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In order to remove N2 from low quality natural gas, a mathematical model has been established by Aspen adsorption, using the CH4-selective sorbent silicalite-1 pellets. The dynamic adsorption isotherm was first simulated by breakthrough simulation of a CH4/N2 mixture at different adsorption pressures and feed flow rates based on breakthrough experiments. The resulting simulated CH4 dynamic adsorption amounts were very close to the experimental data at three different adsorption pressures (100, 200, and 300 kPa). Moreover, a single-bed, three-step pressure swing adsorption (PSA) experiment was performed, and the results were in good agreement with the simulated data, further corroborating the accuracy of the gas dynamic adsorption isotherm obtained by the simulation method. Finally, based on the simulated dynamic adsorption isotherm of CH4 and N2, a four-bed, eight-step PSA process has been designed, which enriched 75% (vol) CH4 and 80% (vol) CH4 to 95% (vol) and 99% (vol), and provided 99% (vol) recovery.

Coagulation and sedimentation process is one of the most popular processes in drinking water treatment. Hydrodynamic breakage has a significant impact on the evolution of floc characteristics and the efficiency of turbidity removal. In this work, the effects of hydrodynamic breakage on floc size, fractal dimension, and floc morphology were investigated with an in-situ recognition system. The experiments were conducted in a continuous flocculation and sedimentation reactor equipped with perforated plates to provide different hydrodynamic breakage conditions. The experimental results indicated that the hydrodynamic conditions significantly influenced the floc destabilization and restructuring processes. A low hydrodynamic shear force provided by P1 led to the increase of both bigger sized flocs but accompanied with small particles (0–10 μm). Excessive velocity gradient provided by P3 produced smaller and looser flocs. An appropriate velocity gradient (i.e., the flow velocity through the perforated plate P2 at 18.9 × 10−3m s−1) was conducive for the formation of larger and more compact structures, with higher average floc size and fractal dimension. This flocculation condition in turn resulted in effective improvements in the turbidity removal efficiency. Floc evolution models were described based on the mechanism of the breakage and restructuring process.

The micro-volume analysis and specific detection are both essential requirements in the field of chemical sensing and biological testing. Membrane prefiltration can be used to improve the selectivity and accuracy of detection. But for traditional porous membrane filtration, it is difficult to achieve the transmembrane transport of micro-volume liquid due to the influence of lateral diffusion on membrane surface. Herein, we studied the focused transmembrane transport of micro-volume liquid in the porous polyethersulfone membrane with asymmetric (Janus) surface wettability. The hydrophilic layer (polydopamine) and hydrophobic layer (fluoropolymer) were deposited with controllable thickness by dip-coating and roller-assisted liquid printing. The micro-volume liquid focusing effect was verified by experiments such as visual wetting circle and fluorescent tracer. The liquid focusing effect of as-prepared Janus membrane was integrated with glucose test strip in the application of micro-volume liquid biosensing. Compared with conventional porous membrane, detected signal amplitude and response time were improved 7.5× and 2.7×, respectively. In summary, this research studied the dynamics of liquid transport through Janus membrane and provides a new strategy for microfluidic detection applications through balancing detection volume, time and selectivity by the advantage of micro-volume liquid focusing effect.

Selective, hard to realize growth retardation of the π-stacking direction over the edge-packing direction has been achieved in perylene microcrystals using an aryl amphiphile. The perylene microcrystals grow predominantly along the edge-packing direction resulting in novel and hitherto unknown perylene square rods. The rods show exciton-polariton waveguiding along the rod axis even though it corresponds to pure edge-packing of the molecules, which is unprecedented in organic microcrystals.

Enhancing the fluorescence of perovskite nanocrystals (PNCs) will not only boost the development of perovskite light-emitting devices (LEDs), but also broaden their applications in various photoelectronic areas. However, an effective approach to flexibly enhance different emission colors with high enhancement factors is still desired. In this work, SiO2 photonic crystals (PCs) are designed to couple with the radiative emission of PNCs. Blue, green, and red fluorescent PNCs emitting at 460, 517 and 620 nm are coated onto PCs with SiO2 particle sizes of 200, 230, and 274 nm, respectively. Fluorescence enhancement factors of 22, 12, and 19 are acquired when the excitation power is 0.078 W. Moreover, the enhancement factor noticeably increases with the excitation power. The enhancement factor for blue PNCs is over 250 with an excitation power of 0.09 W. The enhanced fluorescence of PNCs will facilitate the fluorescence signal acquisition with low noise, which is favorable for optical sensing. As a proof of concept, we demonstrate that the luminescence temperature sensing capability of the PNCs on SiO2 PCs is significantly boosted compared to that of the PNCs on glass.

Materials with specific wettability properties have aroused enormous interest and research for their broad application prospects in chemical reaction, medical diagnosis, biological analysis, etc. Here, inspired by the unique Janus wettability of lotus leaf and Bragg stacks of beetles, we present a free-standing film with Janus wettability and tunable structural color for water quality monitoring. This film is constructed by using a flexible polymer polyurethane (PU) to pack poly(

The demand for xylenes is projected to increase over the coming decades. The separation of xylene isomers, particularly p- and m-xylenes, is vital for the production of numerous polymers and materials. However, current state-of-the-art separation is based upon fractional crystallisation at 220 K which is highly energy intensive. Here, we report the discrimination of xylene isomers via refinement of the pore size in a series of porous metal–organic frameworks, MFM-300, at sub-angstrom precision leading to the optimal kinetic separation of all three xylene isomers at room temperature. The exceptional performance of MFM-300 for xylene separation is confirmed by dynamic ternary breakthrough experiments. In-depth structural and vibrational investigations using synchrotron X-ray diffraction and terahertz spectroscopy define the underlying host–guest interactions that give rise to the observed selectivity (p-xylene < o-xylene < m-xylene) and separation factors of 4.6–18 for p- and m-xylenes., Separation of xylene isomers is essential for the production of a wide range of materials, but current separation methods are energy intensive. Here the authors report separation of the three xylene isomers at room temperature, via refinement of the pore size in a series of porous MOFs at sub-angstrom precision.

Designing high-efficiency and low-cost bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of great significance to produce hydrogen by water electrolysis. Herein, a hierarchical FeCo2S4@CoFe layered double hydroxide (LDH) core–shell structure catalyst was successfully fabricated via a hydrothermal–sulfuration–electrodeposition three-step method. The unique structure can provide more abundant catalytically active sites for the electrochemical reaction. The resulting FeCo2S4@CoFe LDH electrode only requires overpotentials of 115 and 247 mV to reach a current density of 10 mA cm−2 for the HER and OER in 1 M KOH electrolyte, respectively. The electrode also exhibits a low Tafel slope and excellent stability. Furthermore, the bifunctional catalyst for overall water splitting can exhibit a cell voltage of 1.6 V at 10 mA cm−2, along with outstanding durability for 24 h testing. This work provides a new strategy to design effective bifunctional catalysts for overall water splitting.

A detailed analysis of the electrical response of In0.3Ga0.7As surface quantum dots (SQDs) coupled to 5-layer buried quantum dots (BQDs) is carried out as a function of ethanol and acetone concentration while temperature-dependent photoluminescence (PL) spectra are also analyzed. The coupling structure is grown by solid source molecular beam epitaxy. Carrier transport from BQDs to SQDs is confirmed by the temperature-dependent PL spectra. The importance of the surface states for the sensing application is once more highlighted. The results show that not only the exposure to the target gas but also the illumination affect the electrical response of the coupling sample strongly. In the ethanol atmosphere and under the illumination, the sheet resistance of the coupling structure decays by 50% while it remains nearly constant for the reference structure with only the 5-layer BQDs but not the SQDs. The strong dependence of the electrical response on the gas concentration makes SQDs very suitable for the development of integrated micrometer-sized gas sensor devices.

Modified metal–organic frameworks (MOFs) doping with enzymes exhibit high enzyme stability and catalytic performance, which is a research hotspot in the field of enzyme-based sensing. Although the MOF-enzyme constitutes a 3D structure in the nanoscale, the macroscopic assembly configuration still stays in 1D or 2D structures, limiting sensing applications towards complex biological targets. Herein, the MOF-enzyme hybrid nanosystem was assembled into 3D porous conductive supports via a controllable physical embedding method, displaying high enzymatic loading, stability and cascade catalytic performance. The modified MOFs combing with enzymes served as a sensing reaction system, and the conductive hollow fiber membranes (HFMs) served as a functional platform. The multifunctional device integrates pumpless hydrodynamic transport, interconnected conductive polymer, and blood separation modules, showing fast capillary fluid flow, trace sampling (3 μL), high selectivity and accuracy. The linear sensing range was in 2–24 mM glucose, 0.05–6 mM lactic acid, and 0.1–10 mM cholesterol, respectively, with sensitivities of 24.2, 150, 73.6 nA mM−1. Furthermore, this strategy of modular assembly of biosensing array can easily implement multiplex metabolites detection simultaneously.

Iodine detection is crucial for nuclear waste clean-up and first responder activities. For ease of use and durability of response, robust active materials that enable the direct electrical detection of I2 are needed. Herein, a large reversible electrical response is demonstrated as I2 is controllably and repeatedly adsorbed and desorbed from a series of metal–organic frameworks (MOFs) MFM-300(X), each possessing a different metal center (X = Al, Fe, In, or Sc) bridged by biphenyl-3,3′,5,5′-tetracarboxylate linkers. Impedance spectroscopy is used to evaluate how the different metal centers influence the electrical response upon cycling of I2 gas, ranging from 10× to 106× decrease in resistance upon I2 adsorption in air. This large variation in electrical response is attributed not only to the differing structural characteristics of the MOFs but also to the differing MOF morphologies and how this influences the degree of reversibility of I2 adsorption. Interestingly, MFM-300(Al) and MFM-300(In) displayed the largest changes in resistance (up to 106×) yet lost much of their adsorption capacity after five I2 adsorption cycles in air. On the other hand, MFM-300(Fe) and MFM-300(Sc) revealed more moderate changes in resistance (10–100×), maintaining most of their original adsorption capacity after five cycles. This work demonstrates how changes in MOFs can profoundly affect the magnitude and reversibility of the electrical response of sensor materials. Tuning both the intrinsic (resistivity and adsorption capacity) and extrinsic (surface area and particle morphology) properties is necessary to develop highly reversible, large signal-generating MOF materials for direct electrical readout for I2 sensing.

A novel photoelectrochemical (PEC) biosensor based on hybrids of NaYF4:Yb, Tm, zinc oxide (ZnO) and cadmium sulfide (CdS) was constructed to detect alpha-fetoprotein (AFP), which possesses the advantages of low background noise and non-damage to the biological substance. Herein, we prepared NaYF4:Yb,Tm/ZnO/CdS composite film electrode by pulsed laser deposition. The selected materials of ZnO and CdS can make full use of the upconversion luminescence (˜360 nm, ˜480 nm) of NaYF4:Yb,Tm nanophosphors under 980 nm laser excitation. Meanwhile, an effective matching of energy levels between the conduction bands of CdS and ZnO can prompt photoelectrochemical performance of the electrode. The biosensor shows ultrasensitive detection of AFP with a wide linear range from 0.01 ng mL−1 to 200 ng mL−1 and a low detection limit of 5 pg mL−1. Therefore, the proposed PEC biosensor based on upconversion nanophosphors is potentially attractive for achieving excellent photoelectrochemical biosensor for detection of other cancer markers in clinical analysis.

Accurate treatment of photothermal therapy (PTT) is crucial to avoid the unnecessary injury of normal cells and tissues. Therefore the real-time temperature monitoring in the PTT process has drawn more and more attention in recent years. Herein, we designed and prepared one kind of lanthanide (Ln3+)-doped up-conversion nanocomposites with multi-functions, which can not only provide temperature feedback in PTT process, but also play the photodynamic therapy (PDT) function for the synergistic effect of tumor therapy. Based on NaYF4:Yb, Er up-conversion nanoparticles (UCNPs), mesoporous SiO2 was modified on the surface combined with photosensitizer Chlorin e6 (Ce6) molecules, which could be excited by red emission of Er3+ under the 980 nm laser. Cit-CuS NPs were further linked on the surface of the composite served as photothermal conversion agent, therefore, the temperature of the PTT site can be monitored by recording the ratio of I525/I545 of green emissions, especially within the physiological range. Based on the guidance obtained from spectral experiments, we further investigated the dual-modal therapy effect both in vitro and in vivo, respectively, and acquired decent results.

Surface modifications play an important role in endowing implant surface with excellent biocompatibility and bioactivity. Among the bioinspired surface modifications, the mussel-inspired polydopamine (PDA) has aroused great interest of researchers. Herein, we fabricated PDA on diverse implant surfaces, including biopolymer, biometal, and bioceramic. Then the effects of PDA coating on cell responsive behaviors in vitro and bone formation capacity in vivo were evaluated in detail. The results showed that PDA coating was fabricated on diverse samples surface successfully, which could significantly improve the hydrophilicity of different material surfaces. Furthermore, the results indicated that PDA coating exerted direct enhancing on the adhesion, proliferation and osteogenic differentiation of bone marrow derived mesenchymal stromal cells (BMSCs) through FAK and p38 signaling pathways. During the process, the focal adhesion protein expression and osteogenic-related genes expression level (e.g., ALP, BMP2, BSP, and OPN) were considerably upregulated. Most importantly, the in vivo study confirmed that PDA coating remarkably accelerated new bone formation and enhanced osseointegration performance. Our study uncovered the biological responses stimulated by PDA coating to make a better understanding of cell/tissue-PDA interactions and affirmed that PDA, a bioinspired polymer, has great potential as a candidate and functional bioactive coating medium in bone regeneration and orthopedic application.

Injectable bioactive ceramics with excellent osteogenesis play important roles in bone regeneration field. In this study, we creatively fabricated the injectable nano-structured silicon-containing hydroxyapatite (Si-HAp) microspheres in diameter of 70–100 µm via hydrothermal treatment of calcium silicate (CaSiO3) microspheres in Na3PO4 aqueous solution. The fabricated Si-HAp microspheres were constructed by nano-rods with a diameter of 100 nm and length up to 1.5 µm. Comparing with the pure HAp microspheres, the obtained nano-structured Si-HAp microspheres exhibited excellent protein loading properties and sustained protein release capacities. Most importantly, the Si-substitution could apparently enhance the proliferation, osteogenic differentiation and the genes expression of angiogenic factors of rat bone marrow mesenchymal stem cells (rBMSCs). These all indicated that the nano-structured Si-HAp microspheres fabricated via hydrothermal transformation method might be used as promising injectable bioactive biomaterials and drug deliveries for bone regeneration.

Electrospinning is an effective way to fabricate ultralong nanotubes with a large surface area. However, the nanotubes synthesized through this way suffer from difficult controlling of structural parameters. A facile strategy for constructing highly controllable Pt@ZnO nanoparticles (NPs) drive TiO2 nanotubes (NTs) (Pt@ZnO-TiO2 NTs) was developed in this work. First, the polystyrene electrospun nanofibers (∼490 nm) containing Pt@zeolitic imidazolate framework-8 (ZIF-8) was fabricated as a self-sacrificial template and then was decorated by a thinner tetrabutyl orthotitanate layer through soaking. After annealing, the Pt@ZnO NPs were obtained due to the decomposition of Pt@ZIF-8 during calcination. The involving of ZIF-8 can effectively prevent the aggregation of Pt during heat treatment (∼3 nm, monodispersed), and thus highly improves its catalyst property. When Pt@ZnO-TiO2 NTs were evaluated as a sensing material for toluene detection, the obtained sensors exhibited an enhanced sensing response (11.1 to 1 ppm toluene), faster response/recovery times (7.5 and 20.1 s) and a lower detection limit (23 parts per billion) during dynamic measurement, when compared to the pristine TiO2 and directly mixed Pt-TiO2 NTs. This was mainly attributed to the improved oxygen vacancy concentration in the NT composite and resistance modulation effect induced by the unique NT structure, as well as the well-dispersed and small-sized Pt catalyst.

We report a low-cost, highly energy efficient microwave-assisted chelation (MWAC) method, which enabled the post-synthetic modification of synthetic zeolites for adopting hierarchical structures within minutes. Exemplified by Zeolite Y, hierarchical Y zeolites prepared in this way showed exceptional specific external surface areas of >300 m2 g−1 and mesopore volumes of >0.46 cm3 g−1. Comparative assessments revealed that developed zeolites have shown significantly improved catalytic activities for catalysis involving large substrates, such as catalytic cracking and hydrocracking of plastics.

Numerous precipitation methods for creating nanoparticle dispersions that are based on mixing a solution with a miscible nonsolvent have been developed. Here, we show that for polymer particles, the formation is highly dependent on the rate of mixing. We also demonstrate the importance of the glass transition of the polymers on particle formation. A simple model of droplet formation during mixing provides a satisfactory description of the observed dependence of particle size on polymer molecular weight, concentration, solvent ratio, and mixing conditions.

Compared with other drug carriers, graphene materials attract more attention due to their large specific surface area, strong targeting and controlled release. Graphene adsorbs anticancer drugs such as doxorubicin and paclitaxel via strong π-π interaction between graphene and the aromatic conjugated structure in drug molecules. The adsorption stability of benzene as minimum aromatic conjugated structure on graphene surface is investigated in this research. The evolution paths of relative stable and unstable positions strongly depend on the size of graphene. For graphene with different size ratios, the evolution paths of benzene go through different stages with decrease of adsorption height and the most stable adsorption position can be found. Based on the interaction energy, the edge effect of graphene with finite size is used to reveal the mechanism of size effect, which is caused by the competition between van der Waals energy and electrostatic energy. This research can provide a reference for the manufacture and application of graphene as drug carriers.

Personalized precision therapy and rapid osseointegration are the main development directions of dental implants. Three-dimensional (3D) printing is the most promising method to fabricate personalized implants with complex design and structure. Rapid osseointegration guarantees the survival of implants especially at early implant time, and the surface modification via nano-technology is considered as the most effective method to promote osseointegration. Herein, the Ti6Al4V implants were fabricated by 3D-printing method then the nano-topographic surface was constructed on them to improve the biological responses. The results showed that the nano-topographic modification favored the adhesion and osteogenic differentiation of bone marrow derived mesenchymal stromal cells (BMSCs), accelerating the rapid osseointegration in vivo in rat condyle of femur model. It is reasonable to predict that 3D-printed implants with nano-topographic surface modification have a promising future in orthopedic applications.

Recent demonstration of mobilities in excess of 10 cm2 V–1 s–1 have energized research in solution deposition of polymers for thin film transistor applications. Due to the lamella motif of most soluble, semiconducting polymers, the local mobility is intrinsically anisotropic. Therefore, fabrication of aligned films is of interest for optimization of device performance. Many techniques have been developed to control film alignment, including solution deposition via directed flows and deposition on topologically structured substrates. We report device and detailed structural analysis (ultraviolet–visible absorption, IR absorption, near-edge X-ray absorption (NEXAFS), grazing incidence X-ray diffraction, and atomic force microscopy) results from blade coating two high performing semiconducting polymers on unpatterned and nanostructured substrates. Blade coating exhibits two distinct operational regimes: the Landau–Levich or horizontal dip coating regime and the evaporative regime. We find that in the evapora...

Three-dimensional ordered macroporous iridium oxides (3DOM IrO x 0 ≤ x ≤ 2), were synthesized through a simple self–assembly template method and developed as an electrode material for lable–free immunosensor of cancer biomarker alpha-fetoprotein (AFP). The 3DOM IrO x was well modified on flexible fluorine-doped tin oxide (FTO) electrode and such FTO electrodes based 3DOM IrO x immnuosensor enhanced the adsorption of electrolytes, the diffusion of reactants, and also could act as a rapid electron transfer channel benefited both from the advantage of 3DOM architecture and the nature of IrO x itself. These combined characteristics greatly increased the sensitivity, shortened the response time, reduced the interference, promoted the stability and moreover, demonstrated good accuracy to detect AFP in human serum. The optimum structure and sensing properties of immnuosensor were obtained based on 3DOM IrO x annealed at 500 °C. It allows detecting AFP over a wide concentration range from 1 to 250 ng/mL with a detection limit of 0.3 ng/mL, and a higher slope of the calibration equation. The manufactured immunosensor was also used to determine AFP in human serum with satisfactory results. This kind of 3DOM IrO x modified and FTO-based immunosensor has great application potential for the AFP electrochemical detection.

Highly uniform and compositionally graded Pd–Zn nanocrystals (NCs) with particle diameters of approximately 5.0–6.5 nm are obtained via a facile one-pot synthesis process in dimethylformamide (DMF) and water solution. The Pd–Zn NCs are formed by the reduction of transition metal ions coexisting in ascorbic acid (AA) and noble metals. The NCs are characterized by X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. Investigations indicated that the NCs have compositionally graded PdxZn1−x NCs with x ranging from 0.68 to 1.00. Electrochemical measurements reveal that the PdxZn1−x NCs exhibit superior electrocatalytic performance of both activity and stability for the formic acid oxidation (FAO) reaction compared with commercial Pd/C. The optimized Pd0.77Zn0.23 NCs exhibit a FAO catalytic oxidation current density of 1945 mA mgPd−1, which is 8.2 times higher than that of commercial Pd/C (237 mA mgPd−1). CO stripping measurement indicates that the tolerance to CO poisoning has been significantly improved by alloying Zn. The excellent performance can be attributed to the synergistic effect between Pd and Zn in Pd–Zn NCs.

Three-dimensional inverse opal (3DIO) ZnO-Fe3O4 composite structure was prepared by a template method and the gas sensing property was investigated toward trace acetone which is an important biomarker of diabetes. The prepared 3DIO composite sensors have large surface area due to both macropores (larger than 100 nm) and mesoporous structure in skeleton, which make the inner surface accessible and provide more active sites to adsorb more oxygen species and target molecules. 3DIO ZnO-Fe3O4 composite sensor exhibits much higher response toward acetone relative to pure ZnO sensor. The optimal 3DIO sensor exhibited a detection limit as low as 100 ppb acetone and showed 40% response increase from 0.9 ppm (healthy humans) to 1.8 ppm (diabetics) which allow reliable diagnosis of diabetic patients by acetone monitoring.

We have developed a three-dimensional (3D) enzyme loading strategy by modular assembly of enzyme loaded nanoparticles with porous conductive membranes. A 3D conductive structure was fabricated as electrode via the poly-(3,4-ethylenedioxythiophene) (PEDOT) in-situ synthesized on hollow fiber membranes (HFMs) framework, retaining the original gradient porous structures and capillary effect. Using physical entrapment pattern, enzyme-carrying nanoparticles were modularly assembled in the 3D conductive support and their spatial distribution can be regulated by particle size-tuning. The obtained enzyme entrapped 3D composites can be applied as a promising electrode in electrochemical sensing and catalysis. HFMs provide large surface area and gradient porous structure for entrapping the enzyme-carrying nanoparticles in the confined micro-space. The physical entrapment improves the enzymatic stability and promotes full contact between the enzymes and the conductive/catalytic substrates. The conductive support creates an interconnected network to increase the electrode area and the response current, thus enhancing the sensitivity of biosensors. It shows fast current response (~3 s), wide linear range (glucose, 2–24 mM; lactic acid, 0.1–6 mM), high sensitivity, and low detection limit (glucose, 100 µM; lactic acid, 10 µM) towards cancer cell metabolism monitoring. This electrode structure can be further applied in multi-target array detection towards metabolic markers by modulating different enzymes on the conductive HFMs.

This paper describes a facile one-step method for synthesizing Field’s alloy nanoparticles based on nanoemulsification technique. As-prepared Field’s alloy nanoparticles were characterized by X-ray fluorescence spectrometry (XRF), and transmission electron microscopy (TEM). Reaction time influence on particle shape and size were also investigated. The thermal stability of nanoparticles and nanofluid (with ethyl carbamate modified Field’s alloy nanoparticles dispersed in PAO) were evaluated by differential scanning calorimetry (DSC). Results show that the nanofluid exhibit good thermal stability, which may have potential applications in wide area.

Nanocrystals of the charge transfer compound perylene:7,7′,8,8′-tetracyanoquinodimethane (TCNQ) were created using the reprecipitation method, a simple technique for inducing crystallization in solution by the rapid addition of a miscible non-solvent. The nanocrystal size was followed in situ using dynamic light scattering, showing rapid formation of crystals with sizes on the order of 100 nm followed by much slower growth. The complexation of the electron donor perylene and electron acceptor TCNQ was monitored in situ through the appearance of the charge transfer band in the infrared. Both 1:1 and 3:1 cocrystal stoichiometries could be obtained, but the ratio of the components did not always result in the same stoichiometry in the nanocrystals. In particular, a sample prepared with equal molar amounts of the constituents contained both 1:1 and 3:1 forms, as well as pure perylene and TCNQ nanocrystals. This sample also demonstrated non-classical nucleation, with solid particles forming immediately, but longer range order appearing later.

This study described the synthesis and the tribological properties of surface-modified Field’s alloy nanoparticles, which were prepared by a facile one-step nanoemulsion method and using ethyl carbamate as a surfactant, as additives in liquid poly-alfa-olefin (PAO) oil. The size and morphology of nanoparticles were investigated by transmission electron microscopy (TEM). The zeta potential, viscosity, and stability properties of the surface-modified nanoparticles suspended in PAO oil (called nanofluid) with different mass concentrations were measured by a viscometer and Zeta potential analyzer, respectively. The tribological properties of the nanofluid were tested by a ball to disk wear and friction machine. Compared with pure PAO oil, the results showed that the nanofluids had better lubricating behaviors. When the mass concentration of modified nanoparticles was 0.08 wt. %, both the friction coefficient and the wear scar diameter were the lowest.

The study of particle transport in porous media is of great significance for pollution mitigation, grouting reinforcement, municipal solid waste landfill management, and groundwater exploitation. We developed an analytical solution for a corrected convection-dispersion model that takes into account the effects of dispersion on deposition kinetics with regard to the particle concentration decay type. The rationality and correctness of the solution were verified using time, distance, deposition coefficient, diffusion coefficient, and decay coefficient. As the time increased, the particle concentration increased from zero to the peak value, then decreased to zero. However, as distance increased, the peak value of particle concentration gradually decreased. The deposition coefficient affected the magnitude of the peak value and the distance corresponding to the peak value. In addition, the greater the attenuation coefficient, the smaller the peak value. Overall, our method’s prediction results showed that considering the effect of dispersion on deposition kinetics produces better results than when this is not considered.

The adhesion force between a single phenyl ring and monolayer graphene was measured and calculated through experimental and theoretical methods. We used a method based on Poisson distribution statistics to extract the single-bond force between a single phenyl ring and monolayer graphene using an atomic force microscope (AFM) in water environment. The single-bond force was measured as 190.6 ± 8.1 pN, which was in good agreement with the previous research. Based on the experimental results, we proposed a theoretical model of atomic scale to elucidate the formation process of the single-bond force. The single-bond force was the maximum force in the desorption process, which was divided into two stages: processes A and B. The phenyl ring was lifted up and rotated simultaneously from the state of parallel to perpendicular to graphene in process A; it kept moving upward in the perpendicular direction in process B. The single-bond force of 190.6 pN appeared in process A when the ratio of the vertical lifting height and rotating lifting height was 0.981, which was most consistent with experimental result. Moreover, any force curve measured from experiment could be obtained by fitting the single-bond force curve calculated from theory.

Au–Ag nanocages with tunable surface plasmon resonance peaks were synthesized via the galvanic replacement reaction. These tunable nanocubes with strong plasmonic effect were further fabricated into thin films composed of a random assembly of Au–Ag nanocages, which show great broadening of surface plasmon resonance absorption. After optimizing, through coupling with the excitation light, the overall upconversion luminescence intensity of NaYF4:Yb3+, Er3+ on the surface of the Au–Ag nanocage film under 980 nm excitation was improved more than 15 fold.

Metal nanoclusters (NCs) have attracted plenty of attention because of their unique properties and great application potentials. In this work, DNA scaffold Ag–Au alloy nanoclusters (Ag–Au ANCs) were fabricated by a one pot wet-chemical strategy and characterized by various techniques, including TEM, XPS and mass spectrometery (MS). The results indicate that owing to the strong interaction between DNA and Ag+, the silver NCs were formed first, then bundled with Au shells. In the Ag–Au ANCs, some of the Au is in an oxidized state as Au(I), which can largely modify the optical properties of the silver NCs. The Ag–Au ANCs demonstrate tunable emissions from green to red with highly improved stability. The fluorescence of Ag–Au ANCs was explored to detect Hg2+ in contrast to Ag NCs. The detection using Ag–Au ANCs demonstrated highly improved and excellent linearity and selectivity, which could effectively avoid the disturbance of Cu2+ and was promising for applications.

A gallium nitride (GaN) nanowire (NW) UVA photodetector with high responsivity was reported. The GaN NW was grown by horizontal hydride vapor phase epitaxy. The NW morphology is proved tunable via different growth conditions. The axial and radial growths of GaN NWs were investigated through vapor–liquid–solid and vapor–solid mixed growth models. Besides, NWs with different morphologies exhibit different growth crystal orientations, which depend on the flow rate of HCl. NWs with smaller diameters show better optical properties and crystalline quality. More importantly, the UVA detector fabricated by a single NW exhibits excellent responsivity of 4.35 × 104–1.06 × 105 A/W and external quantum efficiency of 1.48 × 107%–3.6 × 107% under different light power densities. The high responsivity and low production cost make the GaN NW UVA detector extremely attractive for several applications, such as fire sensing and missile and rocket warning.

With the development of medical science, analyzing the concentration of the volatile organic compounds (VOCs) in expiration has been considered as a rapid, convenient and noninvasive method for medical diagnosis. The detection of diabetes with acetone as a marker has received extensive attention, but the development of a highly sensitive acetone sensor remains various challenges to improve the sensing performance with nanostructure-controllable novel materials. In this work, an acetone sensor based on three-dimensional inverse opal (3DIO) tungsten oxide (WO3) composite modified with Au (WO3/Au) was obtained through a simple sacrificial template synthesis, which provided more active sites with macropore architecture. Moreover, with modification of Au nanoparticles (NPs), it is obvious that gas sensing property with “spillover effects” and catalytic action was obtained. The 3DIO WO3/Au gas sensor exhibited good selectivity to acetone, and showed great test performance from 100 ppb to 100 ppm. A corresponding actual detection limit of 100 ppb at 410 °C was realized, which could allow real-time and reliable diagnosis of diabetic by acetone monitoring. Furthermore, it also showed good stability and faster response and recovery times compared with pure WO3 sensors. The 3DIO WO3/Au gas sensor shows great potential in practical application of a noninvasive and more accurate monitoring and detection of diabetes.

As efficient artificial light sources, nitride-based light-emitting diodes (LEDs) have been widely used. However, III nitride white light-emitting diodes (WLEDs) are mostly fabricated by combining a blue LED chip with yellow phosphors, which results in inevitable problems, such as low color-rendering index (CRI) and detrimental effect to human eyes. As a solution for healthy lighting, we report a strategy to produce a WLED with an emission spectrum perfectly matched with natural daylight. By utilizing near-ultraviolet LED chips and a mixture of blue/cyan/amber/red phosphors, a CRI (Ra) of 97.9 is achieved for the WLEDs at a correlated color temperature of around 5000 K. The resemblance ratio of these solar-spectrum WLEDs with the standard normalized daylight spectrum (5000 K) is found to as high as 93.4%. Residual UV light in the normalized spectrum is

This paper describes a facile one-step method for synthesizing native or ethyl carbamate modified Field’s alloy nanoparticles based on nano-emulsification technique. The size, morphology and zeta potential of as-prepared native or modified Field’s alloy nanoparticles were characterized by atomic force microscopy (AFM), dynamic light scattering (DLS) and zeta potential analyzer, respectively. A portable ultraviolet–visible (UV-Vis) spectrometer coupled with fiber optics is used to continuously monitor optical transparency of the native and ethyl carbamate modified nanofluid at certain wavelength, which can be used to evaluate the stability of the nanoparticle in the poly-alpha-olefin (PAO) oil. The thermal properties of nanoparticles and nanofluid (native or ethyl carbamate modified Field’s alloy nanoparticles dispersed in PAO) were investigated by differential scanning calorimetry (DSC). Results show that the nanofluid with modified nanoparticles exhibits good thermal properties and stability, which shows promising potential applications in cooling of electronic device, engines and other systems.

A straightforward one-step method had been explored to synthesize native or ethyl carbamate modified Field’s alloy nanoparticles by using a nanoemulsification technique. The characterization of particle size, structure and surface charge of synthesized native or modified Field’s alloy nanoparticles were conducted by atomic force microscopy (AFM), dynamic light scattering (DLS) and zeta potential analyzer in particular. The dispersion stability of the native and modified nanofluid in poly-alpha-olefin (PAO) oil was evaluated using a portable ultraviolet-visible spectrometer by monitoring the optical transparency continuously at certain wavelength. The thermal properties of nanoparticles and nanofluid were characterized by differential scanning calorimetry (DSC). Results show that the modified Field’s alloy nanofluid displays improved thermal properties and excellent dispersion stability, which has bright future in applications for thermal management of electronic devices, electric vehicles, and other energy transfer systems.

Early detection of tumor markers is of great significance, while the common used immunosensors always meet the contradiction between the conductivity and limited surface area for immobilizing more antibodies. Herein, to address this problem, the conductive silver containing EMT zeolite nanoparticles (NPs) were prepared by ion exchange and further applied in Alpha-fetoprotein (AFP) detection. Since no template was involved in the nanosized EMT zeolite synthesis at low temperature, excessive silver ions can be introduced inside the channels of zeolite and bring greatly enhanced conductivity. Besides the native porous feature of zeolite, the silver containing EMT based immunosensors shows very good performance in AFP detection, which well compensates the conductivity and surface area. In human serum, the proposed immunosensor also shows linear and even higher response to AFP relative to that in PBS. This kind of zeolite based immunosensor protocol is potentially attractive for clinical immunoassay.

Artificial fractal structures have attracted considerable scientific interest in circulating tumor cells (CTCs) detection and capture, which plays a pivotal role in the diagnosis and prognosis of cancer. Herein, we designed a bionic TiO2 inverse opal photonic crystal (IOPC) structure for highly efficient immunocapture of CTCs by combination of a magnetic Fe3O4@C6@silane nanoparticles with anti-EpCAM (antiepithelial cell adhesion molecule) and microchannel structure. Porous structure and dimension of IOPC TiO2 can be precisely controlled for mimicking cellular components, and anti-EpCAM antibody was further modified on IOPC interface by conjugating with polydopamine (PDA). The improvement of CTCs capture efficiency reaches a surprising factor of 20 for the IOPC interface compared to that on flat glass, suggesting that the IOPCs are responsible for the dramatic enhancement of the capture efficiency of MCF-7 cells. IOPC substrate with pore size of 415 nm leads to the optimal CTCs capture efficiency of 92% wi...

Efficient targeting is a major challenge in practical photodynamic therapy (PDT). Though the “enhanced permeability and retention” (EPR) effect is a widely used tumor targeting method, magnetic targeting strategy is more promising considering the issue of high targeting efficiency and reducing concentration-dependent toxicity. Herein, magnetic targeting and highly effective Fe3O4@Ce6/C6@silane NPs are reported as a class of precisely controlled photosensitizers (PS) for PDT. On the basis of the amphiphilic silane encapsulation, PS chlorin e6 (Ce6) and Coumarin 6 (C6) as well as Fe3O4 NPs were coloaded into the inside hydrophobic environment of amphiphilic silane, forming a theranostic agent for dual-mode imaging guided and magnetic targeting enhanced in vivo PDT agent. To solve the problem of over-irradiation, the coloaded design of C6 and Ce6 molecules can afford the real time PDT monitoring by ratio emissions with same excitation wavelength. When Fe3O4@Ce6/C6@silane and Ce6/C6@silane NPs are compared in...

It is well known that the morphology of organic semiconductor fi lms plays a signifi cant role in dictating their electrical properties. In particular, anisotropic packing of organic semiconductors typically results in anisotropic charge transport properties, as has been demonstrated for a number of organic semiconductor materials. [ 1–12 ] In single crystal small molecule semiconductors such as rubrene, the anisotropy in charge transport can be directly related to the molecular packing structure and subsequent band structure. [ 13,14 ] In conjugated polymers, orienting the polymer long-axis to be primarily in one-direction has been shown to result in anisotropic charge transport for a number of polymers including poly(3-hexylthiphene) (P3HT), [ 1,11,15 ] poly[9,9′-dioctylfl uorene-co-bithiophene] (F8BT), [ 4,16 ] and Poly[2,5-bis(3-tetradecylthiophen-2-yl) thieno[3,2b ]thiophene] (pBTTT), [ 3,6,12 ]

Because of the extreme toxicity of mercury ions (Hg2+), a great deal of effort has been invested in developing probes that use colorimetric and fluorometric methods to detect them. Nowadays, most of the current fluorescent probes still work in organic solvents or a mixture of organic solvents and water. Conjugated polymers (CPs) can serve as excellent fluorophores because of their strong emission and controllable emission wavelength. In this work, a kind of thiocarbonyl quinacridone-based CPs nanoparticle (PTQA-NPs) was synthesized for selectively detecting Hg2+ in pure water. Additionally, the fabrication of the nanoparticles provides a very sensitive correction for environmental effects, the minimum detectable concentration of Hg2+ for this nanoparticle was as low as 1 ppb. Furthermore, we show the capability of this polymer of monitoring Hg2+ in HeLa cell lines by confocal laser scanning microscopy (CLSM).

The influence of growth rate and substrate temperature on the two-dimensional electron gas (2DEG) of LaVO 3 / SrTiO 3 interfaces has been investigated. It is found that both growth rate and substrate temperature can modulate the structural and electrical properties of the LaVO 3 / SrTiO 3 interfaces through oxygen substrate-to-film transfer. When the LaVO 3 thin films are deposited at a low substrate temperature and a high growth rate, the LaVO 3 / SrTiO 3 interfaces exhibit weak oxygen substrate-to-film transfer and resultant low density of oxygen vacancies in the SrTiO 3 substrate. As a result, the intrinsic effect (polar discontinuity and/or dielectric screening) dominates the interfacial conduction, while the oxygen vacancies play a minor role. In contrast, the oxygen substrate-to-film transfer (oxygen vacancies in the SrTiO 3 substrate) can be enhanced (increased) by depositing the LaVO 3 thin films at lower growth rates and/or higher substrate temperatures. In this case, the contribution of oxygen vacancies to the interfacial conduction would prevail over the intrinsic effect. Our results elucidate the origins of 2DEG in the LaVO 3 / SrTiO 3 interfaces and may also be important for other SrTiO 3-based heterointerfaces.