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Fabrication of superamphiphobic surfaces with controllable oil adhesion in air
No full textResearchers have been chasing controlling liquid adhesion for decades. Up to now, there are plenty of publications about controlling water adhesion in air and controlling oil adhesion underwater. However, the regulation of oil adhesive ability on superamphiphobic surfaces in air has been rarely addressed. In this article, we reported a method to fabricate superamphiphobic surface showing outstanding superhydrophobicity as well as tunable oil adhesion. Herein, a laser-chemical hybrid method was utilized to obtain superamphiphobic surfaces. We fabricated grid-like microstructures on copper substrate by nanosecond laser directly writing (LDW), and created nanorods on the surface by a facile alkali assistant oxidation (AAO) reaction, which was followed by a per-fluomalkylthiolate (PF-thiolate) reaction. By changing the grid spacing (GS) during LDW, the as-prepared superamphiphobic surface showed tunable oil adhesion, and oil (e.g., peanut oil and hexadecane) droplets could easily rolled-off from the surface (i.e., ultralow adhesion) or totally adhered to the surface (i.e., ultrahigh adhesion), upon which we realized oil droplets transportation. This work may provide a simple method of fabricating superamphiphobic surface and controlling oil adhesion in atmosphere, which can be potentially applied in numerous fields like microdmplet manipulation, microfluidic chips, microreactors and so on
Improving thermal conductivity of poly(vinyl alcohol) composites by using functionalized nanodiamond
No full textHighly thermally conductive polymer composites with over 10 W m(-1) K-1 are widely pursued in the commercial field. Unfortunately, the polymer composites with high thermal conductivity are few reported using simple and scalable methods to meet the commercial demands. Therefore, herein highly thermal conductive polymer composites consisting of hydroxyl-rich nanodiamonds (ND-OH) and poly(vinyl alcohol) (PVA) are reported, which exhibits the interfacial properties of composite is closely related to its thermal conductivity. It proves that interface strength between matrix and filler would dominate the thermal conductivity of composite at a relatively low content. While the thermal conductivity would be dominated by the filler-filler interaction at high loadings. The ultrahigh thermal conductivity of the PVA/ND-OH composite is 18.98 W m(-1) K-1 when ND-OH reach at 90 wt%. The polymer composites present the excellent thermal conductivity and show a potential application for thermal management of the next-generation electronic products
Proline-Modified UIO-66 as Nanocarriers to Enhance Candida rugosa Lipase Catalytic Activity and Stability for Electrochemical Detection of Nitrofen
No full textImmobilization can be used to improve the stability of lipases and enhances lipase recovery and reusability, which increases its commercial value and industrial applications. Nevertheless, immobilization frequently causes conformational changes of the lipases, which decrease lipase catalytic activity. in the present work, we synthesized UIO-66 and grafted UIO-66 crystals with proline for immobilization of Candida rugosa lipase (CRL). As indicated by steady-state fluorescence microscopy, grafting of proline onto UIO-66 crystals induced beneficial conformational change in CRL. CRL immobilized on UIO-66/Pro (CRL@UIO-66/Pro) demonstrated higher enzyme activity and better recyclability than that immobilized on UIO-66 (CRL@UIO-66) in both hydrolysis (CRL@UIO-66/Pro: 0.34 U; CRL@UIO-66: 0.15 U) and transesterification (CRL@UIO-66/Pro: 0.93 U; CRL@UIO-66: 0.25 U) reactions. The higher values of k(cat) and k(cat)/K-m of CRL@UIO-66/Pro also showed that it had better catalytic efficiency as compared to CRL@UIO-66. It is also worth noting that CRL@UIO-66/Pro (0.93 U) demonstrated a much higher transesterification activity as compared to free CRL (0.11 U), indicating that UIO-66/Pro has increased the solvent stability of CRL. Both CRL@UIO-66 and CRL@UIO-66/Pro were also used for the fabrication of biosensors for nitrofen with a wide linear range (0-100 mu M), lower limit of detection, and good recovery rate
Construction of Oriented Interconnected BNNS Skeleton by Self-Growing CNTs Leading High Thermal Conductivity
No full textThe development of thermal conduction polymer-based composites is important to solve the heat dissipation of electronic instruments under overheating conditions. The construction of thermal conductive pathways in composites and the reduction of contact resistance between fillers are crucial for concerning excellent thermal conduction properties. Herein, the oriented coherent thermal conductive network in composites is successfully developed via the in situ growth of carbon nanotubes (CNTs) into boron nitride nanosheets (BNNSs) skeleton prepared from ice-templated. The thermal conductivity of composites reaches 3.21 W m(-1) K-1 approximately low filler loading of 9.86 vol%, due to the formation of the covalent bonding between CNTs and BNNSs as reducing the thermal contact resistance by one order of magnitude. More importantly, non-equilibrium molecular dynamics (NEMD) simulations are carried out to demonstrate the influence of CNTs in elevating the heat conductivity between BNNSs. Meanwhile, the volume resistivity of composites up to 10(15) omega cm far met the requirement of electrical insulation. This study provided a valuable idea for the design of thermal management materials for potential applications in integrated circuits
Superhydrophilic Fe3+ Doped TiO2 Films with Long-Lasting Antifogging Performance
No full textBased on the superhydrophilicity of titanium dioxide (TiO2) after ultraviolet irradiation, it has a high potential in the application of antifogging. However, a durable superhydrophilic state and a broader photoresponse range are necessary. Considering the enhancement of the photoresponse of TiO2, doping is an effective method to prolong the superhydrophilic state. In this paper, a Fe3+. doped TiO2 film with long-lasting superhydrophilicity and antifogging is prepared by sol-gel method. The experiment and density-functional theory (DFT) calculations are performed to investigate the antifogging performance and the underlying microscopic mechanism of Fe3+. doped TiO2. Antifogging tests demonstrate that 1.0 mol % Fe3+. doping leads to durable antifogging performance which lasts 60 days. The DFT calculations reveal that the Fe3+ doping can both increase the photolysis ability of TiO2 under sunlight exposure and enhance the stability of the hydroxyl adsorbate on TiO2 surface, which are the main reasons for a long-lasting superhydrophilicity of TiO2 after sunlight exposure
Large and sensitive magnetostriction in ferromagnetic composites with nanodispersive precipitates
No full textLarge and sensitive magnetostriction (large strain induced by small magnetic fields) is highly desired for applications of magnetostrictive materials. However, it is difficult to simultaneously improve magnetostriction and reduce the switching field because magnetostriction and the switching field are both proportional to the magnetocrystalline anisotropy. To solve this fundamental challenge, we report that introducing tetragonal nanoprecipitates into a cubic matrix can facilitate large and sensitive magnetostriction even in random polycrystals. As exhibited in a proof-of-principle reference, Fe-Ga alloys, the figure of merit-defined by the saturation magnetostriction over the magnetocrystalline anisotropy constant-can be enhanced by over 5-fold through optimum aging of the solution-treated precursor. On the one hand, the aging-induced nanodispersive face-centered tetragonal (FCT) precipitates create local tetragonal distortion of the body-centered cubic (BCC) matrix, substantially enhancing the saturation magnetostriction to be comparable to that of single crystal materials. On the other hand, these precipitates randomly couple with the matrix at the nanoscale, resulting in the collapse of net magnetocrystalline anisotropy. Our findings not only provide a simple and feasible approach to enhance the magnetostriction performance of random polycrystalline ferromagnets but also provide important insights toward understanding the mechanism of heterogeneous magnetostriction
Bacillus subtilis extracellular polymeric substances conditioning layers inhibit Escherichia coli adhesion to silicon surfaces: A potential candidate for interfacial antifouling additives
No full textBiofouling on material surfaces is a ubiquitous problem in a variety of fields. In aqueous environments, the process of biofouling initiates with the formation of a layer of macromolecules called the conditioning layer on the solid-liquid interface, followed by the adhesion and colonization of planktonic bacteria and the subsequent biofilm development and maturation. In this study, the extracellular polymeric substances (EPS) secreted by Bacillus subtilis were collected and used to prepare conditioning layers on inert surfaces. The morphologies and antifouling performances of the EPS conditioning layers were investigated. It was found that the initial adhesion of Escherichia coli was inhibited on the surfaces precoated with EPS conditioning layers. To further explore the underlying antifouling mechanisms of the EPS conditioning layers, the respective roles of two constituents of B. subtilis EPS (gamma -polyglutamic acid and surfactin) were investigated. This study has provided the possibility of developing a novel interfacial antifouling additive with the advantages of easy preparation, nontoxicity, and environmental friendliness
Quantification and evaluation of chemical footprint of woollen textiles
No full textThe chemical pollutants discharged in the production processes of textile products cause severe impact on the environment. The chemical footprint (ChF) methodology provides a new way to quantify the toxicity impacts caused by chemical pollutants. ChF does well in identifying priority chemical pollutants and helping enterprises to select greener chemicals to reduce the environment impacts. In this study, the ChF of woollen yarn were assessed with the data that collected from the production processes. The results showed that the ChF of dyeing process (4.10E+06 l) accounted for the largest proportion, because a large number of auxiliaries were used in the dyeing process to prevent uneven dyeing and colour difference, followed by scouring (7.79E+05 l) and finishing (8.11E+03 l). Among all the discharged chemical pollutants, polyoxyethylene nonyl phenyl ether (1.37E+06 l) caused the most ecotoxicity severe impact on the environment due to its high bioaccumulation and high toxicity to ecosystem, followed by sulfuric acid (1.03E+06 l). Sodium chloride and hydrogen peroxide were the two substances that caused the least environmental load. The overall uncertainty caused by toxicity prediction data accounting for 20.2% of the total ChF, and the uncertainty of the scouring process was the most. The results are referable for wool textiles producers to enhance the textile chemicals management
Band flattening and phonon-defect scattering in cubic SnSe-AgSbTe2 alloy for thermoelectric enhancement
No full textWith multiple band valleys and intrinsic low thermal conductivity, rock-salt SnSe possesses great potential as a promising thermoelectric material. Herein, we prepare cubic SnSe-AgSbTe2 alloy and demonstrate the synergistically optimized electronic and thermal transport properties. For the former, AgSbTe2 alloying can tune the Fermi surface and promote the band flattening, concurrently improving the density of state effective mass and carrier concentration. For the latter, the strong phonon-defect scattering caused by AgSbTe2 alloying contributes to a great reduction of lattice thermal conductivity. Collectively, an obviously enhanced ZT(max) of 1.00 at 820 K and Z(Tave) of 0.70 (300-820 K) are achieved in Sn0.5Ag0.25Sb0.25Se0.5Te0.5. Moreover, AgSbTe2 alloying can also improve the mechanical property and the Vickers hardness reaches 1.90 Gpa, which is over four times higher than that of pristine SnSe. (C) 2020 Elsevier Ltd. All rights reserved
Ultrafine- and uniform-grained biodegradable Zn-0.5Mn alloy: Grain refinement mechanism, corrosion behavior, and biocompatibility in vivo
No full textAn ultrafineand uniform-grained Zn-0.5Mn alloy (D3 alloy, stands for deformation rate of 99.5%) is fabricated via multi-pass drawing. The alloy features excellent ductility and elongation properties (up to 245.0% +/- 9.0% at room temperature). Zn-0.5Mn alloys are composed of two phases, namely, Zn and MnZn13. The MnZn13 phase confers multiple effects during refinement by inducing and pinning low-angle boundaries within grains. Meanwhile, the presence of these phases along grain boundaries prevents the growth of new refined grains. D3 shows uniform corrosion behaviors in c-SBF solution on account of the even distribution of the MnZn13 phase in its microstructure. Animal implantation experiments indicate that D3 has good biocompatibility; it does not cause damage to bone tissue or other organs. Taking the results together, D3 may be developed into a new type of biodegradable material with remarkable elongation and corrosion properties and satisfactory biocompatibility for medical applications