Core-shell Particles Research Articles

Innovative surfactant-free synthesis of core-shell SiO2/ZnO particles: rapid ultrasonication and photocatalytic inhibition.

This study demonstrates the preparation of SiO2/ZnO core-shell nanoparticles with controllable shell size and their optical properties. A facile ultrasonication method was utilized to prepare the core-shell particles in the absence of surfactant materials. The synthesis duration was 75% shorter than that required for the common sol-gel method, which favours its potential applicability in the future for mass production. Tetraethyl orthosilicate (TEOS) was used as the silica source, while the core material was prepared using zinc acetate dihydrate. The outer shell size could easily be controlled by changing the molar ratio of silica from 0.25 to 1.00. The experimental results show that increasing the silica ratio was effective in suppressing the self-agglomeration of ZnO and, further, in obtaining agglomeration-free particles. The investigation of the photoluminescence (PL) properties of nanometre-sized ZnO revealed several emission peaks in the ultraviolet (UV) wavelength range, indicating variations in bandgap energy. This did not appear in the spectrum of micrometre-sized ZnO particles. The core-shell particles produced with higher amounts of silica showed higher UV-A and UV-B absorption. In addition, the presence of silica reduced the photocatalytic activity of ZnO by 65% and reduced the PL intensity. The obtained emission peaks, intensity changes, and spectral characteristics open new avenues for further research on tailoring the properties of SiO2/ZnO core-shell structures for specific technological advancements. These advancements hold promising applications in UV attenuation materials, LED technologies, lenses, and solar cells within the realm of optical devices.

Structural Color Materials with Color Mixing Effect Using Noble Metal‐Free Plasmonic Particles in SiO2–ZrN System

AbstractStructurally colored materials with a color mixing effect are developed using SiO2–ZrN core–shell particles, where ZrN nanoparticles used as shells exhibited localized surface plasmon resonances (LSPRs). ZrN nanoparticles (10–30 nm) are attached to monodispersed SiO2 particles by modifying SiO2 particles with polymers. The attached ZrN nanoparticles exhibited a plasmon resonance absorption band at 700 nm. These SiO2–ZrN core–shell particles have a highly monodisperse particle size and assemble into a particle‐stacked film with Bragg diffraction light in the visible spectrum. The particle‐stacked film of the SiO2–ZrN core–shell particles exhibited the maximum reflection depending on the particle size of the SiO2 core. The ratio of the reflection intensity in the long‐wavelength region corresponding to the ZrN absorption to that in the short‐wavelength region of the particle‐stacked film containing the ZrN shell is less than that of the ratio in only SiO2 particle‐stacked film. The results reveal that these particle‐stacked films exhibit a “color mixing effect” that combines specific wavelength absorption through plasmon resonance and specific wavelength diffraction owing to the periodic structure without using precious metals.

Flexible Multimodal Magnetoresistive Sensors Based on Alginate/Poly(vinyl alcohol) Foam with Stimulus Discriminability for Soft Electronics Using Machine Learning.

Flexible foam-based sensors have attracted substantial interest due to their high specific surface area, light weight, superior deformability, and ease of manufacture. However, it is still a challenge to integrate multimodal stimuli-responsiveness, high sensitivity, reliable stability, and good biocompatibility into a single foam sensor. To achieve this, a magnetoresistive foam sensor was fabricated by an in situ freezing-polymerization strategy based on the interpenetrating networks of sodium alginate, poly(vinyl alcohol) in conjunction with glycerol, and physical reinforcement of core-shell bidisperse magnetic particles. The assembled sensor exhibited preferable magnetic/strain-sensing capability (GF ≈ 0.41 T-1 for magnetic field, 4.305 for tension, -0.735 for bending, and -1.345 for pressing), quick response time, and reliable durability up to 6000 cycles under external stimuli. Importantly, a machine learning algorithm was developed to identify the encryption information, enabling high recognition accuracies of 99.22% and 99.34%. Moreover, they could be employed as health systems to detect human physiological motion and integrated as smart sensor arrays to perceive external pressure/magnetic field distributions. This work provides a simple and ecofriendly strategy to fabricate biocompatible foam-based multimodal sensors with potential applications in next-generation soft electronics.

The preparation and feasibility analysis of magnetic orientation method in the study of thermal insulation composite materials in the field of electronic packaging

AbstractAs an emerging field of current technological development, the heat dissipation performance of electronic packaging materials has become the key to determining product reliability. Therefore, the applied thermal interface materials (TIMs) need to simultaneously meet the performance indicators of thermal conductivity, mechanics, and insulation. Although BN had excellent in‐plane thermal conductivity and insulation performance, it is currently difficult to achieve vertical orientation of powder which leads the layered powder cannot complete a continuous and effective heat transfer path along the Z‐axis direction inside the composite material. In order to solve the above two problems, out‐of‐plane thermal conductive composite was prepared by introducing magnetic oriented method. In order to comprehensively evaluate the thermal conductivity, mechanical and electrical properties, BN@Fe3O4/EP magnetic oriented composites were compared with BN@PDA‐Al2O3/EP composite prepared by mechanical blending method. The vertical thermal conductivity of the magnetic oriented composite material was 2.24 W/(m·K) at 30 vol%, which was 3.39 times that of the blended composite material and 12.4 times that of pure EP. This proves that the magnetic oriented composite materials prepared by the research institute can meet the vertical heat transfer needs in the field of electronic packaging and have high research value in this area.Highlights BN@Fe3O4 core–shell particles were prepared with both thermal conductivity and magnetic controllability. The thermosetting composites were prepared by heated through preliminary gel point and then cured at high temperature. The orientation of powder inside the matrix was constructed, resulted in excellent out‐of‐plane heat transfer performance. Comparisons were made between various properties of magnetic oriented materials and conventional blend materials. The magnetic orientation method is feasible in the field of electronic packaging.

Structural characteristics and mechanical properties of partially reacted and non-reacted Al–Fe66Cr10Nb5B19 metallic glass composites

The microstructure and mechanical properties of partially reacted and non-reacted Al–Fe66Cr10Nb5B19 metallic glass composites obtained by spark plasma sintering were comparatively analyzed. For the first time, the compositional features of core-shell particles formed upon the partial reaction of the Fe66Cr10Nb5B19 metallic glass with aluminum were examined using transmission electron microscopy combined with elemental mapping. The key finding is that iron of the alloy selectively dissolved in aluminum. The inner layer of the shell formed via diffusion of aluminum into the metallic glass. The introduction of the glassy reinforcement did not lead to such a dramatic ductility reduction as the formation of a complex “metallic glass core-thick intermetallic shell” reinforcement. In the non-reacted composite, the glassy reinforcement did not reveal its full potential in terms of the strengthening effect.

Preparation and Mechanical Properties of Core-Shell PS&CeO2 Composite Abrasive Particles.

Core-shell composite abrasive particles are a topic of great interest in surface finishing. It is important to explore the preparation technology and performance parameters associated with them. In this paper, a core-shell composite abrasive particle made of polystyrene and cerium oxide (PS&CeO2, CSPC), which is rigid on the outside and flexible on the inside, is proposed. The microstructure, physical phase characteristics, and mechanical properties of the inner core and composite abrasive particles are investigated. PS microspheres and CSPC composite abrasive particles with different structural features were prepared through a series of experiments, morphological observations, and physical and chemical characterization experiments. Their microstructures and physical phase properties were investigated. The indentation load curves of the PS microspheres and CSPC composite abrasive samples were measured by using an atomic force microscope. The analysis focused on the effects of various dimensional and structural parameters on the modulus of elasticity of both PS microspheres and CSPC composite abrasive particles. The analysis shows that the experimentally prepared PS microspheres have good dispersion, a smooth surface, and a uniform particle size distribution. The prepared CSPC composite abrasive particles are regular spheres with rough, rice-like surfaces, low modulus of elasticity, and overall nonrigid and soft elastic properties. The results of this paper can provide a guide for the preparation technology, performance regulation, and application of polymer microspheres and core-shell composite abrasive particles in CMP.

Platinum/Tantalum Carbide Core–Shell Nanoparticles with Sub‐Monolayer Shells for Methanol and Oxygen Electrocatalysis

AbstractCore–shell architectures provide great opportunities to improve catalytic activity, but achieving nanoparticle stability under electrochemical cycling remains challenging. Herein, core–shell nanoparticles comprising atomically thin Pt shells over earth‐abundant TaC cores are synthesized and used as highly durable electrocatalysts for the methanol oxidation reaction (MOR) and the oxygen reduction reaction (ORR) needed to drive direct methanol fuel cells (DMFCs). Characterization data show that a thin oxidic passivation layer protects the TaC core from undergoing dissolution in the fuel cell‐relevant potential range, enabling the use of partially covered Pt/TaC core–shell nanoparticles for MOR and ORR with high stability and enhanced catalytic performance. Specifically, at the anode the surface‐oxidized TaC further enhances MOR activity compared to conventional Pt nanoparticles. At the cathode, the Pt/TaC catalyst feature increases tolerance to methanol crossover. These results show unique synergistic advantages of the core–shell particles and open opportunities to tailor catalytic properties for electrocatalytic reactions.

Organic-inorganic core-shell materials as reinforced fillers of UHMWPE to improve its tribological and mechanical properties

Generally, modification of materials by adding multiple types of nano particles could cause dispersion problems, generally limited the performance improvement effect. Herein, we report the modification of UHMWPE materials by organic-inorganic core-shell particles with PTFE as the core and Al(OH)3 as the shell, which prepared by in-situ polymerization of sodium bicarbonate and aluminum sulfate solution. Core-shell particles were filled in UHMWPE matrix and sintered into composite by spark plasma sintering (SPS). The mechanical and tribological properties of the composites were characterized by tensile compression testing machine, universal micro tribometer (UMT-5), three-dimensional white light interferometer and scanning electron microscope (SEM). The results showed that the addition of core-shell structural materials effectively improved the tribological properties (friction coefficient decreased by 40%, wear rate decreased by 30%) and mechanical properties (compression strength increased by 2.4 times) of the composites. It was demonstrated that the inorganic framework provided strength to improve the mechanical properties and wear resistance of materials, and the organic phase was used as a lubricating phase to reduce the friction coefficient of materials. Surface treatment of core-shell particles both improved the binding between particles and matrix and decreased the formation of agglomerations, thus significantly reducing ploughing phenomena’s effect produced by abrasive wear of agglomeration

Quasi-static and dynamic deformation of aluminum matrix composites reinforced by core-shell Al35Ti15Cu10Mn20Cr20 high-entropy alloy particulates

Core-shell structured particles are potential reinforcement agents for metal matrix composites. In this work, aluminum matrix composites reinforced with core-shell structured Al35Ti15Cu10Mn20Cr20 high-entropy alloy (HEA) particles were fabricated by spark plasma sintering (SPS) and high-temperature diffusion post-treatment. Dynamic compression behavior and adiabatic shear failure mechanism in the composites were investigated by split Hopkinson pressure bar (SHPB), scanning electron microscopy and transmission electron microscopy. Results showed that the shell thickness of the core-shell particles ranged from 0.4 to 1.6 μm, which were formed by thermal diffusion between HEA core and aluminum alloy. The 30 vol% (Al35Ti15Cu10Mn20Cr20)p/2024Al composite showed a high compressive strength (594 MPa) and strain-to-failure (26.7 %) under quasi-static compression, as well as a high flow stress (602 MPa) and strain-to-failure (45.3 %) under dynamic compression, which are superior to common ceramic particles reinforced Al matrix composites. The (Al35Ti15Cu10Mn20Cr20)p/Al composites with ∼20–40 vol% core-shell HEA particles failed as bulging, 45° shearing or splitting when compressed at ∼1000-3000 s−1. Micro-damages in these composites were due to microcracks originated from the HEA core, while propagation of cracks was effectively restrained by the shell. Deformation bands and phase transformation (melting of aluminum) were both observed in the composites under dynamic loads. Chain-shaped deformation bands were formed by the fragmentation and rearrangement of the core-shell particles, instead of the recrystallized structure of metal matrix in particle-reinforced Al matrix composites reported previously. The formation of molten Al phase transformation bands was owing to shear localization and significant adiabatic temperature rise under dynamic compression.

One-step synthesis of Ag@polyaniline core–shell particles for efficient removal of radioactive iodine

One-step synthesis of Ag@polyaniline core–shell particles for efficient removal of radioactive iodine

Preparation of core–shell silica particles with tunable pore size by phenylethanol as swelling agent for chromatographic separation

The core–shell particles with tunable pore size were synthesized by a bi-phase reaction successfully. By adjusting the amount of phenylethanol, fibrous shells with tunable pore sizes ranging from 4 to 19 nm could be obtained in one pot. The obtained silica microspheres were used for chromatographic separation after modification with octyltrichlorosilane and end-capping with N-(trimethoxysilylpropyl)imidazole. Better resolutions of nitroimidazoles and anilines were obtained on the end-capped stationary phase. This particle could serve as an HPLC stationary phase with good reproducibility and particular selectivity.

Regulating the microstructure of Ti@TiAlSi core-shell structured reinforcing particles endows Al–Si alloy matrix composites with high strength and ductility

Forming spherical core-shell (CS) structured reinforcing particles, consisting of a Ti core and a surrounding TiAlSi intermetallic shell, by in situ reaction between Ti and Al matrix is a promising approach to overcome the strength-ductility trade-off in particle reinforced Al–Si matrix composites. However, the phase constituent and microstructure of the shells are highly sensitive to the Al–Si alloy composition and processing parameters of the powder thixoforming method. Therefore, the effects of Si content and partial remelting temperature on the microstructure of CS particles and the tensile properties of the resultant composites were investigated in this study. The results indicate that uniform and compact shell can be achieved only by the τ2-phase reaction layer generated during partial remelting. To form the τ2 phase, the Si content in the liquid phase of the semisolid billet prior to thixoforming must be higher than 10.3 wt%. This can be achieved through adjusting the Si content in the Al–Si alloy matrix or/and partial remelting temperature. Moreover, the Ti core radius to shell thickness ratio of ∼1.5 was proposed to achieve the composites with both high strength and ductility. These findings are helpful for designing the microstructure and fabricating CS particles reinforced metal matrix composites with excellent comprehensive mechanical properties.

Skin Temperature-Triggered Switchable Adhesive Coatings for Wearing Comfortable Epidermal Electronics

Smart adhesives with switchable adhesion strength on demand are crucial for ensuring the stability of the epidermal electronics-skin interface and preventing skin damage caused by device detachment. However, challenges such as harsh triggering conditions, lack of precise control over material comprehensive performance, and difficulty in achieving micron-level controlled integration of materials on device surfaces hinder the application of switchable adhesives in epidermal electronics. Herein, we designed a coatable, thermally-triggered switchable adhesive that has a high adhesion of 68.8 N/m at skin temperature, e.g., 33 °C, and after a slight cooling, e.g., 20 °C, the adhesion decreases to 6.59 N/m, resulting in a high switching ratio of 10.4. The switching time is < 1 min. This unique property is achieved by combining side-chain crystalline polymers and self-adhesive polymers through a strategy of constructing core–shell particles. The results of thermal analyses, rheology, and solid-state nuclear magnetic resonance indicate that a rapid and reversible crystallization-melting transition within the material is the essence of the adhesion switching. By depositing the material on flexible electrodes using spraying technology, we have obtained an ultra-thin (<5 μm), and peelable on-demand epidermal electrode, demonstrating the advantages of emulsion materials in the fabrication of wearing comfortable devices.

Colloidal Photonic Composites with a Long-Range Order by Hot-Pressing Polymer Brush-Grafted Silica Colloids.

Colloidal photonic composites (CPCs) are unique optical materials that combine flexible and responsive polymers with colloidal photonic crystals, and they have promising applications in colorful displays, optical anticounterfeiting, and visual sensors. However, conventional self-assembly strategies for constructing CPCs via solvent evaporation have faced limitations due to the meticulous regulation required during the evaporation process and typically long preparation durations. Here, we present an external force method to achieve a long-range ordered arrangement in CPCs by hot-pressing poly(2-[[(butylamino)carbonyl]oxy]ethyl acrylate (PBCOE)) brush-grafted silica colloidal particles (SiO2-g-PBCOE). We show that the hot-pressing conditions (i.e., temperature and pressure) and the silica volume fraction (φsilica) of the SiO2-g-PBCOE colloidal particles play crucial roles in determining their ordering and optical properties. By optimization of the hot-pressing temperature up to 100 °C and pressure of 5 MPa, a long-range ordered arrangement of SiO2-g-PBCOE colloidal particles with a φsilica of 20.3% can be achieved. For the effect of structural features, our findings reveal that SiO2-g-PBCOE colloidal particles featuring a higher φsilica are more prone to obtain a long-range ordered arrangement compared to a lower φsilica under hot-pressing conditions at relatively low temperature and pressure (50 °C and 5 MPa), which is mainly attributed to the chain entanglement and hydrogen bonding interactions induced by grafted longer polymer brushes, leading to additional energy inputs and weakening the ordering. Significantly, the critical φsilica (φc) of SiO2-g-PBCOE colloidal particles is discerned, strongly influencing the optical properties of the hot-pressed films. Specifically, a hot-pressed SiO2-g-PBCOE film with a critical φsilica of 29.3% displays enhanced optical properties characterized by intensified reflection peaks, narrowed full width at half-maximum (FWHM), and brilliant structural colors. Notably, in this work, we reveal the mechanism of hot-pressing-driven core-shell colloidal particle ordering and the key factors affecting the ordering of colloidal particles, i.e., chain entanglement and hydrogen-bonding interactions, which play a crucial role in obtaining CPCs with controllable structures. Moreover, angle-dependent structural color is observed in the hot-pressed SiO2-g-PBCOE film with a φsilica content of 29.3% due to the unique attributes of the highly ordered arrangement, while the films exhibit mechanochromic properties due to chain entanglement and hydrogen bonding interactions. This work provides valuable insights into the rapid construction of highly ordered CPCs and establishes a solid foundation for external force-assisted ordering of colloidal particles.

Non-destructive chromatographic determination of surface area in reverse phase chromatographic columns

One of the critical but underutilized parameters that affect chromatographic separation is an adsorbent surface area (S.A.). We introduce a concept of direct determination of the total surface area of chromatographic columns by utilizing a nondestructive measurement of eluent component excess adsorption isotherm measurement and the application of the Standard Excess Adsorption Isotherm from acetonitrile-water and methanol-water binary mixtures for direct determination of the S.A. in chromatographic columns. This nondestructive technique was used to determine the surface area of five commercial columns, including three core-shell particle type columns (Kinetex-C18, Ascentis C18, and Hallo C18) and in-housemade C18 columns. The traditional low-temperature nitrogen adsorption (LTNA) technique was compared to the novel chromatographic method of nondestructive surface area determination for adsorbents modified with octadecylsilanes. The chromatographically determined surface area was in good agreement with the conventional techniques for all columns used. The difference between the three techniques is less than 10%. Columns were characterized in terms of adsorbent geometry (e.g., pore volume, column void volume, interparticle volume), ligands bonding density, and the amount of the packing material in a chromatographic column.

Numerical analysis of fracture in core-shell particle reinforced composites

The fracture of core-shell particle reinforced composites was simulated using a crack phase field method. A pre-existing crack may grow along the interface between the core and shell (core debonding), may penetrate the shell and the core (trans-core fracture), or may grow in the matrix (brittle fracture in the matrix). Shell fracture behaviours resulting from the competition between the fracture resistance and fracture driving force are crucial to the crack growth mechanisms. It was found that moderate strength and low modulus of the shell favoured trans-core fracture, and low strength and high modulus of the shell favoured core debonding. The effects on the overall mechanical properties were also identified. The composite strength usually benefited from stiffer and tougher components, regardless of the crack growth mechanisms, while the composite toughness was more complex. The toughening effect was highly related to how the crack evolved, as core debonding improved the toughness at the significant cost of strength, and trans-core fracture contributed most to the toughness with a slight reduction in strength compared with the matrix. These findings indicate design strategies for epoxy composites which can achieve a balance of strength and toughness, enabling the design of safer lightweight composites for electric vehicles and transport applications.

Synthesis and characterization of organosilicon functionalized water-based polyvinylidene chloride emulsion with core-shell structure

The outstanding barrier performance of polyvinylidene chloride (PVDC) has attracted widespread attention. In this work, a series of organosilicon functionalized water-based PVDC emulsions with core-shell structure are synthesized by seed emulsion polymerization using vinylidene chloride (VDC), methyl acrylate (MA), isooctyl acrylate (EHA) as core and vinylidene chloride (VDC), methyl acrylate (MA) as shell. Vinyl-terminated polydimethylsiloxanes (VT-PDMS) are introduced into the core-shell as modifier. The properties of PVDC emulsions and films modified with VT-PDMS are investigated. On the one hand, when VT-PDMS is properly incorporated into the core-shell particles, the Si-O bonds in VT-PDMS are dissociated, which further forms a cross-networking structure, thereby enhances the adhesion of PVDC film to the substrate. The barrier performance of the film is also improved by a small amount of cross network structure. On the other hand, the addition of VT-PDMS leads to the phenomenon of thin film shrinkage, which further enhances the barrier performance of PVDC. All results indicate that the best comprehensive performance is achieved when the VT-PDMS content in the PVDC core is 2 wt%, the adhesion can be increased to 0.527 MPa, the oxygen transmittance is 5.68 cc/m2·24 hr, and the actual time of water barrier after coating starch-based tableware is over 12 hours. This provides an effective line of thinking for the further application of PVDC barrier film in the field of environmental protection food packaging.

Optimization of elution conditions and comparison of emerging biocompatible columns on the resolving power and detection sensitivity of oligonucleotides by ion-pairing reversed-phase liquid chromatography mass spectrometry

A generic performance comparison strategy has been developed to evaluate the impact of mobile-phase additives (ion-pairing agent / counter ion systems), distinct stationary phases on resulting resolving power, and MS detectability of oligonucleotides and their critical impurities in gradient IP-RPLC. Stationary-phase considerations included particle type (core-shell vs. fully porous particles), particle diameter, and pore size. Separations were carried out at 60°C to optimize mass transfer (C-term). The incorporation of an active column preheater mitigated thermal mismatches, leading to narrower peaks and overcoming peak splitting. Acetonitrile as organic modifier outweighed methanol in terms of peak-capacity generation and yielded a 30% lower back pressure. Performance screening experiments were conducted varying ion-pairing agents and counter ions, while adjusting gradient span achieved an equivalent effective retention window. Hexafluoromethylisopropanol yielded superior chromatographic resolution, whereas hexafluoroisopropanol yielded significantly higher MS detection sensitivity. The 1.7 µm core-shell particle columns with 100 Å pores provided maximum resolving power for small (15–35 mers) oligonucleotides. Sub-min analysis for 15–35 polyT ladders was achieved operating a 50 mm long column at the kinetic performance limits. High-resolution separations between a 21-mer modified RNA sequence oligonucleotides and its related (shortmer and phosphodiester) impurities and complementary strand were obtained using a coupled column set-up with a total length of 450 mm.

Modeling of reaction–desorption process by core–shell particles dispersed in continuously stirred tank reactor (CSTR)

Abstract Transient responses of reaction–desorption process were predicted from mathematical solutions of modeling equations for CSTR (continuously stirred tank reactor) containing core–shell adsorbent particles. Analytical solutions on the core–shell particles were derived for core–shell spherical, cylindrical, and slab-type morphologies, assuming inert-cores. Unlike continuous adsorber, CSTRs for reaction–desorption process containing spherical particles exhibited the slowest reduction rate of concentration of adsorbate, because the amount of adsorbed component on the particles is the largest among three kinds of particle shapes. Factors affecting the transient concentration in bulk medium of reaction–desorption process were investigated by adjusting inert-core thickness, inlet flow rate, initial concentration of reactant in inflow stream, amount of adsorbent, and Thiele modulus. Concentration profile inside the particles as well as average intra-particle concentration could be also predicted for comparison with bulk concentration of CSTR. For non-linear isotherm and non-linear reaction kinetics, concentration of active component could be predicted by solving non-linear coupled differential equation using finite element method. For connected CSTRs in series, systems of reaction-diffusion equations were solved by finite element method to study the effect of number of connected reactors. When the number of reactors was sufficiently large, the reactor system could be approximated to fixed bed reactor for reaction–desorption process.

Uniformly coated Cu@Ag core-shell particles with low silver content: Hydroxy acid as a complexing agent with “double-sided adhesive” function

The Cu@Ag core-shell particles are the highly anticipated functional materials in electronic applications which are required to be high electrical conductivity, good thermal properties and low cost. However, it remains a challenge to obtain a completely and uniformly coated Ag shell in low silver content. During the coating process, it is essential to regulate the reduction of Ag+ on the surface of Cu to ensure uniformly silver shell. We developed a strategy to prepare uniformly coated Cu@Ag particles by employing hydroxy acids as complexing agents with “double-sided adhesive” function. Compared to conventional complexing agents, the employed hydroxy acids can not only coordinate with Ag+ but also complex with Cu due to the more carboxyl and hydroxyl groups which act like a “double-sided adhesive”, that can pull Ag+ to the surface of Cu, and then accomplish the coating of Ag with replacement and reduction reaction. The impact of different types of hydroxy acids as complexing agents on the coating effect of silver-clad copper powder was investigated when the silver addition was 15 %. Results indicated that the obtained Cu@Ag particles with tannic acid as complexing agent show high coating quality layer with low surface sliver content (11.4 %). Moreover, the obtained Cu@Ag particles exhibit good dispersibility, promising thermal stability and low electrical resistivity (30 μΩ·cm).