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Kinetic stabilization of cellulose nanocrystals in a photocurable prepolymer for application as an adhesion promoter in UV-curable coatings
摘要： Cellulose nanocrystals (CNC) at low loading levels were shown to reinforce a photocurable coating resulting in improved adhesion. A polyether polyol containing CNC at loading levels of up to 1.8 wt% was grafted with 3-isopropenyl-α,α-dimethylbenzyl isocyanate to functionalize it with a photocurable group. The nanoparticles were kinetically stabilized in the rapidly forming prepolymer of high viscosity. Photoinitiators and a difunctional reactive diluent were added to produce optically transparent coatings and free films upon irradiation by ultraviolet (UV) light. This allowed evaluation of the effects of CNC at low loading levels in a glassy polymer matrix obtained through a rapid cure system. Incorporation of CNC nanoparticles in the polymer matrix resulted in an average improvement in adhesive strength of 154% while enhancing tensile strength by an average of 16%. The technique described could be used as a new approach to reduce adhesive failure in UV-curable coatings without sacrificing their mechanical strength.
关键词： Coatings,Nanoreinforcement,UV curing,Nanocomposite,Adhesion promoter,Cellulose nanocrystals
更新于2025-11-21 11:01:37
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Enhanced Charge Separation in g-C3N4 – BiOI Heterostructures for Visible Light Driven Photoelectrochemical Water Splitting
摘要： Heterojunctions of the low bandgap semiconductor bismuth oxyiodide (BiOI) with bulk multilayered graphitic carbon nitride (g-C3N4) and few layered graphitic carbon nitride sheets (g-C3N4-S) are synthesized and investigated as an active photoanode material for sunlight driven water splitting. HR-TEM and elemental mapping reveals formation of a unique heterostructure between BiOI platelets and the carbon nitride (g-C3N4 and g-C3N4-S) network that consisted of dendritic BiOI nanoplates surrounded by g-C3N4 sheets. The presence of BiOI in g-C3N4-S/BiOI and g-C3N4-S/BiOI nanocomposites extends the visible light absorption profile from 500 nm up to 650 nm. Due to excellent charge separation in g-C3N4/BiOI and g-C3N4-S/BiOI, evident from quenching of the carbon nitride photoluminescence (PL) and a decrease in the PL lifetime, a significant increase in photoelectrochemical performance is observed for both types of g-C3N4-BiOI heterojunctions. In comparison to heterojunctions of bulk g-C3N4 with BiOI, the nancomposite consisting of few layered sheets of g-C3N4 and BiOI exhibits higher photocurrent density due to lower recombination in few layered sheets. A synergistic trap passivation and charge separation is found to occur in the g-C3N4-S/BiOI nanocomposite heterostructure which results in a higher photocurrent and a lower charge transfer resistance.
关键词： visible light driven photocatalysis,earth abundant semiconductor heterostructures,Graphenic semiconductors,photoelectrochemistry
更新于2025-11-21 11:01:37
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A hybrid nanomaterial with NIR-induced heat and associated hydroxyl radical generation for synergistic tumor therapy
摘要： Although photothermal therapy (PTT) and photodynamic therapy (PDT) are widely commended for tumor treatment recently, they still suffer severe challenges due to the non-specificity of photothermal agents (PTAs)/photosensitizers (PSs) and hypoxic tumor microenvironment. Here, an oxygen independent biomimetic nanoplatform based on carbon sphere dotted with cerium oxide and coated by cell membrane (MCSCe) was designed and synthesized with good biocompatibility, homologous targeting ability, and improved photophysical activity. Notably, MCSCe could realize accumulation of hydrogen peroxide (H2O2) in tumor cells and hyperthermia under single laser (808 nm) irradiation, which were simultaneously utilized by itself to produce more toxic hydroxyl radical (·OH). Resultantly, the synergistic therapeutic effect against tumor cells was obtained under near infrared (NIR) laser irradiation.
关键词： cerium oxide,H2O2 self-accumulation,cell membrane,tumor therapy,carbon sphere
更新于2025-11-21 11:01:37
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Vertically aligned MoS <sub/>2</sub> nanosheets on graphene for highly-stable electrocatalytic hydrogen evolution reaction
摘要： Efficient hydrogen evolution reaction (HER) using two-dimensional layered materials as electrocatalyst with high-performance remains a challenging task due to the insufficient edge active sites. In this regard, herein, molybdenum disulphide nanosheets with rich active sulphur sites are vertically grown on graphene surface by chemical vapour deposition process. The direct integration of vertically aligned MoS2 nanosheets on graphene forms van der Waals (vdW) heterojunction which facilitates a barrier free charge transport towards the electrolyte as a result of unique and well-matched energy band alignment at the interface. The prospective combination of Ohmic graphene/MoS2 heterostructure and high electrocatalytic edge activity of sulphur deliver an incredible and small turn on potential of 0.14 V vs. RHE in acid electrolyte solution. Most importantly, the use of vertical vdW device architexture exhibits nearly 8X improvement in HER than that of layered counterpart. Besides, the HER reaction is highly stable over 50 hours of continuous run even after 150 days. The combined analysis of our study make certain that the graphene/MoS2 heterostructure will be an efficient and alternative low-cost electrochemical electrode for large scale applications to harvest hydrogen.
更新于2025-11-21 11:01:37
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Aluminium doping – a cost effective and super-fast method for low temperature crystallization of TiO <sub/>2</sub> nanotubes
摘要： In this paper, low-temperature crystallization of well aligned TiO2 nanotubes within a record time of 20 seconds is reported. This new super-fast crystallization route with a tremendous technological impact due to its low energy budget and reproducibility involves the doping of TiO2 nanotubes with aluminium at different temperatures from 2 °C to 60 °C by applying a negative voltage to amorphous nanotubes. The process offers formation of doped anatase TiO2 nanotubes with a tuned band gap and improved conductivity.
更新于2025-11-21 11:01:37
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One-pot hydrothermal synthesis of MoS <sub/>2</sub> -modified Mn <sub/>0.5</sub> Cd <sub/>0.5</sub> S solid solution for boosting H <sub/>2</sub> production activity under visible light
摘要： The development of low-cost and highly efficient photocatalysts with a visible-light-responsive feature for H2 production from water photosplitting is an interesting but challenging research topic. In this study, a series of MnxCd1?xS products (0 ≤ x ≤ 1.0) have been prepared by a facile hydrothermal method, and the resultant Mn0.5Cd0.5S solid solution exhibits the highest photocatalytic H2 production activity (286 μmol h?1), which is 1.83 times higher than that (156 μmol h?1) of single CdS under visible light (λ ≥ 420 nm) irradiation. After being modified with MoS2 via a one-pot hydrothermal process, the MoS2-modified Mn0.5Cd0.5S (MoS2/Mn0.5Cd0.5S) composites achieve remarkable improvement in their photocatalytic performance under λ ≥ 420 nm light irradiation, and the 0.5 wt% MoS2/Mn0.5Cd0.5S displays the highest H2 production activity (491 μmol h?1), which is much higher than that (286 μmol h?1) of pristine Mn0.5Cd0.5S and also slightly higher than that (417 μmol h?1) of 1.0 wt% Pt/Mn0.5Cd0.5S. The intimate interfacial contact between Mn0.5Cd0.5S nanoparticles and few-layer MoS2 cocatalysts formed during the one-pot hydrothermal process facilitates the electron transfer from Mn0.5Cd0.5S to MoS2, and thus promotes the photogenerated charge separation and provides more active sites for H2 evolution reaction. This work demonstrates that low cost and earth-abundant MoS2 as an effective cocatalyst can replace noble metals for visible-light-driven H2 production over MnxCd1?xS solid solutions.
更新于2025-11-21 11:01:37
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A versatile bacterial membrane-binding chimeric peptide with enhanced photodynamic antimicrobial activity
摘要： Photodynamic therapy (PDT) has become an effective antibiosis method for overcoming antibiotic resistance. In this study, we developed a versatile bacterial membrane-binding chimeric peptide PpIX-[PEG8-(KLAKLAK)2]2 (denoted as PPK) by conjugating a photosensitizer protoporphyrin IX (PpIX) with the antimicrobial peptide (KLAKLAK)2 (KLA) for effective photodynamic inactivation of bacteria. The chimeric peptide PPK with positively charged property and α-helical conformation could rapidly bind to microbial cells through electrostatic interaction and membrane insertion. Moreover, PPK could disrupt bacterial membrane and further elicit lipid bilayer leakage to kill bacteria by toxic reactive oxygen species (ROS) generated by PpIX under 660 nm light. In vitro experiments demonstrated that cationic PPK possessed excellent antimicrobial activity against both Gram-positive bacteria Staphylococcus aureus (S. aureus) and Gram-negative bacteria Escherichia coli (E. coli). Afterward, PPK also exhibited perfect therapeutic effects on S. aureus-infected mice without any systemic side effect. This chimeric peptide PPK will find great potential for photodynamic antibiosis.
更新于2025-11-21 11:01:37
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Correlated Light-Serial Scanning Electron Microscopy (CoLSSEM) for ultrastructural visualization of single neurons in vivo
摘要： A challenging aspect of neuroscience revolves around mapping the synaptic connections within neural circuits (connectomics) over scales spanning several orders of magnitude (nanometers to meters). Despite significant improvements in serial section electron microscopy (SSEM) technologies, several major roadblocks have impaired its general applicability to mammalian neural circuits. In the present study, we introduce a new approach that circumvents some of these roadblocks by adapting a genetically-encoded ascorbate peroxidase (APEX2) as a fusion protein to a membrane-targeted fluorescent reporter (CAAX-Venus), and introduce it in single pyramidal neurons in vivo using extremely sparse in utero cortical electroporation. This approach allows us to perform Correlated Light-SSEM (CoLSSEM), a variant of Correlated Light-EM (CLEM), on individual neurons, reconstructing their dendritic and axonal arborization in a targeted way via combination of high-resolution confocal microscopy, and subsequent imaging of its ultrastructural features and synaptic connections with ATUM-SEM (automated tape-collecting ultramicrotome - scanning electron microscopy) technology. Our method significantly will improve the feasibility of large-scale reconstructions of neurons within a circuit, and permits the description of some ultrastructural features of identified neurons with their functional and/or structural connectivity, one of the main goal of connectomics.
关键词： connectomics,APEX2,in vivo,Correlated Light-SSEM,single neurons,ultrastructural visualization
更新于2025-11-21 11:01:37
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Molten salt synthesis of highly ordered and nanostructured hexagonal boron nitride
摘要： Hexagonal boron nitride (h-BN) is a well-known ceramic that has wide application areas ranging from electronics to metallurgy. However, highly ordered h-BN is conventionally synthesized at high temperatures above 1800 °C. In this work, we investigated the formation of BN from boric acid (H3BO3)-ammonium chloride (NH4Cl) mixture in the sodium chloride (NaCl)-potassium chloride (KCl) eutectic salt. We report the synthesis of highly ordered and nanostructured h-BN at 1000 °C using molten salt synthesis. The effect of starting composition, synthesis temperature, and dwell time on BN formation and its structural ordering were systematically investigated. It is concluded that the molten salt plays important roles in the formation of BN and its structural ordering, which is achieved by i) decomposing the boron (B)-nitrogen (N) bearing reactants that lead to the formation of BN layers, and ii) increasing the mobility of BN layers formed. Furthermore, we propose a possible reaction mechanism that governs the BN formation from the reactant mixture in molten salts and explain the observations based on thermodynamic and kinetic considerations.
关键词： Molten salt synthesis,NaCl-KCl eutectic salt,Boron nitride,Structural ordering,High-resolution transmission electron microscopy
更新于2025-11-21 11:01:37
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Electrochemical synthesis of Zn: ZnO/Ni2P and efficient photocatalytic degradation of Auramine O in aqueous solution under multi-variable experimental design optimization
摘要： Present work is devoted to synthesis Zn: ZnO/Ni2P by electrochemical method and identification and properties investigation by various techniques such as SEM, EDS, XRD and DRS. The experimental results reveal have ability for degradation of Auramine O (AO) following estimation of correlation among response to (main effect and variables interactions) variable like irradiation time, nanocomposite mass, pH and initial AO concentrations by a central composite design (CCD). The optimum condition for the photo-degradation of AO by photocatalyst was 6.72, 61.66 min, 13.13 mg.L-1 and 0.014 g correspond to the pH, irradiation time, AO concentration and photocatalyst mass, respectively. At these optimum conditions, the AO photocatalytic degradation percentages with desirability of 0.94 was 95.47% using reasonable consumption of reagent. The quasi first-order kinetic model derived from Langmuir–Hinshelwood (L–H) efficiently represent real behavior of experimental data of correspond to under study system. The photocatalytic reaction, L–H rate constants and L–H adsorption constants for Zn: ZnO/Ni2P were 0.0375 min-1, 27.39 mg.min-1.L and 0.00048 L.mg-1, respectively.
关键词： photocatalytic degradation,Auremine O,electrochemical synthesis.,Zn: ZnO/Ni2P,response surface methodology
更新于2025-11-21 11:01:37