Project description:Low surface energy coatings have gained considerable attention due to their superior surface hydrophobic properties. However, their abrasion resistance and sustainability of surface hydrophobicity are still not very satisfactory and need to be improved. In this work, a series of utraviolet (UV)-curable fluorosiloxane copolymers were synthesized and used as reactive additives to prepare polyurethane acrylate coatings with low surface energy. The effect of the addition of the fluorinated graft copolymers on the mechanical durability and surface hydrophobicity of the UV-cured hybrid films during the friction-annealing treatment cycles was investigated. The results show that introducing fluorosiloxane additives can greatly enhance surface hydrophobicity of the hybrid film. With addition of 2 wt.% fluorosiloxane copolymers, the water contact angle (WCA) value of the hybrid film was almost tripled compared to that of the pristine PU film, increasing from 58° to 144°. The hybrid film also showed enhanced abrasion resistance and could withstand up to about 60 times of friction under a pressure of 20 kPa. The microstructure formed in the annealed film was found to contribute much to achieve better surface hydrophobicity. The polyurethane acrylate/fluorinated siloxane resin hybrid film prepared in this study exhibits excellent potential for applications in the low surface energy field.
Project description:Polymer electrolytes are attractive candidates to boost the application of rechargeable lithium metal batteries. Single-ion conducting polymers may reduce polarization and lithium dendrite growth, though these materials could be mechanically overly rigid, thus requiring ion mobilizers such as organic solvents to foster transport of Li ions. An inhomogeneous mobilizer distribution and occurrence of preferential Li transport pathways eventually yield favored spots for Li plating, thereby imposing additional mechanical stress and even premature cell short circuits. In this work, we explored ceramic-in-polymer hybrid electrolytes consisting of polymer blends of single-ion conducting polymer and PVdF-HFP, including EC/PC as swelling agents and silane-functionalized LATP particles. The hybrid electrolyte features an oxide-rich layer that notably stabilizes the interphase toward Li metal, enabling single-side lithium deposition for over 700 h at a current density of 0.1 mA cm-2. The incorporated oxide particles significantly reduce the natural solvent uptake from 140 to 38 wt % despite maintaining reasonably high ionic conductivities. Its electrochemical performance was evaluated in LiNi0.6Co0.2Mn0.2O2 (NMC622)||Li metal cells, exhibiting impressive capacity retention over 300 cycles. Notably, very thin LiNbO3 coating of the cathode material further boosts the cycling stability, resulting in an overall capacity retention of 78% over more than 600 cycles, clearly highlighting the potential of hybrid electrolyte concepts.
Project description:Catalytic ceramic membranes (CMs) integrated with different metal oxides were designed and fabricated by an impregnation-sintering method. The characterization results indicated that the metal oxides (Co3O4, MnO2, Fe2O3 and CuO) were uniformly anchored around the Al2O3 particles of the membrane basal materials, which could provide a large number of active sites throughout the membrane for the activation of peroxymonosulfate (PMS). The performance of the CMs/PMS system was evaluated by filtrating a phenol solution under different operating conditions. All the four catalytic CMs showed desirable phenol removal efficiency and the performance was in order of CoCM, MnCM, FeCM and CuCM. Moreover, the low metal ion leaching and high catalytic activity even after the 6th run revealed the good stability and reusability of the catalytic CMs. Quenching experiments and electron paramagnetic resonance (EPR) measurements were conducted to discuss the mechanism of PMS activation in the CMs/PMS system. The reactive oxygen species (ROS) were supposed to be SO4˙- and 1O2 in the CoCM/PMS system, 1O2 and O2˙- in the MnCM/PMS system, SO4˙- and ·OH in the FeCM/PMS system, and SO4˙- in the CuCM/PMS system, respectively. The comparative study on the performance and mechanism of the four CMs provides a better understanding of the integrated PMS-CMs behaviors.
Project description:To measure the toxic potential of asbestos fibers-a known cause of asbestosis, lung cancer, and malignant mesothelioma-asbestos minerals are generally first ground down to small fibers, but it is unknown whether the grinding condition itself changes the fiber toxicity. To evaluate this, we ground chrysotile ore with or without water for 5-30 min and quantified asbestos-induced reactive oxygen species generation in elicited murine peritoneal macrophages as an indicator of fiber toxicity. The toxicity of dry-ground fibers was higher than the toxicity of wet-ground fibers. Grinding with or without water did not materially alter the mineralogical properties. However, dry-ground fibers contained at least 7 times more iron than wet-ground fibers. These results indicate that grinding methods significantly affect the surface concentration of iron, resulting in changes in fiber-induced reactive oxygen species generation or toxicity. Therefore, fiber preparation conditions should be accounted for when comparing the toxicity of asbestos fibers between reported studies.
Project description:High over-all properties, including low dielectric loss, high breakdown strength, high mechanical shock strength, high thermal conductivity and high weight stability, are very difficult to simultaneously achieve in electrical-insulation applicable cured potting-adhesive materials. To deal with this challenge, in this work, we have designed and fabricated a series of epoxy based composite potting-adhesives filled with low-cost and high-performance inorganic micro-particles including alpha-silica, alpha-alumina and alpha-SiC. Combination employment of high-molecular-weight and low-molecular-weight epoxy resins as matrices has been made. Heat-induced curing or crosslink of resin matrices has been carried out. Large band gap of silica filler has endowed the cured composite with high breakdown strength and ageing breakdown strength, and meanwhile relatively high deformation trait of silica has led to high shock strength of cured composite. Silica filler has been found to be superior to other two fillers, namely, optimal over-all properties such as dielectric, breakdown, mechanical and thermal features have been obtained in silica filled cured composite. High breakdown strength of ~48?MV m-1 and shock strength of ~9950?J?m-2 have been achieved in silica loaded composite. This work might open up the way for large-scale fabrication of promising epoxy-based hybrid potting-adhesives.
Project description:Post-Infective Bowel Dysfunction following Campylobacter enteritis is characterised by reduced microbiota diversity and impaired microbiota recovery
Project description:In the present study, a surface-active enzyme, lipase was immobilized in polyethyleneimine (PEI) microcapsules and then modified with oxidized multiwall carbon nanotubes (MWCNTs). The resulting lipase microcapsules exhibited higher activity and stability, since the activity of microcapsules was 21.9 folds than that of the free counterpart. Numerous interfaces which were created in polycondensation enhanced the performance of lipases. Illustrated by confocal laser scanning microscope (CLSM), it was found that microcapsules, whose barrier properties against molecules with diameter >4.6 nm, were with a semipermeable and porous membrane structure. The lipases preferred to locate in the wall of the microcapsules. The oxidized multiwall carbon nanotubes (MWCNTs) were further added to modify microcapsules, resulting in even higher activity. The nanocomposites were examined by scanning electron microscope (SEM) and zeta-potential analyzer. The results indicated the superior catalytic performances were attributed to the augmented interface and decreased positive charge. Finally, the MWCNTs modified microcapsules were utilized in producing biodiesel with a 97.15% yield and retained nearly 90% yield after running 10 cycles. This approach of microcapsulation will be highly beneficial for preparing various bio-active microcapsules with excellent catalytic performance.
Project description:Insulin resistance is a complex metabolic disorder that defies explanation by a single etiological pathway. Accumulation of ectopic lipid metabolites, activation of the unfolded protein response (UPR) pathway, and innate immune pathways have all been implicated in the pathogenesis of insulin resistance. However, these pathways are also closely linked to changes in fatty acid uptake, lipogenesis, and energy expenditure that can impact ectopic lipid deposition. Ultimately, these cellular changes may converge to promote the accumulation of specific lipid metabolites (diacylglycerols and/or ceramides) in liver and skeletal muscle, a common final pathway leading to impaired insulin signaling and insulin resistance.
Project description:Monoclinic bismuth vanadate (BiVO4) is an attractive material with which to fabricate photoanodes due to its suitable band structure and excellent photoelectrochemical (PEC) performance. However, the poor PEC stability originating from its severe photo-corrosion greatly restricts its practical applications. In this paper, pristine and Mo doped BiVO4 ceramics were prepared using the spark plasma sintering (SPS) method, and their photoelectrochemical properties as photoanodes were investigated. The as-prepared 1% Mo doped BiVO4 ceramic (Mo-BVO (C)) photoanode exhibited enhanced PEC stability compared to 1% Mo doped BiVO4 films on fluorine doped Tin Oxide (FTO) coated glass substrates (Mo-BVO). Mo-BVO (C) exhibited a photocurrent density of 0.54 mA/cm2 and remained stable for 10 h at 1.23 V vs. reversible hydrogen electrode (RHE), while the photocurrent density of the Mo-BVO decreased from 0.66 mA/cm2 to 0.11 mA/cm2 at 1.23 V vs. RHE in 4 h. The experimental results indicated that the enhanced PEC stability of the Mo-BVO (C) could be attributed to its higher crystallinity, which could effectively inhibit the dissociation of vanadium in BiVO4 during the PEC process. This work may illustrate a novel ceramic design for the improvement of the stability of BiVO4 photoanodes, and might provide a general strategy for the improvement of the PEC stability of metal oxide photoanodes.