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A BiFeO3/TiO2 p-n heterojunction photocatalyst with ferroelectric synergistic effect under visible-light irradiation was developed through facile hydrolysis and precipitation by forming nanospheres of TiO2 on BiFeO3 nanocube to improve the photocatalytic efficiency. Analyses of the microstructure, optical properties, and photoelectrochemical performance indicate the formation of a core–shell heterostructure of BiFeO3/TiO2 with excellent energy band matching. The BiFeO3/TiO2 p-n heterojunction has enlarged specific surface area, higher sensitivity to visible-light, and improved separation and transfer efficiency of photoelectron-hole pairs than single TiO2 and BiFeO3. Moreover, the composite exhibits superior photocatalytic degradation performance for methylene blue (MB) and common antibiotic tetracycline (TC) under UV and visible-light irradiation. The MB degradation rate within 180 min reaches 78.4% and 90.4% under UV and visible-light irradiation, respectively. Furthermore, the enhanced photocatalytic mechanism of BiFeO3/TiO2 is explored by photoluminescence (PL), electrochemical impedance spectroscopy (EIS), transient photocurrent analysis, radical quenching, and band structure characterization.

Oil and organic pollutants removal becomes an efficient solution to dispose of industrial oily and textile dye wastewater. This study proposes a lotus leaf-like bionic nanofibrous membrane with underwater superoleophobic for highly efficient oil-water separation. Papillary structure of the bionic membrane is formed by electrospraying of PVDF and TiO2 solutions on the surface of beaded-structure PVDF/TiO2 membrane. Dopamine is then decorated on the resultant PVDF/TiO2 membrane by in situ polymerization to be with hydrophilic-underwater oleophobic property for highly efficient oil-water separation. This bionic membrane has > 99 % oil-water separation efficiency, and high flux of 1389 ± 67 L m−2 h−1. Its contact angle of underwater petroleum ether and dichlomethane reaches 155° and 152°, respectively. Moreover, it has excellent water transport capacity, photocatalytic property, as well as high separation efficiency and flux even after 5-cycle filtration. This bionic nanofibrous membrane will become a promising candidate in clean production, industrial oil/water separation, water purification and efficient liquid transmission.

Medical product contamination is a serious threat to patients’ health. However, designing medical covers that ensure Janus performance and outstanding abrasion resistance, mechanical performances has remained a great challenge. In this study, a novel Janus nonwoven fabric nonwoven fabric consists of a hydrophilic inner layer of polylactic acid (PLA)/lowmelting polylactic acid (LPLA) and a coated outer layer of hydrophobic thermoplastic polyurethane (TPU) is successfully fabricated. The subsequent PLA/LPLA-TPU textiles exhibits excellent protective performance of inner absorption. Moreover, the coating improves tensile strength and increases abrasion resistance. A mechanism of mechanical failure is further studied. This kind of nonwoven fabric is suggested to be a promising candidate for medical covers and health supplies.

To simply and effectively enhance the conversion capability of wearable thermoelectric textiles, a two-step in situ method is adopted to fabricate dual-shell photothermoelectric textiles which is made of polypropylene fibers with a photo-thermal layer (PPy) and a thermoelectric layer (PEDOT:Tos). The PPy is tailored to achieve high temperature and photothermoelectric effects. The PPy layer can significantly increase the photothermal conversion efficiencies of as-prepared fabric. The optimized photothermoelectric fabric can improve the generated voltage output from 294.13 to 536.47 μV under the infrared light, and its power density is up to 13.76 nW·m-2. A flexible photothermoelectric strip composed of as-prepared fabric coated with Ag particles and textile substrates with low thermal conductivity shows a voltage output of 2.25, 0.677, and 0.183 mV and a power output of 0.7031, 0.0636, and 0.0049 nW under IR light, sunlight, and on the arm, respectively. The photothermoelectric fabrics display potential as to a new smart wearable device for converting light and electricity.

In this study, electrospun polyvinylidene fluoride (PVDF)-based nanofibrous membranes embedding TiO2 were prepared and used for photocatalytic degradation and oil/water separation. The nanofibrous membranes were characterized by scanning electron microscopy (SEM), transmission electronic microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) spectroscopy, thermal performance analysis, and oil/water separation analysis. And the degradation of rhodamine B dye was also investigated. Results showed that the fiber diameter and thermal stability of the membranes decreased with the increasing of TiO2. Meanwhile, the fiber surface roughness and specific surface area increased. The analysis of TEM, XRD and FTIR indicated that TiO2 existed in the PVDF membranes. When the TiO2 content was 12 %, the fiber diameter of the membranes was about 110 nm, and the photocatalytic degradation of rhodamine B dye efficiency was up to 97 %. The reaction rate constant was 0.02057 min−1. At 0.01 MPa vacuum, oil separated from water effectively, which proves that separation can be easily conducted with a low energy cost. Thus, the prepared membranes have a very high application prospect in the purification of reclaimed water and separation of oil and water.

Janus nanofibrous membranes with thin fiber diameter, small pore size, and easy-tailored wettability/thickness gradient have attracted considerable attention in the directional water transport field. However, designing textiles that ensure continuous directional water transport and outstanding moisture permeable, breathable performances has remained a great challenge. In this study, a novel polyacrylonitrile/polyvinyl alcohol–thermoplastic polyurethane (TPU) sandwich nanofibrous membrane with robust moisture permeable, breathable, and directional water transport performance is successfully fabricated with an innovation strategy combining electrospinning with structure-induced method. A good water vapor transmission rate of 9760 g/m2 d and robust breathability of 103 mm/s are obtained by turning the mass ratio of polyacrylonitrile and polyvinyl alcohol and the opening porous structure of TPU; these values are approximately five times those of commercial membranes. The sandwich fibrous membranes are suggested as promising candidates for various applications, especially in moisture-wicking clothing.

Bio-ceramic hydroxyapatite (HA) coating has been commonly used to repair the bones or as the functionalized surface of bone substitutes due to its excellent biocompatibility, superior osteo-inductivity, and great corrosion resistance. Among many other methods for synthesizing HA coating, coating via the electrochemical deposition has a high degree of crystallinity and purity, which fits the nonlinear, complex, and rugged substrates. Furthermore, HA coating can be adjusted in terms of coating morphology, thickness, and chemical component via changing the parameters, such as electrolyte ion concentration, electrolyte composition, deposition current density, and deposition time, etc. Nevertheless, the properties of electrodeposited HA coating highly pertain to the bubbles generated by water electrolysis on the substrate surface as well as the concentration polarization of electrolyte ions near the cathode during the electrodeposition process. In this study, the critical factors and mechanisms of HA coating using the electrochemical deposition method are comprehensively evaluated, thereby examining the effects of parameter optimization (i.e., current mode, ultrasonic treatment, and postprocessing). Finally, the influences of ion substitution and HA composite coating on the surface structure and properties of the HA-based coatings are also discussed.

Environmental pollution, especially air pollution, seriously endangers public health globally. Due to severe air pollution, air filters still face many challenges, especially in terms of filtration...

Bi2+xWO6 is a cost-effective and environmentally friendly photocatalyst that shows high reactivity in the oxidation of various contaminants under visible light. However, under alkaline conditions, the reactive oxidative species in the Bi2+xWO6 system are still not clear yet. In this study, it is observed that the oxidation rates of As(III) increase with increasing pH values in the Bi2.15WO6 system. Photoluminescence and the Mott–Schottky analyses confirm that OH− promotes the separation and transfer of photogenerated electron–hole pairs over Bi2.15WO6, thus facilitating the oxidation of As(III). Electron spin resonance spectra analysis and quenching experiments rule out contributions of •OH, O2˙−, 1O2 and superoxo species to As(III) oxidation and indicate that surface –OOH and/or H2O2 are indeed the predominant species under alkaline conditions. The improved production of H2O2 by H-donors such as glucose and phenol, as well as the UV-vis diffuse reflectance and Raman analyses, further confirms the formation of surface –OOH on Bi2.15WO6 under alkaline conditions. In the dark, the significant higher oxidation rate of As(III) by H2O2–Bi2.15WO6 than that by H2O2 alone reveals that surface −OOH, instead of H2O2, plays an important role in As(III) oxidation. This study enriches our understanding of the diversity of reactive oxygen species (ROS) in the Bi2.15WO6 system and gives new insight into the mechanism involved in the oxidation of As(III) under alkaline conditions.

The traditional electrospinning needles are easily blocked and the processing is not suitable for mass production. In order to address the problems, this study uses a rotary linear electrode for electrospinning for the production of polyvinyl alcohol (PVA)/chitosan(CS)/graphene(Gr) nanofibrous membranes. The membranes are observed for micro-structure and tested for thermal stability, surface resistivity, and hydrophilicity, thereby examining the influence of the content of chitosan. The test results show that the presence of chitosan improves the hydrophilcity as well as affects the morphology of PVA/CS/Gr nanofibrous membranes where the nanofiber diameter is smaller. Moreover, FTIR results suggest that chitosan and PVA interact to generate hydrogen bonds that stabilize the thermal properties of nanofibrous membranes. In particular, the maximum thermal decomposition temperature of PVA/CS/Gr nanofibrous membranes composed of PVA/CS ratio being 9:1 is 297.7 ℃. Finally, using chitosan also increases the electrical conductivity and decreases the surface resistivity. This fabricated technique provides the possibility of mass-production of PVA/CS/Gr nanofibrous membranes in the future. Keywords: Rotary linear electrospinning, Nanofibrous membrane, Chitosan, Graphene, Thermal stability, Conductivity

Conversion of aqueous arsenite [As(III)] to less toxic arsenate [As(V)] is a critical step for the arsenic pollution remediation. In this study, Ag2O/TiO2 composites synthesized via the pH-induced precipitation method were employed into the photocatalytic oxidation of As(III) under visible light irradiation. X-ray diffraction, transmission electron microscope and X-ray photoelectron spectroscopy analysis verified the formation of Ag2O/TiO2 heterostructures. Compared to pure Ag2O and TiO2, the 30% Ag2O/TiO2 composite exhibited much higher photochemical reactivities for the oxidation of As(III) under visible light irradiation. Under the optimal conditions [pH = 4.0, the photocatalyst dosage being 0.3 g L−1 and initial As(III) concentration being 10 mg L−1], the oxidation and removal percent of As(III) was 60.7% and 83.0% after reaction for 120 min, respectively. Moreover, the formation of Ag(0) over the surface of Ag2O by photo-induced electrons contributed to the high stability of Ag2O/TiO2 composite. It was also found that photo-generated holes and superoxide radicals played the predominant roles in the As(III) oxidation. The improved photocatalytic activities were attributed to the formation of the hetero-junctions between Ag2O and TiO2, the strong visible light absorption, and the high separation efficiency of photo-generated electron-hole pairs resulted from the Schottky barriers at the Ag-Ag2O interface.

Terrorist attacks occur constantly, which subsequently arouses awareness of self-protection. In order to alleviate the harm caused by sharp objects of knives and daggers, a design of flexible stab-resistant materials that are impregnated with the shear thickening fluid (STF)/multi-walled carbon nanotubes (MWCNTs) system and different texture of fabrics is presented. STF/MWCNTs are composed of polyethylene glycol (PEG 200) as the dispersion medium and silica (SiO2) of 12 nm and 75 nm as disperse phase as well as MWCNTs as supplementary reinforcement, in expectation to provide the aramid fabrics with high strengths, low critical shear rate, and a short thickening response time. The textures of aramid fabrics—plain (P), twill (T), satin (S), or basket (B) weave—are saturated in the STF/MWCNTs system. The synergetic influences of silica size and texture on tensile strength, quasi-static knife, and spike stab resistances of the STF/MWCNTs-impregnated aramid fabrics are examined. Results show that the plain aramid fabric immersed in the STF/MWCNTs system containing 12 nm SiO2(SM12) exhibit the maximum tensile strength and quasi-static knife stab resistance, 14.7 MPa and 8.9 MPa, respectively, which is 1.15 and 1.43 times higher than pure aramid fabrics. Moreover, the basket-weave aramid fabric immersed in the STF/MWCNTs system containing 12 nm SiO2have the maximum quasi-static spike stab resistance of 17.12 MPa compared to other textures of fabrics, which is 1.05 times higher than those immersed in the 75 nm SiO2STF/MWCNTs (SM75) system and 1.33 times higher than that of pure basket aramid fabrics.

BACKGROUND: Transforming growth factor-β1 (TGF-β1) plays an important role in chondrocyte growth and the synthesis of extracellular matrix (ECM). Due to the rapid metabolism, controlled release systems for TGF-β1 have attracted increasing interest recently. OBJECTIVE: In this study, a silk fibroin (SF)/chitosan (CS) scaffold incorporated with TGF-β1-loaded microspheres (MSs) was created for cartilage reparation. METHOD: The optimal proportion of the SF/CS composite scaffold was determined by evaluating their micromorphology and the proliferation rate of fibroblasts on the surface. Then, SF/CS/TGF-β1-loaded MS scaffolds were prepared by the adsorption method. TGF-β1 release capacity, degradation patterns, cytocompatibility and in vivo implantation were evaluted. RESULTS: The SF/CS/TGF-β1-loaded MS scaffold showed good TGF-β1 release over more than 16 days, which could sequentially stimulate chondrocyte synthetic activity. In vitro cell proliferation experiments showed the SF/CS/TGF-β1-loaded MS scaffold could promote chondrocytes adhesion, growth, proliferation and maintained the cellular morphology. An in vivo study demonstrated that a low inflammatory response was observed in rats and that the materials exhibited good biocompatibility. CONCLUSION: the results indicated that our SF/CS/TGF-β1-loaded MS scaffold constitute a promising therapeutic option for cartilage reparation.

Particulate matter 2.5 (PM2.5) has become a public hazard to people&rsquo, s lives and health. Traditional melt-blown membranes cannot filter dangerous particles due to their limited diameter, and ultra-fine electrospinning fibers are vulnerable to external forces. Therefore, creating highly efficient air filters by using an innovative technique and structure has become necessary. In this study, a combination of polypropylene (PP) melt-blown and polyvinyl alcohol (PVA)/zeolite imidazole frameworks-8 (ZIF-8) electrospinning technique is employed to construct a PP/PVA/ZIF-8 membrane with a hierarchical fibrous structure. The synergistic effect of hierarchical fibrous structure and ZIF-8 effectively captures PM2.5. The PP/PVA composite membrane loaded with 2.5% loading ZIF-8 has an average filtration efficacy reaching as high as 96.5% for PM2.5 and quality factor (Qf) of 0.099 Pa&minus, 1. The resultant membrane resists 33.34 N tensile strength and has a low pressure drop, excellent filtration efficiency, and mechanical strength. This work presents a facile preparation method that is suitable for mass production and the application of membranes to be used as air filters for highly efficient filtration of PM2.5.

Chitosan (CS) combined with hydroxyapatite (HA) was injected into a composite braid, and a hierarchical pore structure scaffold was obtained by freeze drying and cold atmospheric plasma (CAP) technology. The CS/HA/braid scaffold with hierarchical pore structure was analyzed and characterized by scanning electronic microscopy, Fourier transform infrared spectroscopy, true color confocal microscopy, improved liquid replacement method, and phosphate buffer solution immersion. The mechanical properties and degradation ability of the scaffold were evaluated through compression test and degradation test. Results showed that HA addition endowed the core of the scaffold with macroscopic pore sizes of 80-180 μm, and CAP treatment endowed the shell of the scaffold with microscopic pore sizes ≤10 μm. All scaffolds exhibited high porosity and swelling rates of ≥80 % and ≥300 %, respectively. The scaffold with a hierarchical pore structure had good mechanical properties and twice the degradation rate. In addition, the treated scaffold precipitated intact spherical HA crystals. Under the synergistic effect of HA and CAP treatment, scaffolds achieved 277.6 % cell viability compared with pure CS scaffold. Overall, this method was feasible for preparing bone scaffolds with hierarchical pore structure for potential bone tissue engineering.

Drug-resistant pathogens render tremendous pressure and challenges on the development of biomedical materials with highly efficient barrier and long-lasting antibacterial efficacy. Herein, this study combined metal–organic framework (zeolite imidazolate framework 8 [ZIF-8]) and melt blowing–electrospinning method to construct the bead-on-string structure of PPCL@PDA/TAEG/PCL/ZIF8 hierarchical micro/nanofibrous composite membranes with rechargeable, antibacterial, and high-efficiency filtration properties. The incorporation of bead-on-string structure provides the PPCL@PDA/TAEG/PCL/ZIF8–9 composite membranes with above 99.9% filtration efficiency against ultrafine particles larger than 500 nm in diameter. Moreover, the composite membrane quickly releases reactive oxygen species under daylight conditions. The release amount after charging for 1 h is 13009.41 μg/g for •OH and 405.72 μg/g for H2O2. The composite membranes retain 89.9% and 65.1% of the original charging capacities of •OH and H2O2, respectively, after seven cycles. These membranes also show greater antibacterial activity, and the sterilizing rates against S. aureus and E. coli reach 99% and 95%, respectively, in daytime and nighttime. These daylight-driven rechargeable micro/nanofibrous membranes can be used in the development of reusable medical protective materials with highly efficient filtration and daylight-driven rechargeable antibacterial efficacy.

Ag2O/TiO2 composites synthesized in this study were applied into the photocatalytic degradation of methyl orange (MO) under UV and visible light irradiation. X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscope analysis demonstrated that Ag2O nanoparticles were well distributed on the surface of TiO2 and the heterostructure of Ag2O/TiO2 was formed. Compared with the pure TiO2 and Ag2O, the 3% and 50% Ag2O/TiO2 composite displayed much higher photocatalytic activities in MO degradation under UV and visible light irradiation, respectively. The degradation rate constant of 50% composite was 0.01508 min−1 under visible light, which was almost 20.1 and 1.2 times more than that of the pure TiO2 and Ag2O, respectively. Moreover, the formation of Ag(0) on the surface of Ag2O under illumination contributed to the high stability of Ag2O/TiO2 photocatalysts. It was also found that hydroxyl radicals during the photocatalytic process played the predominant role in MO degradation. The enhanced photochemical activities were attributed to the formation of the heterostructure between Ag2O and TiO2, the strong visible light absorption and the high separation efficiency of photogenerated electron–hole pairs resulted from the highly dispersed Ag2O particles.

The fate of arsenic in the water environment is of great concern. Here, the influences of oxalic acid and UV light illumination on the dissolution of naked ferrihydrite (Fhy), Fhy loaded with As(V) [Fhy*-As(V)], as well as the fate of As(V) at pH 3.0 were studied. With the assistance of oxalic acid, complexes of Fe(III)-oxalic acid produced on Fhy/Fhy*-As(V) were reduced to Fe(II)-oxalic acid by photo-induced electrons under UV light irradiation. UV light has nearly no impact on the release of As(V) in the system of Fhy*-As(V) without the assistance of oxalic acid. Nevertheless, in the existence of oxalic acid, UV light illumination resulted in the contents of liberated As(V) decreased by 775&ndash, 1300% compared to that without light. Considering the coexistence of As(V), oxalic acid as well as iron oxides in aquatic environments, the present study revealed that UV illumination could enhance the retention of As(V) on Fhy in the acidic water environment containing oxalic acid.

In this article, expanded vermiculite (EV)-enhanced polyurethane foam bionic composites inspired by pomelo peel is proposed. The columnar lattice structure mold is employed to constitute the periodic interface structure and gradient foam structure, and the nylon nonwoven fabric is combined as the surface layer. The effects of EV content on the thermal, compression, and dynamic cushion properties of bionic composites are investigated. Results show that residual char increases with EV content, which conduces to decrease the release of heat flow. The proposed bionic composite with columnar lattice structure has optimal compressive modulus, energy absorption and dynamic cushion efficacy when 1 wt% EV is added. However, its performance decreases slowly when EV fillers are continuously added because the cell morphology is changed from round to irregular shape and the interfacial adhesion of filler&ndash, matrix is weakened. Owing to their unique bionic structure, composites can absorb 99% of the energy impacted by flat impactor within a smaller deformation and achieve 97% absorption efficiency for a hemispheric impactor in cushion test.

In order to solve the recycling of the puncture-resistant soft composites, this study constructs a multiscale self-healing gel-fabric soft composite synergistically toughened by Pluronic/PMEA hydrogel, hydroxyapatite nanoparticles (HAP NPs) and aramid fabric. Results show that the gel matrix has a self-healing efficiency of 85% after puncture damage, and the stab resistances are highly positively associated with the toughness of the hydrogel matrix. When toughened by 4% HAP NPs, the spike and knife resistances of soft composites are improved by 132% and 130%, respectively. After being laminated, the composite exhibits a self-repairing efficiency of 52% and still has excellent performance after multiple punctures. At lamination angle of 45° and the gel volume fraction of 45%, the composite has the best puncture resistance properties, and the 37 layers can resist against the E1 stab resistance energy. The synergistic toughened mechanism is due to the interfacial shear strength between the fiber and the gel matrix. Overall, this research provides a novel structural design for the recycling of high-performance puncture-resistant composites.

Recycling of puncture-resistant soft composites is challenging. In this paper, we report a new strategy of designing puncture-resistant composites with self-healing and synergistic toughening efficacy for secondary utilization after puncture damage. Puncture-resistant soft composites are prepared with Pluronic/PMEA hydrogel and aramid fabrics. The composites exhibit extremely high toughness and puncture resistance that are superior to those of their neat components. This result proves that the tough hydrogel and aramid fabrics have a synergistic effect, which provides the composites with a maximal spike-resistant peak force of 155 N and a maximal knife- resistant peak force of 182 N. The peak force of the composites is about 12 times that of neat fabric. In addition, the Pluronic/PMEA hydrogel matrix attains 85% self-healing efficiency at 100℃ in 3 h. The proposed soft composites with effective puncture- resistant performance can serve as an important guidance for future design of recyclable puncture-resistant composites after damage.

Hydrogels have extensively studied as adsorbents, raw materials for the preparation of adsorbent hydrogels have low strength, while high strength hydrogels have weak adsorption capacity. In this study, PVA hydrogel was crosslinked via trihydroxy melamine and epichlorohydrin, and β-cyclodextrin with strong adsorption capacity was added to remove the heavy metal ions. Results showed that the addition of trihydroxy melamine with 8%, the compressive strength of the hydrogel was increased by approximately 20%. The Langmuir isotherm model showed that the adsorption capacity of the hydrogel for Pb(II) and Ni(II) reached 505.9 mg/g and 286.7 mg/g, respectively, and the efficiency of removing the low-concentration heavy metal ions in water more than 99%. The hydrogel is low cost, and maintained highly removal efficiency under low pH. The removal efficiency of the hydrogel remained above 90% after five repeated adsorption-desorption experiments. The hydrogels have a potential to be used in wastewater treatment as adsorbents.

The application of long-lasting antibacterial microorganism materials has presented enormous challenges, especially when infection by pathogenic bacteria triggers global public health and safety issues. In this study, PPCL@PDA-TAEG melt-blown membranes with rechargeable, storable, and antibacterial property are constructed by grafting bisbenzophenone-structured 4,4, -terephthaloyl diphthalic anhydride photosensitizer and epigallocatechin gallate antibacterial agent on the PPCL melt-blown membranes. Result shows that after chemical grafting, the synergistic effects of rechargeable and antibacterial performance on the melt-blown membrane are achieved under ordinary daylight irradiation. Moreover, the resultant melt-blown membranes show enhanced chemical stability, and the UV–vis absorption peak intensity remains above 80% after 1 month of storage under dark conditions. The sterilization rate of Staphylococcus aureus and Escherichia coli can reach 99.9% and 95%, respectively. The air permeability and moisture permeability of PPCL@PDA-TAEG melt-blown membranes are 22.3% and 43.7% higher, respectively, than those of PPCL melt-blown membranes. This facile and low-cost method for preparing PPCL@PDA-TAEG melt-blown membranes provides a new strategic direction for designing biomedical medical materials with long-lasting antibacterial efficacy.

With the expanding utilization and development electronic devices, electromagnetic interference (EMI) shielding materials with good flexibility and lightweight have been desired to eliminate the radiation pollution. However, many EMI shielding materials are usually limited in practical application due to the large thickness and poor mechanical properties. Herein, ultra-thin and lightweight conductive composite films with both unique undulating layered structure and sandwich structure were constructed via a simple solution dip-coating method. The PAN@TiO2 (PT) film as a substrate endowed the Ti3C2Tx film a certain strength, the polydopamine was decorated on the PT film surface to enhance the combination fastness of the PT film and Ti3C2Tx, and the Ti3C2Tx sheets built a conductive network. The conductive composite film (high tensile strength of 93.55 MPa) possessed an average EMI shielding effectiveness (SE) of 32 dB and a specific SE of 4085.92 dB cm2/g owing to their excellent electrical conductivity of 92.68 S/cm. The bio-inspired strategy provides a promising approach in fabricating flexible and ultrathin composite materials for highly efficient EMI shielding applications. Furthermore, this strategy offers a feasible idea for preparing multifunctional films.

Sulfate radical (SO4•−) is always thought to be an important oxidizing species in the metal-sulfite [S(IV)] systems, however, the oxidizing species correlated with the metal species have rarely been mentioned. In this study, the oxidizing species that oxidize arsenite [As(III)] in the Cu(II)-S(IV) system were investigated under alkaline conditions. Kinetic results indicate that complexation between Cu(II) and S(IV) is the pre-requisite to initiate various oxidizing species, followed by internal electron transfer from S(IV) to Cu(II) with the formation of SO3•− and the CuI(SO3)n−2n+1 complexes. Quenching experiments rule out contributions of SO5•−, peroxymonosulfate (HSO5−, PMS), hydroxyl radical (•OH), superoxide radical (O2•−) and singlet oxygen (1O2) to As(III) oxidation in the Cu(II)-S(IV) system and indicate that some kinds of peroxo species contribute. On the other side, apart from the oxidizing species such as SO5•−, PMS and SO4•− generated via a series of reactions between SO3•− and O2, the CuI(SO3)n−2n+1 complexes also react with O2 to form CuII-O2•−-(SO32−)n superoxo species and CuIII-O22−-(SO32−)n peroxo species, as revealed by Raman analysis. UV–vis spectrum further confirms the presence of Cu(III) in the Cu(II)-S(IV) system. We therefore suggest that both SO4•− and the Cu(III)-peroxo species play important roles in the oxidation of As(III) in the Cu(II)-S(IV) system. This study enriches our understanding on the diversity of oxidizing species in the metal-S(IV) systems under alkaline conditions.

Increasing oily wastewater is produced by various industrial, various oil-water separation technologies and materials have been developed to solve this issue. A facile method is proposed to build multi-scaled and hierarchical membranes with efficiently oil/water separation and photocatalysis. The multi-scaled, hierarchical membrane is fabricated by a hydrophilic polyacrylonitrile (PAN) electrospinning nanofibrous and PAN/TiO2 electrospraying spheres, then the polydopamine (PDA) decorated membrane via in-situ growth. This multi-scaled, hierarchical structure endows the membrane with superhydrophilicity (water contact angle ∼ 0°), and underwater superoleophobicity (oil contact angle ∼152°). And the multi-scaled, hierarchical membrane shows superior water permeation and hydrophilic properties than pure PAN membranes. In addition, the membrane indicates an excellent photocatalytic ability for organic pollutant (∼98 %). And after 5 cycles, the water flux still maintains a high level showing good recyclability. This multi-scaled, hierarchical nanofibrous membrane shows very promising application potentials in oil-water separation and photocatalysis.

Medical product contamination can seriously threaten patients’ health. Because of severe pollution, nonwoven medical covers still face lots of challenges, especially in terms of versatile protection performance. The application of biodegradable polylactic acid (PLA) fiber has been limited by the single hydrophilicity and poor mechanical performance. Herein, a low cost and large-scale PLA/low-melt (polylactic acid) LMPLA-thermoplastic polyurethane (TPU)/triclosan nonwovens was prepared through needle punch-pad-coat method. As observed as by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and Fourier transform infrared spectroscopy (FT-IR) analyses, a membrane structure was formed on the PLA/LMPLA nonwovens surface, which dramatically improved the waterproof, antimicrobial, mechanical and abrasion resistant performance and imparted relative high breathability. By varying the stroke frequency as well as the triclosan concentration, the modified nonwovens with 0.1 wt% triclosan displayed excellent water repellency (90%), modest breathability (136.9 mm/s), robust tensile strength (12.72 MPa), and good antimicrobial performance against Staphylococcus aureus and Escherichia coli. Furthermore, abrasion resistant property could reach 10000 continuous abrasion cycles, up to 10-fold and 50% higher than that of the control fabric and previous reported PU nonwoven. These results are of great significance for the design of low cost, eco-friendly, sustainable, and mass production of medical products.

Inspired by worm morphology, this study report a low-cost and facile synthesis approach to construct a worm-like P-type flexible thermoelectric material—poly(3,4-ethylene dioxythiophene):p-toluenesulfonic acid (PEDOT:Tos) coated polypropylene (PP) nonwoven fabrics via low-temperature interfacial polymerization. This as-prepared thermoelectric fabric made of fibers with a core-shell structure has an electrical conductivity of 2.19 S/cm and the Seebeck coefficient of 16.15 μV K−1 at a temperature difference of 30 °C. Furthermore, it presents good mechanical and washing stability by bending and ultrasonic test. A thermoelectric device designed of five pairs of thermoelectric material (p-type) and copper wire (n-type) generates 0.512 mV voltage at a temperature difference of 10 °C. This thermoelectric device has a prospect in the application of portable and interactive devices. This study proposes an easy way to manufacture bioinspired thermoelectric fabric with high thermoelectric performance and high potential applications, such as in wearable and flexible sensors.

Conversion of aniline wastes to value-added products is always a promising method to treat aniline wastewater. In this study, a selective oxidation of aniline contaminants by Bi2·15WO6 was carried out under visible light and alkaline conditions. Kinetic results show that the oxidation rates of aniline increase with increasing pH values under visible light. UV-vis absorption spectra and GC-MS analysis confirm that azobenzene is the primary oxidation product with aminophenol and N,N'-diphenylhydrazine as the secondary products. The analyses from Mott-Schottky, electrochemical impedance spectroscopy (EIS), transient photocurrent and photoluminescence (PL) further indicate that OH- promotes the separation and transfer of photogenerated electron-hole pairs on the surface of Bi2·15WO6, thus facilitating oxidation of aniline. Quenching experiments and electron spin resonance (ESR) analysis confirm that h+ is the predominant specie in the Bi2·15WO6 system and aniline radical cation (PhNH2•+) is an important intermediate. The Hammett and ΔBDEN-H plots further reveal that e- abstraction from aniline with the formation of PhNH2•+, followed by H+ abstraction from PhNH2•+ with the formation of anilino radicals (PhNH•), is the prerequisite for the formation of N,N'-diphenylhydrazine, which is then oxidized to azobenzene via the hydrogen-abstraction pathway. This work provides a cost-effective method to selectively oxidize aniline to azobenzene.

Oil/water separation has become an urgent issue in environmental protection. Superhydrophilic and underwater superoleophobic membrane is promising materials for effective oil/water separation. In this paper, a novel oil/water separation nonwoven fabric with robust tensile strength and hydrophilic-underwater superoleophobic is successfully fabricated. This nonwoven fabric using low melt point polyester (LPET) fibers with a unique sheath-core structure to incorporate thermal bonding as reinforcement. Moreover, poly(N-isopropylacrylamide) (PNIPAM) dip-coated is also employed to modify the nonwoven fabrics to acquire the hydrophilic-underwater superoleophobic properties. The mechanical property, microstructure, water and underwater oil contact angle, and oil/water separation properties of PP/LPET nonwoven fabrics are measured, examining the effects of LPET fiber ratio and PNIPAM concentration. The test results show that an improvement in the mechanical properties after increasing the LPET content. The coated of PNIPAM endows the nonwoven fabric with a low water contact angle of from 80 ° to 0 ° (within 8 s), and underwater superoleophobicity with a high oil contact angle of 150 ° . This nonwoven fabric can effective separation oil/water mixture with high permeate flux (∼21850 L ∙ m−2 ∙ h−1) and high separation efficiency (∼99%), solely driven by gravity. This kind of nonwoven fabrics is suggested as a promising candidate for oil/water separation and water purification.

Medical product contamination is a seriously threatens patients’ health. However, few studies on the protective properties of nonwoven medical covers have been conducted. This work aims to develop bioenvironmentally friendly novel Janus polylactic acid (PLA)/low melt polylactic acid (LMPLA) nonwoven medical covers with asymmetric wettability and excellent mechanical, and abrasion resistance while maintaining outstanding breathability performance. The Janus fabrics have a dual structure with hydrophilic PLA/LMPLA nonwoven fabrics and hydrophobic short fluoroalkyl chain polymers/polyurethane membranes. Janus textiles are prepared through needle punch/ hot press bonding manufacturing and spray coating. The subsequent nonwoven fabrics exhibit an outstanding wettability gradient that offers the excellent protective performance of inner-layer liquid absorption to prevent flowback and outer-layer liquid repellence. Furthermore, the coating increases the tensile strength and abrasion resistance (of the fabrics by 2.5 times those of a previously reported PU coating reported in published paper). This kind of nonwoven fabrics is suggested to be a promising candidate for medical covers and health supplies.

SO4 − and OH radicals are important oxidative species that play important roles in the oxidation of organic contaminants by peroxomonosulfate (PMS)/persulfate (PS) and Co3O4 under acidic conditions. However, the facet effect of Co3O4 on the catalytic oxidation of phenol by PS under alkaline conditions has not been investigated yet. In this study, we synthesized three Co3O4 nanoparticles with different facets [rod (110), cube (100) and octahedra (111)]. The Co3O4 rods show the highest catalytic reactivity in the oxidation of phenol by PS, followed by Co3O4 cubes and Co3O4 octahedra. Quenching experiments and EPR analysis rule out contributions of SO4 −, OH, O2 − and 1O2 to phenol oxidation and suggest that H-abstraction from phenol to phenoxyl radicals is an important pathway in all Co3O4-PS systems. The analysis of total organic carbon (TOC) and solid characterizations reveal that more than 96.6 % phenol has been transformed into polyphenols, instead of being mineralized into smaller organic molecules or CO2 in the rod-PS-phenol system. The DFT (density functional theory) calculations further confirm that PS is more readily activated via a non-radical pathway on the Co3O4(110) plane with appropriate Co(II)-Co(II) distances, and the activated O O bonds then abstract H atoms from phenol molecules with the production of phenoxyl radicals, as well as SO4 − and OH radicals. The produced phenoxyl radicals then link together to form dimers, trimers, oligomers and eventually insoluble polymers. This study not only enriches our understanding on the facet effect of different Co3O4 in the oxidation of phenol, but also gives new insight into turning phenolic wastes into polyphenol "treasures".

Hydroxyapatite (HA) coating is prepared by ultrasonic-assisted electrodeposition from the electrolytes containing hydrogen peroxide (H2O2). Effects of H2O2 concentrations (0, 0.5, 2.0, 4.0 mL/L) on the morphology, chemical bonds, crystallinity and roughness of the HA coatings are investigated. The results show that the HA coating via ultrasonic-assisted electrodeposition is spindle-like in the absence of H2O2, but becomes flake-like and wrinkle-like morphology after adding different concentrations of H2O2 into the electrolyte. The SEM image of HA coating at half of the deposition time (i.e. 30 min) reveals the transition from spindle-like to wrinkle-like. TEM image shows that wrinkle-like HA coating electrodeposited at 4.0 mL/L H2O2 is also found with spindle-like HA crystal nanostructure. The influencing mechanism of H2O2 on the HA coating nanostructure is also proposed. This study provides a new idea for the preparation of hydroxyapatite electrodeposited coatings.

Oxidation of ammonia (NH4+/NH3) from wastewater is a challenge due to its high stability and solubility in aqueous environments. A simple Ag2O/TiO2 (P25) catalyst was synthesized and used for photocatalytic oxidation of aqueous NH4+/NH3. Under UV illumination, the oxidation rate of NH4+/NH3 by 1% Ag2O/P25 is increased with increasing pHs, with a rate constant of 0.383 h−1 at pH 11.8. OH/h+ are important oxidative species that dominate the oxidation of NH4+/NH3. The respective contributions of Pathway I (the h+ mediated process) and Pathway II (the e− mediated process) are 66.2% and 33.8% to the oxidation of NH4+/NH3. Oxidation selectivity toward N2 is more favorable under high concentrations of NH4+/NH3 and low concentrations of Ag2O/P25. The improved separation of e−-h+ pairs on Ag2O/P25 facilitates generation of OH and h+, thus triggering the high conversion yield of NH4+/NH3. XPS analysis further suggests that Ag(I), instead of the photogenerated Ag(0), plays the predominant role in photocatalytic oxidation of NH4+/NH3. This work enriches our understanding on the photooxidation mechanism of NH4+/NH3 by Ag2O/P25.

Subsurface damage and edge chipping remain a persistent technical challenge for the abrasive machining of dental restorations made from glass ceramics, and they impede the fabrication of long-lasting dental restorations. This paper reports on an integration of ultrasonic assistance to dental high-speed rotary abrasive machining for improvement of the surface quality of glass ceramics. An ultrasonic assisted computer-controlled high-speed rotary cutting apparatus was designed and fabricated with functions of ultrasonic vibration, automatic cutting, and force measurement. A multi-phase feldspar glass ceramic with the highest brittleness among glass ceramics was selected for the study. Machining forces, surface roughnesses, and edge chipping damage were evaluated for a range of cutting conditions with and without ultrasonic vibrations. Our most significant finding is that ultrasonic assisted machining led to a clear and consistent reduction of edge chipping and thus subsurface damage. Ultrasonic machining also achieved significant reductions in normal and tangential forces, and surface roughness at higher removal rates (p

Esthetic high-strength lithium disilicate glass ceramics (LDGC) are used for monolithic crowns and bridges produced in dental CAD/CAM and oral adjusting processes, which machinability affects the restorative quality. A machinability study has been made in the simulated oral clinical machining of LDGC with a dental handpiece and diamond burs, regarding the diamond tool wear and chip control, machining forces and energy, surface finish and integrity. Machining forces, speeds and energy in in vitro dental adjusting of LDGC were measured by a high-speed data acquisition and force sensor system. Machined LDGC surfaces were assessed using three-dimensional non-contact chromatic confocal optical profilometry and scanning electron microscopy (SEM). Diamond bur morphology and LDGC chip shapes were also examined using SEM. Minimum tool wear but significant LDGC chip accumulations were found. Machining forces and energy significantly depended on machining conditions (p