Solid-state precipitation is an effective strategy for tuning the mechanical and functional properties of ad-vanced alloys.Structure design and modification necessitate good knowledge of the kinetic evolution of preci...Solid-state precipitation is an effective strategy for tuning the mechanical and functional properties of ad-vanced alloys.Structure design and modification necessitate good knowledge of the kinetic evolution of precipitates during fabrication,which is strongly correlated with defect concentration.For Fe-Ga alloys,giant magnetostriction can be induced by the precipitation of the nanoscale tetragonal L60 phase.By introducing quenched-in vacancies,we significantly enhance the magnetostriction of the aged Fe81Ga19 polycrystalline alloys to~305 ppm,which is close to the level of single crystals.Although vacancies were found to facilitate the generation of the L60 phase,their impact on the precipitation mechanism and kinetics has yet to be revealed.This study combined transmission electron microscopy(TEM)and time-resolved small-angle neutron scattering(SANS)to investigate the precipitation of the L60 phase during the isothermal aging at 350 and 400℃,respectively.The evolution of L60 nanophase in morphology and number density in as-cast(AC)and liquid nitrogen quenched(LN)Fe81Ga19 alloys with aging time were quantitatively compared.Interestingly,the nucleation of the L60 phase proceeds progressively in AC while suddenly in LN specimens,indicating the homogenous to heterogeneous mechanism switching in-duced by concentrated vacancies.Moreover,excess vacancies can change the shape of nanoprecipitates and significantly accelerate the growth and coarsening kinetics.The magnetostrictive coefficient is opti-mized when the size(long-axis)of L60 precipitates lies between 100 and 110Åwith a number density between 3.2-4.3×10-7Å-3.Insight from this study validates the feasibility of achieving high magnetoe-lastic properties through precise manipulation of the nanostructure.展开更多
Eutectic high-entropy alloys,composed of FCC/B2 phases with a narrow solidification interval and excel-lent fluidity,have become a new hotspot in additive manufacturing.Nevertheless,their microstructures exhibit signi...Eutectic high-entropy alloys,composed of FCC/B2 phases with a narrow solidification interval and excel-lent fluidity,have become a new hotspot in additive manufacturing.Nevertheless,their microstructures exhibit significant sensitivity to processing parameters,feedstocks,and composition,ultimately limiting the alloys’engineering applications.Here,a hypereutectic Al_(0.7)CoCrFeNi_(2.4)alloy with a low cracking sus-ceptibility index was designed by Thermo-Calc calculation and fabricated by laser powder bed fusion.Results show that the as-printed Al_(0.7)CoCrFeNi_(2.4)alloy manifests a stable cellular structure,coupled with appreciable ultimate tensile strength(≥1200 MPa)and ductility(≥20%)over a wide range of process-ing parameters.After aging at 800℃for 30 min,outstanding strength(1500 MPa)and elongation(15%)were obtained.Considerable mechanical properties after aging stem from a triple strengthening mecha-nism,i.e.,L1_(2) nanoprecipitates and rod-shaped B2 particles within the FCC matrix,along with Cr-enriched spherical nanoparticles in the B2 phase.Meanwhile,hierarchical structure,i.e.,FCC dominated matrix,a discontinuous B2 phase,a precipitation-free zone in the B2 phase,and a K-S orientation relationship be-tween FCC and B2,facilitate to maintain excellent plasticity.These results guide designing HEAs by AM with controllable microstructures and outstanding mechanical properties for industrial applications.展开更多
Additive manufacturing of aluminum alloys has received significant attention in the aerospace industry;however,achieving sufficient high strength,especially at elevated temperatures,remains challenging.Here,a crack-fr...Additive manufacturing of aluminum alloys has received significant attention in the aerospace industry;however,achieving sufficient high strength,especially at elevated temperatures,remains challenging.Here,a crack-free and near-full dense Al-1Fe-0.6Cu-1.3Zr alloy was fabricated by the laser powder bed fusion(LPBF)technique.The Al-Fe-Cu-Zr alloy exhibits heterogeneous microstructures with two distinct zones.One is the so-called coarse-grain zones(CGZs)with an average grain size of 0.95μm,where(Al,Cu)Fe_(3) nanoparticles precipitate in the Al matrix and Fe and Cu cosegregate at the grain boundaries(GBs).The other is fine-grain zones(FGZs)with an average grain size of 0.45μm,where an Al 3 Zr nanoparti-cle precipitates in each of theα-Al grains(serves as the nuclei),and Fe-rich nanoprecipitates and Fe/Cu cosegregation appear at the GBs.As a result,the LPBF Al-Fe-Cu-Zr alloy,with these unique heteroge-neous structures,displays high strength at both room temperature and elevated temperatures,e.g.,with high yield strengths of 500 MPa at room temperature,and 163 MPa at 573 K,both are higher than those of additive manufactured Al-based alloys reported thus far.It is suggested that the high strength over a wide temperature range of the current LPBF Al alloy is mainly attributed to the combination of the precipitation strengthening mechanism and grain-boundary strengthening mechanism.展开更多
As an emerging 2D conjugated material,graphitic carbon nitride(CN) has attracted great research attention as important catalytic medium for transforming solar energy.Nanostructure modulation of CN is an effective way ...As an emerging 2D conjugated material,graphitic carbon nitride(CN) has attracted great research attention as important catalytic medium for transforming solar energy.Nanostructure modulation of CN is an effective way to improve catalytic activities and has been extensively investigated,but remains challenging due to complex processes,time consuming or low yield.Here,taking advantage of recent discovered good solvents for CN,a nanoprecipitation approach using poor solvents is proposed for preparation of CN nanoparticles(CN NPs).With simple processes of CN dissolution and precipitation,we can quickly synthesize CN NPs(^40 nm) with a yield of up to 50%,the highest one to the best of our knowledge.As an example of potential applications,the as-prepared CN NPs were applied to photocatalytic degradation of dyes with an evident boosted performance up to 2.5 times.This work would open a new way for batch preparation of nanostructured CN and pave its large-scale industrial applications.展开更多
Nanoparticles have been given considerable attention and applied in many fields because of their properties that are superior to and more distinct than those of conventional materials. In practice, a stable and reprod...Nanoparticles have been given considerable attention and applied in many fields because of their properties that are superior to and more distinct than those of conventional materials. In practice, a stable and reproducible manufacturing process is highly desirable. This review presents the flash nanoprecipitation, a new technique that can rapidly produce nanoparticles. Moreover, the mixing process, the mechanism of particle formation, and the mixer design are discussed.Furthermore, the factors controlling the size stability of the produced nanoparticles are summarised in this review.展开更多
High-strength Fe-Mn-Al-C-Ni low-density steels are highly desirable in lightweight transportation,safe infrastructure,and advanced energy applications.However,these steels generally suffer from limited ductility owing...High-strength Fe-Mn-Al-C-Ni low-density steels are highly desirable in lightweight transportation,safe infrastructure,and advanced energy applications.However,these steels generally suffer from limited ductility owing to the formation of coarse B2 particles at grain boundaries.In this study,we proposed a strategy to introduce copious intragranular B2 nanoprecipitates within fully-recrystallized fine austenitic grains in a Fe-26Mn-11Al-0.9C-5Ni ultralight steel by a simple cold rolling and annealing process.Compared with steel where B2 particles are mainly distributed at grain boundaries,the yield strength and ultimate tensile strength of this steel increased from 768 MPa and 1100 MPa to 954 MPa and 1337 MPa,respectively,whereas the total elongation increased from 38%to 50%.The higher yield strength was primarily due to the synergistic strengthening effect of intragranular B2 nanoprecipitates and grain refinement.The excellent ductility and sustained work hardening were mainly attributed to the strong dislocation storage capability mediated by the intragranular B2 nanoprecipitates and the greater dynamic slip band refinement strengthening effect.Hence,the achievement of copious intragranular B2 nanoprecipitation in fully recrystallized ultralight steel offers an effective pathway for developing lightweight materials with high strength and large ductility.展开更多
Engineered nanoparticles have emerged as new types of materials for a wide range of applications from therapeutics to energy.Still,fabricating nanomaterials presenting complex inner morphologies and shapes in a simple...Engineered nanoparticles have emerged as new types of materials for a wide range of applications from therapeutics to energy.Still,fabricating nanomaterials presenting complex inner morphologies and shapes in a simple manner remains a great challenge.Herein,we report the template-free one-pot continuous gradient nanoprecipitation of different types of non-compatible polymers to spontaneously form nanostructured particles.The continuous addition of antisolvent induces precipitation and(re)organization of polymer chains at the forming particle interface,ultimately and naturally developing complex inner morphologies and shapes while particle grows.This low-energy-cost bottom-up assembly approach applies to various functional polymers,possibly embedded with metal nanoparticles,for continuous growth into well-organized nanoparticles.UV crosslinking of the particles and core removal allows both confirming the building process and leading to hollow or multivoid nanomaterials.展开更多
The equimolar NbZrTi medium-entropy alloy(MEA)has attracted attention due to its excellent comprehensive mechanical properties.In this study,the designed body-centered cubic NbZrTiAl_(4)(atomic percent,at%)MEA by Al a...The equimolar NbZrTi medium-entropy alloy(MEA)has attracted attention due to its excellent comprehensive mechanical properties.In this study,the designed body-centered cubic NbZrTiAl_(4)(atomic percent,at%)MEA by Al addition,having a superplastic extensibility of~5000%under cold rolling,enables directly fabricated ultrathin foils with a thickness down to~0.2 mm without any treatments.Particularly,the annealed NbZrTiAl_(4) MEA foils,containing a coherent nanoscale B2,exhibit an ultrahigh yield strength of up to~1130 MPa,which even surpasses the bulk counterpart,while maintaining a good fracture elongation of up to~14%.The Al addition induced a stronger solid solution strengthening and fine-grain strengthening in the foils.Complex dislocation interactions and dislocation–B2 interactions promoted a dynamical formation of dislocation bands,which yielded work-hardening ability and tensile ductility.These findings provide a novel strategy for the design of ultrathin refractory medium-entropy foils to break through their performance limits at ultrahigh temperatures and guide the design of high-performance lightweight foils for structural applications.展开更多
Nanoparticles are considered to be a powerful approach for the delivery of poorly watersoluble drugs. One of the main challenges is developing an appropriate method for preparation of drug nanoparticles. As a simple, ...Nanoparticles are considered to be a powerful approach for the delivery of poorly watersoluble drugs. One of the main challenges is developing an appropriate method for preparation of drug nanoparticles. As a simple, rapid and scalable method, the flash nanoprecipitation(FNP) has been widely used to fabricate these drug nanoparticles, including pure drug nanocrystals, polymeric micelles,polymeric nanoparticles, solid lipid nanoparticles, and polyelectrolyte complexes. This review introduces the application of FNP to produce poorly water-soluble drug nanoparticles by controllable mixing devices, such as confined impinging jets mixer(CIJM), multi-inlet vortex mixer(MIVM) and many other microfluidic mixer systems. The formation mechanisms and processes of drug nanoparticles by FNP are described in detail. Then, the controlling of supersaturation level and mixing rate during the FNP process to tailor the ultrafine drug nanoparticles as well as the influence of drugs, solvent, anti-solvent, stabilizers and temperature on the fabrication are discussed. The ultrafine and uniform nanoparticles of poorly watersoluble drug nanoparticles prepared by CIJM, MIVM and microfluidic mixer systems are reviewed briefly. We believe that the application of microfluidic mixing devices in laboratory with continuous process control and good reproducibility will be benefit for industrial formulation scale-up.展开更多
Subject Code:E01 With the support from the National Natural Science Foundation of China,significant progress has been made in developing maraging steels with high performances by the research group led by Prof.LV Zhao...Subject Code:E01 With the support from the National Natural Science Foundation of China,significant progress has been made in developing maraging steels with high performances by the research group led by Prof.LV Zhaoping(吕昭平)from the State Key Laboratory for Advanced Metals and Materials,University展开更多
Thermoelectric(TE)performance of polycrystalline stannous selenide(SnSe)has been remarkably promoted by the strategies of energy band,defect engineering,etc.However,due to the intrinsic insufficiencies of phonon scatt...Thermoelectric(TE)performance of polycrystalline stannous selenide(SnSe)has been remarkably promoted by the strategies of energy band,defect engineering,etc.However,due to the intrinsic insufficiencies of phonon scattering and carrier concentration,it is hard to simultaneously realize the regulations of electrical and thermal transport properties by one simple approach.Herein,we develop Cu and Ce co-doping strategy that can not only greatly reduce lattice thermal conductivity but also improve the electrical transport properties.In this strategy,the incorporated Cu and Ce atoms could induce high-density SnSe_(2) nanoprecipitation arrays on the surface of SnSe microplate,and produce dopant atom point defects and dislocations in its interior,which form multi-scale phonon scattering synergy,thereby presenting an ultralow thermal conductivity of 0.275 W·m^(−1)·K^(−1) at 786 K.Meanwhile,density functional theory(DFT)calculations,carrier concentration,and mobility testing reveal that more extra hole carriers and lower conducting carrier scattering generate after Cu and Ce co-doping,thereby improving the electrical conductivity.The co-doped Sn_(0.98)Cu_(0.01)Ce_(0.01)Se bulk exhibits an excellent ZT value up to~1.2 at 786 K and a high average ZT value of 0.67 from 300 to 786 K.This work provides a simple and convenient strategy of enhancing the TE performance of polycrystalline SnSe.展开更多
Lipid-based nanostructures have garnered considerable interests over the last two decades,and have achieved tremendous clinical success including thefirst clinical approval of a liposome(Doxil)for cancer therapy in 199...Lipid-based nanostructures have garnered considerable interests over the last two decades,and have achieved tremendous clinical success including thefirst clinical approval of a liposome(Doxil)for cancer therapy in 1995 and the recent COVID-19 mRNA lipid nanoparticle vaccines.Compared to liposomes which have a lipid bilayer surrounding an aqueous core,lipid nanoparticles with a particle structure have several attractive advantages for encapsulating poorly water-soluble drugs such as better stability due to the particle structure,high drug encapsulation efficiency because of a pre-or co-drug-loading strategy.While many studies have reported the synthesis of lipid nanoparticles for hydrophobic drug encapsulation,the pre-cise control of drug loading and encapsulation efficiency remains a significant challenge.This work reports a new concentration-controlled nanoprecipitation plat-form technology for fabricating lipid nanoparticles with tunable drug loading up to 70 wt%.This method is applicable for encapsulating a wide range of drugs from very hydrophobic to slightly hydrophilic.Using this facile method,nanoparticles with tunable drug loading exhibited excellent properties such as small particle size,narrow size distribution,good particle stability,showing great promise for future drug delivery applications.展开更多
Increasing drug loading remains a critical challenge in the development and translation of nanomedicine.High drug-loading nanoparticles have demonstrated unique advantages such as less carrier material used,better-con...Increasing drug loading remains a critical challenge in the development and translation of nanomedicine.High drug-loading nanoparticles have demonstrated unique advantages such as less carrier material used,better-controlled drug release,and improved efficacy and safety.Herein,we report a simple and efficient salt concentration screening method for making polymer nanoparticles with exceptionally high drug loading(up to 66.5 wt%)based on phase separation-induced nanoprecipitation.Upon addition of salt,phase separation occurs in a miscible solvent-water solution delaying the precipitation time of drugs and polymers to different extents,facilitating their co-precipitation thus the formation of high drug-loading nanoparticles with high encapsulation efficiency(>90%)and excellent stability(>1 month).This technology is versatile and easy to be adapted to various hydrophobic drugs,different polymers,and solvents.This salt-induced nanoprecipitation strategy offers a novel approach to fabricating polymer nanoparticles with tunable drug loading,and opens great potentials for future nanomedicines.展开更多
Controllable profragrance nanoparticles are in great demand for long-lasting scent in flavor and fragrance industries.However,the practical applications of controllable fragrance release are limited by the non-tunable...Controllable profragrance nanoparticles are in great demand for long-lasting scent in flavor and fragrance industries.However,the practical applications of controllable fragrance release are limited by the non-tunable size,structural heterogeneity and poor reproducibility.Herein,a coumarin-derived phototrigger(CM-OH)is covalently conjugated with alcohol fragrances to obtain the corresponding profragrances(CM-R)which enable to release fragrances under the light controlling conditions.Furthermore,we introduce a new engineering strategy to construct fine tunable and highly uniform profragrance nanoparticles with flash nanoprecipitation(FNP)technology,which features commercial available amphiphilic pluronic F127 polymers by encapsulation of photoactivatable profragrances CM-R in hydrophobic cores to enhance the long-lasting photo-controllable fragrance release.With the assistance of FNP technology,amphiphilic pluronic polymer and profragrances CM-R in organic solution are instantaneously mixed and subsequently precipitated in the multi-inlet vortex mixer(MIVM),thus obtaining the pluronic F127-encapsulated profragrance nanoparticles with good homogeneity.Compared to the traditional thermodynamic encapsulation method,the novel kinetic FNP technology can not only tune the size of profragrance nanoparticles with narrow distribution,but also distinctly improve the batch-to-batch reproducibility,which affords an alternative method for scale-up preparation of amphiphilic profragrance nanoparticles in precisely controllable fragrance delivery system.展开更多
The primary aim of the study was to prepare narrow sized polymeric nanoparticles by implementing few modifications to the conventional nanoprecipitation technique and to evaluate the effect of various process paramete...The primary aim of the study was to prepare narrow sized polymeric nanoparticles by implementing few modifications to the conventional nanoprecipitation technique and to evaluate the effect of various process parameters on prepared polymeric nanoparticles.Eudragit E 100 nanoparticles were prepared by modified nanoprecipitation technique and step-by-step optimization was carried out to evaluate the effect of various process parameters such as organic solvent,polymer concentration,percentage of organic solvent,mode of addition of organic solvent in to aqueous phase,volume of aqueous phase,poloxamer 188 concentration,β-cyclodextrin concentration,temperature generated during sonication process,sonication duration,and drug concentration on the particle size,surface area,distribution width and uniformity of the prepared nanoparticles.The optimized process parameters were implemented to fabricate dual drug loaded Eudragit E 100 nanoparticles which were spherical in shape with mean particle size in the range of 118 to 140 nm,polydispersity index in the range of 0.187 to 0.254 and zeta potential in the range of 16.6 to 28.8 mV.Thus developed modified nanoprecipitation method can be used to fabricate narrow sized polymeric nanoparticles.展开更多
A novel Nb–V–Ce multi-microalloyed low-alloy cast steel for offshore platform nodes was investigated to achieve the properties similar to X80 pipeline steel,including high yield strength and low-temperature impact e...A novel Nb–V–Ce multi-microalloyed low-alloy cast steel for offshore platform nodes was investigated to achieve the properties similar to X80 pipeline steel,including high yield strength and low-temperature impact energy.The experimental results demonstrate that the addition of elements such as Nb,V and Ce can markedly improve the strength of the low-alloy cast steel.Maintaining a constant level of elements such as Nb,V and Ce,while reducing the content of Si to 0.28 wt.%,leads to substantial enhancements in impact energy at−40℃,meeting the mechanical properties criteria of X80 pipeline steel.The excellent mechanical properties of the multi-microalloyed low-alloy cast steel result from the reason that the multi-addition of microalloying elements refines the grains and facilitates the formation of nanoprecipitates like NbC.Moreover,decreasing Si content can enhance the recovery of martensitic laths in cast steel during the tempering process,reducing stress from dislocation movement and improving plasticity.展开更多
The strength improvement in the heat-treatable Al-Zn-Mg-Cu alloys is generally achieved by increasing the volume fraction of nanoprecipitates and reducing the grain size.However,utilizing one of them usu-ally leads to...The strength improvement in the heat-treatable Al-Zn-Mg-Cu alloys is generally achieved by increasing the volume fraction of nanoprecipitates and reducing the grain size.However,utilizing one of them usu-ally leads to a drastic decrease in ductility.Herein,we architect a hierarchical microstructure integrating bimodal grain structures,nanoprecipitates,and hard-brittle coarse particles wrapped by ductility coarse grain(CG)bands via conventional cold rolling(CR)deformation and heat treatment methods to break the strength-ductility dilemma in the Al-8.89Zn-1.98Mg-2.06Cu-0.12Zr-0.05Sc-0.05Hf(wt.%)alloy.The results reveal that the coupling of high-volume fraction(∼1.2%)nanoprecipitates,∼52%narrow CG bands,and most coarse particles encapsulated by CG bands contribute to the 45%CR sample with outstanding over-all mechanical properties(a tensile strength of 655 MPa,a yield strength of 620 MPa,and an elongation of 15.5%).Microstructure-based strength analysis confirms that the high strength relates to a trade-offbetween the hierarchical features,namely high-volume fraction nanoprecipitates to counterbalance the strength loss caused by grain coarsening.The excellent ductility is due to the introduction of medium CG content with a narrow width that can trigger a cross-scale strain distribution during plastic deforma-tion,suppressing the catastrophic failure in the fine grain(FG)regions and facilitating the dimple fracture along the CG bands.This study proposes a feasible approach for tailoring hierarchical microstructures in Al-Zn-Mg-Cu alloys to achieve a superior strength-ductility combination.展开更多
This study reports the response of helium(He)ion irradiation on binary-phase structured alloy V_(34)Ti_(25)Cr_(10)Ni_(30)Pd1.The alloy consists of a VCr matrix with nano-sized TiNi precipitates and a B2 TiNi matrix wi...This study reports the response of helium(He)ion irradiation on binary-phase structured alloy V_(34)Ti_(25)Cr_(10)Ni_(30)Pd1.The alloy consists of a VCr matrix with nano-sized TiNi precipitates and a B2 TiNi matrix with nano-sized VCr precipitates.VCr is chemical-disordered and TiNi has a B2-ordered structure.The alloy was subjected to 400 keV He ion irradiation with a fluence of 1×10^(17)ions cm^(−2)at 450℃.The results show He bubbles within the chemical-disordered VCr matrix exhibit a near-spherical shape with a smaller size and higher density compared to that in chemical-ordered TiNi phase with a larger size,lower density,and faceted shape.This indicates the chemical-disordered VCr phase effectively suppresses He accumulation compared to the B2-ordered TiNi phase,emphasizing the dominance of chemical struc-tures in He bubble formation.The calculation of density functional theory(DFT)shows that Ti and Ni have lower vacancy formation energy than that of V and Cr,respectively,which results in the increased vacancy production in TiNi.Consequently,He bubbles in TiNi have a larger bubble size consistent with experimental observations of radiation-induced Ni segregation.These findings elucidate the roles of or-dered and disordered chemical structures in He bubble evolution,offering insights for the development of gas ion irradiation-resistant materials.展开更多
The heterogeneity ofα-Al(Fe,Mn)Si dispersoids andβ″precipitates was tuned to enhance the strength−ductility synergy of air-cooled Al−Mg−Si alloys.Scanning electron microscopy(SEM)and transmission electron microscop...The heterogeneity ofα-Al(Fe,Mn)Si dispersoids andβ″precipitates was tuned to enhance the strength−ductility synergy of air-cooled Al−Mg−Si alloys.Scanning electron microscopy(SEM)and transmission electron microscopy(TEM)were employed to elucidate the microstructural parameters of these two strengthening phases.The results show that the microstructural heterogeneity can be triggered by the absence of homogenization,resulting in the presence of dispersoid-free zones(DFZs)and dispersoid zones(DZs),in conjunction with bimodalβ″precipitates.Further analytical calculations,from the strengthening model,clarify that the strategically dispersedα-Al(Fe,Mn)Si andβ″particles create“soft”and“hard”domains within the alloy,resultantly improving the mechanical properties.展开更多
The aim of this study was to develop and characterize methotrexate-loaded polymeric nanoparticles by nanoprecipitation technique.Eudragit■S 100 and ethyl cellulose were employed to develop methotrexate-loaded nanopar...The aim of this study was to develop and characterize methotrexate-loaded polymeric nanoparticles by nanoprecipitation technique.Eudragit■S 100 and ethyl cellulose were employed to develop methotrexate-loaded nanoparticles by nanoprecipitation technique.Six different formulations(f1,f2,f3,f4,f5 and f6)were prepared with each polymer by varying the drug to polymer ratios(1:1,1:1.5,1:2,1:3,1.5:1 and 2:1).Dimethyl sulfoxide(DMSO)was used as a solvent and Tween■20 as a surfactant.Among the six formulations of polymeric nanoparticles prepared by nanoprecipitation technique,F4 formulation was considered as a best formulation with each polymer.Based on comparison results of mean particle diameter,zeta potential,drug content and entrapment efficiency,Eudragit■S 100 was considered to be the most suitable polymer for preparation of methotrexate-loaded nanoparticles by nanoprecipitation technique.Based upon the evaluation studies,the best formulation was characterized for scanning electron microscopy(SEM),particle size,zeta potential and anti-cancer activity in MCF-7 cell line by MTT assay.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12275154)the Guangdong Basic and Applied Basic Research Foundation,China(Project No.2021B1515140028)+1 种基金the Youth Innovation Promotion Association,CAS(No.2020010)the National Key Research and Development Program of China,grant number(Nos.2021YFA1600701 and 2021YFB3501201).
文摘Solid-state precipitation is an effective strategy for tuning the mechanical and functional properties of ad-vanced alloys.Structure design and modification necessitate good knowledge of the kinetic evolution of precipitates during fabrication,which is strongly correlated with defect concentration.For Fe-Ga alloys,giant magnetostriction can be induced by the precipitation of the nanoscale tetragonal L60 phase.By introducing quenched-in vacancies,we significantly enhance the magnetostriction of the aged Fe81Ga19 polycrystalline alloys to~305 ppm,which is close to the level of single crystals.Although vacancies were found to facilitate the generation of the L60 phase,their impact on the precipitation mechanism and kinetics has yet to be revealed.This study combined transmission electron microscopy(TEM)and time-resolved small-angle neutron scattering(SANS)to investigate the precipitation of the L60 phase during the isothermal aging at 350 and 400℃,respectively.The evolution of L60 nanophase in morphology and number density in as-cast(AC)and liquid nitrogen quenched(LN)Fe81Ga19 alloys with aging time were quantitatively compared.Interestingly,the nucleation of the L60 phase proceeds progressively in AC while suddenly in LN specimens,indicating the homogenous to heterogeneous mechanism switching in-duced by concentrated vacancies.Moreover,excess vacancies can change the shape of nanoprecipitates and significantly accelerate the growth and coarsening kinetics.The magnetostrictive coefficient is opti-mized when the size(long-axis)of L60 precipitates lies between 100 and 110Åwith a number density between 3.2-4.3×10-7Å-3.Insight from this study validates the feasibility of achieving high magnetoe-lastic properties through precise manipulation of the nanostructure.
基金The authors would like to acknowledge experimental help and invaluable discussions from Shanzi Yu,Xianglong Li,Zhongliang Shu,Shichao Liu,Ruifeng Xu,Pengda Niu,Dan Li,Rou Ding,Min Liu,Haoyang Li,and Taomei Zhang.The authors would also like to acknowledge the financial support from the Natural science foundation of China(No.52271046,No.52171052)the Natural Science Foundation of Hunan Province,China(No.2022JJ20061,No.2023JJ30684)+4 种基金the Key R&D Program of Guangdong Province,China(No.2019B010943001)the Transformation and Industrializa-tion Plan of Scientific and Technological Achievements of Hunan Province,China(No.2020GK2031)the National Natural Science Foundation of China(No.52171052)the funding from State Key Laboratory of Powder Metallurgy,Central South Universitythe Fundamental Research Funds for the Central Universities of Central South University.
文摘Eutectic high-entropy alloys,composed of FCC/B2 phases with a narrow solidification interval and excel-lent fluidity,have become a new hotspot in additive manufacturing.Nevertheless,their microstructures exhibit significant sensitivity to processing parameters,feedstocks,and composition,ultimately limiting the alloys’engineering applications.Here,a hypereutectic Al_(0.7)CoCrFeNi_(2.4)alloy with a low cracking sus-ceptibility index was designed by Thermo-Calc calculation and fabricated by laser powder bed fusion.Results show that the as-printed Al_(0.7)CoCrFeNi_(2.4)alloy manifests a stable cellular structure,coupled with appreciable ultimate tensile strength(≥1200 MPa)and ductility(≥20%)over a wide range of process-ing parameters.After aging at 800℃for 30 min,outstanding strength(1500 MPa)and elongation(15%)were obtained.Considerable mechanical properties after aging stem from a triple strengthening mecha-nism,i.e.,L1_(2) nanoprecipitates and rod-shaped B2 particles within the FCC matrix,along with Cr-enriched spherical nanoparticles in the B2 phase.Meanwhile,hierarchical structure,i.e.,FCC dominated matrix,a discontinuous B2 phase,a precipitation-free zone in the B2 phase,and a K-S orientation relationship be-tween FCC and B2,facilitate to maintain excellent plasticity.These results guide designing HEAs by AM with controllable microstructures and outstanding mechanical properties for industrial applications.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.52061160483 and 92166130)the Hubei Science Fund for Distinguished Young Scholars(No.2020CFA086).The authors are also grateful to the Analytical and Testing Center,Huazhong University of Science and Technology for technical assistance.
文摘Additive manufacturing of aluminum alloys has received significant attention in the aerospace industry;however,achieving sufficient high strength,especially at elevated temperatures,remains challenging.Here,a crack-free and near-full dense Al-1Fe-0.6Cu-1.3Zr alloy was fabricated by the laser powder bed fusion(LPBF)technique.The Al-Fe-Cu-Zr alloy exhibits heterogeneous microstructures with two distinct zones.One is the so-called coarse-grain zones(CGZs)with an average grain size of 0.95μm,where(Al,Cu)Fe_(3) nanoparticles precipitate in the Al matrix and Fe and Cu cosegregate at the grain boundaries(GBs).The other is fine-grain zones(FGZs)with an average grain size of 0.45μm,where an Al 3 Zr nanoparti-cle precipitates in each of theα-Al grains(serves as the nuclei),and Fe-rich nanoprecipitates and Fe/Cu cosegregation appear at the GBs.As a result,the LPBF Al-Fe-Cu-Zr alloy,with these unique heteroge-neous structures,displays high strength at both room temperature and elevated temperatures,e.g.,with high yield strengths of 500 MPa at room temperature,and 163 MPa at 573 K,both are higher than those of additive manufactured Al-based alloys reported thus far.It is suggested that the high strength over a wide temperature range of the current LPBF Al alloy is mainly attributed to the combination of the precipitation strengthening mechanism and grain-boundary strengthening mechanism.
基金financially supported in part by the National Natural Science Foundation of China(Nos.21775018,21675022)the Natural Science Foundation of Jiangsu Province(Nos.BK20160028,BK20170084)+1 种基金the Open Funds of the State Key Laboratory of Electroanalytical Chemistry(No.SKLEAC201909)the Fundamental Research Funds for the Central Universities。
文摘As an emerging 2D conjugated material,graphitic carbon nitride(CN) has attracted great research attention as important catalytic medium for transforming solar energy.Nanostructure modulation of CN is an effective way to improve catalytic activities and has been extensively investigated,but remains challenging due to complex processes,time consuming or low yield.Here,taking advantage of recent discovered good solvents for CN,a nanoprecipitation approach using poor solvents is proposed for preparation of CN nanoparticles(CN NPs).With simple processes of CN dissolution and precipitation,we can quickly synthesize CN NPs(^40 nm) with a yield of up to 50%,the highest one to the best of our knowledge.As an example of potential applications,the as-prepared CN NPs were applied to photocatalytic degradation of dyes with an evident boosted performance up to 2.5 times.This work would open a new way for batch preparation of nanostructured CN and pave its large-scale industrial applications.
基金financially supported by the National Natural Science Foundation of China(No.21544005)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.15KJB430034)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Nanoparticles have been given considerable attention and applied in many fields because of their properties that are superior to and more distinct than those of conventional materials. In practice, a stable and reproducible manufacturing process is highly desirable. This review presents the flash nanoprecipitation, a new technique that can rapidly produce nanoparticles. Moreover, the mixing process, the mechanism of particle formation, and the mixer design are discussed.Furthermore, the factors controlling the size stability of the produced nanoparticles are summarised in this review.
基金financial support from the Xiongan Science and Technology Innovation Talent Project of MOST,China(No.2022XACX0500)the State Key Research and Development Program of MOST,China(No.2021YFB3702400).
文摘High-strength Fe-Mn-Al-C-Ni low-density steels are highly desirable in lightweight transportation,safe infrastructure,and advanced energy applications.However,these steels generally suffer from limited ductility owing to the formation of coarse B2 particles at grain boundaries.In this study,we proposed a strategy to introduce copious intragranular B2 nanoprecipitates within fully-recrystallized fine austenitic grains in a Fe-26Mn-11Al-0.9C-5Ni ultralight steel by a simple cold rolling and annealing process.Compared with steel where B2 particles are mainly distributed at grain boundaries,the yield strength and ultimate tensile strength of this steel increased from 768 MPa and 1100 MPa to 954 MPa and 1337 MPa,respectively,whereas the total elongation increased from 38%to 50%.The higher yield strength was primarily due to the synergistic strengthening effect of intragranular B2 nanoprecipitates and grain refinement.The excellent ductility and sustained work hardening were mainly attributed to the strong dislocation storage capability mediated by the intragranular B2 nanoprecipitates and the greater dynamic slip band refinement strengthening effect.Hence,the achievement of copious intragranular B2 nanoprecipitation in fully recrystallized ultralight steel offers an effective pathway for developing lightweight materials with high strength and large ductility.
基金National Natural Science Foundation of China,Grant/Award Number:21902117Natural Science Foundation of Tianjin,Grant/Award Number:20JCQNJC01110。
文摘Engineered nanoparticles have emerged as new types of materials for a wide range of applications from therapeutics to energy.Still,fabricating nanomaterials presenting complex inner morphologies and shapes in a simple manner remains a great challenge.Herein,we report the template-free one-pot continuous gradient nanoprecipitation of different types of non-compatible polymers to spontaneously form nanostructured particles.The continuous addition of antisolvent induces precipitation and(re)organization of polymer chains at the forming particle interface,ultimately and naturally developing complex inner morphologies and shapes while particle grows.This low-energy-cost bottom-up assembly approach applies to various functional polymers,possibly embedded with metal nanoparticles,for continuous growth into well-organized nanoparticles.UV crosslinking of the particles and core removal allows both confirming the building process and leading to hollow or multivoid nanomaterials.
基金funded by the Youth Fund Project of GRINM(No.66922309)the National Natural Science Foundation of China(No.52301220)。
文摘The equimolar NbZrTi medium-entropy alloy(MEA)has attracted attention due to its excellent comprehensive mechanical properties.In this study,the designed body-centered cubic NbZrTiAl_(4)(atomic percent,at%)MEA by Al addition,having a superplastic extensibility of~5000%under cold rolling,enables directly fabricated ultrathin foils with a thickness down to~0.2 mm without any treatments.Particularly,the annealed NbZrTiAl_(4) MEA foils,containing a coherent nanoscale B2,exhibit an ultrahigh yield strength of up to~1130 MPa,which even surpasses the bulk counterpart,while maintaining a good fracture elongation of up to~14%.The Al addition induced a stronger solid solution strengthening and fine-grain strengthening in the foils.Complex dislocation interactions and dislocation–B2 interactions promoted a dynamical formation of dislocation bands,which yielded work-hardening ability and tensile ductility.These findings provide a novel strategy for the design of ultrathin refractory medium-entropy foils to break through their performance limits at ultrahigh temperatures and guide the design of high-performance lightweight foils for structural applications.
基金supported by Research Committee of University of Macao (MYRG2017-00200-ICMS)Macao Science and Technology Development Fund (FDCT 0013/2018/A1)
文摘Nanoparticles are considered to be a powerful approach for the delivery of poorly watersoluble drugs. One of the main challenges is developing an appropriate method for preparation of drug nanoparticles. As a simple, rapid and scalable method, the flash nanoprecipitation(FNP) has been widely used to fabricate these drug nanoparticles, including pure drug nanocrystals, polymeric micelles,polymeric nanoparticles, solid lipid nanoparticles, and polyelectrolyte complexes. This review introduces the application of FNP to produce poorly water-soluble drug nanoparticles by controllable mixing devices, such as confined impinging jets mixer(CIJM), multi-inlet vortex mixer(MIVM) and many other microfluidic mixer systems. The formation mechanisms and processes of drug nanoparticles by FNP are described in detail. Then, the controlling of supersaturation level and mixing rate during the FNP process to tailor the ultrafine drug nanoparticles as well as the influence of drugs, solvent, anti-solvent, stabilizers and temperature on the fabrication are discussed. The ultrafine and uniform nanoparticles of poorly watersoluble drug nanoparticles prepared by CIJM, MIVM and microfluidic mixer systems are reviewed briefly. We believe that the application of microfluidic mixing devices in laboratory with continuous process control and good reproducibility will be benefit for industrial formulation scale-up.
文摘Subject Code:E01 With the support from the National Natural Science Foundation of China,significant progress has been made in developing maraging steels with high performances by the research group led by Prof.LV Zhaoping(吕昭平)from the State Key Laboratory for Advanced Metals and Materials,University
基金support of the National Natural Science Foundation of China(Grant Nos.51702193 and 51502165)the Natural Science Basic Research Program of Shaanxi(Grant No.2022JM-202)+3 种基金the Shaanxi Provincial Education Department Serves Local Scientific Research Plan(Grant No.20JC008)the General Project in Industrial Area of Shaanxi Province(Grant No.2020GY281)the Natural Science Foundation of Shaanxi Provincial Department of Education(Grant No.20JK0525)the Scientific Research Fund of Shaanxi University of Science&Technology(Grant Nos.BJ16-20 and BJ16-21).
文摘Thermoelectric(TE)performance of polycrystalline stannous selenide(SnSe)has been remarkably promoted by the strategies of energy band,defect engineering,etc.However,due to the intrinsic insufficiencies of phonon scattering and carrier concentration,it is hard to simultaneously realize the regulations of electrical and thermal transport properties by one simple approach.Herein,we develop Cu and Ce co-doping strategy that can not only greatly reduce lattice thermal conductivity but also improve the electrical transport properties.In this strategy,the incorporated Cu and Ce atoms could induce high-density SnSe_(2) nanoprecipitation arrays on the surface of SnSe microplate,and produce dopant atom point defects and dislocations in its interior,which form multi-scale phonon scattering synergy,thereby presenting an ultralow thermal conductivity of 0.275 W·m^(−1)·K^(−1) at 786 K.Meanwhile,density functional theory(DFT)calculations,carrier concentration,and mobility testing reveal that more extra hole carriers and lower conducting carrier scattering generate after Cu and Ce co-doping,thereby improving the electrical conductivity.The co-doped Sn_(0.98)Cu_(0.01)Ce_(0.01)Se bulk exhibits an excellent ZT value up to~1.2 at 786 K and a high average ZT value of 0.67 from 300 to 786 K.This work provides a simple and convenient strategy of enhancing the TE performance of polycrystalline SnSe.
基金Australian Research Council Projects,Grant/Award Number:DP200101238Australian National Health and Medical Research Council projects of Australia,Grant/Award Number:APP2008698+1 种基金Australian Research Council Discovery Early Career Researcher Award,Grant/Award Number:DE230101044Australian Government Research Training Program Scholarships。
文摘Lipid-based nanostructures have garnered considerable interests over the last two decades,and have achieved tremendous clinical success including thefirst clinical approval of a liposome(Doxil)for cancer therapy in 1995 and the recent COVID-19 mRNA lipid nanoparticle vaccines.Compared to liposomes which have a lipid bilayer surrounding an aqueous core,lipid nanoparticles with a particle structure have several attractive advantages for encapsulating poorly water-soluble drugs such as better stability due to the particle structure,high drug encapsulation efficiency because of a pre-or co-drug-loading strategy.While many studies have reported the synthesis of lipid nanoparticles for hydrophobic drug encapsulation,the pre-cise control of drug loading and encapsulation efficiency remains a significant challenge.This work reports a new concentration-controlled nanoprecipitation plat-form technology for fabricating lipid nanoparticles with tunable drug loading up to 70 wt%.This method is applicable for encapsulating a wide range of drugs from very hydrophobic to slightly hydrophilic.Using this facile method,nanoparticles with tunable drug loading exhibited excellent properties such as small particle size,narrow size distribution,good particle stability,showing great promise for future drug delivery applications.
基金Australian Research Council,Grant/Award Number:DP200101238National Health and Medical Research Council projects of Australia,Grant/Award Number:APP2008698。
文摘Increasing drug loading remains a critical challenge in the development and translation of nanomedicine.High drug-loading nanoparticles have demonstrated unique advantages such as less carrier material used,better-controlled drug release,and improved efficacy and safety.Herein,we report a simple and efficient salt concentration screening method for making polymer nanoparticles with exceptionally high drug loading(up to 66.5 wt%)based on phase separation-induced nanoprecipitation.Upon addition of salt,phase separation occurs in a miscible solvent-water solution delaying the precipitation time of drugs and polymers to different extents,facilitating their co-precipitation thus the formation of high drug-loading nanoparticles with high encapsulation efficiency(>90%)and excellent stability(>1 month).This technology is versatile and easy to be adapted to various hydrophobic drugs,different polymers,and solvents.This salt-induced nanoprecipitation strategy offers a novel approach to fabricating polymer nanoparticles with tunable drug loading,and opens great potentials for future nanomedicines.
基金support provided by National Key Research and Development Program(2016YFA0200300)NSFC Science Center Program(21788102)+3 种基金Creative Research Groups(21421004)NSFC/China(21636002 and 21622602)Shanghai Municipal Science and Technology Major Project(2018SHZDZX03)Program of Introducing Talents of Discipline to Universities(B16017).
文摘Controllable profragrance nanoparticles are in great demand for long-lasting scent in flavor and fragrance industries.However,the practical applications of controllable fragrance release are limited by the non-tunable size,structural heterogeneity and poor reproducibility.Herein,a coumarin-derived phototrigger(CM-OH)is covalently conjugated with alcohol fragrances to obtain the corresponding profragrances(CM-R)which enable to release fragrances under the light controlling conditions.Furthermore,we introduce a new engineering strategy to construct fine tunable and highly uniform profragrance nanoparticles with flash nanoprecipitation(FNP)technology,which features commercial available amphiphilic pluronic F127 polymers by encapsulation of photoactivatable profragrances CM-R in hydrophobic cores to enhance the long-lasting photo-controllable fragrance release.With the assistance of FNP technology,amphiphilic pluronic polymer and profragrances CM-R in organic solution are instantaneously mixed and subsequently precipitated in the multi-inlet vortex mixer(MIVM),thus obtaining the pluronic F127-encapsulated profragrance nanoparticles with good homogeneity.Compared to the traditional thermodynamic encapsulation method,the novel kinetic FNP technology can not only tune the size of profragrance nanoparticles with narrow distribution,but also distinctly improve the batch-to-batch reproducibility,which affords an alternative method for scale-up preparation of amphiphilic profragrance nanoparticles in precisely controllable fragrance delivery system.
文摘The primary aim of the study was to prepare narrow sized polymeric nanoparticles by implementing few modifications to the conventional nanoprecipitation technique and to evaluate the effect of various process parameters on prepared polymeric nanoparticles.Eudragit E 100 nanoparticles were prepared by modified nanoprecipitation technique and step-by-step optimization was carried out to evaluate the effect of various process parameters such as organic solvent,polymer concentration,percentage of organic solvent,mode of addition of organic solvent in to aqueous phase,volume of aqueous phase,poloxamer 188 concentration,β-cyclodextrin concentration,temperature generated during sonication process,sonication duration,and drug concentration on the particle size,surface area,distribution width and uniformity of the prepared nanoparticles.The optimized process parameters were implemented to fabricate dual drug loaded Eudragit E 100 nanoparticles which were spherical in shape with mean particle size in the range of 118 to 140 nm,polydispersity index in the range of 0.187 to 0.254 and zeta potential in the range of 16.6 to 28.8 mV.Thus developed modified nanoprecipitation method can be used to fabricate narrow sized polymeric nanoparticles.
基金supported by the National Natural Science Foundation of China(No.52071195)Key Project of the National Natural Science Foundation of China(No.52130109).
文摘A novel Nb–V–Ce multi-microalloyed low-alloy cast steel for offshore platform nodes was investigated to achieve the properties similar to X80 pipeline steel,including high yield strength and low-temperature impact energy.The experimental results demonstrate that the addition of elements such as Nb,V and Ce can markedly improve the strength of the low-alloy cast steel.Maintaining a constant level of elements such as Nb,V and Ce,while reducing the content of Si to 0.28 wt.%,leads to substantial enhancements in impact energy at−40℃,meeting the mechanical properties criteria of X80 pipeline steel.The excellent mechanical properties of the multi-microalloyed low-alloy cast steel result from the reason that the multi-addition of microalloying elements refines the grains and facilitates the formation of nanoprecipitates like NbC.Moreover,decreasing Si content can enhance the recovery of martensitic laths in cast steel during the tempering process,reducing stress from dislocation movement and improving plasticity.
基金supported by the Key Laboratory Fund of National Key Laboratory of Science and Technology on High-strength Structural Materials(Nos.412130024,623020031)the Pre-research Fund(No.412130024).
文摘The strength improvement in the heat-treatable Al-Zn-Mg-Cu alloys is generally achieved by increasing the volume fraction of nanoprecipitates and reducing the grain size.However,utilizing one of them usu-ally leads to a drastic decrease in ductility.Herein,we architect a hierarchical microstructure integrating bimodal grain structures,nanoprecipitates,and hard-brittle coarse particles wrapped by ductility coarse grain(CG)bands via conventional cold rolling(CR)deformation and heat treatment methods to break the strength-ductility dilemma in the Al-8.89Zn-1.98Mg-2.06Cu-0.12Zr-0.05Sc-0.05Hf(wt.%)alloy.The results reveal that the coupling of high-volume fraction(∼1.2%)nanoprecipitates,∼52%narrow CG bands,and most coarse particles encapsulated by CG bands contribute to the 45%CR sample with outstanding over-all mechanical properties(a tensile strength of 655 MPa,a yield strength of 620 MPa,and an elongation of 15.5%).Microstructure-based strength analysis confirms that the high strength relates to a trade-offbetween the hierarchical features,namely high-volume fraction nanoprecipitates to counterbalance the strength loss caused by grain coarsening.The excellent ductility is due to the introduction of medium CG content with a narrow width that can trigger a cross-scale strain distribution during plastic deforma-tion,suppressing the catastrophic failure in the fine grain(FG)regions and facilitating the dimple fracture along the CG bands.This study proposes a feasible approach for tailoring hierarchical microstructures in Al-Zn-Mg-Cu alloys to achieve a superior strength-ductility combination.
基金supported by the National Magnetic Con-finement Fusion Energy Research Project from the Ministry of Science and Technology of China(No.2022YFE03030004 and 2019YFE03120003)the National Natural Science Foundation of China(No.12275010,12275176,12275001,12335017,11921006,U21B2082,U22B2064 and U20B2025)+3 种基金the Beijing Municipal Natural Science Foundation(No.1222023)the Shenzhen Science and Technology Program(No.RCYX20210609103904028)Engang Fu acknowledges the support from the Science Fund or Creative Research Groups of NSFC,the Ion Beam Materials Laboratory(IBML)and Electron Microscopy Laboratory(EML)the High-performance Computing Platform(HPC)at Peking University.Xing Liu acknowledges the discussion with Prof.Ning Gao and Dr.Yifan Zhang.
文摘This study reports the response of helium(He)ion irradiation on binary-phase structured alloy V_(34)Ti_(25)Cr_(10)Ni_(30)Pd1.The alloy consists of a VCr matrix with nano-sized TiNi precipitates and a B2 TiNi matrix with nano-sized VCr precipitates.VCr is chemical-disordered and TiNi has a B2-ordered structure.The alloy was subjected to 400 keV He ion irradiation with a fluence of 1×10^(17)ions cm^(−2)at 450℃.The results show He bubbles within the chemical-disordered VCr matrix exhibit a near-spherical shape with a smaller size and higher density compared to that in chemical-ordered TiNi phase with a larger size,lower density,and faceted shape.This indicates the chemical-disordered VCr phase effectively suppresses He accumulation compared to the B2-ordered TiNi phase,emphasizing the dominance of chemical struc-tures in He bubble formation.The calculation of density functional theory(DFT)shows that Ti and Ni have lower vacancy formation energy than that of V and Cr,respectively,which results in the increased vacancy production in TiNi.Consequently,He bubbles in TiNi have a larger bubble size consistent with experimental observations of radiation-induced Ni segregation.These findings elucidate the roles of or-dered and disordered chemical structures in He bubble evolution,offering insights for the development of gas ion irradiation-resistant materials.
基金supported by the National Natural Science Foundation of China(Nos.52301025,52371065,52301179)the Fundamental Research Program of Shanxi Province,China(Nos.202203021222039,202203021212124)。
文摘The heterogeneity ofα-Al(Fe,Mn)Si dispersoids andβ″precipitates was tuned to enhance the strength−ductility synergy of air-cooled Al−Mg−Si alloys.Scanning electron microscopy(SEM)and transmission electron microscopy(TEM)were employed to elucidate the microstructural parameters of these two strengthening phases.The results show that the microstructural heterogeneity can be triggered by the absence of homogenization,resulting in the presence of dispersoid-free zones(DFZs)and dispersoid zones(DZs),in conjunction with bimodalβ″precipitates.Further analytical calculations,from the strengthening model,clarify that the strategically dispersedα-Al(Fe,Mn)Si andβ″particles create“soft”and“hard”domains within the alloy,resultantly improving the mechanical properties.
文摘The aim of this study was to develop and characterize methotrexate-loaded polymeric nanoparticles by nanoprecipitation technique.Eudragit■S 100 and ethyl cellulose were employed to develop methotrexate-loaded nanoparticles by nanoprecipitation technique.Six different formulations(f1,f2,f3,f4,f5 and f6)were prepared with each polymer by varying the drug to polymer ratios(1:1,1:1.5,1:2,1:3,1.5:1 and 2:1).Dimethyl sulfoxide(DMSO)was used as a solvent and Tween■20 as a surfactant.Among the six formulations of polymeric nanoparticles prepared by nanoprecipitation technique,F4 formulation was considered as a best formulation with each polymer.Based on comparison results of mean particle diameter,zeta potential,drug content and entrapment efficiency,Eudragit■S 100 was considered to be the most suitable polymer for preparation of methotrexate-loaded nanoparticles by nanoprecipitation technique.Based upon the evaluation studies,the best formulation was characterized for scanning electron microscopy(SEM),particle size,zeta potential and anti-cancer activity in MCF-7 cell line by MTT assay.
