Search Results (1,165)

This work reports the synthesis and characterization of Carbon Quantum Dots (CQDs) embedded in an organic–inorganic hybrid SiO₂: PMMA matrix, designed as a novel plastic scintillator material. The CQDs were synthesized through a solvo-hydrothermal method and incorporated using a sol–gel polymerization process, resulting in a mechanically durable and optically active hybrid. Structural analysis with X-ray diffraction and TEM confirmed crystalline quantum dots approximately 10 nm in size. Extensive optical characterization, including band gap measurement, photoluminescence under 325 nm UV excitation, lifetime evaluations, and quantum yield measurement, revealed a blue emission centered at 426 nm with a decay time of 3–3.6 ns. The hybrid scintillator was integrated into a compact cosmic ray detector using a photomultiplier tube optimized for 420 nm detection. The system effectively detected secondary atmospheric muons produced by low-energy cosmic rays, validated through the vertical equivalent muon (VEM) technique. These findings highlight the potential of CQD-based hybrid materials for advanced optical sensing and scintillation applications in complex environments, supporting the development of compact and sensitive detection systems. Full article

Lead-free A₂ZrX₆ “defect” perovskites hold significant potential for many optoelectronic applications due to their stability and tunable properties. Extending a previous work, we present a first-principles density functional theory (DFT) study, utilizing PBE and HSE06 functionals, to systematically investigate the impact of A-site cation and X-site halogen substitutions on the structural and electronic properties of these materials. We varied the A-site cation, considering ammonium, methylammonium, dimethylammonium, trimethylammonium, and phosphonium, and the X-site halogen, trying Cl, Br, and I. Our calculations reveal that both these substitutions significantly affect the band gap and the lattice parameters. Increasing A-site cation size generally enlarges the unit cell, while halogen electronegativity directly correlates with the band gap, yielding the lowest values for iodine-containing systems. We predict a broad range of band gaps (from ~4.79 eV for (PH₄)₂ZrCl₆ down to ~2.11 eV for MA₂ZrI₆ using HSE06). The (PH₄)₂ZrX₆ compounds maintain cubic crystal symmetry, unlike the triclinic of the ammonium-derived systems. Finally, our calculations show that the MA cation yields the smallest band gap among the ones studied, a result that is attributed to its size and the charges of the hydrogen atoms attached to nitrogen. Thus, our findings offer crucial theoretical insights into A₂ZrX₆ structure–property relationships, demonstrating how A-site cation and halogen tuning enables control over electronic and structural characteristics, thus guiding future experimental efforts for tailored lead-free perovskite design. Full article

The development of biomaterials with tailored properties is indispensable for biomedical applications. In this study, amorphous silica/sodium alginate (SiO₂/SA) hybrids were synthesized via the sol–gel method by incorporating 2, 5, and 8% sodium alginate into the silica matrix. The hybrids were characterized to evaluate their structural, surface, thermal, moisture-responsive, and biological properties. FTIR and XRD analyses confirmed the formation of organic–inorganic networks and amorphous structures. BET measurements revealed a specific surface area of 325 m²/g for SiO₂/SA2%, decreasing with higher SA content to 104.3 m²/g for SiO₂/SA8%; the moisture sorption capacity followed a similar trend. Thermal analysis indicated improved stabilization of the polymer within the silica matrix. Cytotoxicity tests on HaCaT (human keratinocyte) cells line revealed moderate toxicity for the SiO₂/SA2% hybrid (~40% cell viability inhibition (CVI)), while increasing the SA content reduced cytotoxicity, with a CVI of 33% for SiO₂/SA5% and ~15% for SiO₂/SA8%, all within non-toxic ranges according to ISO standards. The SiO₂/SA5% hybrid demonstrated the best balance between functional properties and biocompatibility. These preliminary results suggest that further optimization with intermediate SA concentrations (e.g., 6–7%) could further reduce cytotoxicity while maintaining desirable properties, supporting the potential of silica/sodium alginate hybrids in future biomedical applications. Full article

This study investigates the development of a sustainable flame-retardant treatment for cotton fabrics using a hybrid coating composed of chitosan, phytic acid, APTES, and eggshell powder at concentrations of 2% and 4%, applied in one and two cycles. FTIR confirmed the deposition of the organic–inorganic layer through the appearance of characteristic bands. Thermogravimetric analysis (TGA/dTGA) revealed enhanced thermal stability for all treated samples, with increased char yield and a shift in the main cellulose degradation peak. Vertical flammability tests demonstrated that all coated fabrics achieved self-extinguishing behavior within 12 s, meeting NFPA 701 criteria. The 2% eggshell formulation with two applications (S2%-II) exhibited the best balance between flame retardancy and mechanical performance. Tensile tests indicated improved fiber cohesion for treated samples, while SEM micrographs confirmed uniform coating deposition and particle integration. Colorimetric analysis showed that the treatment did not cause a significant change in the natural color of the cotton. Although washing resistance remains a limitation due to the natural origin of the components, the samples remained stable over time without microbial growth or staining, suggesting potential for upholstery and covering fabrics not subjected to domestic washing. The results highlight the feasibility of using agro-industrial waste to create eco-friendly flame-retardant finishes for cotton textiles. Full article

Proton-exchange membranes (PEMs) are the pivotal components of vanadium redox flow batteries (VRFBs) and play a critical role in the comprehensive output performance of VRFB systems. Currently, the most widely commercialized membranes are Nafion series membranes produced by DuPont, Wilmington, DE, USA, but the high vanadium permeability and cost hinder their large-scale promotion. Hence, there is an active demand for developing a low-cost, high-performance, and energy-efficient PEM to promote the commercialization of VRFB systems. In this paper, sulfonated poly(ether ether ketone) (SPEEK) as matrix and zirconia nanoparticles as inorganic filler were used for composite modification to prepare a series of SPEEK–ZrO₂ organic–inorganic hybrid membranes for VRFBs. The thickness of these membranes was 50–100 μm. Compared with Nafion 115 (thickness 128 μm), composite membranes demonstrated obvious cost advantages. The results showed that the SP–Z-X series membranes had higher water uptake (53.26–71.1%) and proton conductivity (0.11–0.24 S cm⁻¹). SP–Z-5 displayed the best comprehensive output performance at 200 mA cm⁻² (CE: 99.01%, VE: 81.95%, EE: 81.11%). These hybrid membranes are very cost-effective and exhibit high potential for application in VRFB applications, and are expected to lead to the industrial application of VRFBs on a large scale. Full article

Two-dimensional (2D) organic−inorganic hybrid perovskites (OIHPs) have emerged as promising candidates for next-generation optoelectronic applications. While vertical heterostructures of 2D OIHPs have been explored through mechanical stacking, the controlled fabrication of lateral heterostructures remains a significant challenge. Here, we present a lithography-free, van der Waals mask-assisted strategy for the deterministic fabrication of 2D OIHP lateral heterostructures. Mechanically exfoliated 2D materials such as graphene serve as removable masks that enable selective conversion of unmasked perovskite regions via ion exchange reaction. This technique enables the fabrication of various lateral heterostructures, such as BA₂MA₂Pb₃I₁₀/MAPbI₃, PEAPbI₄/MAPbI₃, as well as BA₂MAPb₂I₇/MAPbBr₃. Furthermore, complex multiheterostructures and superlattices can be constructed through sequential masking and conversion processes. Moreover, to investigate the electronic properties and demonstrate potential device applications of the lateral heterostructures, we have fabricated an electrical diode based on a BA₂MA₂Pb₃I₁₀/MAPbI₃ lateral heterostructure. Stable electrical rectifying behavior with a rectification ratio of around 10 was observed. This general and flexible approach provides a robust platform for constructing 2D OIHPs lateral heterostructures and opens new pathways for their integration into high-performance optoelectronic devices. Full article

Addressing the inherent brittleness of cement to mitigate infrastructure failures stemming from cracking is imperative. To accomplish both early crack resistance and subsequent self-healing capabilities, a biomimetic microstructure composed of a sodium polyacrylate (CSPA) network interwoven with hydration products was developed. The calcium-enriched polymer network formed via in situ polymerization of sodium acrylate (ANa) can enhance the mechanical properties of cement and achieve efficient self-healing of cracks. The porous structure of sodium polyacrylate (PANa) formed in pore solution at room temperature to simulate cement hydration conditions was observed by scanning electron microscopy (SEM). Feature peaks found by Fourier transform infrared (FTIR) spectroscopy as well as confocal Raman microscopy (CRM) suggested that ANa was polymerized successfully. Notably, CSPA samples demonstrated a remarkable 104% increase in flexural strength, attributed to the efficient transmission and dissipation of external forces along the polymer network embedded within the cement matrix. Additionally, after a 28-day hydration, CSPA specimens exhibited enhanced compressive strength compared to blank cement samples. This enhancement stems from the formation of a uniform polymer network, which effectively decreased the porosity and densified the microstructure of cement. Moreover, this organic–inorganic hybrid structure contributes to efficient crack healing, as the calcium-rich polymer network binds calcium ions and promotes the generation of healing products. The healing products consist of calcium hydroxide (CH), CaCO₃ (aragonite), C-S-H (calcium–silicate–hydrate), and PANa. Full article

The dairy industry generates significant amounts of wastewater, including microfiltration (MF) retentate, a byproduct thickened with organic and inorganic pollutants. This study focuses on the treatment of two times concentrated MF retentate using a hybrid system based on biological treatment in a sequential batch reactor (SBR) and adsorption on activated carbon. The first stage involved cross-flow microfiltration using a 0.2 µm PVDF membrane at 0.5 bar, resulting in reductions of 99% in turbidity and 79% in chemical oxygen demand (COD), as well as a partial reduction in conductivity. The second stage involved 24-h biological treatment in a sequential batch reactor (SBR) with activated sludge (activated sludge index: 80 cm³/g, MLSS 2500 mg/dm³), resulting in further reductions in COD (62%) and TOC (30%), as well as the removal of 46% of total phosphorus (TP) and 35% of total nitrogen (TN). In the third stage, the decantate underwent adsorption in a column containing powdered activated carbon (PAC; 1 g; S_(BET) = 969 m² g⁻¹), reducing the concentrations of key indicators to the following levels: COD 84%, TOC 70%, TN 77%, TP 87% and suspended solids 97%. Total pollutant retention ranged from 24.6% to 97.0%. These results confirm that the MF–SBR–PAC system is an effective, compact solution that significantly reduces the load of organic and biogenic pollutants in MF retentates, paving the way for their reuse or safe discharge into the environment. Full article

The increasing use of pharmaceutically active compounds (PhACs), endocrine-disrupting compounds (EDCs), and personal care products (PCPs) has led to the widespread presence of organic micropollutants (OMPs) in aquatic environments, posing a significant global challenge for environmental conservation. In recent years, advanced materials-based nanofiltration (NF) technologies have emerged as a promising solution for water and wastewater treatment. This review begins by examining the sources of OMPs, as well as the risk of OMPs. Subsequently, the key criteria of NF membranes for OMPs are discussed, with a focus on the roles of pore size, charge property, molecular interaction, and hydrophilicity in the separation performance. Against that background, this review summarizes and analyzes recent advancements in materials such as metal organic frameworks (MOFs), covalent organic frameworks (COFs), graphene oxide (GO), MXenes, hybrid materials, and environmentally friendly materials. It highlights the porous nature and structural diversity of organic framework materials, the advantage of inorganic layered materials in forming controllable nanochannels through stacking, the synergistic effects of hybrid materials, and the importance of green materials. Finally, the challenges related to the performance optimization, scalable fabrication, environmental sustainability, and complex separation of advanced materials-based membranes for OMP removal are discussed, along with future research directions and potential breakthroughs. Full article

The hybrid inorganic–organic material concept plays a bold role in multifunctional materials, combining different features on one platform. Once varying properties coexist without cancelling each other on one matrix, a new type of supermaterial can be formed. This concept showed that silver nanoparticles can be embedded together with inorganic and organic surface coatings and silicon quantum dots for symbiotic antibacterial character and UV-excited visible light fluorescent features. Additionally, fluorosilane material can be coupled with this prepolymeric structure to add the hydrophobic feature, showing water contact angles around 120°, providing self-cleaning features. Optical properties of the components and the final material were investigated by UV-Vis spectroscopy and PL analysis. Atomic investigations and structural variations were detected by XPS, SEM, and EDX atomic mapping methods, correcting the atomic entities inside the coating. FT-IR tracked surface features, and statistical analysis of the quantum dots and nanoparticles was conducted. Multifunctional final materials showed antibacterial properties against E. coli and S. aureus, exhibiting self-cleaning features with high surface contact angles and visible light fluorescence due to the silicon quantum dot incorporation into the sol-gel-produced nanocomposite hybrid structure. Full article

Poly(organo)phosphazenes (PPZs) are increasingly recognized as versatile biomaterials for drug delivery applications in nanomedicine. Their unique hybrid structure—featuring an inorganic backbone and highly tunable organic side chains—confers exceptional biocompatibility and adaptability. Through precise synthetic methodologies, PPZs can be engineered to exhibit a wide spectrum of functional properties, including the formation of multifunctional nanostructures tailored for specific therapeutic needs. These attributes enable PPZs to address several critical challenges associated with conventional drug delivery systems, such as poor pharmacokinetics and pharmacodynamics. By modulating solubility profiles, enhancing drug stability, enabling targeted delivery, and supporting controlled release, PPZs offer a robust platform for improving therapeutic efficacy and patient outcomes. This review explores the fundamental chemistry, biopharmaceutical characteristics, and biomedical applications of PPZs, particularly emphasizing their role in zero-dimensional nanotherapeutic systems, including various nanoparticle formulations. PPZ-based nanotherapeutics are further examined based on their drug-loading mechanisms, which include electrostatic complexation in polyelectrolytic systems, self-assembly in amphiphilic constructs, and covalent conjugation with active pharmaceutical agents. Together, these strategies underscore the potential of PPZs as a next-generation material for advanced drug delivery platforms. Full article

This study reports the development of a sustainable biocatalyst system for free fatty acid (FFA) production from cocoa bean shell (CBS) oil using Burkholderia cepacia lipase (BCL). CBS was explored as both a support material and a reaction substrate. Six immobilized systems were prepared using organic (CBS), inorganic (silica), and hybrid (CBS–silica) supports via physical adsorption or covalent binding. Among them, the covalently immobilized enzyme on CBS (ORG-CB) showed the most balanced performance, achieving a catalytic efficiency (Ke) of 0.063 mM⁻¹·min⁻¹ (18.6% of the free enzyme), broad pH–temperature tolerance, and over 50% activity retention after eight reuse cycles. Thermodynamic analysis confirmed enhanced thermal resistance for ORG-CB (Ed = 32.3 kJ mol⁻¹; ΔH‡ = 29.7 kJ mol⁻¹), while kinetic evaluation revealed that its thermal deactivation occurred faster than for the free enzyme under prolonged heating. In application trials, ORG-CB reached 60.1% FFA conversion from CBS oil, outperforming the free enzyme (49.9%). These findings validate CBS as a dual-function material for enzyme immobilization and valorization of agro-industrial waste. The results also reinforce the impact of immobilization chemistry and support composition on the operational and thermal performance of biocatalysts, contributing to the advancement of green chemistry strategies in enzyme-based processing. Full article

In this work, the synthesis and structural characterization of the smallest possible member of the family of bis-functionalized {MnMo₆O₂₄} Anderson–Evans polyoxometalates (POMs) is reported. The synthesis of the title compound TBA₃{[HC(CH₂O)₃]₂MnMo₆O₁₈} (1) was accomplished by using trimethylolmethane as the capping unit (TBA: tetra(n-butyl)ammonium, n-B_u4N⁺). The molecular structure of the organic–inorganic POM gave rise to yet undisclosed ¹H-NMR features, which are discussed thoroughly. Single-crystal X-ray diffraction (XRD) analysis revealed a highly regular 3D packing of the polyoxoanions within a matrix of TBA cations. The hybrid POM is of particular interest regarding potential applications in photocatalysis (i.e., hydrogen evolution) and energy storage. Thus, the electrochemical and thermal properties of 1 are also analyzed. Full article

The development of sustainable and functional nanocomposites has attracted considerable attention in recent years due to their broad spectrum of potential applications, including wood preservation. Also, a global goal is to reuse the large volumes of waste for environmental issues. In this context, the aim of the study was to obtain soda lignin particles, to graft ZnO nanoparticles onto their surface and to apply these hybrids, embedded into a biodegradable polymer matrix, as protection/preservation coating for oak wood. The organic–inorganic hybrids were characterized in terms of compositional, structural, thermal, and morphological properties that confirm the efficacy of soda lignin extraction and ZnO grafting by physical adsorption onto the decorating support and by weak interactions and coordination bonding between the components. The developed solution based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and lignin-ZnO was applied to oak wood specimens by brushing, and the improvement in hydrophobicity (evaluated by water absorption that decreased by 48.8% more than wood, humidity tests where the treated sample had a humidity of 4.734% in comparison with 34.911% for control, and contact angle of 97.8° vs. 80.5° for untreated wood) and UV and fungal attack protection, while maintaining the color and aspect of specimens, was sustained. L.ZnO are well dispersed into the polymer matrix, ensuring a smooth and less porous wood surface. According to the results, the obtained wood coating using both a biodegradable polymeric matrix and a waste-based preservative can be applied for protection against weathering degradation factors, with limited water uptake and swelling of the wood, UV shielding, reduced wood discoloration and photo-degradation, effective protection against fungi, and esthetic quality. Full article

Polyoxometalate (POM)-type supramolecular materials have unique structures and hold immense potential for development in the fields of biomedicine, information storage, and electrocatalysis. In this study, (NH₄)₃ [AlMo₆O₂₄H₆]·7H₂O was employed as a polyacid anion template, pentacyclic imidazole molecules served as organic ligands, and the moderate-temperature hydrothermal and natural evaporation methods were used in combination for the design and synthesis of two octamolybdenum-oxo cluster (homopolyacids containing molybdenum-oxygen structures as the main small-molecular structures)-based organic–inorganic hybrid compounds, [(C₃N₂H₅)(C₃N₂H₄)][(β-Mo₈O₂₆H₂)]_0.5 (1) and {Zn(C₃N₂H₄)₄}{[(γ-Mo₈O₂₆)(C₃N₂H₄)₂]_0.5}·2H₂O (2). Structural and property characterization revealed that both compounds crystallized in the P-1 space group with relatively stable three-dimensional structures under the action of hydrogen bonding. Upon temperature stimulation, the [Zn(C₃N₂H₄)₄]²⁺ cation and water molecules in 2 exhibited obvious oscillations, leading to significant dielectric anomalies at approximately 250 and 260 K when dielectric testing was conducted under heating conditions. Full article