聚氯乙烯人工革抗菌防霉技术应用研究

介绍了聚氯乙烯人工革的实验室抗菌防霉试验方法,阐述了材料抗菌防霉测试机理,以及聚氯乙烯人工革产品在设定的试验条件下的抗菌防霉试验情况,并对聚氯乙烯人工革抗菌防霉的测试方法进行了评价.     

Three-dimensional ordered microporous silica supported p-lanthanum ferrite and n-ceria as heterojunction photocatalyst to activate peroxymonosulfate for bisphenol a degradation

In this study, three-dimensional ordered microporous silica supported p-lanthanum ferrite and n-ceria (n-CeO₂@p-LaFeO₃/3DOM SiO₂) was successfully synthesized as a visible light-driven photocatalyst for activating peroxymonosulfate (PMS) to degrade Bisphenol A (BPA). In a wide pH range (2–12), the BPA degradation efficiency maintained at a high level, organic matter and natural inorganic ions had no significant negative impact. When the BPA concentration was as low as 2 mg·L⁻¹, the removal rate in 60 min still reached 95.56%, indicating that the novel photocatalyst has potential application in the treatment of trace pollutants. The pore confinement effects of catalysts and the synergistic effect between LaFeO₃ and CeO₂ result in the excellent photocatalytic performance. We proposed the possible mechanism of BPA degradation, specifically involving the recognition and generation mechanism of reactive oxygen species (ROSs), adsorption processes and diffusion processes. In summary, the novel n-CeO₂@p-LaFeO₃/3DOM SiO₂ would be a promising candidate photocatalytic material for practical sewage treatment.     

Preparation and luminescent modulation of KGaSiO4:Eu3+ phosphors using for multiple anti-counterfeiting

Anti-counterfeiting technology is of great significance to information security. To obtain high-quality anti-counterfeiting materials, the developments of inorganic materials are crucial. In this paper, a series KGaSiO₄:xEu³⁺ phosphors with persistent luminescence, photoluminescence, and thermochromic have been successfully prepared and the application of quadruple anti-counterfeiting is realized. The X-ray diffraction and Rietveld refinement indicate that the phosphors are pure phase. With Eu³⁺ ions doping, the structure change, site occupancies, and color-tunable phenomenon are carefully investigated. Different from another Eu³⁺ doping phosphor, the emission of KGaSiO₄:0.2% Eu³⁺ phosphor changes with the excitation light in the region of 240 nm–306 nm. The emission color can be modulated with the surrounding temperature. Surprisingly, this phosphor can emit green afterglow light, which is attributed to the different luminescent properties of the matrix and doping of Eu³⁺ ions. The series of phosphors exhibit abundant luminescent properties. Based on their wavelength dependence, concentration quenching, long afterglow, and thermochromic properties, the KGaSiO₄:xEu³⁺ phosphors can be effective materials for quadruple-modal anti-counterfeiting devices.     

Inhibition of electric field on inception soot formation: A ReaxFF MD and DFT study

The attenuation of soot formation from polycyclic aromatic hydrocarbons during the fuel combustion process is important to human health and environmental pollution. This work studies the mechanism of inhibition soot formation process under electric field. The process of soot formation with the chemical bonding and physical stacking of PAHs nucleation was investigated under the influence of electric field by using ReaxFF molecular dynamics and density functional theory. MD simulation reveals that the electric field in 1 × 10⁻⁵–1 × 10⁻⁴ V/Å induces an alternation in dispersion and stacking of PAH cluster to inhibit the PAH nucleation. The electric field inhibits the dehydrogenation and C–C bond cracking of the initial PAH during chemical growth of PAHs. Due to instability of the 5–7 membered rings, there are fewer bonding sites for large graphite lamella growth. The elucidation of reaction enthalpy of dehydrogenation, dimer growth, and the binding energy of π-π stacking with different direction field, are explored using DFT. The computational work discloses the inhibition mechanism of electric field on PAH development. The characterization results obtained by scanning electron microscopy and the temperature-programmed oxidation shows the coke content and particle size can be reduced under the influence of electric field which validates the computational result. The scientific insights gained here is useful for understanding soot inhabitation phenomenon.     

In-situ CdS nanowires on g-C3N4 nanosheet heterojunction construction in 3D-Optofluidic microreactor for the photocatalytic green hydrogen production

Herein, we reported a simple and cost-effective fabrication method to develop an effective corrugated serpentine OFMR (C-SOFMR) with advanced features, such as expansion/contraction and wavy microstructure. A laminar flow with no back mixing was observed in plain serpentine OFMR (P-SOFMR). While, stretching and folding of fluid along with back mixing was observed in C-SOFMR. Further, the CdS nanowires on g-C₃N₄ nanosheet (CN/CdS) heterojunction was synthesized in situ both P-SOFMR and C-SOFMR and utilized the device for the photocatalytic green hydrogen generation. The CN/CdS heterojunction endowed with narrow band gap energy (2.01 eV). The longer CdS nanowires (∼110 nm) benefit the electronic interface with CN in the CN/CdS heterojunction and lead to the spatial separation (reduced recombination) of excitons along the CdS axial direction. The charges generated were utilized efficiently for the HER reaction in both P-SOFMR and C-SOFMR at higher flow rates attributing to the rapid micro-mixing and mass transfer. The CN/CdS heterojunction showed the highest photocatalytic activity (6.38 μmol h⁻¹ in C-SOFMR and 6.16 μmol h⁻¹ in P-SOFMR at 1.0 mL min⁻¹) due to its good optronic properties. This study is a path forward for the utilization of advanced optofluidic devices to produce green hydrogen directly from solar energy.     

Insights into morphology-dependent Au/TiO2catalyst in glycerol aqueous solutions towards photothermal reforming hydrogen production

Probing the effect of spatial morphology of catalyst on its photothermal catalytic performance is crucial for solar-driven renewable catalytic reforming of hydrogen production. In this study, Au nanoparticles loaded on various morphologies of TiO₂ nanoparticles were synthesized and characterized. The experimental results indicated that decorating TiO₂ with Au nanoparticles could dramatically increase its photocatalytic activities by 20–40 times. The photothermal conversion efficiency of Au/TiO₂ (12.74%–25.54%) was higher than those of TiO₂ due to the introduction of LSPR of Au nanoparticles could effectively improve the utilization of solar spectrum. Titania nanoflower (TNF) nanoparticles with high light absorption capacity, better colloidal dispersion stability, porous properties and narrow band gap represented the highest H₂ productivity (144.13 μmol·g⁻¹·h⁻¹). The coarse surface structure was also conducive to the dispersion of gold particles on the surface of the carrier and the growth rate of Au/TNF hydrogen production (40 times) which was higher than that of other morphology within 2 h. The results of glycerol photothermal hydrogen generation highlighted the effect of temperature on colloidal dispersion stability and hydrogen production capability of nanoparticle suspension. It demonstrated that the photothermal effect aroused a temperature rise that would deteriorate the dispersion stability of the suspension although a local entropy increase in the catalyst nanoparticles might occur. At the same time, the temperature rise caused by the photothermal effect efficiently produces hydrogen in the reaction temperature range. Therefore, an ideal temperature setting for maximal hydrogen generation could be validated and improved the photothermal synergistic impact on biomass-reformed hydrogen generation.     

Synergistic effect of gold NPs modified graphitic carbon nitride nanotubes (g-CNT) with the role of hot electrons and hole scavengers for boosting solar hydrogen production

The efficient and selective photocatalysts for the evolution of hydrogen are highly demanding, however, many semiconductors are complex in nature and have lower photocatalytic efficiency. This is because of their small exposed surface area, poor light penetration, and unregulated charge recombination rate. Herein, well-designed graphitic carbon nitride with hierarchical nanotextures loaded with plasmonic gold (Au) nanoparticles has been investigated for stimulating photocatalytic H₂ evolution. Hole scavengers, diffusion effects, duration, and mass transfer were used to evaluate the photoactivity activity in a slurry type continuous flow photoreactor system. Due to better charge carrier separation and enhanced light permeability, H₂ evolution was boosted by two times when bulk g-C₃N₄ structure was alternated with graphitic carbon nitride nanotubes (g-CNT). The maximum H₂ generation rate was 455 μmol g⁻¹ h⁻¹ with 0.3% Au/g-CNT nanotexture, which was 17.8 and 8.9 times greater than utilizing g-C₃N₄ and g-CNT samples, respectively. The key factors influencing this improvement in photoactivity were the unique interlayer opening, higher light penetration, more light utilization due to plasmonic effect, enhanced surface reactive active sites, and decreased charge carrier recombination. The hot electrons due to plasmonic gold was another important feature to promote H₂ evolution rate under solar energy. It is possible to employ these freshly developed nanotextures, which have a gold plasmonic effect, for solar energy conversion and other energy-related applications.