Effects of Preparation Conditions on the Yield and Embedding Ratio of Vinyl Silicone Oil Microcapsules

Self-healing materials could repair themselves without external influences when they are damaged. In this paper, microcapsules are prepared by in-situ polymerization method, utilizing vinyl silicone oil as core material, polyurea formaldehyde as wall material and polyvinyl alcohol as dispersant. The morphology and structure of the microcapsules are tested with scanning electron microscopy, optical microscopy and laser particle analyzer. Effect of the reaction temperature, stirring speed and polyvinyl alcohol concentration on the yield, embedding ratio, particle size and its distribution are studied. Results show that the microcapsules can be successfully prepared by in-situ polymerization method. Under the reaction condition of temperature 60 °C, stirring speed 1000 r/min, dispersant concentration 0.1 wt.%, the yield and embedding ratio of the microcapsule are found to be 52.5 % and 50.1 %, respectively. The prepared microcapsules have smooth surface, good dispersibility, narrow particle size distribution and the average particle size is 13 μm

In situ Carbon Modification of g-C3N4 from Urea Co-crystal with Enhanced Photocatalytic Activity Towards Degradation of Organic Dyes Under Visible Light

An in situ strategy was introduced for synthesizing carbon modified graphitic carbon nitride(g-C3N4) by using urea/4-aminobenzoic acid(PABA) co-crystal(PABA@Urea) as precursor materials. Via co-calcination of the PABA co-former and the urea in PABA@Urea co-crystals, C guest species were generated and compounded into g-C3N4 matrix in situ by replacing the lattice N of the carbon nitride and forming carbon dots onto its layer surface. The carbon modification dramatically enhanced visible-light harvesting and charge carrier separation. Therefore, visible light photo-catalytic oxidation of methylene blue(MB) pollution in water over the carbon modified g-C3N4 (C/g-C3N4) was notably improved. Up to 99% of methylene blue(MB) was eliminated within 60 min by the optimal sample prepared from the PABA@Urea co-crystal with a PABA content of 0.1%(mass ratio), faster than the degradation rate over bare g-C3N4. The present study demonstrates a new way to boost up the photocatalysis performance of g-C3N4, which holds great potential concerning the degradation of organic dyes from water

Influence of Nanosemiconductor Materials on Thermal Stability of Solar Cells

In order to overcome the problem of long-term stability of perovskite solar cells, the author proposes a method to study the effects of nanosemiconductor materials on the thermal stability of solar cells. In this method, n = 3 and n = 1 (C6H5(CH2)2NH3)2(CH3NH3)n-1Pbn I3n+1 two-dimensional nanoperovskite films were investigated on glass substrates and indium tin oxide (ITO) substrates, respectively, on the thermal stability. Experimental results show that the glass-based nanoperovskite PMPI3 film was partially decomposed into PbI2 after being heated at 160°C. When the temperature reaches 180°C, the film is completely decomposed into PbI2, and the perovskite PMPI3 film with ITO as the substrate is completely decomposed into PbI2 when the heating temperature reaches 140°C. The charge transfer between the perovskite film and the substrate is the physical reason for its easier thermal decomposition on the ITO substrate. Suggestions for improving the thermal stability of perovskite solar cell devices are given from the aspects of device design and fabrication process

Advancing Strategies of Biofouling Control in Water-Treated Polymeric Membranes

Polymeric membranes, such as polyamide thin film composite membranes, have gained increasing popularity in wastewater treatment, seawater desalination, as well as the purification and concentration of chemicals for their high salt-rejection and water flux properties. Membrane biofouling originates from the attachment or deposition of organic macromolecules/microorganisms and leads to an increased operating pressure and shortened service life and has greatly limited the application of polymeric membranes. Over the past few years, numerous strategies and materials were developed with the aim to control membrane biofouling. In this review, the formation process, influence factors, and consequences of membrane biofouling are systematically summarized. Additionally, the specific strategies for mitigating membrane biofouling including anchoring of hydrophilic monomers, the incorporation of inorganic antimicrobial nanoparticles, coating/grafting of cationic bactericidal polymers, and the design of multifunctional material integrated multiple anti-biofouling mechanisms, are highlighted. Finally, perspectives on the challenges and opportunities in anti-biofouling polymeric membranes are shared, shedding light on the development of even better anti-biofouling materials in near future

Perylene tetracarboxylic bisimide decorated g-C3N4 with enhanced photocatalytic activity

A water-soluble perylene bisimide derivative, N, N'-di(2-succinic acid)-perylene-3, 4, 9, 10-tetracarboxylic bisimide (PASP) was synthesized by using 3, 4, 9, 10-perylenetetracarboxylic dianhydride and L-aspartic acid as starting materials. The PASP were grafted onto graphitic carbon nitride (g-C3N4) via hydrothermal method to prepare PASP modified g-C3N4 hybrid photocatalyst (g-C3N4-PASP). The composition, structure, morphology and optical properties of the prepared g-C3N4-PASP samples were typically characterized by X-ray diffraction(XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy(XPS), scanning electron microscopy(SEM), transmission electron microscopy(TEM), UV-Vis diffuse reflectance spectroscopy(UV-Vis DRS), and solid-state fluorescence spectroscopy. In addition, the photocatalytic activities of the prepared g-C3N4-PASP photocatalysts were evaluated by decomposition of methylene blue(MB) pollutant in water solution under visible light. The results reveal that PASP can be facilely linked to the g-C3N4 covalently via amide bond by hydrothermal treatment; compared to pristine g-C3N4, the g-C3N4-PASP possesses obviously higher specific surface area, dramatic red shifted absorption edge of 614 nm, and more efficient charge separation. Therefore, the visible light photo-catalytic degradation of MB pollution in water over the g-C3N4-PASP is notably improved. The g-C3N4-PASP could degrade 99.4% of MB dyes in 60 min under visible light irradiations (λ >420 nm), with a pseudo-first-order rate constant 2 times higher than that of pristine g-C3N4

Bioactive secondary metabolites produced by fungi of the genus Diaporthe (Phomopsis): Structures, biological activities, and biosynthesis

Diaporthe and its anamorph Phomopsis, a genus of endophytic, saprotrophic, and plant pathogenic fungi, are found in many different ecosystems worldwide. Diaporthe (Phomopsis) fungi generate natural products such as pyrones, polyketides, alkaloids, and terpenoids. Most of these natural products show antibacterial, anti-inflammatory, and/or cytotoxic activity. In this review, we describe the 331 bioactive secondary metabolites isolated from 75 known species and various unidentified species of Diaporthe and Phomopsis from 2016 to 2021. These products comprise 143 bioactive compounds from Diaporthe and 188 from Phomopsis, including quinones, alkaloids, terpenoids, pyrones, polyketides, diphenyl ketones, diphenyl ethers, steroids, and fatty acids. The major activities of these compounds are as cytotoxic, antibacterial, and anti-inflammatory chemicals. All 21 fungi in the genus Diaporthe (Phomopsis) with available whole genome sequencing data contain several gene clusters for secondary metabolite biosynthesis. Such gene clusters and biosynthetic mechanisms have been identified for rugulosin A, terpestacin, and sch-642305. Diaporthe (Phomopsis) fungi produce abundant novel active natural products with great potential for drug development. In addition, these fungi provide important resources for research on the biosynthesis of secondary metabolites

Denitrifying sulfide removal process on high-salinity wastewaters in the presence of Halomonas sp

Biological conversion of sulfide, acetate, and nitrate to, respectively, elemental sulfur (S), carbon dioxide, and nitrogen-containing gas (such as N) at NaCl concentration of 35–70\ua0g/L was achieved in an expanded granular sludge bed (EGSB) reactor. A C/N ratio of 1:1 was noted to achieve high sulfide removal and S conversion rate at high salinity. The extracellular polymeric substance (EPS) quantities were increased with NaCl concentration, being 11.4-mg/g volatile-suspended solids at 70\ua0mg/L NaCl. The denitrifying sulfide removal (DSR) consortium incorporated Thauera sp. and Halomonas sp. as the heterotrophs and Azoarcus sp. being the autotrophs at high salinity condition. Halomonas sp. correlates with the enhanced DSR performance at high salinity