Nanomaterials最新文献

Selective laser sintering (SLS) is an additive manufacturing method that enables the creation of complex-shaped polymer-based structures with great control over the desired properties. In this study, polyamide 12 (PA12)-based powders containing 0.8 wt.% graphene oxide (GO), introduced via a wet-mixing impregnation method, were processed by selective laser sintering (SLS). Implementation of a double laser scanning strategy increased the tensile strength of the composites by 2.5% relative to pristine SLS-processed PA12 and enhanced the thermal conductivity to 0.74 W·m^-1·K^-1. The results indicate that the laser sintering process is an effective approach to produce low filler content polymer-matrix composites with enhanced thermal properties while preserving mechanical integrity and maintaining electrical insulation behavior.

Carbon dots (CDs) have emerged as a promising non-viral gene delivery vector due to their excellent biocompatibility and tunable surface properties. In this study, four CDs with gradient-positive zeta potentials (7.23 mV, 16.7 mV, 25.3 mV, 34.5 mV) were synthesized via a hydrothermal method. Among these, CDs-3 with an optimal zeta potential of 25.3 mV stood out, exhibiting ultra-low cytotoxicity (cell viability > 80% even at 50 μg/mL) and a transfection efficiency of nearly 100% (for GFP plasmid delivery), significantly outperforming commercial vectors Lipo2000 and PEI. A stable CDs-3/siIhh delivery system was constructed at a mass ratio of 2:1. In vitro evaluations confirmed that CDs-3/siIhh could efficiently regulate the Indian Hedgehog (Ihh) signaling pathway and osteoarthritis (OA)-related markers in both normal and IL-1β-induced inflammatory ATDC5 chondrocytes. Its regulatory effect was significantly superior to that of the commercial Lipo2000/siIhh and PEI/siIhh systems. This consistent "transcription-translation" regulation, combined with the carrier's safety and excellent cellular internalization capacity in chondrocytes, highlights its potential for OA gene therapy. Collectively, our work develops a novel, safe, and efficient positive-potential CD-based gene delivery vector, providing a promising gene regulatory capacity by leveraging optimized surface charge engineering.

In this work, by employing NH₄F as a structure-directing agent (SDA) and VO(acac)₂, we have manipulated the morphology of Co₃O₄, leading to the creation of a novel hexagram-like structure with exceptional evenness in distribution. To comprehend the growth mechanism and elucidate the functions of various agents involved, experiments were conducted under diverse conditions with varying reagent ratios. The results indicate that, under the influence of NH₄F as the structure-directing agent (SDA), the hexagram-shaped Co₃O₄ structure exhibits sensitivity to both reaction time and temperature, implying that its growth mechanism is regulated by the Kirkendall effect and involves partial cation exchange. Additionally, with alteration of reagent ratios, Co₃O₄ with ball-flower morphology was synthesized successfully. Through cross-section SEM examination, the observed growth mechanisms for both the hexagram and ball-flower structures were substantiated. Lastly, electrochemical performance tests of the hexagram and ball-flower structures on SC electrode were carried out, and specific capacitances were 452 C/g (1062 F/g) and 696 C/g (1339 F/g), respectively. The hexagram-shaped Co₃O₄ structure displays exceptional SC electrode material characteristics, retaining an outstanding capacitance of 93.1% even after 10,000 cycles, highlighting its superior cycle performance. This paper hopes to inspire further SC electrode materials studies based on its novel morphology modulation strategy.

The continued performance scaling of AI gigafactories requires the development of energy-efficient devices to meet the rapidly growing global demand for AI services. Emerging materials offer promising opportunities to reduce energy consumption in such systems. In this work, we propose an electro-optic microring modulator that exploits a graphene (Gr) and transition-metal dichalcogenide (TMD) interface for phase modulation of data-bit signals. The interface is configured as a capacitor composed of a top Gr layer and a bottom WSe₂ layer, separated by a dielectric Al₂O₃ film. This multilayer stack is integrated onto a silicon (Si) waveguide such that the microring is partially covered, with coverage ratios varying from 10% to 100%. In the design with the lowest power consumption, the device operates at 26.3 GHz and requires an energy of 5.8 fJ/bit under 10% Gr-TMD coverage while occupying an area of only 20 μm². Moreover, a modulation efficiency of V_πL = 0.203 V·cm and an insertion loss of 6.7 dB are reported for the 10% coverage. The Gr-TMD-based microring modulator can be manufactured with standard fabrication techniques. This work introduces a compact microring modulator designed for dense system integration, supporting high-speed, energy-efficient data modulation and positioning it as a promising solution for sustainable AI gigafactories.

High-temperature proton exchange membranes (HT-PEMs) are critical components of high-temperature fuel cells, facilitating proton transport and acting as a barrier to fuel and electrons; however, their performance is hampered by persistent issues of phosphoric acid leaching and oxidative degradation. Herein, a novel HT-PEM with abundant hydrogen bond network is constructed by incorporating nanoscale polyhedral oligomeric silsequioxane functionalized with eight pendent sulfhydryl groups (POSS-SH) into poly(4,4'-diphenylether-5,5'-bibenzimidazole) (OPBI) matrix. POSS, a cage-like nanostructured hybrid molecule, features a well-defined silica core and highly designable surface organic groups, offering unique potential for enhancing membrane performance at the molecular level. Through controlled reactions between sulfhydryl groups and allyl glycidyl ether (AGE), two functional POSS crosslinkers-octa-epoxide POSS (OE-POSS) and mixed sulfhydryl-epoxy POSS (POSS-S-E)-were synthesized. These were subsequently used to fabricate crosslinked OPBI membranes (OPBI-OE-POSS and OPBI-POSS-S-E) via epoxy-amine coupling. The OPBI-POSS-S-E membranes demonstrated exceptional oxidative stability, which is attributed to the free radical scavenging ability of the retained sulfhydryl groups on the nano-sized POSS framework. After soaking in Fenton's reagent at 80 °C for 108 h, the OPBI-POSS-S-E-20% membrane retained 79.4% of its initial weight, significantly surpassing both the OPBI-OE-POSS-20% and pristine OPBI membranes. The PA-doped OPBI-POSS-S-E-20% membrane achieved a proton conductivity of 50.8 mS cm^-1 at 160 °C, and the corresponding membrane electrode assembly delivered a peak power density of 724 mW cm^-2, highlighting the key role of POSS as a nano-modifier in advancing HT-PEM performance.

Aniline (ANI) was electropolymerized on ITO substrates with different surface resistivities. The process was performed by cyclic voltammetry from an aqueous, homogeneous solution containing sulfuric acid and the aniline monomer using various numbers of cycles and scan rates. The resulting polymer films (PANI) were characterized by ATR-IR spectroscopy, spectroscopic ellipsometry and atomic force microscopy. The influence of ITO surface resistivity on the electropolymerization process, the quality of the obtained PANI layers, and their optical properties was evaluated. Homogeneous PANI films were produced on ITO substrates with surface resistivities of 15-25 Ω/sq, encompassing both emeraldine salt and emeraldine base forms. Although the film's growth was rapid, it also led to adhesion issues. In contrast, for ITO substrates with surface resistivities of 70-100 Ω/sq and 80-100 Ω/sq, the resulting films showed improved adhesion but were less homogeneous. Nevertheless, the conductive emeraldine salt form of polyaniline was successfully obtained. The conductive form of polyaniline was obtained without any additional modifications to the electropolymerization procedure. Notably, the literature provides no systematic analysis of electropolymerization on ITO substrates with different surface resistivities, which opens up new research opportunities and provides a basis for the rational design and optimization of PANI-based electro-optical coatings for advanced sensing applications.

Peroxymonosulfate (PMS)-based advanced oxidation is often hindered by pH instability and the lack of post-reaction separation. Herein, commercial magnesium hydroxide (Mg(OH)₂) is introduced as a multifunctional catalyst to address these limitations. Mg(OH)₂ effectively catalyzed PMS decomposition via a nonradical pathway dominated by singlet oxygen (¹O₂) generation, achieving rapid and complete degradation of electron-rich pollutants like bisphenol A (BPA) within 40 min. The system exhibits exceptional pH self-regulation, stabilizing the solution at ~9.8 and maintaining high efficiency across an initial pH range of 3-11. Mechanistic studies confirm ¹O₂ as the primary reactive species with a steady-state concentration of 1.67 × 10^-12 M. The catalyst demonstrates strong resistance to common anions and humic acid, along with excellent stability over four cycles. Furthermore, Mg(OH)₂ enables in situ flocculation and removal of degradation products. This work highlights Mg(OH)₂ as an efficient, stable, and multifunctional activator, offering a integrated strategy for practical wastewater treatment.

Polypropylene microplastics (PP-MPs) represent a persistent class of marine pollutants due to their hydrophobicity, high crystallinity, and resistance to environmental degradation. This review summarizes recent advances in understanding the environmental behavior, physicochemical aging, and ecotoxicological risks of PP-MPs, with emphasis on microbial degradation pathways involving bacteria, fungi, algae, and filter-feeding invertebrates. The biodegradation of PP-MPs is jointly regulated by environmental conditions, polymer properties, and the structure and function of plastisphere communities. Although photo-oxidation and mechanical abrasion enhance microbial colonization by increasing surface roughness and introducing oxygenated functional groups, overall degradation rates remain low in marine environments. Emerging mitigation strategies include biodegradable polymer alternatives, multifunctional catalytic and adsorptive materials, engineered microbial consortia, and integrated photo-biodegradation systems. Key research priorities include elucidating molecular degradation mechanisms, designing programmable degradable materials, and establishing AI-based monitoring frameworks. This review provides a concise foundation for developing ecologically safe and scalable approaches to PP-MP reduction and sustainable marine pollution management.

In this study, a gold nanocage composite perovskite quantum dot fluorescent probe (MB-GNCs-PQDs) was designed and constructed. The GNCs-PQDs composite system was formed by the combination of gold nanocages (GNCs) and perovskite quantum dots (PQDs). Spectral analysis confirmed that its fluorescence intensity was significantly enhanced by 15.38% compared with that of pure PQDs. Furthermore, amino modification was performed on the nanomaterial. Through the specific design of molecular beacons (MB), the fluorescence emission spectrum of the probe was matched with the absorption peak of the quencher group BHQ2, and the effective closure of the fluorescence signal was achieved based on the Fluorescence Resonance Energy Transfer (FRET) effect. Subsequently, MB was immobilized on the surface of the composite system via amino covalent conjugation to complete the probe preparation. The prepared probe was applied to the detection of miRNA-4529-3P and miR-301b-3p, which are tumor markers of non-small cell lung cancer (NSCLC). The hybridization of target molecules with MB could trigger the disruption of FRET and the recovery of fluorescence signal, exhibiting excellent recognition performance. This study provides an experimental basis for the preparation of composite fluorescent probes, and the developed probe has potential application value in the field of tumor marker detection.

Accurate measurement of material mechanics parameters is crucial for evaluating process quality and product reliability and is a major challenge in the development of 3D heterogeneous integration technology. Aiming to perform high-accuracy measurements of the elastoplastic nonlinear constitutive parameters of microelectronic materials using the nanoindentation testing technique, we take advantage of a neural network to construct a forward characterization model to characterize these response characteristic parameters for different materials, design an improved algorithm for obtaining a reverse iterative solution of the forward characterization model, and develop a material mechanics parameter measurement method to solve overdetermined equations using the least-squares method. This method was further improved by addressing the issues of algorithm stability and solution uniqueness, achieving high-precision and fast reverse solutions for elastoplastic constitutive parameters. The relative error of the material parameters is less than 3% (95% confidence interval), the maximum error is less than 8%, and the inversion convergence error of the key indentation response characteristic parameters is less than 0.1%. The difference between the measured material parameters and the theoretical model in the influence on the process stress of TCV (through ceramic via) products is verified through finite element simulation.