The core-shell 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/2,4,6-Trinitrotoluene(CL-20/TNT)composite was prepared by spray-drying method in which sensitive high energy explosive(CL-20)was coated with in...The core-shell 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/2,4,6-Trinitrotoluene(CL-20/TNT)composite was prepared by spray-drying method in which sensitive high energy explosive(CL-20)was coated with insensitive explosive(TNT).The structure and properties of different formulations of CL-20/TNT composite and CL-20/TNT mixture were characterized by scanning electron microscopy(SEM),Transmission electron microscopy(TEM),Laser particle size analyzer,X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),differential scanning calorimetry(DSC),impact sensitivity test and detonation performance.The results of SEM,TEM,XPS and XRD show that e-CL-20 particles are coated by TNT.When the ratio of CL-20/TNT is 75/25,core-shell structure is well formed,and thickness of the shell is about 20e30 nm.And the analysis of heat and impact show that with the increase of TNT content,the TNT coating on the core-shell composite material can not only catalyze the thermal decomposition of core material(CL-20),but also greatly reduce the impact sensitivity.Compared with the CL-20/TNT mixture(75/25)at the same ratio,the characteristic drop height of core-shell CL-20/TNT composite(75/25)increased by 47.6%and the TNT coating can accelerate the nuclear decomposition in the CL-20/TNT composites.Therefore,the preparation of the core-shell composites can be regarded as a unique means,by which the composites are characterized by controllable decomposition rate,high energy and excellent mechanical sensitivity and could be applied to propellants and other fields.展开更多
A spray-drying assisted solid-state method to prepare spherical layer-structured H_(2)TiO_(3) ion sieve(LSTIS)particles is reported herein.The effects of synthesis parameters(calcination temperature,calcination time,a...A spray-drying assisted solid-state method to prepare spherical layer-structured H_(2)TiO_(3) ion sieve(LSTIS)particles is reported herein.The effects of synthesis parameters(calcination temperature,calcination time,and the lithium-titanium molar ratio)on adsorption-desorption performance(the delithiation ratio,titanium dissolution loss,and the adsorption capacity)were investigated.The as-prepared LSTIS exhibited an equilibrium adsorption capacity of 30.08 mg·g^(-1)(average of 25.85 mg·g^(-1) over 5 cycles)and ultra-low titanium dissolution loss of less than 0.12%(average of 0.086%over 5 cycles).The LSTIS showed excellent selectivity toward Li^(+) in Na^(+),K^(+),Mg^(2+),and Ca^(2+) coexisting saline solutions where its adsorption capacity reached 27.45 mg·g^(-1) and the separation factors of Li^(+) over the coexisting cations exceeded 100.The data suggests that the LSTIS is promising to competitively enrich Li^(+) from saline solutions.展开更多
Well-shaped spherical agglomerates of FePO4 particles were prepared by a novel method:chemical co-precipitation combined with spray-drying.Tap density analysis,Brunauer-Emmett-Teller analysis,characterizations of X-ra...Well-shaped spherical agglomerates of FePO4 particles were prepared by a novel method:chemical co-precipitation combined with spray-drying.Tap density analysis,Brunauer-Emmett-Teller analysis,characterizations of X-ray diffraction,scanning electron microscopy,and transmission electron microscopy confirmed that the micron-sized spherical agglomerates with high specific surface area and high tap density were composed of the uniform nano-sized particles.The effects of pH and reaction time on the morphology of the FePO4 particles were investigated by experimental and theoretical analyses.The analyses revealed that amorphous FePO4 was responsible for forming a well-shaped spherical agglomerate,and the ideal spherical particles were obtained at pH 3.The reaction time also played a significant role in controlling the size and surface morphology of the FePO4 particles,and smooth spherical FePO4 particles were obtained at a reaction time of 6 h.By this novel method,poly-porous spherical iron phosphate particles were prepared,which can be used with high efficiency in some special fields,especially as a precursor for synthesizing LiFePO4 and catalysts.展开更多
Nutmeg essential oil with volatile components is sensitive to oxygen, light, water and high temperature. Spray-drying is widely used as an encapsulation technique for improving compound stability during processing and...Nutmeg essential oil with volatile components is sensitive to oxygen, light, water and high temperature. Spray-drying is widely used as an encapsulation technique for improving compound stability during processing and storage. In this study, influence of encapsulated matrix on spray-dried nutmeg essential oil microcapsule was investigated using blends of maltodextrin and either gum Arabic(GA-MD), or octenyl succinic acid modified starch(OSA-MD) as wall materials. Characteristics of spray-dried powders from these 2 wall materials were evaluated and compared. Powder property analysis indicated that GA-MD microcapsules presented larger size, higher moisture and poorer flowability compared with OSA-MD microcapsules. Fourier transforms infrared spectroscopy and thermogravimetric analysis showed that both GA-MD and OSA-MD microcapsules improved the stability of nutmeg essential oil. However, GA-MD microcapsules exhibited higher storage stability than OSA-MD microcapsules. This research provided theoretical foundation for wall material choice of microcapsule and nutmeg essential oil utilization in food industry.展开更多
Poly(octamethylene citrate)(POC)is a promising bioelastomer material in the biomedical field.However,its thermosetting nature poses a significant challenge to processing and molding,especially manufacturing the POC-ba...Poly(octamethylene citrate)(POC)is a promising bioelastomer material in the biomedical field.However,its thermosetting nature poses a significant challenge to processing and molding,especially manufacturing the POC-based elastomer particles as potential,degradable and toughened fillers.Firstly,a Pickering emulsion with a pre-polymer(pre-POC)solution in dimethyl carbonate as a dispersed oil phase,a Pullulan(PUL)aqueous solution as a continuous water phase,and chitin nanocrystal(ChiNC)as a particle-type emulsifier was constructed.Secondly,the POC-based core/shell structured microspheres were prepared by spray-drying of the emulsions,and characterized by a scanning electron microscope and a transmission electron microscope.Finally,the POC-based core/shell structured microspheres were used as elastomer fillers to strengthen and toughen a chitosan film,resulting in 26%increase in the tensile strength and 45%increase in the strain at break;the POC-based core/shell structured microsphere as a double-layer drug release system was built in which the hydrophilic drug of tetracycline hydrochloride(TCH)was released from the outer layer and the hydrophobic drug of curcumin was released from the inner layer,roughly following the Ritger-Peppas model.展开更多
Spray-drying is a widely used industrial technique to achieve the scale-up fabrication of functional powders.In this work,we report the spray-drying fabrication of perovskite quantum dot(PQD)microspheres from a precur...Spray-drying is a widely used industrial technique to achieve the scale-up fabrication of functional powders.In this work,we report the spray-drying fabrication of perovskite quantum dot(PQD)microspheres from a precursor solution at a scale of 2000 kg·a^(−1).The obtained PQDs are embedded in polymer microspheres,resulting in a high photoluminescence quantum yield and enhanced stability.By controlling the precursor concentration,the average size of the polymer microspheres can be tuned from 40.97 to 0.44μm.The as-prepared PQD-embedded polymer microspheres are mixed with ultraviolet adhesive to fabricate PQD-enhanced optical films for liquid crystal display(LCD)backlights.These films exhibit long-term operational stability under heat,humidity,and blue light irradiation(remaining at more than 90%initial photoluminescence intensity after a 1000 h aging test at 60℃ with 90%relative humidity and 70℃ with 455 nm 150 W·m^(−2) blue light irradiation).In addition,we demonstrate the use of PQD-embedded polymer microspheres as patterned color converters for micro light-emitting diode applications.Overall,this work demonstrates the scale-up fabrication of PQDs toward industrialization in display technology.展开更多
The applications of nanoparticles suffer from their extremely small size and intrinsic trend of agglom-eration.Rearranging nanoparticles to form micro-sized nanoaggregates(MNAs)with increased size,ordered structure,as...The applications of nanoparticles suffer from their extremely small size and intrinsic trend of agglom-eration.Rearranging nanoparticles to form micro-sized nanoaggregates(MNAs)with increased size,ordered structure,as well as controllable size,shape,and morphology is a crucial step in various fields of science and technology to maintain the unique characteristics of nanoparticles while obtaining greatly enhanced or new performance at the microscale.The structure of MNAs prominently affects their functionality,which is determined by the arrangement of nanoparticles and the interaction between primary particles.Several methods have been proposed to prepare the MNAs,in which spray-drying technology stands out considering the feasibility,scalability for industry,cost,and efficiency.Forced assembly of nanoparticles through spray-drying under tunable process parameters yields diverse physical properties and structural arrangements of nanoparticles of the MNAs,they therefore exhibit enormous potential in a wide range of application fields.This review presents the construction and applications of spray-dried MNAs.The factors that influence the size,morphology,and structure of the MNAs are discussed in detail.In addition,the outstanding application performance resulting from the tightly packed nanoparticles in regular-shaped MNAs obtained by the spray-drying process is illustrated.展开更多
[Objective] Effects of different contents of calcium oxide on physicochemi- cal properties of spray-dried bayberry powder were studied. [Method] Bayberry pow- der produced from bayberry juice adding 0, 2 and 4 g/L cal...[Objective] Effects of different contents of calcium oxide on physicochemi- cal properties of spray-dried bayberry powder were studied. [Method] Bayberry pow- der produced from bayberry juice adding 0, 2 and 4 g/L calcium oxide using the spray drying technique has been selected. The physicochemical properties of the spray-dried bayberry powder were investigated by determining moisture content, colour, apparent density, wettability, angle of repose and moisture absorption rate of bayberry powder. [Result] The results showed that the content of calcium oxide had a significant effect on the moisture content and colour of bayberry powder. Effects of different contents of calcium oxide on the apparent density of spray-dried bayber- ry powder were not obvious. Adding calcium oxide had a significant effect on the wettability, angle of repose and moisture absorption rate of spray-dried bayberry powder, nevertheless, there was not obvious difference on these properties between adding 2 and 4 g/L calcium oxide. [Conclusion] The results confirmed that the con- tent of calcium oxide had a significant effect on the properties of spray-dried bay- berry powder.展开更多
LiMnxFe1-xPO_(4) is a promising cathode candidate due to its high security and the availability of a high 4.1 V operating voltage and high energy density.However,the poor electrochemical kinetics and structural instab...LiMnxFe1-xPO_(4) is a promising cathode candidate due to its high security and the availability of a high 4.1 V operating voltage and high energy density.However,the poor electrochemical kinetics and structural instability currently hinder its broader application.Herein,inspired by the hydrogen-bonded cross-linking and steric hindrance effect between short-chain polymer molecules(polyethylene glycol-400,PEG-400),the pomegranate-type LiMn_(0.5)Fe_(0.5)PO_(4)-0.5@C(P-LMFP@C)cathode materials with 3D ion/electron dual-conductive network structure were constructed through ball mill-assisted spray-drying method.The intermolecular effects of PEG-400 promote the spheroidization and uniform PEG coating of LMFP precursor,which prevents agglomeration during sintering.The 3D ion/electron dual-conductive network structure in P-LMFP@C accelerates the Li^(+)transport kinetics,improving the rate performance and cycling stability.As a result,the designed P-LMFP@C has remarkable electrochemical behavior,boasting excellent capacity retention(98%after 100 cycles at the 1C rate)and rate capability(91 mAh·g^(-1)at 20C).Such strategy introduces a novel window for designing high-performance olivine cathodes and offers compatibility with a range of energy storage materials for diverse applications.展开更多
The purpose of this study was to develop the immediate release stomach-specific spraydried formulation of valsartan(VAL) using Eudragit?E PO(EPO) as the carrier for enhancing dissolution rate in a gastric environment....The purpose of this study was to develop the immediate release stomach-specific spraydried formulation of valsartan(VAL) using Eudragit?E PO(EPO) as the carrier for enhancing dissolution rate in a gastric environment. Enhanced solubility and dissolution in gastric pH was achieved by formulating the solid dispersion using a spray drying technique. Different combinations of drug–polymer–surfactant were dissolved in 10% ethanol solution and spraydried in order to obtain solid dispersion microparticles. Use of the VAL–EPO solid dispersion microparticles resulted in significant improvement of the dissolution rate of the drug at pH 1.2 and pH 4.0, compared to the free drug powder and the commercial product. A hard gelatin capsule was filled with the VAL–EPO solid dispersion powder prior to the dissolution test.The increased dissolution of VAL from solid dispersion microparticles in gastric pH was attributed to the effect of EPO and most importantly the transformation of crystalline drugs to amorphous solid dispersion powder, which was clearly shown by scanning electron microscopy(SEM), differential scanning calorimetry(DSC), and powder X-ray diffraction(PXRD) studies. Thus, VAL, a potential antihypertensive drug in the form of a solid dispersion microparticulate powder, can be effectively delivered in the immediate release dosage form for stomach-specific drug delivery.展开更多
Design and fabrication of cost-effective transition metal and their oxides-based nanocomposites are of paramount significance for metal-air batteries and water-splitting.However,the traditional optimized designs for n...Design and fabrication of cost-effective transition metal and their oxides-based nanocomposites are of paramount significance for metal-air batteries and water-splitting.However,the traditional optimized designs for nanostructure are complicated,low-efficient and underperform for wide-scale applications.Herein,a novel hierarchical framework of hollow Ni/NiFe2O4-CNTs compositemicrosphere forcibly-assembled by zero-dimensional(OD)Ni/NiFo204 nanoparticle(<16 nm)and one-dimensional(1D)self-supporting CNTs was fabricated successfully.Benefitted from the unique nanostructure,such monohybrids can achieve remarkable oxygen evolution reaction(OER)performance in alkaline media with a low overpotential and superior durability,which exceeds most of the commercial catalysts based on IrO/RuO2 or other non-noble metal nanomaterials.The enhanced OER performance of Ni/NiFe2OA-CNTs composite is mainly ascribed to the increased catalytic activity and the optimized conductivity induced by the effects of strong hierarchical coupling and charge transfers between CNTs and Ni/NiFe204 nanoparticles.These effects are greatly boosted by the polarized heterojunction interfaces confirmed by electron holography.The density functional theory(DFT)calculation indicates the epitaxial Ni further enriches the intrinsic electrons contents of NiFe204 and thus accelerates absorption/desorption kinetics of OER intermediates.This work hereby paves a facile route to construct the hollow composite microsphere with excellent OER electrocatalytic activity based on non-noble metal oxide/CNTs.展开更多
The dry powder inhalation of antibiotics for the treatment of lung infections has attracted drastically increasing attention as it offers rapid local therapy at lower doses and minimal side effects.In this study,aztre...The dry powder inhalation of antibiotics for the treatment of lung infections has attracted drastically increasing attention as it offers rapid local therapy at lower doses and minimal side effects.In this study,aztreonam(AZT)was used as the model antibiotic and spraydried to prepare powders for inhalation.Amino acids of glycine(GLY),histidine(HIS)and leucine(LEU)were used as excipients to modify the spray-dried particles.It was demonstrated that the GLY-AZT spray-dried powders formed huge agglomerates with the size of 144.51μm,which made it very difficult to be delivered to the lungs(FPF:0.29%w/w only).In comparison with the AZT spray-dried powders,HIS-modified spray-dried powders showed increased compressibility,indicating larger distance and less cohesion between particles;while the LEU-modified spray-dried particles showed a hollow structure with significantly decreased densities.The fine particle fraction for HIS-and LEU-modified powders was 51.4%w/w and 61.7%w/w,respectively,and both were significantly increased(one-way ANOVA,Duncan’s test,P<0.05)compared to that of AZT spray-dried powders(45.4%w/w),showing a great potential to be applied in clinic.展开更多
The aim of this study was to produce fine particles with different corrugated degree of surface by spray-drying and to investigate the effect of surface morphology on in vitro aerosol performance of the particles with...The aim of this study was to produce fine particles with different corrugated degree of surface by spray-drying and to investigate the effect of surface morphology on in vitro aerosol performance of the particles within HFA 134a based metered dose formulations.Compositions of rizatriptan and scutellarin were spray-dried using different spray-drying parameters,and particles were suspended within HFA 134a.The surface morphology were determined using scanning electron microscopy(SEM),while the aerodynamic performance of MDIs was evaluated using a next generation pharmaceutical impactor.The surface morphology of spraydried particles could vary from smooth to moderately corrugated,and to raisin-like depending upon spray-drying parameters and preparation compositions.In general,increasing inlet temperature,decreasing feed concentration and/or adding leucine to the feed solution tended to increase the corrugated degree of particle surface.Deposition results indicated that raisinlike particle based MDIs for all compositions of the two drugs produced significantly better aerodynamic performance in terms of fine particle fractions and mass median aerodynamic diameters relative to the formulations of the corresponding smooth or slightly corrugated particles when the particle compositions were the same.The present results demonstrated that wrinkled particles increased fine particle fractions within surfactant-free MDI formulations.展开更多
The isothermal kinetics of the Fischer-Tropsch synthesis （FTS） over Fe-Cu-K spray-dried catalyst was studied in a spinning basket reactor. The experiments were carried out at a constant temperature of 523 K, n（H2...The isothermal kinetics of the Fischer-Tropsch synthesis （FTS） over Fe-Cu-K spray-dried catalyst was studied in a spinning basket reactor. The experiments were carried out at a constant temperature of 523 K, n（H2）/n（CO） feed ratios of 0.8 2.0, reactor pressures of 1.1 2.5 MPa, and space velocity of 0.556× 10^-3 Nm^3/kgcat·s. Kinetic model for hydrocarbon formation was derived on the basis of simplified carbide mechanism to reduce the number of parameters. Two individual rate constants for methane and ethene were considered. Furthermore, the model was modified empirically by non-intrinsic effect, such as physisorption and fictitious olefin pressures that were taken into account, and the influences of secondary reaction of α-olefins on product distribution. The simulation results showed that the experimental phenomena of FTS and the deviations from ASF distribution, such as the relatively high yield of methane and low yield of ethene observed experimentally could be depicted basically.展开更多
Slurry parameters were controlled prior to spray-drying to visualize and govern an understanding of which parameters govern hollow coring and granule morphology during spray-drying. An aqueous alumina using a polyviny...Slurry parameters were controlled prior to spray-drying to visualize and govern an understanding of which parameters govern hollow coring and granule morphology during spray-drying. An aqueous alumina using a polyvinyl alcohol binder (PVA) system was analyzed and granules were processed by altering the slurry specific gravity and viscosity value prior to spray-drying. Spray-dried granules were uniaxial dry-pressed at varying moisture contents to show the plasticizing effects of moisture during compaction. A novel characterization method using a field emission electron microscope (FESEM) was implemented to image the green microstructures of the granules and compacted samples. Slurries with a higher specific gravity and viscosity resulted in denser granules with spherical shapes. Viscosity affected the binder segregation during the spray-drying process. Granules stored at higher moisture contents resulted in denser compacts with fewer intergranular pores and cracks along granule boundaries. Using a FESEM resulted in higher resolution for green microstructural characterization.展开更多
Lycopene is very susceptible to degradation once released from the protective chromoplast environment.In this study,oil-in-water(O/W)nanoemulsions coupled with spray drying technology were applied for the encapsulatio...Lycopene is very susceptible to degradation once released from the protective chromoplast environment.In this study,oil-in-water(O/W)nanoemulsions coupled with spray drying technology were applied for the encapsulation and stabilization of lycopene extracted from tomato waste.Tomato extract was obtained by ultrasound-assisted extraction.Nanoemulsions were prepared by a high-speed rotor stator using isopropyl myristate as the oil phase and Pluronic F-127 as the emulsifier for the aqueous external phase.The effect of emulsification process parameters was investigated.Spray drying of the produced emulsions was attempted to obtain a stabilized dry powder after the addition of a coating agent.The effect of different coating agents(maltodextrin,inulin,gum arabic,pectin,whey and polyvinylpyrrolidone),drying temperature(120-170℃),and feed flow rate(3-9 ml·min^(-1))on the obtained particles was evaluated.Results revealed that the emulsion formulation of 20/80(O/W)with 1.5%(mass fraction)of Pluronic F-127 as stabilizer in the aqueous phase resulted in a stable nanoemulsion with droplet sizes in the range of 259-276 nm with a unimodal and sharp size distribution.The extract in the nanoemulsion was well protected at room temperature with a degradation rate of lycopene of about 50%during a month of storage time.The most stable emulsions were then processed by spray drying to obtain a dry powder.Spray drying was particularly successful when using maltodextrin as a coating agent,obtaining dried spherical particles with mean diameters of(4.87±0.17)μm with a smooth surface.The possibility of dissolving the spray dried powder in order to repristinate.The original emulsion was also successfully verified.展开更多
Using nitrate precursors, a novel spray-drying assisted citrate gel process for the preparation of neodymium-doped yttrium alumi- num garnet （YAG） phase was developed. Synthesis of single-phase polycrystalline YAG w...Using nitrate precursors, a novel spray-drying assisted citrate gel process for the preparation of neodymium-doped yttrium alumi- num garnet （YAG） phase was developed. Synthesis of single-phase polycrystalline YAG was achieved at temperatures as low as 800 ℃ using the spray-drying methodology whilst conventional approaches currently available require 1000 ℃. Initially, a solution was prepared by mixing aluminum and yttrium nitrates, citric acid, etilenglycol and neodymium oxide. This solution was dried by pulverization （spray dryer） to obtain aggregated precursor powders of the compound. These aggregates were calcined at 800, 850 and 900 ℃ to determine the phase evolution from amorphous to crystalline by X-ray diffraction （XRD）. The morphology of aggregates was characterized by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. Moreover, through XRD it was determined that the crystallization of YAG phase started at about 800 ℃ without any intermediate phases. The powders were composed of spherical aggregates with an average diameter of 1 um. From these powders, ceramic fibers with additions of 2at.% and 5at.% Nd, were extracted from the melt with diameters ranging from 30 um to 50 um.展开更多
Iron-based electrodes have attracted great attention for sodium storage because of the distinct cost effectiveness.However,exploring suitable iron-based electrodes with high power density and long duration remains a b...Iron-based electrodes have attracted great attention for sodium storage because of the distinct cost effectiveness.However,exploring suitable iron-based electrodes with high power density and long duration remains a big challenge.Herein,a spray-drying strategy is adopted to construct graphene-coated Na_(2.4)Fe_(1.8)(SO_(4))_(3) nanograins in a 3D graphene microsphere network.The unique structural and compositional advantages endow these electrodes to exhibit outstanding electrochemical properties with remarkable rate performance and long cycle life.Mechanism analyses further explain the outstanding electrochemical properties from the structural aspect.展开更多
β-Carotene is one of the most abundant natural pigments in foods;however,usage of β-carotene is limited because of its instability.Microencapsulation techniques are usually applied to protect microencapsulated p-car...β-Carotene is one of the most abundant natural pigments in foods;however,usage of β-carotene is limited because of its instability.Microencapsulation techniques are usually applied to protect microencapsulated p-carotene from oxidization.In this study,β-carotene was microencapsulated using different drying processes:spray-drying,spray freeze-dryi ng,coati ng,and spray granulation.The properties of morphology,particle size,water con tent,thermal characteristic,and chemical stability have been explored and compared.Scanning electron microscopy measure?ments showed that the coated powder had a dense surface surro un ded by starch and suggested that the coati ng process gave a microencapsulated powder with the smallest bulk density and the best compressibility among the prepared powders.The chemical stabilities of microcapsules were evaluated during six months of storage at different temperatures.The coated powder had the highest mass fraction of β-carotene,which indicated that the coating process was superior to the three other drying processes.展开更多
Chitosan and β-cyclodextrin were used to prepare microspheres with theophylline for pulmonary delivery by spray drying method. The characteristics, mucociliotoxicity, permeation rate and drug release were studied. Th...Chitosan and β-cyclodextrin were used to prepare microspheres with theophylline for pulmonary delivery by spray drying method. The characteristics, mucociliotoxicity, permeation rate and drug release were studied. The drug entrapments of microspheres Ⅰ, Ⅱ and Ⅲ were from 35.70% to 21.09% and 13.33%, while yields and encapsulation efficiencies were higher than 45% and about 90% respectively. The microspheres possessed low tap densities （0.34-0.48 g/cm^3）, appropriate diameters （3.35-3.94 μm） and theoretical aerodynamics diameters （2.20-3.04 μm）. SEM images showed the microspheres were spherical with smooth or wrinkled surface surfaces. FT-IR demonstrated theophylline had formed hydrogen bonds with chitosan and fl-cyclodextrin. The microspheres could effectively reduce the ciliotoxicity and easy to penetrate the memberine. The in vitro release of the microspheres was related to the ratio of drug/polymer and microspheres Ⅱ had a prolong release, providing the release of 72.00% in 12 h. The results suggestes that chitosan/β-cyclodextrin microspheres Ⅱ are a promising carrier as sustained release for pulmonary delivery.展开更多
文摘The core-shell 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/2,4,6-Trinitrotoluene(CL-20/TNT)composite was prepared by spray-drying method in which sensitive high energy explosive(CL-20)was coated with insensitive explosive(TNT).The structure and properties of different formulations of CL-20/TNT composite and CL-20/TNT mixture were characterized by scanning electron microscopy(SEM),Transmission electron microscopy(TEM),Laser particle size analyzer,X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),differential scanning calorimetry(DSC),impact sensitivity test and detonation performance.The results of SEM,TEM,XPS and XRD show that e-CL-20 particles are coated by TNT.When the ratio of CL-20/TNT is 75/25,core-shell structure is well formed,and thickness of the shell is about 20e30 nm.And the analysis of heat and impact show that with the increase of TNT content,the TNT coating on the core-shell composite material can not only catalyze the thermal decomposition of core material(CL-20),but also greatly reduce the impact sensitivity.Compared with the CL-20/TNT mixture(75/25)at the same ratio,the characteristic drop height of core-shell CL-20/TNT composite(75/25)increased by 47.6%and the TNT coating can accelerate the nuclear decomposition in the CL-20/TNT composites.Therefore,the preparation of the core-shell composites can be regarded as a unique means,by which the composites are characterized by controllable decomposition rate,high energy and excellent mechanical sensitivity and could be applied to propellants and other fields.
基金financially supported by the Prospective Joint Research Project of Industry,University and Research in Jiangsu Province(BY2016005-11)National Science and Technology Support Plan(No.2013BAE111B03)。
文摘A spray-drying assisted solid-state method to prepare spherical layer-structured H_(2)TiO_(3) ion sieve(LSTIS)particles is reported herein.The effects of synthesis parameters(calcination temperature,calcination time,and the lithium-titanium molar ratio)on adsorption-desorption performance(the delithiation ratio,titanium dissolution loss,and the adsorption capacity)were investigated.The as-prepared LSTIS exhibited an equilibrium adsorption capacity of 30.08 mg·g^(-1)(average of 25.85 mg·g^(-1) over 5 cycles)and ultra-low titanium dissolution loss of less than 0.12%(average of 0.086%over 5 cycles).The LSTIS showed excellent selectivity toward Li^(+) in Na^(+),K^(+),Mg^(2+),and Ca^(2+) coexisting saline solutions where its adsorption capacity reached 27.45 mg·g^(-1) and the separation factors of Li^(+) over the coexisting cations exceeded 100.The data suggests that the LSTIS is promising to competitively enrich Li^(+) from saline solutions.
文摘Well-shaped spherical agglomerates of FePO4 particles were prepared by a novel method:chemical co-precipitation combined with spray-drying.Tap density analysis,Brunauer-Emmett-Teller analysis,characterizations of X-ray diffraction,scanning electron microscopy,and transmission electron microscopy confirmed that the micron-sized spherical agglomerates with high specific surface area and high tap density were composed of the uniform nano-sized particles.The effects of pH and reaction time on the morphology of the FePO4 particles were investigated by experimental and theoretical analyses.The analyses revealed that amorphous FePO4 was responsible for forming a well-shaped spherical agglomerate,and the ideal spherical particles were obtained at pH 3.The reaction time also played a significant role in controlling the size and surface morphology of the FePO4 particles,and smooth spherical FePO4 particles were obtained at a reaction time of 6 h.By this novel method,poly-porous spherical iron phosphate particles were prepared,which can be used with high efficiency in some special fields,especially as a precursor for synthesizing LiFePO4 and catalysts.
基金supported by the National High Technology Research and Development Program of China(2017YFD0400200)National Natural Science Foundation of China(31701643,31171661,21105119 and 31271879)Research Foundation of the Director General of Oil Crops Research Institute,Chinese Academy of Agricultural Sciences
文摘Nutmeg essential oil with volatile components is sensitive to oxygen, light, water and high temperature. Spray-drying is widely used as an encapsulation technique for improving compound stability during processing and storage. In this study, influence of encapsulated matrix on spray-dried nutmeg essential oil microcapsule was investigated using blends of maltodextrin and either gum Arabic(GA-MD), or octenyl succinic acid modified starch(OSA-MD) as wall materials. Characteristics of spray-dried powders from these 2 wall materials were evaluated and compared. Powder property analysis indicated that GA-MD microcapsules presented larger size, higher moisture and poorer flowability compared with OSA-MD microcapsules. Fourier transforms infrared spectroscopy and thermogravimetric analysis showed that both GA-MD and OSA-MD microcapsules improved the stability of nutmeg essential oil. However, GA-MD microcapsules exhibited higher storage stability than OSA-MD microcapsules. This research provided theoretical foundation for wall material choice of microcapsule and nutmeg essential oil utilization in food industry.
文摘Poly(octamethylene citrate)(POC)is a promising bioelastomer material in the biomedical field.However,its thermosetting nature poses a significant challenge to processing and molding,especially manufacturing the POC-based elastomer particles as potential,degradable and toughened fillers.Firstly,a Pickering emulsion with a pre-polymer(pre-POC)solution in dimethyl carbonate as a dispersed oil phase,a Pullulan(PUL)aqueous solution as a continuous water phase,and chitin nanocrystal(ChiNC)as a particle-type emulsifier was constructed.Secondly,the POC-based core/shell structured microspheres were prepared by spray-drying of the emulsions,and characterized by a scanning electron microscope and a transmission electron microscope.Finally,the POC-based core/shell structured microspheres were used as elastomer fillers to strengthen and toughen a chitosan film,resulting in 26%increase in the tensile strength and 45%increase in the strain at break;the POC-based core/shell structured microsphere as a double-layer drug release system was built in which the hydrophilic drug of tetracycline hydrochloride(TCH)was released from the outer layer and the hydrophobic drug of curcumin was released from the inner layer,roughly following the Ritger-Peppas model.
基金supported by the Hefei Innovation Research Institute of Beihang University,the National Natural Science Foundation of China(52203321)the China Postdoctoral Science Foundation under Grant(2022M710289)the Postdoctoral Research Funding Program of Hefei.
文摘Spray-drying is a widely used industrial technique to achieve the scale-up fabrication of functional powders.In this work,we report the spray-drying fabrication of perovskite quantum dot(PQD)microspheres from a precursor solution at a scale of 2000 kg·a^(−1).The obtained PQDs are embedded in polymer microspheres,resulting in a high photoluminescence quantum yield and enhanced stability.By controlling the precursor concentration,the average size of the polymer microspheres can be tuned from 40.97 to 0.44μm.The as-prepared PQD-embedded polymer microspheres are mixed with ultraviolet adhesive to fabricate PQD-enhanced optical films for liquid crystal display(LCD)backlights.These films exhibit long-term operational stability under heat,humidity,and blue light irradiation(remaining at more than 90%initial photoluminescence intensity after a 1000 h aging test at 60℃ with 90%relative humidity and 70℃ with 455 nm 150 W·m^(−2) blue light irradiation).In addition,we demonstrate the use of PQD-embedded polymer microspheres as patterned color converters for micro light-emitting diode applications.Overall,this work demonstrates the scale-up fabrication of PQDs toward industrialization in display technology.
基金supported by the National Natural Science Foundation of China(grant Nos.22278028,22288102 and 22168010).
文摘The applications of nanoparticles suffer from their extremely small size and intrinsic trend of agglom-eration.Rearranging nanoparticles to form micro-sized nanoaggregates(MNAs)with increased size,ordered structure,as well as controllable size,shape,and morphology is a crucial step in various fields of science and technology to maintain the unique characteristics of nanoparticles while obtaining greatly enhanced or new performance at the microscale.The structure of MNAs prominently affects their functionality,which is determined by the arrangement of nanoparticles and the interaction between primary particles.Several methods have been proposed to prepare the MNAs,in which spray-drying technology stands out considering the feasibility,scalability for industry,cost,and efficiency.Forced assembly of nanoparticles through spray-drying under tunable process parameters yields diverse physical properties and structural arrangements of nanoparticles of the MNAs,they therefore exhibit enormous potential in a wide range of application fields.This review presents the construction and applications of spray-dried MNAs.The factors that influence the size,morphology,and structure of the MNAs are discussed in detail.In addition,the outstanding application performance resulting from the tightly packed nanoparticles in regular-shaped MNAs obtained by the spray-drying process is illustrated.
基金Supported by the Project of Natural Science Fund of Zhejiang Province(Y3110376)~~
文摘[Objective] Effects of different contents of calcium oxide on physicochemi- cal properties of spray-dried bayberry powder were studied. [Method] Bayberry pow- der produced from bayberry juice adding 0, 2 and 4 g/L calcium oxide using the spray drying technique has been selected. The physicochemical properties of the spray-dried bayberry powder were investigated by determining moisture content, colour, apparent density, wettability, angle of repose and moisture absorption rate of bayberry powder. [Result] The results showed that the content of calcium oxide had a significant effect on the moisture content and colour of bayberry powder. Effects of different contents of calcium oxide on the apparent density of spray-dried bayber- ry powder were not obvious. Adding calcium oxide had a significant effect on the wettability, angle of repose and moisture absorption rate of spray-dried bayberry powder, nevertheless, there was not obvious difference on these properties between adding 2 and 4 g/L calcium oxide. [Conclusion] The results confirmed that the con- tent of calcium oxide had a significant effect on the properties of spray-dried bay- berry powder.
基金supported by the Key Technologies R&D Program of Xiamen(No.3502Z20231057)Industry Leading Key Projects of Fujian Province(No.2022H0057)+2 种基金the National Natural Science Foundation of China(No.21975212)High-Level Talent Start-Up Foundation of Xiamen Institute of Technology for financial support(No.YKJ23017R)Graduate Science and Technology Innovation Program of Xiamen University of Technology(No.YKJCX2023194).
文摘LiMnxFe1-xPO_(4) is a promising cathode candidate due to its high security and the availability of a high 4.1 V operating voltage and high energy density.However,the poor electrochemical kinetics and structural instability currently hinder its broader application.Herein,inspired by the hydrogen-bonded cross-linking and steric hindrance effect between short-chain polymer molecules(polyethylene glycol-400,PEG-400),the pomegranate-type LiMn_(0.5)Fe_(0.5)PO_(4)-0.5@C(P-LMFP@C)cathode materials with 3D ion/electron dual-conductive network structure were constructed through ball mill-assisted spray-drying method.The intermolecular effects of PEG-400 promote the spheroidization and uniform PEG coating of LMFP precursor,which prevents agglomeration during sintering.The 3D ion/electron dual-conductive network structure in P-LMFP@C accelerates the Li^(+)transport kinetics,improving the rate performance and cycling stability.As a result,the designed P-LMFP@C has remarkable electrochemical behavior,boasting excellent capacity retention(98%after 100 cycles at the 1C rate)and rate capability(91 mAh·g^(-1)at 20C).Such strategy introduces a novel window for designing high-performance olivine cathodes and offers compatibility with a range of energy storage materials for diverse applications.
文摘The purpose of this study was to develop the immediate release stomach-specific spraydried formulation of valsartan(VAL) using Eudragit?E PO(EPO) as the carrier for enhancing dissolution rate in a gastric environment. Enhanced solubility and dissolution in gastric pH was achieved by formulating the solid dispersion using a spray drying technique. Different combinations of drug–polymer–surfactant were dissolved in 10% ethanol solution and spraydried in order to obtain solid dispersion microparticles. Use of the VAL–EPO solid dispersion microparticles resulted in significant improvement of the dissolution rate of the drug at pH 1.2 and pH 4.0, compared to the free drug powder and the commercial product. A hard gelatin capsule was filled with the VAL–EPO solid dispersion powder prior to the dissolution test.The increased dissolution of VAL from solid dispersion microparticles in gastric pH was attributed to the effect of EPO and most importantly the transformation of crystalline drugs to amorphous solid dispersion powder, which was clearly shown by scanning electron microscopy(SEM), differential scanning calorimetry(DSC), and powder X-ray diffraction(PXRD) studies. Thus, VAL, a potential antihypertensive drug in the form of a solid dispersion microparticulate powder, can be effectively delivered in the immediate release dosage form for stomach-specific drug delivery.
基金This work was supported by the Ministry of Science and Technology of China(973 Project)(No.2018YFA0209102)the National Natural Science Foundation of China(Nos.11727807,51725101,51672050,and 61790581)。
文摘Design and fabrication of cost-effective transition metal and their oxides-based nanocomposites are of paramount significance for metal-air batteries and water-splitting.However,the traditional optimized designs for nanostructure are complicated,low-efficient and underperform for wide-scale applications.Herein,a novel hierarchical framework of hollow Ni/NiFe2O4-CNTs compositemicrosphere forcibly-assembled by zero-dimensional(OD)Ni/NiFo204 nanoparticle(<16 nm)and one-dimensional(1D)self-supporting CNTs was fabricated successfully.Benefitted from the unique nanostructure,such monohybrids can achieve remarkable oxygen evolution reaction(OER)performance in alkaline media with a low overpotential and superior durability,which exceeds most of the commercial catalysts based on IrO/RuO2 or other non-noble metal nanomaterials.The enhanced OER performance of Ni/NiFe2OA-CNTs composite is mainly ascribed to the increased catalytic activity and the optimized conductivity induced by the effects of strong hierarchical coupling and charge transfers between CNTs and Ni/NiFe204 nanoparticles.These effects are greatly boosted by the polarized heterojunction interfaces confirmed by electron holography.The density functional theory(DFT)calculation indicates the epitaxial Ni further enriches the intrinsic electrons contents of NiFe204 and thus accelerates absorption/desorption kinetics of OER intermediates.This work hereby paves a facile route to construct the hollow composite microsphere with excellent OER electrocatalytic activity based on non-noble metal oxide/CNTs.
基金support from Natural Science Foundation of Jiangsu Province(BK2011295)Youth Fund of Soochow University(SDY2011A21)。
文摘The dry powder inhalation of antibiotics for the treatment of lung infections has attracted drastically increasing attention as it offers rapid local therapy at lower doses and minimal side effects.In this study,aztreonam(AZT)was used as the model antibiotic and spraydried to prepare powders for inhalation.Amino acids of glycine(GLY),histidine(HIS)and leucine(LEU)were used as excipients to modify the spray-dried particles.It was demonstrated that the GLY-AZT spray-dried powders formed huge agglomerates with the size of 144.51μm,which made it very difficult to be delivered to the lungs(FPF:0.29%w/w only).In comparison with the AZT spray-dried powders,HIS-modified spray-dried powders showed increased compressibility,indicating larger distance and less cohesion between particles;while the LEU-modified spray-dried particles showed a hollow structure with significantly decreased densities.The fine particle fraction for HIS-and LEU-modified powders was 51.4%w/w and 61.7%w/w,respectively,and both were significantly increased(one-way ANOVA,Duncan’s test,P<0.05)compared to that of AZT spray-dried powders(45.4%w/w),showing a great potential to be applied in clinic.
基金the National Natural Science Foundation of China(grant no.81172997)the Ministry of Science and Technology of the People’s Republic of China(grant no.2012ZX09301-002-030)for the financial supports.
文摘The aim of this study was to produce fine particles with different corrugated degree of surface by spray-drying and to investigate the effect of surface morphology on in vitro aerosol performance of the particles within HFA 134a based metered dose formulations.Compositions of rizatriptan and scutellarin were spray-dried using different spray-drying parameters,and particles were suspended within HFA 134a.The surface morphology were determined using scanning electron microscopy(SEM),while the aerodynamic performance of MDIs was evaluated using a next generation pharmaceutical impactor.The surface morphology of spraydried particles could vary from smooth to moderately corrugated,and to raisin-like depending upon spray-drying parameters and preparation compositions.In general,increasing inlet temperature,decreasing feed concentration and/or adding leucine to the feed solution tended to increase the corrugated degree of particle surface.Deposition results indicated that raisinlike particle based MDIs for all compositions of the two drugs produced significantly better aerodynamic performance in terms of fine particle fractions and mass median aerodynamic diameters relative to the formulations of the corresponding smooth or slightly corrugated particles when the particle compositions were the same.The present results demonstrated that wrinkled particles increased fine particle fractions within surfactant-free MDI formulations.
基金This work was supported by Chinese Academy of Sciences (No. KGCX1-SW-02)National Ministry of Science and Technology of via 863 plan (No. 2001AA523010)Shanxi Natural Science Foundation (No. 20031032)National Natural Science Foundation of China (No. 20473111, 20590361).
文摘The isothermal kinetics of the Fischer-Tropsch synthesis （FTS） over Fe-Cu-K spray-dried catalyst was studied in a spinning basket reactor. The experiments were carried out at a constant temperature of 523 K, n（H2）/n（CO） feed ratios of 0.8 2.0, reactor pressures of 1.1 2.5 MPa, and space velocity of 0.556× 10^-3 Nm^3/kgcat·s. Kinetic model for hydrocarbon formation was derived on the basis of simplified carbide mechanism to reduce the number of parameters. Two individual rate constants for methane and ethene were considered. Furthermore, the model was modified empirically by non-intrinsic effect, such as physisorption and fictitious olefin pressures that were taken into account, and the influences of secondary reaction of α-olefins on product distribution. The simulation results showed that the experimental phenomena of FTS and the deviations from ASF distribution, such as the relatively high yield of methane and low yield of ethene observed experimentally could be depicted basically.
文摘Slurry parameters were controlled prior to spray-drying to visualize and govern an understanding of which parameters govern hollow coring and granule morphology during spray-drying. An aqueous alumina using a polyvinyl alcohol binder (PVA) system was analyzed and granules were processed by altering the slurry specific gravity and viscosity value prior to spray-drying. Spray-dried granules were uniaxial dry-pressed at varying moisture contents to show the plasticizing effects of moisture during compaction. A novel characterization method using a field emission electron microscope (FESEM) was implemented to image the green microstructures of the granules and compacted samples. Slurries with a higher specific gravity and viscosity resulted in denser granules with spherical shapes. Viscosity affected the binder segregation during the spray-drying process. Granules stored at higher moisture contents resulted in denser compacts with fewer intergranular pores and cracks along granule boundaries. Using a FESEM resulted in higher resolution for green microstructural characterization.
文摘Lycopene is very susceptible to degradation once released from the protective chromoplast environment.In this study,oil-in-water(O/W)nanoemulsions coupled with spray drying technology were applied for the encapsulation and stabilization of lycopene extracted from tomato waste.Tomato extract was obtained by ultrasound-assisted extraction.Nanoemulsions were prepared by a high-speed rotor stator using isopropyl myristate as the oil phase and Pluronic F-127 as the emulsifier for the aqueous external phase.The effect of emulsification process parameters was investigated.Spray drying of the produced emulsions was attempted to obtain a stabilized dry powder after the addition of a coating agent.The effect of different coating agents(maltodextrin,inulin,gum arabic,pectin,whey and polyvinylpyrrolidone),drying temperature(120-170℃),and feed flow rate(3-9 ml·min^(-1))on the obtained particles was evaluated.Results revealed that the emulsion formulation of 20/80(O/W)with 1.5%(mass fraction)of Pluronic F-127 as stabilizer in the aqueous phase resulted in a stable nanoemulsion with droplet sizes in the range of 259-276 nm with a unimodal and sharp size distribution.The extract in the nanoemulsion was well protected at room temperature with a degradation rate of lycopene of about 50%during a month of storage time.The most stable emulsions were then processed by spray drying to obtain a dry powder.Spray drying was particularly successful when using maltodextrin as a coating agent,obtaining dried spherical particles with mean diameters of(4.87±0.17)μm with a smooth surface.The possibility of dissolving the spray dried powder in order to repristinate.The original emulsion was also successfully verified.
基金Universidad Michoacana de San Nicolás de Hidalgo (UMSNH) (1.24.-2005-2007)
文摘Using nitrate precursors, a novel spray-drying assisted citrate gel process for the preparation of neodymium-doped yttrium alumi- num garnet （YAG） phase was developed. Synthesis of single-phase polycrystalline YAG was achieved at temperatures as low as 800 ℃ using the spray-drying methodology whilst conventional approaches currently available require 1000 ℃. Initially, a solution was prepared by mixing aluminum and yttrium nitrates, citric acid, etilenglycol and neodymium oxide. This solution was dried by pulverization （spray dryer） to obtain aggregated precursor powders of the compound. These aggregates were calcined at 800, 850 and 900 ℃ to determine the phase evolution from amorphous to crystalline by X-ray diffraction （XRD）. The morphology of aggregates was characterized by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. Moreover, through XRD it was determined that the crystallization of YAG phase started at about 800 ℃ without any intermediate phases. The powders were composed of spherical aggregates with an average diameter of 1 um. From these powders, ceramic fibers with additions of 2at.% and 5at.% Nd, were extracted from the melt with diameters ranging from 30 um to 50 um.
基金financial support by the National Natural Science Foundation of China(Nos.21673165 and 21972108)National Key Research Program of China(No.2016YFB0901500)the supercomputing system in the Supercomputing Center of Wuhan University。
文摘Iron-based electrodes have attracted great attention for sodium storage because of the distinct cost effectiveness.However,exploring suitable iron-based electrodes with high power density and long duration remains a big challenge.Herein,a spray-drying strategy is adopted to construct graphene-coated Na_(2.4)Fe_(1.8)(SO_(4))_(3) nanograins in a 3D graphene microsphere network.The unique structural and compositional advantages endow these electrodes to exhibit outstanding electrochemical properties with remarkable rate performance and long cycle life.Mechanism analyses further explain the outstanding electrochemical properties from the structural aspect.
基金Project supported by the Hubei Province Technology Innovation Project(No.2017ACA083),China
文摘β-Carotene is one of the most abundant natural pigments in foods;however,usage of β-carotene is limited because of its instability.Microencapsulation techniques are usually applied to protect microencapsulated p-carotene from oxidization.In this study,β-carotene was microencapsulated using different drying processes:spray-drying,spray freeze-dryi ng,coati ng,and spray granulation.The properties of morphology,particle size,water con tent,thermal characteristic,and chemical stability have been explored and compared.Scanning electron microscopy measure?ments showed that the coated powder had a dense surface surro un ded by starch and suggested that the coati ng process gave a microencapsulated powder with the smallest bulk density and the best compressibility among the prepared powders.The chemical stabilities of microcapsules were evaluated during six months of storage at different temperatures.The coated powder had the highest mass fraction of β-carotene,which indicated that the coating process was superior to the three other drying processes.
基金the National Natural Science Foundation of China(No.30670566)Natural Science Foundation of Shandong Province
文摘Chitosan and β-cyclodextrin were used to prepare microspheres with theophylline for pulmonary delivery by spray drying method. The characteristics, mucociliotoxicity, permeation rate and drug release were studied. The drug entrapments of microspheres Ⅰ, Ⅱ and Ⅲ were from 35.70% to 21.09% and 13.33%, while yields and encapsulation efficiencies were higher than 45% and about 90% respectively. The microspheres possessed low tap densities （0.34-0.48 g/cm^3）, appropriate diameters （3.35-3.94 μm） and theoretical aerodynamics diameters （2.20-3.04 μm）. SEM images showed the microspheres were spherical with smooth or wrinkled surface surfaces. FT-IR demonstrated theophylline had formed hydrogen bonds with chitosan and fl-cyclodextrin. The microspheres could effectively reduce the ciliotoxicity and easy to penetrate the memberine. The in vitro release of the microspheres was related to the ratio of drug/polymer and microspheres Ⅱ had a prolong release, providing the release of 72.00% in 12 h. The results suggestes that chitosan/β-cyclodextrin microspheres Ⅱ are a promising carrier as sustained release for pulmonary delivery.
