•In-situ fabricated three-dimensional graphene network.•A facile and eco-friendly method via self-deposition of PS/rGO@PtNPs particles.•Better conductive network and interconnective diffusion channel for electrolyte.•Higher MO catalytic performance than closed-stacked rGO/Pt catalyst.Graphene is an attractive catalyst support for direct methanol fuel cells (DMFCs). However, the close-packed structure and hydrophobicity of the graphene sheets will prevent noble metal nanoparticles (NMNPs) from exposed to the electrolyte, leading to a reduction in the utilization of NMNPs. In this work, a unique 3D graphene/PtNPs composite catalyst with double network channels is in-situ fabricated. The superficial rGO sheets of PS/rGO@PtNPs composite particles are interconnected to form 3D network structure due to the supporting of the PS microspheres. The 3D structure not only provides interconnected channel for diffusion of the electrolyte into the composite catalysts, but also forms an ideal graphene network to increase the connectivity and conductivity of the composite catalysts. Compared with the close-packed rGO/PtNPs catalyst, the PS/rGO@PtNPs composites with 3D network structure have higher catalytic activity, reaches up to 586.96 mA/mg for methanol oxidation reaction.Wrapping PS microspheres with graphene sheets, attaching PtNPs on the resultant PS/rGO composite particles to prepare PS/rGO@PtNPs composite particles, and finally constructing 3D ordered rGO/PtNPs network structure through in-situ self-deposition of the ternary composites, which evidently increased the catalytic activity in methanol oxidation reaction than the close-packed rGO/PtNPs composite.

Polystyrene microspheres coated with modified Ag nanoparticles (PS/mAgNPs) were facilely fabricated via the proposed thermodynamically driven heterocoagulation method, and then their catalytic property was investigated using the reduction reaction of 4-nitrophenol as a model system. The surface modification of Ag nanoparticles (AgNPs) with less gold can subsequently lead to significant improvements in not only the coverage of the PS substrate with AgNPs but also the catalytic efficiency of the resultant composite catalyst. Furthermore, ammonia was found to have an evident cooperative effect with AgNPs in the catalytic reaction, as the reaction rate distinctly increased after introducing a trace amount of ammonia into the system.

•Nanosized PS/P(S-EA) core/shell-like particles were prepared at low surfactant amount.•Film formation proceeded smoothly at room temperature without any coalescents.•Films had nanosized sea-island structure after self-diffusion of macromolecules.•The VOC-free films had better mechanical properties and optical transparency.A series of styrene-acrylic nanocomposite latices [PS/P(S-EA)] are prepared with a considerably low surfactant amount and relatively high solid content via a two-step quasi-microemulsion polymerization. The composite particles have nanosized core/shell-like structure composed of polystyrene (PS) core and P(S-EA) (styrene-ethyl acrylate copolymer) shell phases. The film-forming mechanism of such nanocomposite latices and the film performance was investigated. Based on the particle design, the film formation can smoothly proceed at room temperature and the formed films had microphase separated sea-island structure. Especially, a visible rise in Tg of the film's continuous phase was observed and thus, it afforded the films excellent use properties. It is notable that the success can be attributed to the self-diffusion of macromolecule chains instead of the assistance of any coalescent. The nanocomposite latices should be a potential raw material for manufacturing environment-friendly VOC (volatile organic compounds)-free waterborne coatings.

The fabrication of graphene-based polymer composite materials is of interest and significance from an academic and an application viewpoint. The widely used method to obtain such composites was liquid-phase blend of graphene nanosheets (GNSs) and polymer solutions followed by casting or heat pressing. Until now, the challenge of dispersing the GNSs uniformly in the polymer matrix to form controllable and regular structure still remains. Here, we developed a unique “particle-constructing” method for fabricating highly ordered 3D graphene-based polymer composite materials, throughout which the GNSs formed intact, uniform and well-defined network structure. The strategy contains two steps: wrapping polymer microspheres with GNSs and mold-compressing them at room temperature, followed by an appropriate heat treatment. The composite materials exhibited outstanding electrical properties involving extremely low percolation threshold and much higher conductivity. The method can be easily extended to fabricate highly ordered GNS aerogels and more GNS-based composite materials. The results represent an important step toward developing GNS-based composite materials with high performance.

A facile and controllable method of immobilizing gold nanoparticles (AuNPs) on hollow silica particles (SiO2HPs) is proposed and the resultant SiO2HP/AuNP composite particles exhibit high catalytic activity. The carrier SiO2HPs decorated with amino groups are prepared in a W/O inverse emulsion, having a well-defined hollow structure, mesoporous wall and dense bush-like surface morphology. A large number of ultrafine AuNPs are generated via in situ reduction of chloroauric acid by the amino groups and firmly anchored on the bush-like silica shell. The structure and morphology of the composites are governed by changing the weight percentage of 3-aminopropyltriethoxysilane in the total amount of monomers (wa), which have been extensively characterized. Benefiting from the unique multiple structures, the composite particles exhibited outstanding catalytic efficiency and repeatability, which are confirmed by two oxidation–reduction reactions of 2-nitroaniline/NaBH4 and 4-nitrophenol/NaBH4.

Polystyrene/polypyrrole (PS/PPy) core–shell nanocomposite particles with uniform and tailored morphology have been successfully synthesized using the “naked” PS particulate substrate with the aid of a proposed strategy, the so-called swelling–diffusion–interfacial polymerization method. After initially forming pyrrole-swollen PS particles, diffusion of the monomer toward the aqueous phase was controlled through the addition of hydrochloric acid, eventually leading to its polymerization on the substrate particle surface. This process allows the nanocomposite particles to possess uniform and intact PPy overlayer and affords much more effective control over the structure and morphology of the resultant nanocomposites by simply changing the PS/pyrrole weight ratio or the addition amount of the doping acid. In particular, the nanocomposite particles with a thin, uniform, and intact PPy overlayer and their corresponding PPy hollow particles were obtained at a low addition amount of pyrrole. The resultant nanocomposite particles have been extensively characterized using scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and thermogravimetry.

The design and fabrication of functional nanocomposites is an active area of research because composite particles have significantly improved physical and chemical properties over those of their single-component counterparts. Traditionally, chemical pretreatments of the components were used to enhance their physicochemical or chemical interactions. Here, we propose a novel approach to taking advantage of the beauty of thermodynamics. A series of functional materials, including graphene nanosheets, carbon nanotubes, noble metals, magnetic materials, conducting polymers, attapulgite, and etc. were incorporated with polystyrene particles by a thermodynamic driving force. This unique approach is facile and versatile and shows the considerable significance of developments in both scientific methodology and particle engineering.

Gold nanoparticles-coated polystyrene (AuNPs-coated PS) composite particles with raspberry-like morphology are successfully prepared by blending the preformed aqueous dispersions of PS microspheres and AuNPs based on colloid thermodynamics. A series of thermodynamic factors is systematically investigated for the influence on the heterocoagulation between the PS microspheres and AuNPs. The synthesized AuNPs-coated PS composite particles have been extensively characterized by scanning electron microscopy, transmission electron microscopy, thermogravimetry and zeta potential measurement. The results indicate that the structure and morphology of the resultant AuNPs-coated PS composite particles are significantly affected by the amount of poly(vinylpyrrolidone), the pH and composition of medium.Graphical abstractHighlights► AuNPs-coated PS composite particle is prepared based on colloid thermodynamics. ► This unique heterocoagulation is affected by a series of thermodynamic factors. ► The structure and morphology of composite particle can be effectively controlled.

Herein, we reported a facile and controllable one-step process to fabricate micrometer-sized and monodisperse polystyrene/gold nanoparticles@polyaniline (PS/AuNPs@PANi) composite particles by means of the “Swelling–Diffusion–Interfacial-Polymerization Method” (SDIPM). Utilization of chloroauric acid as the oxidant for aniline monomer afforded the shell of the resultant composite particles simultaneously containing PANi and AuNPs. The PS/AuNPs@PANi composite particles were extensively characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and thermogravimetry. As a result, the synthesized PS/AuNPs@PANi composite particles show uniform size distribution and well-defined morphology, and furthermore, the structure and morphology of the AuNPs@PANi shell could be well controlled by simply changing the addition rate of chloroauric acid and weight ratio of aniline/PS. In addition, the mechanism governing the formation of PS/AuNPs@PANi composite particles was discussed.Graphical abstract.Highlights► PS/AuNPs@PANi composite particles were prepared by distinct SDIPM. ► PS/AuNPs@PANi composite particles had good morphology and narrow size distribution. ► We simplified the preparation process to be completed in one-step.

Herein, we propose a facile and efficient method to obtain the polystyrene/graphene nanosheets (PS/GNSs) nanocomposite particles. As far as we know, it is the first example that GNSs are attached onto the surface of PS microspheres, with such smooth morphology, and without relying on any surface pretreatments of substrate microspheres.

By means of a facilely designed strategy, we successfully fabricated the multilayer and conductive organo-silica/polystyrene/polyaniline (organo-silica/PS/PANi) composite particles. First, organo-silica/PS core/shell composite particles were synthesized by seeded emulsion polymerization and the vinyl groups located on the surface of organo-silica nanoparticles were used to induce in situ polymerization of styrene. The influence of the route of the addition of styrene on the morphology of organo-silica/PS composite particles was investigated. Then, the coating of organo-silica/PS composite particles with PANi was achieved by virtue of the “Swelling–Diffusion–Interfacial-Polymerization Method” (SDIPM). The whole preparation process was monitored by transmission electron microscope, scanning electron microscope, Fourier transform infrared, Raman spectroscopy, dynamic light scattering, and thermogravimetry. As a result, the multilayer and conductive organo-silica/PS/PANi nanocomposites possessed of a uniform size and well-defined morphology, and furthermore, their structure could be well controlled by simply changing the weight ratio of aniline/PS.Graphical abstractA facile strategy is exploited intelligently to fabricate the multilayer and conductive organo-silica/polystyrene/polyaniline (organo-silica/PS/PANi) composite particles with well-defined morphology and a narrow size distribution.Research highlights► We simplified preparation process without any surface treatments of substrates. ► Organo-silica/PS/PANi composite particles were prepared by distinct SDIPM. ► Multilayer composite particles had good morphology and narrow size distribution.

By means of the “Swelling–Diffusion–Interfacial-Polymerization Method” (SDIPM), we successfully coated polyaniline (PANi) onto micrometre-size, uncharged polystyrene (PS) particles, which were synthesized by dispersion polymerization. After initially forming aniline-swollen PS particles, diffusion of the aniline toward the aqueous phase was controlled through a slow addition of hydrochloric acid, eventually leading to its polymerization on the substrate particle surface. The resultant PS/PANi composite particles have been extensively characterized using scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared (FTIR) and Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and C, H, and N elemental microanalysis. At very low aniline/PS weight ratio, the thin, uniform, but intact PANi overlayer was obtained owing to its unique “inside-out” formation mechanism and considerably high efficiency of aniline to transform into the resultant composites. As increasing the initial amount of addition of aniline, the uniform size and well-defined morphology of the PS/PANi core-shell composite particles could still be maintained with a relatively high PANi mass loading yield.

Polystyrene/poly(3,4-ethylenedioxythiophene) (PS/PEDOT) nanocomposite particles with uniform size and well-defined morphology have been synthesized using the proposed strategy, which involves swelling of 3,4-ethylenedioxythiophene (EDOT) into PS seed particles, followed by its diffusion and polymerization on the PS surface. This process affords much more effective control over the structure and morphology of the resultant nanocomposites by changing the EDOT/PS weight ratio, reaction temperature, and the rate of addition of the doping acid. The PS/PEDOT nanocomposite particles have been extensively characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), elemental microanalyses and X-ray photoelectron spectroscopy (XPS). Furthermore, the correlation between nanostructure of the resultant nanocomposite particle and its electromagnetic response performance (e.g., mass extinction effect in infrared region) was investigated.

The fabrication of hollow silica particles is of interest from both academic and application viewpoints. In this paper, we propose a distinctly novel method by which hollow silica particles are successfully fabricated in a self-stable system without any surfactants during a self-consumptive templated process. In detail, it was carried out by adopting a two-step feeding of tetraethoxysilane including initial dropping and subsequent addition of residual TEOS in one batch. The synthesized hollow particles have been extensively characterized using a scanning electron microscope, transmission electron microscope and N2 sorption analysis. The results indicated that the morphology of the resultant hollow silica particles was governed by simply changing the volume ratio of the precursor added in two steps, the reaction temperature and the concentration of ammonia. Additionally, the mechanism governing the formation of the hollow silica particles is discussed.

By means of the “swelling−diffusion−interfacial polymerization method” (SDIPM), we successfully coated polyaniline (PANi) onto the positively charged polystyrene (PS) particles, which electrostatically repulse each other. After initially forming aniline-swollen PS particles, diffusion of the monomer toward the aqueous phase was controlled through a slow addition of hydrochloric acid, eventually leading to its polymerization on the particle surface. It is an unique, facile, and efficient approach based on raw substrate particles with cationic surface, in comparison with the previous efforts focusing on laborious surface modification or customized design of the substrate particles. The synthesized composite particles have been extensively characterized using scanning electron microscope, transmission electron microscope, Fourier transform infrared, Raman spectroscopy, and thermogravimetry. The resultant PS/PANi core/shell conductive composites possessed a uniform, intact PANi overlayer, and furthermore, their mophology can be well controlled by simply changing weight ratio of aniline/PS. The importance of the results just consists in the fact that the limitation of constructing an overlayer on similarly charged substrate particles should be overcome by adopting the unique SDIPM.

Hollow polystyrene particles were prepared via miniemulsion polymerization of styrene and divinylbenzene adopting the isooctane as hydrophobe, whose structure and properties were characterized using transmission electron microscopy and thermogravimetry. Great attention was paid to the kinetic effects on controlling the particle structure rather than the thermodynamic part. The influence of factors such as divinylbenzene/styrene molar ratio, isooctane content, and the type and amount of initiator on the ultimate structure of polystyrene particles were researched. A similar evolution of the particle structure and an obvious turning point from porous to hollow were both distinctly observed along with the changing in all these parameters. All the phenomena and results can be well illuminated from the diffusion control based on the kinetic viewpoint and especially, it further reveals that the particle structure can be powerfully and effectively controlled under kinetics in a broad sense.

Most ordinary polystyrene (PS) microspheres without any surface modification and hard magnetic cobalt ferrite (CoFe2O4) nanoparticles were, respectively, used as large host particles and small guest particles in a heterocoagulation system. In order to achieve a regular heterocoagulation for fabricating PS–CoFe2O4 composite particles having tailored morphology, chief attention was focused on controlling over the heterocoagulation process instead of the surface modification of the polymer microspheres. A process was adopted, which included blending the two colloids at pH 1 and then, adjusting the pH value of the blending colloid to an optimal range of 2–4 under a suitable weight ratio of the two kinds of particles. The results of TEM, SEM, ζ-potential, TGA and magnetization measurements have confirmed the high density of coverage of the CoFe2O4 nanoparticles onto the surface of polystyrene particles.

A heterocoagulation strategy based on colloidal steric stabilization theory has been developed, through which polystyrene (PS) and silica (SiO2) particles without any surface modification or functionalization self-assembled rapidly via solution to afford nanocomposite particles with raspberry-like morphology. The formation mechanism is fully studied on the basis of a thermodynamic analysis. The soluble stabilizer and the solvent quality are the main determining factors, which have a significant influence on this self-assembly process and the silica coverage of resultant composites. The relative size of PS to SiO2 candidates also has the effect of control on the extent of self-assembly. Furthermore, this strategy can be applied to fabricate a broad range of composite materials, including PS/TiO2, PS/AgI, as well as PS/PS composites.

A preparation manner for monodispersed polystyrene (PS) nanoparticles polymerized by using a novel addition procedure of a monomer is suggested. In systems containing a smaller amount of surfactant compared with conventional microemulsion polymerization, the polymerization processes consists of three stages: adding dropwise the first part of the monomer for a few minutes at 80°C and polymerizing for 1 h; adding collectively the residual part of the monomer and polymerizing at the same temperature for another 1 h; and then polymerizing at 85°C for another 1 h. Based on discussions on the nucleation mechanism of particles in the polymerization system, the influences of monomer weight added dropwise, and amounts of initiator and emulsifier on the size and distribution of PS particles were investigated. PS nanoparticles with smaller diameter such as a number-average diameter of 18.7 nm and better monodispersity were obtained since the dropped styrene amount was suitable under 20wt-% emulsifier amount and 3wt-% initiator amount based on the monomer.

Herein, we propose a facile and efficient method to obtain the polystyrene/graphene nanosheets (PS/GNSs) nanocomposite particles. As far as we know, it is the first example that GNSs are attached onto the surface of PS microspheres, with such smooth morphology, and without relying on any surface pretreatments of substrate microspheres.

The fabrication of hollow silica particles is of interest from both academic and application viewpoints. In this paper, we propose a distinctly novel method by which hollow silica particles are successfully fabricated in a self-stable system without any surfactants during a self-consumptive templated process. In detail, it was carried out by adopting a two-step feeding of tetraethoxysilane including initial dropping and subsequent addition of residual TEOS in one batch. The synthesized hollow particles have been extensively characterized using a scanning electron microscope, transmission electron microscope and N2 sorption analysis. The results indicated that the morphology of the resultant hollow silica particles was governed by simply changing the volume ratio of the precursor added in two steps, the reaction temperature and the concentration of ammonia. Additionally, the mechanism governing the formation of the hollow silica particles is discussed.

A facile and controllable method of immobilizing gold nanoparticles (AuNPs) on hollow silica particles (SiO2HPs) is proposed and the resultant SiO2HP/AuNP composite particles exhibit high catalytic activity. The carrier SiO2HPs decorated with amino groups are prepared in a W/O inverse emulsion, having a well-defined hollow structure, mesoporous wall and dense bush-like surface morphology. A large number of ultrafine AuNPs are generated via in situ reduction of chloroauric acid by the amino groups and firmly anchored on the bush-like silica shell. The structure and morphology of the composites are governed by changing the weight percentage of 3-aminopropyltriethoxysilane in the total amount of monomers (wa), which have been extensively characterized. Benefiting from the unique multiple structures, the composite particles exhibited outstanding catalytic efficiency and repeatability, which are confirmed by two oxidation–reduction reactions of 2-nitroaniline/NaBH4 and 4-nitrophenol/NaBH4.