Electrospraying Si/SiO_(x)/C and Sn/C nanosphere arrays on carbon cloth for high-performance flexible lithium-ion batteries

Exploring electrode materials with larger capacity,higher power density and longer cycle life was critical for developing advanced flexible lithium-ion batteries(LIBs).Herein,we used a controlled two-step method including electrospraying followed with calcination treatment by CVD furnace to design novel electrodes of Si/Si_(x)/C and Sn/C microrods array consisting of nanospheres on flexible carbon cloth substrate(denoted as Si/Si_(x)/C@CC,Sn/C@CC).Microrods composed of cumulated nanospheres(the diameter was approximately 120 nm)had a mean diameter of approximately 1.5μm and a length of around 4.0μm,distributing uniformly along the entire woven carbon fibers.Both of Si/Si/Si_(x)/C@CC and Sn/C@CC products were synthesized as binder-free anodes for Li-ion battery with the features of high reversible capacity and excellent cycling.Especially Si/Six/C electrode exhibited high specific capacity of about 1750 mA∙h∙g^(−1)at 0.5 A∙g^(−1)and excellent cycling ability even after 1050 cycles with a capacity of 1388 mA∙h∙g^(−1).Highly flexible Si/Si_(x)/C@CC//LiCoO_(2)batteries based on liquid and solid electrolytes were also fabricated,exhibiting high flexibility,excellent electrical stability and potential applications in flexible wearable electronics.

Influence of solvent mixtures on HPMCAS-celecoxib microparticles prepared by electrospraying

Hypromellose acetate succinate(HPMCAS) microparticles containing the poorly-water soluble drug celecoxib(CEL) were prepared by electrospraying intended for oral drug delivery. Various solvent mixtures with different solubility for CEL and HPMCAS were used to induce changes in the polymer structural conformation of the microparticles. The performance of the prepared microparticles was evaluated by studying the solid state from, particle size and morphology, radial drug distribution and drug release. CEL was amorphous in all electrosprayed HPMCAS microparticles. The particle size and morphology was dependent on the solubility of HPMCAS in the solvent mixture used with poorer solvents resulting in smaller microparticles with rougher appearance. The CEL distribution on the particles surface was relatively homogeneous and similar for all microparticles. Drug release from the microparticles was observed at a higher rate depending on the solubility of HPMCAS in the solvent used for electrospraying, and in all cases an at least 4-fold higher rate was observed compared with the crystalline drug. Drug precipitation from the supersaturated solution was inhibited by HPMCAS for all microparticles based on its parachute effect while crystalline CEL did not reach supersaturation. This study demonstrated that electrospraying can be used to produce microparticles with tailored properties for pharmaceutical application by adjusting solvent selection.

ELECTROSPRAYING/ELECTROSPINNING OF POLY(γ-STEARYL-LGLUTAMATE):FORMATION OF SURFACES WITH SUPERHYDROPHOBICITY

Electrospraying/electrospinning of poly(γ-stearyl-L-glutamate) (PSLG) was investigated on a series solutions with different concentrations in chloroform.Field emission scanning electron microscopy (FESEM) and attenuated Iotal reflectance Fourier transform infrared spectroscopy (FT-IR/ATR) were used to characterize the morphology and structure of the electrosprayed/electrospun polypeptide mats.It was found that electrospraying of PSLG with concentrations lower than 16 wt% afforded beads,while microfibers cou...

Polymer-based nanoparticulate solid dispersions prepared by a modified electrospraying process

A modified electrospraying process is exploited to enhance the dissolution profiles of a poorly water-soluble drug. With polyvinylpyrrolidone (PVP) as a hydrophilic polymer matrix and ketoprofen (KET) as a model drug, polymer-drug composites in the form of nanoparticles were prepared and characterized. The surface morphologies, the physical status of the drug, and the drug-polymer interactions were studied using FESEM, DSC, XRD, and ATR-FTIR. FESEM observations demonstrated that the nanoparticles gradually decreased in size from 640 ± 350, to 530 ± 320, 460 ± 200 and 320 ± 160 nm as the KET content increased from 0, to 9.1%, 16.7% and 33.3% w/w, respectively. Results from DSC and XRD suggested that KET was distributed in the PVP matrix in an amorphous manner at the molecular level. This is thought to be due to their compatibility, arising through hydrogen bonding as demonstrated by ATR- FTIR spectra. In vitro dissolution tests showed that the nanoparticles released the incorporated KET within 1 min, evidencing markedly improved dissolution over pure KET and a KET-PVP physical mixture. Electrospraying can hence offer a facile route to develop new polymer composites for biomedical applications, in particular for improving dissolution rate of poorly water-soluble drugs.

Preparation of TiO2 and SiC Films from Their Precursors Using Electrospraying

Titanium dioxide(TiO2) films were prepared by cone - jet mode electrospraying a titanium ethoxideprecursor solution onto a silicon substrate.The effects of spraying time,substrate temperature and aging on thesurface morphology of the films prepared were studied.Thin films obtained after spraying for 600 s were aged atroom temperature to form a porous TiO2 network with pores in the size range of 100 - 500 nm.Thicker filmswere prepared by spraying for 3 000 s,but these cracked on drying although it can be concluded that films pre-pared using a higher substrate temperature were denser.By this method,SiC coating was also prepared on anAl2O3 substrate using polysilane as a precursor.The result implies the potential of an industrial production ofdye sensitized solar cells by electrospraying technique.

Wastewater Decontamination from Microorganisms by Electrospraying Corona Discharge

A novel water treatment technique, based on a combination of electrospraying and pulsed corona discharge, has been used for bio-decontamination of wastewater. The electrospraying process has been found to increase the surface area of the treated wastewater, and hence increases the efficiency of the corona treatment process. The phase diagram of the discharge, which characterizes the discharge regimes, has been identified experimentally. The survival ratio of the microorganisms has been investigated experimentally as a function of the applied voltage and the numbers of treatment runs using air and oxygen as working gases. Microorganism surface has been examined using scanning electron microscope (SEM), which enabled in understanding the decontamination mechanisms of the treated microorganism. A complete decontamination has been achieved after only one run for an applied voltage higher than 16 kV when the discharge system was operated in oxygen gas. Optical emission spectrum of the electrosprayed water confirmed the existence of OH-radicals responsible for decontamination process.

Generation of biomaterial particles with controlled dimensions via electrospraying

It is well known that small biomaterial particles can lead to superior properties demanded by advanced applications in tissue engineering. Electrospraying has been considered as a promising approach to prepare fine particles, but reducing the particle size during such jetting process is always challenging. This is because the size of the as-sprayed particles is always limited by the device outlet diameter used. In the study we show that hydroxyapatite (HA) relics of 2 - 3 μm with low standard deviation can be deposited using a large nozzle (diameter of 1100 μm) only by reducing the nozzle tip angle from 90° to 15°. The mechanism of such phenomenon was extensively discussed, and a range of refined HA patterns were successfully prepared using the updated electrspraying configuration. We anticipate our findings to have a significant impact on the research of nanostructured biomaterials with superior properties which are realized by reducing the particle size using a greener electrically-driven processing technique.

Fabrication and photocatalytic activity of TiO2 composite membranes via simultaneous electrospinning and electrospraying process

In present study, a simultaneous electrospinning and electrospraying（SEE） process was employed to produce microclusters of TiO2 nanoparticles and interlock them in nanofibrous network. The photocatalytic composite membranes（PCMs） were fabricated by electrospraying TiO2 nanoparticle suspension into microcluster form that dispersed and entrapped within nylon-6 electrospun fiber membrane. Three PCMs membrane with TiO2 content of 52.0, 83.6,and 91.7 wt.% were successfully fabricated. The membrane consisted of TiO2 microclusters,ranging in sizes from around 0.3 to 10 μm, distributed uniformly within the nylon-6 nanofibrous network. PCMs photocatalytic activity against Methylene Blue（MB） in aqueous solution showed more than 98% MB removal efficiency after 120 min of photocatalytic oxidation（PCO） for all PCMs. For PCM with the highest TiO2 content tested for 5 PCO cycles, it was found that most of their TiO2 content remained incorporated within the nanofibrous structure. The concept of nanoparticles clusters entrapment with SEE fabrication employed here provide a simple and effective method for reducing detachment of nanostructure phase from nanocomposite membrane.

Epoxy microcapsules for high-performance self-healing materials using a novel method via integrating electrospraying and interfacial polymerization

The high-efficiency fabrication of high-quality microcapsules containing epoxy is crucial to the further development of the potential practical self-healing epoxy systems based on microencapsulated two-part epoxy-amine chemistry.Herein,a novel microencapsulation technique based on non-equilibrium droplets via integrating electrospraying and interfacial polymerization(ES-IP)was established to efficiently microencapsulate epoxy monomers.The ES-IP technique,consisting of three continuous steps,i.e.electrospraying to massively generate droplets,enwrapping every single droplet through instant interfacial polymerization,and thickening shell at an elevated temperature,has great flexibility to regulate the microencapsulation process and the microcapsule quality.The fabricated core-shell structured epoxy microcapsules(Ep-MCs)were comprehensively characterized for their properties,showing that they have high cleanness with rare impurities,controllable and tunable size,good thermal stability and tightness,and high effective core fraction.The high-quality Ep-MCs were adopted to formulate a self-healing epoxy based on the microencapsulated epoxy-amine chemistry.The highest healing efficiency,in terms of the recovered mode I fracture toughness,of 110±17%was achieved after being healed at room temperature(~25℃)for 48 h.While the developed ES-IP technique facilitates the microencapsulation technique based on non-equilibrium droplets,the fabricated high-quality Ep-MCs greatly promote the further developments of the practical self-healing materials.

Adsorption of As(Ⅲ)from aqueous solution based on porous magnetic/chitosan/ferric hydroxide microspheres prepared via electrospraying

Porous chitosan（CS）/magnetic（Fe304）/ferric hydroxide（Fe（OH）3） microsphere as novel and low-cost adsorbents for the removal of As（Ill） have been synthesized via the electrospraying technology by a simple process of two steps. Characterization of the obtained adsorbents was studied by transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, X-ray photoelectron spectroscopy （XPS）, and X-ray diffraction （XRD）. The adsorption kinetics and equilibrium isotherms were in- vestigated in batch experiments. The Langmuir, Freundlich isotherm and pseudo-second order kinetic models agree well with the experimental data. The adsorption of As（III） onto CS/Fe3OdFe（OH）3 microspheres occurred rapidly and reached adsorption equilibrium after about 45 min. The maximum adsorption capacity of CS/Fe3OJFe（OH）3 microspheres, calculated by the Langmuir isotherm model, was 8.47 mg g 1, which is higher than that of CS/Fe304/Fe（OH）3 prepared by the conventional method （4.72 mg g-l）. The results showed that the microspheres had a high adsorption capacity for As（III） and a high separation efficiency due to their microporous structure and superparamagnetic characteristics. Present research may eventually lead to a simple and low cost method for fabricating microporous materials and application for removal of arsenic from aqueous solution.

Red-blood-cell-shaped chitosan microparticles prepared by electrospraying

Red-blood-cell-shaped chitosan microparticles with acid-triggered dissolution and auto-fluorescence were successfully fabricated by a simple strategy combining electrospraying with a solvent diffusion process controlled by solvent evaporation. The sizes of the prepared chitosan microparticles were rela- tively uniform. Control of the solvent diffusion process was crucial for the formation of microparticles with concave morphology. A chitosan aqueous solution containing 20vo1% ethanol as the evaporable solvent and 30 vol% dimethyl sulfoxide as the diffusible solvent was optimal for preparation of chitosan microparticles with the desired red-blood-cell-like size and shape. These chitosan microparticles will be highly attractive for many biological and biomedical aoolications.

Structure Controlling and Adsorption Application of Polyethersulfone Porous Microspheres Prepared via Electrospraying

The focus of this work is to control the structure of electrosprayed polymer microspheres and then study the effect of different structures on the microspheres＇ adsorption properties. Scanning electron microscopy （SEM） coupled with image analysis software was employed to evaluate the size distributions and the structure of microspheres. According to the observation and analysis results, two types of polyethersulfone （PES） porous microspheres （perfect sphere-shaped and collapsed） were prepared via electrospraying technology by adjusting the solvent and polymer molecular weight. The porous PES microspheres can remove bisphenol A （BPA） from its aqueous solution effectively. Compared with collapsed microspheres, the rough microspheres had much higher specific surface area and better mobility in the BPA aqueous solution, so it showed a better adsorption capacity than that of collapsed microspheres. The solvent evaporation rate and the occurrence rate of phase separation significantly affect the structure and morphology of microspheres.

Hierarchically electrospraying a PLGA@chitosan sphere-in-sphere composite microsphere for multi-drug-controlled release

Sequential administration and controlled release of different drugs are of vital importance for regulating cellular behaviors and tissue regeneration,which usually demands appropriate carriers like microspheres(MS)to control drugs releases.Electrospray has been proven an effective technique to prepare MS with uniform particle size and high drug-loading rate.In this study,we applied electrospray to simply and hierarchically fabricate sphere-in-sphere composite microspheres,with smaller poly(lactic-co-glycolic acid)MS(~8-10 lm in diameter)embedded in a larger chitosan MS(~250-300 lm in diameter).The scanning electron microscopy images revealed highly uniform MS that can be accurately controlled by adjusting the nozzle diameter or voltage.Two kinds of model drugs,bovine serum albumin and chlorhexidine acetate,were encapsulated in the microspheres.The fluorescence-labeled rhodamine-fluoresceine isothiocyanate(Rho-FITC)and ultraviolet(UV)spectrophotometry results suggested that loaded drugs got excellent distribution in microspheres,as well as sustained,slow release in vitro.In addition,far-UV circular dichroism and matrixassisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS)results indicated original secondary structure and molecular weight of drugs after electrospraying.Generally speaking,our research proposed a modified hierarchically electrospraying technique to prepare sphere-in-sphere composite MS with two different drugs loaded,which could be applied in sequential,multi-modality therapy.

New Flexible Electrospun PET/TiO2 Composite Photoanode Layer for Dye-Sensitized Solar Cells, DSSCs, and Its Photovoltaic Performances

Flexible polymer-based dye-sensitized solar cells (DSSCs) offer promising potential for lightweight, cost-effective and versatile photovoltaic applications. However, the critical challenge in their widespread applications is the weak thermal stability of most polymeric substrates, which can only withstand a maximum temperature processing of 150˚C. In this study, a facile and low-cost strategy is proposed to develop at low temperature DSSC flexible photoanode based on a polymeric matrix. Highly porous nanocomposites fibrous mats composed of polyethylene terephthalate (PET) and titanium dioxide (TiO2) nanobars were prepared through an electrospinning process using different configurations (uniaxial electrospinning, coaxial electrospinning, and electrospray-assisted electrospinning). These techniques enabled precise control of the microstructure and the positioning of TiO2 within the composite nanofibers. Therefore, the as-produced photoanodes were loaded with N719 dye and tested in DSSC prototype using iodide-triiodide electrolyte and platinum (Pt) coated counter electrode. The results show that incorporating TiO2 on the fiber surface through the electrospray-assisted electrospinning enhanced the performance of the nanofiber composite, leading to improved dye loading capacity, electron transfer efficiency and photovoltaic performance.

Biomimetic Erythrocyte-Like Particles from Microfluidic Electrospray for Tissue Engineering

Microparticles have demonstrated value for regenerative medicine.Attempts in this field tend to focus on the development of intelligent multifunctional microparticles for tissue regeneration.Here,inspired by erythrocytes-associated self-repairing process in damaged tissue,we present novel biomimetic erythrocyte-like microparticles(ELMPs).These ELMPs,which are composed of extracellular matrix-like hybrid hydrogels and the functional additives of black phosphorus,hemoglobin,and growth factors(GFs),are generated by using a microfluidic electrospray.As the resultant ELMPs have the capacity for oxygen delivery and near-infrared-responsive release of both GFs and oxygen,they would have excellent biocompatibility and multifunctional performance when serving as microscaffolds for cell adhesion,stimulating angiogenesis,and adjusting the release profile of cargoes.Based on these features,we demonstrate that the ELMPs can stably overlap to fill a wound and realize controllable cargo release to achieve the desired curative effect of tissue regeneration.Thus,we consider our biomimetic ELMPs with discoid morphology and cargo-delivery capacity to be ideal for tissue engineering.

Experimental study of the effect of gas discharge on ionic liquid electrospray

Ionic liquid electrospray(ILE) in an atmospheric environment is often accompanied by the gas discharge phenomenon. It interferes with the normal operation of the electrospray and the measurement of experimental parameters. In this study, electrospray experiments were conducted on the ionic liquid EMI-BF4. The observations revealed that the operating modes of the ionic liquid depend on the voltage polarity at high voltages. Additionally, a correspondence between the operating mode of ILE and the current signal in the circuit was established. The shape of the liquid cone formed at the needle tip bore a striking resemblance to the plume of corona discharge, suggesting that the motion trajectory of electrons influenced the curvature of the liquid cone. Steamer theory provided a clear explanation for the change in curvature as the voltage increased.

固相萃取-超高效液相色谱-电喷雾串联质谱法同时测定地表水中16种全氟有机化合物

建立了固相萃取-超高效液相色谱-电喷雾串联三重四极杆质谱联用技术分析水中16种全氟有机化合物的高通量检测方法。样品经 WAX 固相萃取柱富集和净化后，采用 Waters ACQUITY UPLCTM BEH C18色谱柱，含2 mmol/L乙酸铵的甲醇和含2 mmol/L乙酸铵的水作为流动相进行梯度洗脱，质谱采用电喷雾负离子电离，多反应监测模式检测。16种全氟有机化合物在0.5~100μg/L或1.0~100μg/L 浓度范围内线性关系良好，相关系数为0.9987~0.9999，方法的检出限为0.06~0.46 ng/L；高、中、低3个添加水平的回收率为67.6％~103％，相对标准偏差为2.94％~12.0％。结果表明，该方法灵敏、准确且检测范围广，分析速度快，是一种适于实际水样中全氟有机化合物检测分析的方法。

电喷雾解吸电离质谱法直接测定蔬菜表面的莠去津残留

A direct determination method for the atrazine residue on the vegetable was developed by using desorption electrospray ionization mass spectrometry (DESI MS) without any sample pretreatment.Acetonitrile-water (1:1,v/v),which contained 0.1% formic acid,was used as the spray solvent.The working conditions,such as ESI gas inlet pressure,ESI flow rate,ESI spray voltage,spray-to-sample distance,spray-to-cone-hole distance and the collision induced dissociation (CID) voltage for MS/MS,were optimized for both DESI and esquires 6 000 mass spectrometer.The linear range of atrazine on cabbage leaves was 25.25-2 525 pg/mm2,the R2 was 0.991 6,and the relative standard deviations were between 3.37% and 26.17%.The LOD of atrazine calculated by S/N=3 was 2.50 pg/mm2.

β-环糊精与蛋白质非共价复合物的电喷雾质谱研究

电喷雾质谱(ESI-MS)已经广泛应用于非共价复合物的检测和研究[1,2].ESI是一种极软的离子化过程,它不仅能在不断裂共价键的情况下使分子离子化,而且可以在离子化过程中保持分子间弱的非共价键作用.……

液相色谱-电喷雾离子阱质谱法测定贝类中软骨藻酸

记忆缺失性贝类毒素(amnesic shellfish toxin,简称ASP)主要成分软骨藻酸(domoic acid,简称DA)是一种氨基酸类的生理活性物质(图1),因最早从红藻属的树枝软骨藻(chondria armata)分离出来而被命名为软骨藻酸.……