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Binder-free NiFe-based electrocatalyst with aligned pore channels has been prepared by freeze casting and served as a bifunctional catalytic electrode for oxygen and hydrogen evolution reaction (OER and HER). The synergistic effects between Ni and Fe result in the high electrocatalytic performance of porous NiFe electrodes. In 1.0 M KOH, porous Ni7Fe3 attains 100 mA cm−2 at an overpotential of 388 mV with a Tafel slope of 35.8 mV dec−1 for OER, and porous Ni9Fe1 exhibits a low overpotential of 347 mV at 100 mA cm−2 with a Tafel slope of 121.0 mV dec−1 for HER. The Ni9Fe1//Ni9Fe1 requires a low cell voltage of 1.69 V to deliver 10 mA cm−2 current density for overall water splitting. The excellent durability at a high current density of porous NiFe electrodes has been confirmed during OER, HER and overall water splitting. The fine electrocatalytic performances of the porous NiFe-based electrodes owing to the three-dimensionally well-connected scaffolds, aligned pore channels, and bimetallic synergy, offering excellent charge/ion transfer efficiency and sizeable active surface area. Freeze casting can be applied to design and synthesize various three-dimensionally porous non-precious metal-based electrocatalysts with controllable multiphase for energy conversion and storage.

Ti3SiC2 has the unique properties integrating the advantages of metals and ceramics, and good open pore structure when alloyed with Al. In this work, porous Ti3SiC2 compounds with different Al/Si atom ratios were prepared through the reactive synthesis of elemental powders at 1300 °C. The results indicate that the phase compositions are determined by Al element mole number, and that the pore structure can be controlled through varying Ti particle size. The MAX phase transits from Ti3SiC2 with Al element mole number no more than 0.6 to Ti3AlC2 with Al element mole number in the range of 0.8–1.2. When Al element mole number is 0.6, the porous compound has a single MAX phase of Ti3SiC2 with uniform microporous structure and high bending strength. Porous Ti3SiC2 alloyed with 0.6Al has a slow linear increase rate of 0.0083%/μm in open porosity with increasing Ti particle size, and a strict linear relationship between the maximum aperture and Ti particle size with the increase rate of 0.0342 μm/μm. The pore structure formed by the phase transition mechanism for porous MAX phase has the smallest tortuosity factor compared with that formed by the clearance mechanism and the Kirkendall effect.

Fiber brushes with expanded graphite (EG) as a lubricant were successfully prepared. Compression properties of brushes filled with unbent fibers and bent fibers with different packing fractions wer...

Spectral fitting method (SFM) was proposed to obtain the refractive index (RI) and thickness of chalcogenide films based on transmission spectra. It extended the Swanepoel method to the films on the order of hundreds of nanometers in thickness. The RI and thickness of the films can be obtained quickly and accurately by using the SFM based on the transmission spectrum with only one peak and valley. The method’s reliability theoretically was evaluated by simulation analysis. The results showed that the accuracy of the RI and thickness was better than 0.2% by using the SFM regardless of thin or thick film. Finally, the RI and thickness of the new ultralow loss reversible phase-change material Sb2Se3 films were obtained experimentally by the SFM. This work should provide a useful guideline for obtaining the RI and thickness of the transparent optical films.

Melanoma is a common, highly fatal skin cancer. Photoacoustic imaging can achieve highly sensitive and high-contrast detection of melanin molecules in tissues, also inheriting the high penetration depth and high spatial resolution characteristics of ultrasound imaging, thus it is a very promising non-invasive diagnostic tool for early melanoma. In this work, we built an acoustic-resolution-based photoacoustic microscopy system, using 1064 nm/532 nm pulsed light to observe melanoma in the back of a mouse with simultaneous photoacoustic/ultrasound imaging. Through the fusion of multi-modal images, accurate positioning of melanoma and its surrounding normal tissues were realized. This work will further promote the application of photoacoustic imaging in the clinical diagnosis of early melanoma.

B2-structured Fe-20.5Al-18Cr (wt.%) intermetallic filter material developed for high-temperature coal-gas purification was fabricated by reactive synthesis using blended Fe/Al/Cr powders. This method addresses the problems presented in the manufacture of porous Fe-Al-Cr materials with high content of Al, making the production more convenient, flexible and controllable. The exothermic effect, volume swelling, pore formation and diffusion reactions during the reactive synthesis of porous Fe-20.5Al-18Cr were investigated systematically. A comparative study with porous Fe20Cr7Al material produced from prealloyed powders was carried out synchronously. The results show that during sintering the Fe-20.5Al-18Cr compact presents limited exothermic behavior and obvious volume expansion, and that the abundant pores and compositional homogenization can be obtained through the interactions of Fe/Al/Cr powders after final sintering. As compared with sintered Fe20Cr7Al porous material, porous Fe-20.5Al-18Cr possesses bigger permeability constants and lower oxidation and sulfidation rates. Pilot-scale filtration tests reveal that Fe-20.5Al-18Cr filter material can robustly serve in the corrosive H2S-contained and alkali-metals-oxides-loaded high-temperature coal gas during a period of 1000 h.

Porous NiCu alloy with oriented pore structure was successfully prepared by freeze casting method with Ni powders and Cu powders as the source materials, and water as the solvent. The pore structure of porous NiCu alloy was analyzed, finding that the porous NiCu alloy frozen at lower temperature having thinner wall thickness and narrower pore width. The electrocatalytic performance for hydrogen evolution reaction (HER) in 6 M KOH at room temperature was evaluated by cyclic voltammetry, linear sweep voltammetry and electrochemical impedance spectroscopy techniques. Results show that porous NiCu alloy frozen at − 50 °C exhibits the most excellent electrocatalytic activity for HER.

Porous NiMo alloys with Mo content of 5 at.% were fabricated by freezing casting method. The pores are elongated, and the media pore size is 8.1 μm. The electrocatalytic activity of the synthesized NiMo alloy foam as cathodes for hydrogen evolution reaction (HER) in 6.0 M potassium hydroxide solution was investigated. Results show that the electrodes which pore orientation is parallel to the hydrogen overflow direction present higher electrocatalytic activity than the electrodes with pore orientation perpendicular to the hydrogen overflow direction. The Tafel slope is 94 and 117 mV dec−1, respectively at a current density of 10 mA/cm2 at room temperature.

Heavy metal ions monitoring in water is practically significant for the environment and the human health. In this work, a lab-on-a-chip biosensor was developed for multiplexed quantitation of heavy metal ions by the integration of triple-channel volumetric bar-chart chip with DNA-nanoparticle probes. This method possesses the capability for rapid detection of Cu2+, Pb2+ and Hg2+ simultaneously with high sensitivity, selectivity and accuracy. Due to the highly catalase-like activity of the urchin-like platinum nanoparticles, this sensor exhibits high sensitivity with the detection limits of 1.0 nM, 1.0 nM and 1.8 nM for sensing of Cu2+, Pb2+ and Hg2+ respectively, which are much lower than the requirement of the United States Environmental Protection Agency (EPA) in drink water and superior to the colorimetric method based on the metal ion-specific DNA assay. The accuracy and reliability were verified by our Atomic Absorption Spectrometry (AAS) and Atomic Fluorescence Spectroscopy (AFS) measurements of real water sample. As the results can be directly read out without the need of the external instruments or complicate data processing, this sensor is extremely practical for environmental applications.

A non-equiatomic refractory high entropy alloy (RHEA), (W35Ta35Mo15Nb15)95Ni5 with high density of 14.55 g/cm3 was fabricated by powder metallurgical process of mechanical alloying (MA) and spark plasma sintering (SPS). The mechanical alloying behavior of the metallic powders was studied systematically, and the microstructure and phase composition for both the powders and alloys were analyzed. Results show that the crystal consists of the primary solid solution and marginal oxide inclusion (Nb5.7Ni4Ta2.3O2). In addition, the maximum strength, yield strength and fracture strain are, 2562 MPa, 2128 MPa, 8.16%, respectively.

A bulk fine-grained W35Ta35Mo10Nb10V10 (at%) high-density high-entropy alloy (HEA) was successfully fabricated by mechanical alloying (MA) and spark plasma sintering (SPS) with varying parameters. Microstructure evolution and mechanical behavior of the HEA samples in various processing conditions were investigated. The alloying effect in the mixed high-purity powders becomes more significant as the increase of ball milling time during MA. Upon SPS at various temperatures ranging from 1600 to 1800 °C, a supersaturated body-centered-cubic (BCC) matrix prevails with the precipitation of Ta2VO6 oxides. After SPS at 1700 °C for 10 min, the average mass density, ultimate compressive strength and microhardness of the bulk HEA at room temperature are 14.65 g cm−3, 2519 MPa and 6.50 GPa, respectively. The mechanisms responsible for the high strength and hardness include massive substitutional solid solution strengthening by the alloying of multiple principal elements, grain boundary strengthening, precipitation strengthening by Ta2VO6 particles, and interstitial solid solution strengthening by interstitials (e.g., tramp O from processing) in the matrix. The systematic information on the relationships among processing parameters, alloy densities, microstructure characteristics (e.g., grain sizes, volume fractions and sizes of precipitated oxides) and mechanical properties provide useful insights for the development of novel high-density and high-strength materials.

Novel perovskite ferroelectric (1-x)KNbO3-xBi(Ni1/2Ti1/2)O3 nanofibers were synthesized by electrospinning for the first time. The synthesized 0.99KNbO3-0.01Bi(Ni1/2Ti1/2)O3 nanofibers displayed the optimal photocatalytic activity with a hydrogen production rate of 0.57 μmol·h−1 for 20 mg under visible light radiation. By first principles calculations, a midgap of Ni 3d was formed between the O 2p states at the valence band maximum and the Nb 4d states at the conduction band minimum due to the addition of Bi(Ni1/2Ti1/2)O3, which may be the principal reason for the visible light response in this work. In addition, the hydrogen production rate of polarized 0.99KNbO3-0.01Bi(Ni1/2Ti1/2)O3 nanofibers was twice as high as that of unpolarization under visible light irradiation, indicating that the internal dipole field can accelerate the separation of photogenerated electron-hole pairs. This may provide a new viewpoint for improving the visible light response of perovskite-oxide ferroelectrics.

High-purity porous Ti3SiC2 with a porosity of 54.3% was prepared by reactive synthesis and its oxidation behavior was evaluated under air in the temperature range from 400 to 1000 °C. Thermogravimetric analysis and differential scanning calorimetry (TG-DSC), scanning electron microscope (SEM), X-ray diffractometometry (XRD), energy dispersive spectrometer (EDS), Raman spectrum, BET surface area analysis, and pore-parameter testing were applied to the studies of the oxidation kinetics, phase composition, micro morphology, and porous structure parameters of porous Ti3SiC2 before and after oxidation. The results showed that the formation of TiO2 oxidized products with different modifications was the primary factor influencing the oxidation resistance and structural stability of porous Ti3SiC2. Cracks were observed in the samples oxidized in the full temperature range of 400-1000 °C because of the growth stress and thermal stress. At 400-600 °C, anomalous oxidation with higher kinetics and the aberrant decrement in pore size and permeability were attributed to the occurrence of severe cracking caused by the formation of anatase TiO2. At raised temperatures over 600 °C, the cracking phenomena were alleviated by the formation of rutile TiO2, but the outward growth of the oxide scales detrimentally decreased the connectivity of porous Ti3SiC2.

The mechanical properties and tribological behaviors of Cu-WS2 composites fabricated by spark plasma sintering (SPS) using two different WS2 particle sizes of 0.6 and 5.0 µm and Cu powders as raw materials were investigated. The results indicate that the bending strength and tribological behavior of Cu-WS2 composites are greatly affected by the size of WS2 particles. The bending strength of Cu-WS2 composites with the WS2 particle size of 5.0 μm is 292.2 MPa. As the size of WS2 particle decreases to 0.6 µm, the bending strength also decreases to 181.5 MPa. Moreover, as the WS2 particle size decreases from 5.0 to 0.6 µm, the wear rate of Cu-WS2 composite sharply increases from 2.99×10−14 to 6.13×10−14 m3/(N·m) and its friction coefficient increases from 0.158 to 0.172. The size of WS2 particle (5.0 μm) plays an important role in forming transfer film formed on the counter-face. The sample with 5.0 μm WS2 particle forms smoother and more continuous transfer film, which results in a low wear rate and friction coefficient of the Cu-WS2 composites.

Ti3SiC2, belongs to MAX phases, usually has the characteristics of low purity and high energy consumption synthesis process. In this work, porous Ti3(Si,Al)C2 quaternary intermetallic compound was fabricated through a reactive synthesis of Ti, Si, Al and graphite elemental powders at relatively low temperature of 1300 °C. The quaternary compound has been characterized by a solid solution based on Ti3SiC2 with the purity of 99.5 vol%. The maximum pore size, open porosity and permeability of porous Ti3(Si,Al)C2 compound were determined to be 7.1 μm, 44.0% and 16.8 m3 m−2 kPa−1·h−1, respectively. The pore size distribution of porous Ti3(Si,Al)C2 exhibits a characteristic of a single main peak with the average pore size of 4.4 μm. Low-cost and easy synthesis method, high purity and uniform aperture distribution impart the new porous material potential applications in purification and separation fields.

Tungsten coating was fabricated on a pure copper substrate by chemical vapor deposition technique (CVD). The deposition rate was about 0.6 mm/h, and the average thickness of the W coating is197.3 μm. The thermal shock resistance of tungsten coating was investigated by thermal shock test, and the interface bonding force was characterized by scratch method. Experimental results show that the coating sample has good thermal shock resistance at 500 °C, and the W coating could sustain thermal shock 50 cycles at 1000 °C without visible failure. According to the scratch test results, it can be found that the effect of thermal shock frequency on the bonding force was obvious. After 10 thermal shocks, the interface bonding strength does not decrease significantly, but it decreases sharply after 30 thermal shocks at different temperatures.

A highly efficient strategy for the synthesis of polylactide with the UV absorption ability was established by employing a Salan-yttrium complex (acting as a fast runing catalyst) combined with large excess hydroxyl functionalized benzophenone, BP′-OH. During polymerization, BP′-OH, acting as the chain transfer agent, attached to the active rare-earth metal catalyst via a rapid-reversible exchange reaction to initiate the polymerization. Thus, more polyester chains appeared to grow from one active metal species, and the UV absorption fragments were incorporated into the polymer chains at specific sites, in situ. A high productivity up to 1000 molLA/mol(Salan-Y) was successfully achieved and 100 BP′-labeled PLA chains grew from each active metal center.

In this study, Cu foams with oriented pore structure were successfully prepared by freeze casting using Cu powders as the raw materials. The effect of cooling temperature on the microstructure and compressive stress were discussed. Results show that the pore size and porosity decrease with lowering the frozen temperatures. Furthermore, the Cu foam with pores parallel to the loading axis has larger compressive strength than that normal to the loading axis under the same strain. The 0.2% yield strength decreases from 25.4 to 12.6 MPa and 23.7 to 8.6 MPa, respectively in the direction parallel or normal to the freezing direction when the porosity increases from 65% to 80%.

WS2 scaffolds with long-range order lamellar structures and preferred orientation particles were fabricated by freeze casting. The nucleation and growth processes of ice crystals were controlled via the double-side temperature fields and polydimethylsioxane (PDMS) wedge, which resulted in the formation of lamellar structure ranging at the centimeter scale. Additionally, the WS2 platelets particles in each layer of WS2 scaffolds are arranged in preferred orientation along (0 0 1) plane. This novel WS2 scaffold is expected to be a potential novel porous material for numerous applications, especially in sliding process.

Porous titanium scaffolds with long-range lamellar structure were fabricated using a novel bidirectional freeze casting method. Compared with the ordinarily porous titanium materials made by traditional freeze casting, the titanium walls can offer the structure of ordered arrays with parallel to each other in the transverse cross-sections. And titanium scaffolds with different pore width, wall size and porosity can be synthesized in terms of adjusting the fabrication parameters. As the titanium content was increased from 15vol.% to 25vol.%, the porosity and pore width decreased from 67±3% to 50±2% and 80±10μm to 67±7μm, respectively. On the contrary, as the wall size was increased from 18±2μm to 30±3μm, the compressive strength and stiffness were increased from 58±8MPa to 162±10MPa and from 2.5±0.7GPa to 6.5±0.9GPa, respectively. The porous titanium scaffolds with long-range lamellar structure and controllable pore structure produced in present work will be capable of having potential application as bone tissue scaffold materials.

Porous WS2 scaffolds with aligned lamellar pore were fabricated by freeze casting, and the pore morphology and size can be well controlled by adjusting the processing parameters during freeze casting process. The results indicated that the porosity and the compressive strength of porous WS2 were greatly affected by the concentration of gelatin. As the gelatin addition increased from 1 to 5 wt%, the porosity of porous WS2 scaffolds with initial solid content of 3 vol% decreased from 95.12 to 90.23%, and their compressive strength increased from 0.22 to 1.16 MPa. Moreover, the lamellar spacing and wall thickness could be tailored from 90 to 320 and 5 to 30 μm respectively by changing the cooling temperature. And the compressive strength of scaffolds has a slight increase with the decreases of cooling temperature. The porous WS2 scaffold with fine aligned lamellar structure and proper compressive strength are expected to be used for scaffold materials.

Porous Ti3SiC2 with high purity was synthesized using TiH2, Si and C powders with mole ratio of Ti to Si to C being 3:1.2:2 by reactive synthesis method. The corrosion behaviors of porous Ti3SiC2 in nitric acid and aqua regia were investigated by immersing test. Scanning electron microscope (SEM), X-ray diffractometer (XRD), energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS) were used to analyze the morphology, compositions and element contents of the samples before and after corrosion to determine the corrosion product and corrosion mechanism. The mass loss values of porous Ti3SiC2 are 26.9 and 132.5 μg/cm2, respectively after immersing in nitric acid and aqua regia for 600 h. The results indicate that Ti3SiC2 transforms to Ti5Si3 which has better corrosion resistance in nitric acid and aqua regia with mass loss values of 9.34 and 7.06 μg/cm2 under the same immersing time, respectively. The dramatic dissolution of porous Ti3SiC2 in the acids is due to its special microstructure.

Remote-controlled manipulation of gene editing was achieved in vivo., As an RNA-guided nuclease, CRISPR-Cas9 offers facile and promising solutions to mediate genome modification with respect to versatility and high precision. However, spatiotemporal manipulation of CRISPR-Cas9 delivery remains a daunting challenge for robust effectuation of gene editing both in vitro and in vivo. Here, we designed a near-infrared (NIR) light–responsive nanocarrier of CRISPR-Cas9 for cancer therapeutics based on upconversion nanoparticles (UCNPs). The UCNPs served as “nanotransducers” that can convert NIR light (980 nm) into local ultraviolet light for the cleavage of photosensitive molecules, thereby resulting in on-demand release of CRISPR-Cas9. In addition, by preparing a single guide RNA targeting a tumor gene (polo-like kinase-1), our strategies have successfully inhibited the proliferation of tumor cell via NIR light–activated gene editing both in vitro and in vivo. Overall, this exogenously controlled method presents enormous potential for targeted gene editing in deep tissues and treatment of a myriad of diseases.

The present study aimed to optimize the fermentation process of sophorolipids production by using response surface methodology (RSM). The pre-fermentation temperature, temperature shift time and late fermentation temperature were selected as the 3 major considering-factors according to the results of preliminary experiment. Subsequently, response surface methodology was applied for the yield optimization of sophorolipids. The second-degree equation for the yield of sophorolipids had an extremely high coefficient of determination (0.9914) and the probability (P) value of the regression model was less than 0.001. The results showed the optimal conditions in the actual fermentative production of sophorolipids were pre-fermentation temperature of 26 °C, temperature shift time of 60 h and late fermentation temperature of 30 °C. Under these conditions, the yield of sophorolipids reached 99.08 g/L, which was 11.97% higher than that merely under constant temperature.

Ti3C2 sheets with typical lamellar structure have been successfully obtained by etching Ti3AlC2 powders in HF. The electromagnetic interference shielding effectiveness (EMI SE) of the Ti3C2/paraffin composites with different Ti3C2 contents were measured in the frequency of 2.0–18.0 GHz. Results show that EMI SE increases with the filled content of Ti3C2, and the total shielding effectiveness reaches up to a maximum of 39.1 decibels (dB) for the Ti3C2/paraffin composites with 60 wt% Ti3C2 and a thickness of 2.0 mm. The Ti3C2/paraffin composites are both absorptive and reflective to electromagnetic radiation, and the main shielding effectiveness is resulting from absorption. Our findings suggest these kinds of 2D transition metal carbides (MXene) will be good candidates for fabricating EMI SE composites with high performance and light weight.

The secondary phase particles of La2O3 play a crucial role in the determination of the yield strength over MoLa alloys, but few work focuses on their intrinsic modulation of shape and size. Herein, a nanostructuring strategy of the secondary phase particles is proposed to enhance the mechanical performances of MoLa alloys, in which the shape and size effects of secondary phase particles have been discussed. Moreover, the strengthening mechanism is also analyzed. It is found that the La2O3 nanospheres with a small size of 84 nm exhibit the best strengthening ability, leading to a high yield strength of 765 MPa in the sintered state. Smaller particles are easily involved into the Mo matrix interior to be intragranular, which are beneficial for the further strengthening. The strengthening contributions are quantitatively calculated, providing a predicted yield strength value, which is in good agreement with the measured one.

A novel porous filter material was fabricated by element reactive synthesis method. The synthesized porous Ti3SiC2 membrane material presents a microstructure of both large substrate pores and small membrane pores, indicating large filtration flux and high filtration accuracy simultaneously. Microorganism filtration properties of the porous Ti3SiC2 membrane material were investigated by filtering the Escherichia coli suspension, which demonstrates excellent performance of the porous materials on filtration.

The photoelectrocatalytic water splitting of molybdenum disulfide is hindered by the intrinsic large electrical resistance among adjacent layers, serious photo-generated carrier recombination and limited utilization of visible light. Herein, we construct MoS2/MoO2 heterostructures via a facile in situ hydrothermal route, in which a Schottky junction is established between the MoS2 semiconductor and metallic MoO2. As a result, the photoelectrochemical current density of MoS2/MoO2 is enhanced about 1.6 times than that of pure MoS2, achieving −10.3 mA cm−2 at −1.8 V vs. SCE, which can be attributed to the reduced electron transfer resistance, enlarged photo-generated carrier separation efficiency and enhanced light absorption due to the presence of metallic MoO2.

In this work, Tungsten carbide (WC)/tungsten (W) coating samples were successfully fabricated by in-situ synthesis method. The thermal shock behavior of the samples were evaluated by rising the samples to 500 °C, 800 °C and 1000 °C, keeping 10 min, and then cooling to room temperature under hydrogen protection. It was found that the coating present excellent thermal shock resistance at 500 °C, with only hairline cracks generated, while the coating began to peel off from the substrate after thermal shock at 1000 °C for 50 cycles. The mechanism of crack propagation during the thermal shock process was also discussed. The interface bonding strength of coating/substrate was tested by scratching method, and the results showed that the interface bonding strength decreased dramatically after thermal shock at 1000 °C for 50 cycles, and the interface bonding strength decreased by 50.8% after 50 cycles thermal shock.

This work prepared a series of porous FeAlCr intermetallic compounds with the Cr content ranging from 5 wt% to 20 wt% by a reactive synthesis method using element powders. These porous FeAlCr materials correspond to the B2-structured FeAl intermetallic (α2) that distinguishes them from the traditional FeCrAl solid-solution alloy (α1) porous materials. The exothermic behaviors, phase characteristics, pore structures and oxidation behaviors of porous FeAlCr with the variation of Cr content were systematically studied. The results showed that upon increasing the Cr content, the released heat during synthesis process was remarkably reduced, while the volume expansion, pore size and open porosity were increased in direct proportion. The linear changes in sample size and pore structure were ascribed to the preferential growth of Al4Cr phase. The oxidation behaviors of porous FeAlCr materials at 600 °C followed a parabolic-linear law, and their oxidation mass gain rates were much slower than those of other reported Ni-based and Fe–Cr alloys. This work proves that to a certain extent the high content of Cr is conducive to the controllable synthesis and high-temperature oxidation resistance of porous FeAlCr materials.

Pb pollution, which is provoked by lead-based anodes in large-scale industrial production, has seriously endangered human health and destroyed the ecological environment in the past decades. In this work, environmentally friendly porous FexSiy intermetallics are prepared by elemental powder reactive synthesis as anodes in zinc electrowinning for the first time. The as-prepared porous FexSiy anodes (Fe3Si, Fe5Si3, and FeSi) have been investigated in terms of electrochemical performance. Among the three anodes, porous Fe5Si3 anode shows relatively better comprehensive properties in 160 g·L−1 H2SO4. Porous Fe5Si3 anode exhibits electrocatalytic activity and long-term stability under the condition of zinc electrowinning, which guarantees a service life up to 400 h. The activity for OER shows that porous Fe5Si3 anode is delivering an overpotential of 1.072 V and tafel slope of 326.6 mV·dec at current density of 50 mA·cm−2. The electrocatalytic activity is positively correlated with the open porosity. The oxides formed in the anode surface are mainly composed of Fe2O3 and amorphous SiO2, which protect the anode against corrosion and help to the activity for OER. This result demonstrated that Fe5Si3 as alternative anode material has potential application value in industry.

A modified water-based freeze casting to fabricate long-range order lamellar Ti6Al4V scaffolds with macropores and high porosity has been developed by using the pre-frozen WS2 substrate as the template. Pores morphologies of the scaffolds relied on the previous ice crystal which had formed in templates and thus could be adjusted by altering the template structure. The decrease of gelatin in WS2 slurry transformed the bottom template from cell pore structure into the lamellar structure followed by improvement of lamellar orientation of the top Ti6Al4V scaffold. The pore widths of the scaffolds were in the range of 84–217 μm which were difficult to realize without the assisted template. The scaffolds also exhibited mechanical compatibility with bone tissues, indicating that the template-assisted freeze casting is a promising approach to fabricate macroporous Ti6Al4V implants.

Industrial TiCl4 liquid, which is a key intermediate in Ti metallurgy, is hard to be purified by traditional porous metals or ceramics due to its characteristics of easy hydrolysis, toxicity and corrosivity. In this work, porous TiAl intermetallic filter tubes were fabricated through a reactive synthesis process, and their filtration properties in industrial TiCl4 liquid were investigated. The cyclic corrosion kinetics of porous TiAl in TiCl4 follows a parabolic rate law, in which the corrosion rate constant is 4.8%, 0.06% and 0.04% of that of porous Ti, Ni and 316L stainless steel, respectively. After the cyclic corrosion of 408 h, the maximum aperture reduction rate of porous TiAl is 3.9%, which is far lower than that of porous Ti, Ni and 316L, indicating good pore structure stability. Porous TiAl filter tubes exhibit clean filtration performance in the solid-liquid separation of raw TiCl4 suspension with stable filtrate solid content of 0.1 wt% and high filtration flux of 8.17 m3 · m−2 · h−1 at the maximum aperture of 17.0 μm. The filtration equation and the filter medium resistance of porous TiAl are determined.

Quantum dots are important fluorescent semiconductor nano-crystals with distinguished electrical and optical properties and have gained great interest in many fields. The chemical and physical synthetic methods are usually not favorable for biological application due to high energy-consumption procedure and residual toxic chemicals. The development of novel “green” routes to prepare bio-compatible cadmium sulfide quantum dots constitutes a promising substituted approach. We used the white rot fungus Trametes versicolor for the biosynthesis of cadmium sulfide quantum dots taking account of the adsorption property of this fungus. Multiple physical characterizations involving scanning electron microscope (SEM), ultraviolet-visible (UV–vis) and photoluminescence (PL) spectroscopy, fourier transform infrared spectroscopy (FTIR), thermo-gravimetric (TG), transmission electron microscopy (TEM) and X-ray diffraction (XRD) confirmed surface, optical and thermal characteristics, crystalline nature, size and shape distributions of the nanoparticles. This study provided a suitable and efficient approach to synthesize stable biocompatible cadmium sulfide quantum dots using the fungus Trametes versicolor with great potentials in the biological and biomedical researches.

Porous ternary compound Ti 3 SiC 2 with purity of higher than 99.0 wt.% was fabricated through a reactive synthesis method using titanium hydride, silicon and graphite elemental powders. The parameters of pore structure including the maximum pore size, open porosity and air permeability, obey the Hagen–Poiseuille formula with the constant G = 0.226 m −1 Pa −1 s −1 for the reactively synthesized porous Ti 3 SiC 2 . The porous Ti 3 SiC 2 shows excellent corrosion resistance in concentrated acids. Further, a typical filter application in zinc metallurgy has been reported. The excellent overall performance predicts the porous Ti 3 SiC 2 material has a broad application in industry.

In this paper, micrometer-sized porous Ti3SiC2 metal ceramic was fabricated through a reactive synthesis method using titanium hydride, silicon and graphite elemental powders. The factors including raw powders, pressing pressure, sintering procedure affecting the purity and the pore property of porous Ti3SiC2 were systematically studied. The results indicate that the purity, pore property including maximum pore size and porosity can be effectively controlled by adjusting the synthesis parameters.

A novel porous material Ti3SiC2 is synthesized using reactive synthesis of mixed elemental powders. The synthesized porous Ti3SiC2 has high purity more than 99.0%. By adjusting the fabrication parameters, porous Ti3SiC2 can be synthesized with average pore diameters ranging from ∼200 nm to over ∼40 μm and open porosity ranging from ∼19.5% to ∼53.2%. The pore formation mechanism has been studied. Also, the synthesized porous Ti3SiC2 material presents promising mechanical properties. This novel porous material has the potential to replace the traditional inorganic porous material.

Porous Ti3SiC2 was fabricated with high purity, 99.4 vol %, through reactive sintering of titanium hydride (TiH2), silicon (Si) and graphite (C) elemental powders. The reaction procedures and the pore structure evolution during the sintering process were systematically studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). Our results show that the formation of Ti3SiC2 from TiH2/Si/C powders experienced the following steps: firstly, TiH2 decomposed into Ti; secondly, TiC and Ti5Si3 intermediate phases were generated; finally, Ti3SiC2 was produced through the reaction of TiC, Ti5Si3 and Si. The pores formed in the synthesis procedure of porous Ti3SiC2 ceramics are derived from the following aspects: interstitial pores left during the pressing procedure; pores formed because of the TiH2 decomposition; pores formed through the reactions between Ti and Si and Ti and C powders; and the pores produced accompanying the final phase synthesized during the high temperature sintering process.

A highly efficient strategy for synthesizing the first biocompatible polyesters with AIE characteristics has been established via immortal ring-opening polymerizations of cyclic esters bearing nonluminophores. In the process, the large excess hydroxyl-modified AIE active compound, acting as the chain transfer agent, attaches to the active rare-earth metal catalyst via the rapid-reversible exchange reaction to initiate the polymerization. Thus, more polyester chains appear to grow from one active metal species, and the AIE fragments are incorporated into the polymer chains at specific sites, in situ. The resultant polyesters have linear, block, or star-shaped microstructures mimicking those of the modified AIE compounds. The polymerization solutions can be directly fabricated to large-area thin solid films. The obtained PLA, for instance, emits fluorescence in water/THF mixtures owing to aggregation, the intensity of which is 2850-fold stronger than that in THF solution. This strategy avoids complicated pr...

Hyaluronan-grafted liposomes (HA-liposomes) preferentially target CD44-overexpressing tumor cells in vitro via receptor-mediated endocytosis. We investigated the pharmacokinetics and biodistribution of HA-liposomes with various sizes of HA (MW 5-8, 50-60, and 175-350 kDa) in mice. Incorporation of negatively charged HA on the liposome surface compromised its blood circulation time, which led to decreased tumor accumulation in CD44+ human breast cancer MDA-MB-231 xenografts compared to PEGylated liposomes (PEG-5000). Clearance of HA-liposomes was HA polymer length-dependent; high MW (175-350 kDa, highest ligand binding affinity) HA-liposomes displayed faster clearance compared to low MW (5-8, 50-60 kDa) HA-liposomes or PEGylated liposomes. Surface HA ligand density can also affect clearance of HA-liposomes. Thus, HA is not an effective stealth coating material. When dual coating of PEG and HA was used, the PEG-HA-liposomes displayed similar blood circulation time and tumor accumulation to that of the PEGylated liposomes; however, the PEG-HA-liposomes displayed better cellular internalization capability in vivo. Tumor histology showed that PEG-HA-liposomes had a more direct association with CD44+ cancer cells, while PEGylated liposomes located predominantly in the tumor periphery, with less association with CD44+ cells. Flow cytometry analysis of ex vivo tumor cells showed that PEG-HA-liposomes had significantly higher tumor cell internalization compared to PEGylated liposomes. This study demonstrates that a long blood circulation time is critical for active tumor targeting. Furthermore, the use of the tumor-targeting ligand HA does not increase total tumor accumulation of actively targeted liposomes in solid tumors; however, it can enhance intracellular delivery.

Catalyst systems obtained from the inexpensive, ligand-free and commercially available MgnBu2 and alcohols were used for the ring-opening polymerization (ROP) of e-caprolactone (e-CL) under mild conditions. The catalytic system of MgnBu2/Ph2CHOH showed very high activity as compared with the system of MgnBu2/Ph3COH, which applied a more bulky methanol derivative. Interestingly, in the presence of excess amount of alcohol (Ph2CHOH), i.e., varying the OH-to-Mg ratio in a wide range from 10 : 1 to 800 : 1, the system MgnBu2/Ph2CHOH still remained highly active, and produced up to 800 polycaprolactone (PCL) chains per Mg center, suggesting a “living immortal” polymerization mode. The molecular weights of the obtained PCLs are accurately controlled when the ratio of [CL]0/[Mg]0 changed from 500 to 8000 together with narrow molecular weight distributions. Moreover, diblock PCL-b-PLA copolymers with narrow PDIs have been facilely achieved. Furthermore, the allyl- and propargyl-functionalized diphenylmethanols could be employed as the chain transfer agents (CTA) in this system for in situ construction of allyl- and propargyl-functionalized PCLs that were facilely modified further to PCLs with multiple functionality as building blocks for amphiphilic and topological microstructured PCLs via coupling and click reactions.

Four new acceptor–donor–acceptor based organic small molecules with the benzo[1,2-b:4,5-b′]dithiophene (BDT) unit as the central donor group, benzothiadiazole (BT) or fluoro-substituted benzothiadiazole as the acceptor, and different end-capping groups (BTBDT1–BTBDT4) have been synthesized and tested for solution-processed bulk-heterojunction organic solar cells. The absorption spectra, electronic energy levels, hole mobilities and solar cell performance of these compounds were investigated. All compounds show broad absorption in the visible range. The PCE of the solar cell device based on BTBDT3/PC71BM (1:2, w/w) reached 3.91% with a Jsc of 10.08 mA cm−2, a Voc of 0.90 V and a FF of 0.43, under illumination of AM 1.5G, 100 mW cm−2.

We demonstrate a label-free photonic biosensor with double slots based on micro-ring resonator. The footprint is less than 25 μm × 15 μm. Finite-difference time-domain (FDTD) method is used to analyze the influence of several key parameters on the performance of the double-slots micro-ring resonators. An asymmetric structure is considered for the ring waveguide in order to improve the sensor's bending efficiency. Our numerical analysis shows that the sensitivity of double-slot micro-ring resonator sensor with the radius of 5 μm reaches a value of 708 nm/RIU. The quality factor of 580 and the free spectral range (FSR) of 33 nm are achieved.

The mechanical behaviors of single crystalline micro-sized tungsten whiskers were experimentally characterized using nanoindentation. Nucleation and multiplication of dislocations were seen as displacement burst or pop-in events in the load–displacement curves during loading segment. The Hertzian contact theory and Kick's law were used to describe the elastic deformation of the material, whereas the theoretical strength of the perfect tungsten whiskers can be derived from the critical pop-in load. The elastic–plastic deformation after the pop-in agrees well with the Taylor relation. Either only one major pop-in or a series of discontinuities was observed in the experiments, attributed to the different critical loads at which the first pop-in occurs. Creep behaviors of the whiskers were also investigated under a constant load for 600 s. The stress exponent n was calculated using the displacement–time curve and agrees well with the value obtained using the traditional tensile creep testing method. The creep behavior is dominated by the dislocation-controlled (power-law) mechanism with an n of ~5. Additionally, the stress exponent n is proved to increase with increasing the holding load, and remains stable with increasing the loading rate in the range of testing parameters selected in the experiments.

A temperature-controlled selective filtration technology for synchronous removal of arsenic and recovery of antimony from the fume produced from reduction smelting process of lead anode slimes was proposed. The chromium (Cr) alloyed FeAl intermetallic with an asymmetric pore structure was developed as the high-temperature filter material after evaluating its corrosive resistance, structural stability and mechanical properties. The results showed that porous FeAl alloyed with 20wt.% Cr had a long term stability in a high-temperature sulfide-bearing environment. The separation of arsenic and antimony trioxides was realized principally based on their disparate saturated vapor pressures at specific temperature ranges and the asymmetric membrane of FeAl filter elements with a mean pore size of 1.8μm. Pilot-scale filtration tests showed that the direct separation of arsenic and antimony can be achieved by a one-step or two-step filtration process. A higher removal percentage of arsenic can reach 92.24% at the expense of 6∼7% loss of antimony in the two-step filtration process at 500∼550°C and 300∼400°C. The FeAl filters had still good permeable and mechanical properties with 1041h of uninterrupted service, which indicates the feasibility of this high-temperature filtration technology.

One dimensional W/WO2.72 heterostructures were successfully synthesized using WO3 as the raw material by a simple two-step chemical vapor deposition process. The morphology and microstructure of the W/WO2.72 heterostuctures were characterized using scanning electron microscopy and transmission electron microscopy. The results indicate that the long and straight central axial W whiskers grow along [1 1 0] direction, while the branched WO2.72 nanowires grow on the side surface of the W whiskers along the radial direction, with [0 1 0] as the growth direction. The as-synthesized heterostuctures exhibit enhanced field emission property over the single W whiskers, and could be used as a candidate for field-emission devices and ultrahigh sensitivity sensors due to their unique composition and structure.