Nano Precipitation Research Articles

Introduction of Novel Drug Shipping Gadget Nanocapsule

Nano drugs are vesicular structures in which the medicine is contained in a hollow with an inner liquid middle and a polymeric membrane surrounding it . A Nano pill is nanoscale shall made from a secure polymer Nano pill consists of a thin membrane surrounding a middle (Liquid, stable) with their length starting from 10nm to one thousand nm. Nano capsules are submicroscopic colloidal drug provider structures composed of an oily or an aqueous middle surrounded via a skinny polymer membrane. The membrane can be composed of natural or artificial polymers. Kinds of polymers can be hired inside the manufacture of Nano tablets. 1) Polymers discovered in nature 2) Polymers that have been synthesized . a) Solvent evaporation b) Nano precipitation c) emulsification / Solvent diffusion d) Salting out e) Dialysis f) incredible vital fluid era are some of the strategies used to create nano pills. The nanometric length of Nano capsule may be exciting for many programs like cosmetics, perfumes or pharmaceutical industries. this text is an prolonged overview of these Nanocapsule technologies and their applications for the remedy of diverse diseases. The Nanocapsule is used in various fields for drug transport in case of tumors, as a Nano capsule Bandages to combat infection, as a liposomal Nanocapsule in meals technology and Agriculture, in turning in radio remedy and as a self-recovery material. Nano capsules are subjected to a diffusion of characterization and evaluation methods. To attain managed launch and efficient drug focused on, dispersed polymer nanocapsules can be employed as nano-sized drug providers. Nanocapsules variety in length from 10 nm to a thousand nm and are available in a selection of sizes. Nanocapsule is a Nanoparticle that is spherical, hole shape with a diameter much less than 200nm in which favored substance may be placed. They may be packed with a solvent, both polar or non polar.

Synergetic effect of in-situ TiB2 reinforcement and nano precipitation on wear behavior of ZE41 magnesium matrix composite

The rise in carbon dioxide pollution and energy consumption has increased the demand for lightweight materials such as magnesium in automotive and aerospace industries. However, magnesium alloys face challenges like poor wear resistance and mechanical strength. To overcome these limitations, a promising approach involves developing heterogeneous hybrid microstructures through reinforcement addition and microstructural engineering. This study focuses on the tribological performance of a newly developed in-situ sub-micron sized TiB2/ZE41 composite under various microstructural conditions, comparing it to the unreinforced ZE41 Mg alloy. Wear experiments were conducted using a pin-on-disc tribometer under normal loads of 10, 20, 40, and 60 N at a sliding velocity of 1 m/s. Scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) was used to analyze the worn surfaces in order to identify damage types and surface distortions. By correlating worn surface microstructures with test parameters, predominant wear mechanisms for each material condition under specific loads were determined. Results consistently showed that the presence of in-situ TiB2 reinforcements, β-phase, and rare-earth precipitates enhanced wear resistance regardless of the load conditions. Additionally, the study established a scientific understanding of the wear behavior of ZE41 Mg alloy, with and without in-situ TiB2 particles and precipitates, through analysis of dominant wear mechanisms, wear-induced subsurface deformation mechanisms, kernel average misorientation, grain orientation spread, and microhardness evaluation.

A molecular dynamics investigation of nano-twins and nano-precipitates effects in CoCrFeNi-based high-entropy alloys

Abstract This study systematically investigates the effects of twin boundaries and precipitates on the performance of CoCrFeNi HEAs matrix using molecular dynamics simulation methods. By constructing corresponding HEAs models and conducting simulations of their structural evolution and mechanical behavior at the nanoscale, the influence mechanisms of nanotwins (NTs) and nano-precipitates (NPs) on the mechanical properties of the material were explored through in-depth analysis of simulation results. The findings suggest that twin boundaries effectively impede the movement and slip of dislocations and stacking faults in the material. As a result, this enhances its mechanical properties and inhibits plastic deformation, ultimately improving its ductility. Meanwhile, precipitates also impact the material's performance, and the shape of precipitates may exert different effects on the material, while the phase interface between precipitates and the matrix can hinder the expansion of defects. The presence of twin boundaries can enhance the strengthening effect of precipitates, further improving the material's performance. This study provides a new perspective for understanding the relationship between the microstructure and mechanical properties of HEAs materials, offering important references for the design and optimization of HEAs materials.

A high-pressure strategy to refine and multiply nanoprecipitates for improved strength-ductility synergy in a medium-entropy FeCrNiTiAl alloy

Dispersion strengthening is one of the most effective methods to strengthen a metallic material. The strength of an aged alloy is largely affected by the precipitate size and number density of precipitates, which are often controlled by the change in temperature, time, and composition. Here we report a new high-pressure (HP) strategy for regulating the nanoprecipitates (NPs) in a Fe50Cr16Ni27Ti4Al3 medium-entropy alloy. Using a HP of 4 GPa largely refines the size of NPs from 15 to 4nm (due to the suppressed grain-growth rate) and increases the number density of NPs by two orders of magnitude (due to the increased nucleation rate). The decreased size and increased density of NPs lower the spacing distance of high-density dislocation walls and result in the formation of microbands during deformation, causing sustainable strain-hardening in the MEA, thereby improving both strength and ductility.

Additive manufacturing of high entropy shape memory alloy with outstanding properties through multi-remelting in-situ alloying

With the introduction of a fourth dimension, time, into 3D printing, 4D printing enables unparalleled control over spatial and temporal aspects of 3D products in respond to external stimuli. However, the recovery performance of the 4D printed shape memory alloys still falls short of expectations. In this study, a novel high entropy shape memory alloy (HESMEA) was developed using in-situ alloying laser powder bed fusion (LPBF) by introducing a moderate amount of silicon (10 % atomic percent) to a metastable Fe50Mn30Co10Cr10 HEA matrix. Multi-remelting strategy was employed to improve the chemical homogeneity of the printed HESMA with enhanced diffusion occurring during the remelt scan. The 3-remelting HESMA exhibited a near uniform chemical distribution, showcasing an excellent combination of shape memory performance and mechanical properties, with an admirable recoverable strain of 5.2 % and a high yield strength of about 500 MPa. It was found that the high recovery strain was attributed to low stacking fault energy of the HESMA matrix, while combination of refined grain size, high density dislocations and nano precipitation contributed to high yield strength of the HESMA. Overall, the solid solution matrix and hierarchical strengthening characteristics of the newly developed HESMA makes it particularly suitable for 4D printing with excellent comprehensive properties.

Formulation and Evaluation of Aprepitant Nanosuspension by Nano Precipitation Techniques

Objective: The majority of new chemical substances generated by the drug development process are poorly water-soluble or lipophilic. Formulation of a poorly water-soluble substance is a difficult task for the pharmaceutical industry. It is widely acknowledged that using nanosuspension in drug administration enhances the drug’s solubility, dissolution, and ultimately bioavailability. This study aimed to examine the particle sizes of nanosuspensions made by nanoprecipitation techniques and improve their effectiveness. Methods: Aprepitant’s nanosuspension has been produced by nanoprecipitation techniques. The particle size, polydispersity index, along zeta potential of the produced nanosuspensions were measured. The optimized nanosuspension has been investigated further for solubility, dissolution, surface morphology, FT-IR, DSC as well as stability studies. objective: The majority of new chemical substances generated by the drug development process are poorly water soluble or lipophilic. Formulation of a poorly water-soluble substance is a difficult task for the pharmaceutical industry. It is widely acknowledged that using nanosuspension in drug administration enhances the drug’s solubility, dissolution, and ultimately bioavailability. This study aimed to examine the particle sizes of nanosuspensions made by nano precipitation techniques and improve its effectiveness. Results: The combination of tween 80 and poloxamer 188 as stabilizer resulted in the preparation of an optimized nanosuspension (F9) with a particle size of 738 nm, polydispersity index 0.236, zeta potential -15.1 mV and an improved solubility and dissolution profile compared to pure drugs. Positive performance improvement was observed in the solubility and dissolution studies. The crystallinity changed upon nanosizing, as demonstrated by the SEM, FT-IR and DSC analysis. method: Aprepitant’s nanosuspension has been produced by nano precipitation techniques. The particle size, polydispersity index along with zeta potential of the produced nanosuspensions were measured. The optimized nanosuspension has been investigated further for solubility, dissolution, surface morphology, FT-IR, DSC as well as stability studies. Conclusion: The nanoprecipitation method was effective in producing a stable Aprepitant nanosuspension with improved solubility and dissolution rate.

Thermoelectric performance optimization of GeMnSbTe compounds through increasing the Mn solid solubility: Effects of the co-doping of rare earth elements

GeTe is a p-type thermoelectric (TE) material that exhibits a high ZT value and holds promise for a wide range of applications. In this study, a series of Ge0.86Mn0.1Sb0.04Te + 1 mol.% RE (Rare Earth elements = Er, Tm, Yb, Lu) compounds are synthesized through the melt-quenching method followed by fast-hot-pressing. Findings indicate that the TE properties are improved by simultaneously increasing the Seebeck coefficient and reducing the thermal conductivity, making the peak ZT value experiences an enhancement of 73%, while the average ZT value through 450–800 K shows an improvement of 70%. The solid solubility of Mn is significantly increased by the addition of the REs, that promotes the regulating effect of Mn on the energy band. A diverse range of microstructures including ordered atomic staggered arrays, van der Waals interstitials, dislocation enrichment, dislocation networks, nano precipitation phases with cavity structures, interstitial clusters, and vacancy clusters are introduced by REs, significantly contributing to the reduction of the κL. Thus, this study offers valuable insights and mechanism analysis into enhancing the properties of GeMnSbTe materials by incorporating REs, and proves that Tm has better thermoelectric performance optimization effect in this.

Formulation and Evaluation of Teneligliptin Nanosuspension

In this present study, the drug Teneligliptin is selected for the management of Type-2 Diabetes mellitus. The drug-excipient compatibility study results showed that there is no chemical change occur between the drug and the excipients and there was no functional group change observed. Teneligliptin is poorly water-soluble drug and it was fabricated as nanosuspension of Nine formulations by using nano precipitation technique. In this method, nano size particle size of Teneligliptin was obtained by using different type of various proportions of stabilizers along with other ingredient at different stirring speed. For the prepared formulation (F1-F9) the particle size, polydispersibility index and zeta potential were done. Among nine formulations, formulation 8(F8) results revealed that the values are desirable and stable. The total drug content of all the formulation ranges from 81% to 99%, The average particle size of F1 to F9 batches was found to be in the range of 0.211 nm to 0.486 nm The scanning electron microspore study stated that the nano size particles were spherical in shape. Among all the formulations (F8) was optimized which showed maximum highest percentage of drug release at 24 hours. The cumulative percentage of drug release of formulation 8 (F8) increase with the optimum concentration of stabilizers and tween 80. The release rate of optimized formulation 8(F8) was fitted with various release kinetic studies and the selected formulation followed zero order kinetics. The results of stability study was confirmed that the prepared Teneligliptin nanosuspension is stable during the stability study. Thus, it can be concluded that the nanosuspension method was commercially feasible and cost effective.

Research on microstructure and mechanical properties of hot extruded Mg-Gd-Y-Sm-Zr alloy at room and high temperatures

In this study, the age hardening behavior of hot extruded Mg-8Gd-4Y-1Sm-0.5Zr (GWS841) alloy, mechanical properties and microstructural evolution of hot extruded GWS841 alloy during elevated temperature tensile processes were mainly investigated. The results show that the hot extrusion aged GWS841 alloy possess excellent mechanical properties at room and high temperature, which are 397 MPa, 386 MPa, 376 MPa, and 312 MPa at 25 °C, 200 °C, 250 °C, and 300 °C, respectively. After aging for 200 °C × 96 h, the hot extruded GWS841 alloy reaches its maximum hardness and room temperature tensile strength, and strengthening precipitation phase, being nano β′ phase, approximately 12 nm × 20 nm in size, precipitates simultaneously in three prismatic planes, (1‾21‾0)α、 (1‾1‾20)α and (21‾1‾0)α planes, which present precipitation strengthening behavior. During tensile testing at 200 °C, the strengthening precipitate remains β′ phase. During elevated tensile processes at 250 °C and 300 °C, strengthening precipitation phase undergoes significant transformation at grain boundary, β′ phase → β phase, and additionally, nano precipitation zone formed by rare earth atoms aggregation along grain boundary, which strengthen the grain boundary. During elevated tensile deformation at 300 °C, β′ phase completely disappeared and transformed into nano rare earth atom cluster region uniformly distributing inner grain.

The Effect of Deformation Temperature on the Yield Stress of Ultrafine-Grained Al-Cu-Zr Alloy Containing Grain Boundary Nanoprecipitates

A theoretical model is suggested that describes the effect of deformation temperature on the yield stress of an ultrafine-grained (UFG) Al-Cu-Zr alloy structured with severe plastic deformation. Within the model, nanoprecipitates (NPs) of Al2Cu act as sources of lattice dislocations in the presence of a number of extrinsic grain-boundary dislocations (EGBDs) near the NPs. It is shown that the number of EGBDs near the NPs decreases with a drop in the deformation temperature that increases the yield stress of the Al-Cu-Zr alloy. The proposed model is in good quantitative agreement with available experimental results.

Atomistic insights into the synergistic effect of nanotwins and nano-precipitates on the mechanical behavior of superalloys

As one of the typical nanostructures, nanotwins (NTs) have been utilized to evade the trade-off between strength and ductility, which is also applicable to improve the mechanical properties of superalloys. However, the optimization capability of mechanical properties by tailoring NTs has encountered bottleneck for the reasons such as inverse Hall-Petch effect and anisotropic effect. Based on the experimental observation of a special distribution pattern of NTs and nano-precipitates (NPs) in superalloys, that is, NPs are located at the twin boundaries (TBs), our work aims to study the distinctive synergistic deformation mechanism between NTs and NPs, which could become a new microstructure design strategy to optimize the mechanical properties of superalloys. Specifically, molecular dynamic (MD) method was employed to unveil the synergistic deformation mechanism of NTs and NPs in a model Ni-based superalloy. As expected, the introduction of NPs onto TBs can inhibit dislocation motion along or parallel to TBs, despite the softening deformation mode of NTs is activated. Moreover, the existence of NPs onto TBs can greatly improve the strengthening efficiency of NTs by impeding twin thickening/thinning. On the other hand, both phase boundaries and NPs interior have obstructive effect on dislocation motion, which could also be beneficial for material strengthening. More interestingly, anti-phase boundary (APB) structure will form along with the dislocations cutting through NPs. Subsequently, the APB structure can act as channels for dislocation slip and dislocation nucleation site induced by a kind of TB confinement effect, which may effectively accommodate plastic deformation. Our research outcomes could be utilized to facilitate the development of high-performance superalloys via rational collaborative design of NTs and NPs.

Microstructure and Mechanical Behavior of Quaternary Eutectic α+θ+Q+Si Clusters in As-Cast Al-Mg-Si-Cu Alloys.

Cu additions notably strengthen Al-Mg-Si and Al-Si-Mg alloys due to the dense precipitation of quaternary nano precipitates during ageing. However, the chemical evolution and mechanical behaviors of the quaternary micro-scale Q constituent phase occurring in cast and homogenized states have rarely been studied. Meanwhile, there exists a type of AlCuMgSi cluster in the cast state, which has been regarded as Q particles. The accurate identification of phase constituents is the basis for the future design of alloys with better performance. In our work, this type of cluster was revealed to consist of α-Al, θ-Al2Cu, Q, and Si phases through micro-to-atomic scale studies using scanning and transmission electron microscopes. The skeleton of the dendrite was θ phase. The second phases in the dendritic eutectic cluster dissolved quickly during a 4 h homogenization at 550 °C. The Q phase was found to effectively absorb the Fe impurities during casting and homogenization. As a result, the formation of other harmful Fe-rich intermetallics was suppressed. These Q constituent particles were observed to break into separate pieces in an intermediately brittle manner when compressed in situ in a scanning electron microscope. These findings provide insights into the thermodynamic modeling of the Al-Mg-Si-Cu system and alloy design.

Effect of Coiling Temperature on Microstructure and Properties of Titanium Strengthened Weathering Building Steel

For weathering steel used in building, it is necessary not only to ensure weather resistance, but also to improve the strength and yield ratio. This study investigates the strengthening effect of Ti microalloying on the tested steel by conducting continuous cooling transformation tests of undercooled austenite and comparative tests of microstructure and performance at different coiling temperatures, with 0.07 wt.% Ti added to the weathering building test steel. The results show that, with an increase in cooling rate (0.1~50 °C/s), the room temperature microstructure of different cooling rates gradually transitions as follows: F + P, F + P + B, F + B and B + M; in addition, the hardness increases. Polygonal ferrite and pearlite were obtained by coiling at 650 °C; quasi-polygonal ferrite, acicular ferrite, pearlite and a small amount of bainite were obtained by coiling at 600 °C; and bainite was obtained by coiling at 550 °C. With a decrease in coiling temperature, the strength of the test steel increased, the yield ratio increased, the elongation after fracture decreased and the elongation at the yield point decreased. Compared with those observed at 650 °C, the nano precipitation phases observed in the sample at 600 °C were smaller in size, higher in number and higher in dislocation density. The combined action of second-phase precipitation strengthening and dislocation strengthening increased the strength and yield ratio of the test steel. This study will be helpful in guiding the improvement of strength grades for weathering steel used in building and industrial production.

Reduction-Hypersensitive Podophyllotoxin Prodrug Self-Assembled Nanoparticles for Cancer Treatment.

Podophyllotoxin (PPT) has shown strong antitumor effects on various types of cancers. However, the non-specific toxicity and poor solubility severely limits its clinical transformation. In order to overcome the adverse properties of PPT and explore its clinical potential, three novel PTT-fluorene methanol prodrugs linked by different lengths of disulfide bonds were designed and synthesized. Interestingly, the lengths of the disulfide bond affected the drug release, cytotoxicity, pharmacokinetic characteristics, in vivo biodistribution and antitumor efficacy of prodrug NPs. To be more specific, all three PPT prodrugs could self-assemble into uniform nanoparticles (NPs) with high drug loading (>40%) via the one-step nano precipitation method, which not only avoids the use of surfactants and cosurfactants, but also reduces the systemic toxicity of PPT and increases the tolerated dose. Among the three prodrug NPs, FAP NPs containing α-disulfide bond showed the most sensitive tumor-specific response and fastest drug release rate, thus demonstrating the strongest in vitro cytotoxicity. In addition, three prodrug NPs showed prolonged blood circulation and higher tumor accumulation. Finally, FAP NPs demonstrated the strongest in vivo antitumor activity. Our work will advance the pace of podophyllotoxin towards clinical cancer treatment.

Targeting self-enhanced ROS-responsive artesunatum prodrug nanoassembly potentiates gemcitabine activity by down-regulating CDA expression in cervical cancer

Prodrug self-delivery carriers with targeting that specifically responded to tumor microenvironments have good potential to improve the application dilemma of approved clinical therapeutic drugs (systemic distribution and side effects). It's noted the conversion of gemcitabine (GEM) to inactive ingredients under the action of cytidine deaminase (CDA) during metabolism in vivo limits its clinical effect. A high level of reactive oxygen species (ROS) results in a high level of oxidative stress in tumor cells, which changes the expression of CDA and optimizes the metabolism of GEM in vivo and overcome drug resistance. In this study, the ROS responsive and ROS self-supplied prodrug of artemisia (ART)-thioacetal bond (TK)-GEM was synthesized and self-vectors based on ART-TK-GEM (TK@FA NPs) was prepared by using nano precipitation. ROS responsive characteristics ensure specific release of prodrugs in tumor cells with high level of ROS thereby reducing side effects on normal cells and tissues. The endogenous ROS and newly generated ROS by ART can reduce the expression of CDA and optimizes the metabolism of GEM, and the accumulated ROS can also induce apoptosis of tumor cells, realizing synergistic anti-tumor effect of chemical drugs and traditional Chinese medicines. This paper proposes a simple method by using clinically approved drugs to improve the insufficient effect of existing chemotherapy and overcome resistance, which has potential to appropriately shorten the drug development cycle and accelerate the clinical investigation of drugs.

Diverse Methods to Nanomanufacture Colloidal Dispersions of Polyaniline without Templates

Different methods which could be used to produce colloidal dispersions of polyaniline (PANI) nano-objects without templates are described. While the methods are non-deterministic, different nano-objects (nanospheres, nanofibers, nanobelts, nanorice, nanotubes, nanorods, nanodisks, etc.) can be produced. Those most used are: (i) solution polymerization with steric stabilizers (SPS) to produce nanospheres, (ii) interfacial polymerization (IP) to produce nanofibers and (iii) solution polymerization in the presence of additives (SPA) to produce nanotubes. Oxidation of aniline in aqueous solution could produce nanotubes, nanofibers and other shapes by controlling mass transport/concentration of reactants, pH, and the presence of oligomers/additives. The different models proposed to explain the formation of various nano-objects are discussed. Mechanochemical polymerization (MCP) could produce nanofibers or nanospheres by controlling the aniline/oxidant ratio. PANI nanospheres of tunable sizes can also be produced by nanoprecipitation (NPT) of preformed PANI from its solutions using an antisolvent. The geometrical constraints to the small nano-objects made of high-molecular-weight rigid polymers are described. The conditions to produce nanostructures also affect the intrinsic properties of PANI (conductivity, crystallinity, and electroactivity). Selected technological applications of PANI nano-objects manufactured as colloidal dispersions without templates are discussed. Based on the reviewed work and models, future lines of work are proposed.

Electrostatic accelerator facilities and their applications at Peking University

<p indent="0mm">Electrostatic accelerators are powerful tools in many research fields, such as nuclear physics, materials science, and archaeology. Three electrostatic accelerators, the 1.7 MV tandem, the single stage Van de Graaff with a terminal voltage of 4.5 MV, and the EN tandem with a terminal voltage of 6 MV, were installed in 1980s and have been put into operation since the early 1990s at Peking University. The 1.7 MV tandem accelerator is equipped with a radio frequency charge exchange negative ion source and a cesium sputtering negative ion source, which can produce most of the ions from H to Au. It accelerates the ions to energies from several hundreds of keV to several MeV. The accelerator is used for ion irradiation, ion beam modification of materials, as well as ion beam analysis (IBA), such as Rutherford backscattering spectroscopy (RBS) and channeling. Many significant achievements have been made by using the ion irradiation beamline, especially in the research of nuclear materials. The superlattice steel containing a high density of B2-ordered Ni(Al, Fe) superlattice nanoprecipitates (NPs) was irradiated with <sc>6 MeV</sc> Au ions at different high temperatures. The superlattice steel exhibits extraordinary radiation tolerance, namely, zero void swelling at 400–600°C under an average radiation damage of up to <sc>2350 dpa,</sc> outperforming most of the other steels studied to date. This paper demonstrates a counterintuitive strategy to enhance the radiation resistance of metallic materials by simply ordered superlattice NPs. For the 4.5 MV electrostatic accelerator, the isotope ions of hydrogen or helium can be produced in the energy range of <sc>0.7–3.8 MeV,</sc> and continuous or pulsed quasi-monoenergetic neutron fields <sc>(0.03–7 MeV,</sc> <sc>14–19 MeV)</sc> can be generated by ion beam bombarding targets. The neutron fields have applied it to measure (n, α) reaction cross section. Based on the 4.5 MV electrostatic accelerator, a total-IBA system has been established. Total-IBA can obtain self-consistency results through analyzing spectra of different emission particles, without massive modification of equipment. RBS-nuclear reaction analysis (NRA)-particle-induced X-ray emission analysis (PIXE) integrated IBA experiment was carried out to study a Fe-based alloy. The incident particle is ³He⁺ under <sc>3.0 MeV.</sc> The integrated charge is obtained by fitting the RBS spectrum. The content and depth distribution of C element can be determined by analyzing the NRA spectrum. The signal of O element can also be observed in the NRA spectrum, and its depth distribution can be obtained by fitting RBS. More than ten trace elements are analyzed by PIXE, and P has the lowest content, which is <sc>158.2 ppm.</sc> The 6 MV EN tandem accelerator, which has supported much basic and application research at Peking University, was transferred from Oxford University, UK. It is suitable for accelerator mass spectrometry (AMS), ion irradiation and ion beam analysis. The accelerator can also be applied for detector calibration. CR-39 nuclear track detectors were irradiated by <sc>3–8 MeV</sc> mono-energetic protons and <sc>6–30 MeV</sc> mono-energetic carbon ions, which were produced by the 6 MV tandem accelerator. The relationships between particle energy and orbital diameter in CR-39 detectors are established. These data on CR-39 detectors will be useful for identifying reaction products in laser-plasma experiments with complex conditions. With the technique development such as modern ion beam analysis technology and multi-beam to one target, more attractive applications are expected.

Polymer based nanoparticles for BCS class II drugs -“A mini Review”

Nanoparticles are technologically advanced with tuned biological, physical and chemical properties being classified on the basis of composition, and origin. Nanoparticles improve the formulation design but their toxic effects are inevitable. The present article aims to present the possible methods of production, their challenges and characterization of the nanoparticles. Conventional methods of the preparation of the nanoparticles like solvent evaporation, solvent diffusion and nano precipitation has been discussed to prove their present viability. The applications of the nanoparticles in drug delivery are significant and a number of marketed formulations have been cited in the work. The surface area and chemistry in the evaluation of nanoparticles and their effect on the formulation characteristic has also been discussed on the present work.

Alloying regulation mechanism toward microstructure evolution of Sn-bi-based solder joint under current stress

Sn–Bi-based solder alloys have triggered substantial concern in development of low-temperature interconnecting materials of multi-level packaging electronic devices. However, with the high-density current treatment, dramatic atom migration occurs in Sn–Bi-based solder joint, which accelerates the evolution of solder joint microstructure, including the aggregation of Bi phase and the excessive growth of interfacial intermetallic compound (IMC). In this work, Sb element shows a unique influence mechanism on the electromigration (EM) resistance of Sn-Bi-based solder joint. Doped Sb in Sn58Bi-1Sb (SB-Sb) solder massive precipitate as Sn-Sb and Bi-Sb nano precipitations under current stress. These nano precipitates show the ability to capture the migrating atoms, inhibit the migration of Bi atoms and Sn atoms, and enhance the EM resistance of solder joint. Importantly, Bi twin crystal structure is observed in Sn-Bi-Sb solder for the first time. The variation of twins' phase orientations in different positions of solder joint is associated with atomic migration paths induced by the current stress and would eliminate the overgrowth of the Bi rich phase and IMCs. The presented study provides the valuable insights into the regulates mechanism of alloy elements on atom migration in Sn-Bi-based solder joint.

Capture capability of different intrinsic structures for helium bubbles in micro-nano composite 304L steels

• Micro-nano composite 304L stainless steel (MN304-La) is implanted with He + and annealed at 900 °C. • Nano-precipitates, grain boundaries, and dislocation are three intrinsic structures coexisting in MN304-La. • Three intrinsic structures have competing processes for capturing helium bubbles. • Nano-precipitates exhibit the strongest strength in capturing helium bubbles compared to grain boundaries and dislocations. The formation and migration of helium bubbles lead to performance degradation of structural materials in nuclear reactors. Intrinsic structures in nuclear materials can significantly influence the behavior and distribution of these helium bubbles under irradiation. Micro-nano composite 304L stainless steel (MN304-La) possesses three main kinds of intrinsic structures: grain boundaries (GBs), dislocations, and La-rich nano-precipitates (NPs). In this study, the helium bubbles on different intrinsic structures in MN304-La after He + ions implantation were characterized and analyzed. We compared the capabilities of different intrinsic structures in capturing helium bubbles and confirmed that NPs exhibit the strongest strength in capturing helium bubbles among the three kinds of intrinsic structures. We found that the competition of intrinsic structures for capturing helium bubbles depends on both the capture strength of the intrinsic structures and the capture distance to the helium bubbles.