0.6Fe₂O₄/NF can be attributed to the synergistic effects of multivalent transition metal redox couples and entropy-induced cationic disorder. Complementary structural modeling and Hirshfeld surface analysis further elucidated cation site occupancy and interatomic interactions vital to catalytic stability.

We report the improvement of semiconducting behaviour, dielectric and magnetic property in Mg_0.5Ni_0.5Fe_2−xGd_xO₄ (where x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) synthesized by solid state reaction route. The physical properties have been studied using X-ray diffraction, field effect scanning electron microscopy (FESEM), atomic force microscopy (AFM), UV–Vis spectroscopy, dielectric spectroscopy and magnetic measurement. Rietveld analysis reveals the existence of spinel cubic phase and a secondary phase of GdFeO₃ orthorhombic structure. The Williamson–Hall graph shows the decrease of average crystallite size of spinel phase from 101 to 59 nm due to compressive strain with increasing Gd concentration. The FESEM images exhibited an agglomerate of fine particles due to their magnetic nature. The roughness has been observed in AFM depends on the material, type of dopant, and method of processing. UV spectra analysis shows a decreasing trend of band gap after incorporating Gd³⁺. The dielectric constant shows decreasing trend and dielectric loss shows increasing trend with respect to frequency for all the ferrites. The reflection loss graph indicates the optimal doping with Gd occurs at x = 0.3 for maximum absorption making it a suitable candidate for application like electromagnetic interference shielding or radar absorbing material. The nature of the M-H loop for all the specimens show ferromagnetic behavior. The synthesized samples have modified electrical and magnetic behaviors suitable for microwave applications.

The symmetry breaking in octahedral silsesquioxane and its germanium analogues (Si₈O₁₂H₈ and Ge₈O₁₂H₈) has been investigated using the M06-2X/6-31++G(3df, 3pd) method and group theory. Both structures undergo ({O}_{h}downarrow {T}_{h}) symmetry breaking, characterized by pseudo-Jahn−Teller stabilization energies of 0.22 kcal/mol for Si-POSS and 9.82 kcal/mol for Ge-POSS. Under the influence of the pseudo-Jahn–Teller effect, the distortion vector involves the vibrational a_2g mode with imaginary frequency. The distortion forces in O_h-POSS are predominantly localized on the oxygen atoms and driven by the coupling between the lowest unoccupied molecular orbital (a_1g) and the highest occupied molecular orbital (a_2g). The symmetry breaking is attributed to a pseudo-Jahn–Teller mechanism of type (a_2g x a_1g) = a_2g. The symmetrical substitution of oxygen atoms by X (where X = C, N, P) results in viable T_h-Si₈X₁₂H₈ and T_h-Ge₈X₁₂H₈ structures. The observed pseudo-Jahn–Teller distortion and substitutional symmetry breaking caused by X indicates a consistent electronic relaxation mechanism, characterized by the formation of C=C, N=N and P=P bonds on the POSS cubic faces, which serves as hallmarks of stability. Additionally, we find that the volume of substituted T_h-symmetrical POSS is sufficiently large to accommodate small ions.

Utilizing the spin degree of freedom of electrons to control and store electronic data has become an emerging aspect of advanced spintronic technology. In my present work, I have comprehensively investigated the above room-temperature ferromagnetism and thermoelectric behavior of X₂TiMoO₆ (X = Mg, Ca, Sr, Ba) for a detailed understanding of the field. The formation energy, phonon dispersion spectrum, and tolerance factor have been assessed to determine their thermodynamic, dynamic, and structural stabilities. The optimization analysis explains that ferromagnetic (FM) states liberate more energy than antiferromagnetic (AFM) states, thereby enhancing the stability of the FM states. The Curie temperature and spin polarization are calculated using the Heisenberg model and polarization density, which confirms above-room temperature ferromagnetism. Moreover, the Study investigates various aspects of ferromagnetism, including exchange constants, hybridization, crystal field energy, and exchange energies. The transformation of the magnetic moment from Ti and Mo to the Sr and O sites reveals that the electron spin is mainly responsible for ferromagnetism rather than the cluster of magnetic ions. Furthermore, a comprehensive analysis of transport behavior, including the Seebeck coefficient, electrical & thermal conductivities, and power factor, is executed to see their thermoelectric effects on the spin of electrons and energy harvesting.

This study evaluates two biopolymer-based nanoparticles derived from Giant Reed (cellulose) and chitin as sustainable precursors for dual applications: heavy metal adsorption and liquid crystal formation. The novelty lies in upcycling Giant Reed-based cellulose nanoparticles (Cel-NPs) as metal adsorbents and reusing their metal-chelated forms as effective liquid crystal biopolymers, achieving a zero-waste strategy. The nanoparticles were characterized using Transmission Electron Microscopy (TEM), Attenuated Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), X-ray Diffraction (XRD), and Polarized Optical Microscopy (POM) to evaluate their morphology, functional groups, crystallinity, and liquid crystalline behavior. Comparative analysis between Cel-NPs and chitin nanoparticles (Ch-NPs), including their esterified derivatives (ECel-NPs and ECh-NPs), was conducted. Metal chelation studies showed Cel-NPs exhibited higher affinities for Cu²⁺, Zn²⁺, and Cd ²⁺ (29.01 ± 1.1, 30.33 ± 1.2, and 20.69 ± 0.8 mg/g, respectively) compared to Ch-NPs (24.96 ± 0.99, 29.78 ± 1.2, and 17.34 ± 0.7 mg/g). Structural modifications metal loading and esterification with decanoyl chloride enhanced the crystallinity indices of the nanoparticles and significantly improved their liquid crystalline behavior. Notably, the critical concentration for liquid crystal formation dropped from 1 wt% to 0.5 wt% for modified Cel-NPs, and from 5 wt% to 0.5 wt% for modified Ch-NPs, highlighting their potential in advanced biofunctional materials. *Corresponding information: A. H. Basta. email: altaf_halim@yahoo.com, and altaf_basta2004@yahoo.com.