Polymer Shell Research Articles

Preparation and Performance Research of Magnetic Polymer Microspheres

In this thesis, polystyrene magnetic polymer microspheres with good monodispersity and carboxyl functional groups were prepared. The adsorption properties of styrene-acrylic acid magnetic polymer microspheres to bovine serum albumin have been studied.. Using Fe3O4 magnetic fluid as the magnetic core and styrene-acrylic acid copolymer as the polymer shell, composite microspheres with very small particle diameters were prepared by the dispersion polymerization method.

3D printed polymeric formwork for lattice cementitious composites

How to design energy-efficient building materials, theoretically requiring a balance of mechanical properties and thermal conductivity , remains a crucial challenge in construction & building fields. Recently there is an increased interest in using 3D concrete printing technology to automatically manufacture complicated and customized constructions. Nevertheless, majority of printed constructions are still solid and have a low quality in the interface performance. Inspired by the lightweight lattice architecture, 3D core-framework lattice cementitious composites (CS-LCCs) is proposed in this work, which consists of printed polymeric framework and cement mortar . Results show that although the average compressive strength of CS-LCCs is lower than that of the cubic sample fabricated using the cement mortar (40 × 40 × 40 mm 3 ), the specific strength of CS-LCCs approaches that of cubic one. The ductility of CS-LCCs is obviously improved due to the effect of polymeric framework. According to the test and finite element analysis , a hinging and stretching couple deformation mechanism is used to elaborate the deformation mechanism of CS-LCCs. Additionally, the CS-LCCs also exhibit low thermal conductivities at various temperatures owing to the ordered porous characteristic of lattice. ● A core/shell lattice-inspired cementitious composites is proposed. ● High specific strength and ductility are obtained owing to the effect of polymeric shell. ● Multi-crack propagation mode and deformation mechanism are elaborately discussed. ● Low thermal conductivity is achieved compared to that of the counterpart solid materials.

Determining patterns in reducing the level of bio-destruction of thermally modified timber after applying protective coatings

This paper reports the analysis of the biological destruction of timber and the use of protective materials, which established that the scarcity of data to explain and describe the process of bioprotection, neglect of environmentally friendly agents lead to the biodegradation of timber structures under the action of microorganisms. Devising reliable methods for studying the conditions of timber protection leads to designing new types of protective materials and application technologies. Therefore, it becomes necessary to determine the conditions for the formation of a barrier for bacteria permeability and to establish a mechanism for inhibiting material biodegradation. Given this, the dependence has been derived to determine the proportion of destroyed material under the effect of microorganisms when using an antiseptic-hydrophobicizer, which makes it possible to evaluate biopenetration. Based on the experimental data and theoretical dependences, the share of destroyed timber was determined under the effect of microorganisms, which is equal to 1 for natural timber. At the same time, this value for thermally modified timber is 0.033, and, when it is protected with oil ‒ 0.009, respectively, exposed to the action of microorganisms for 60 days. It should be noted that the presence of oil, wax, and azure leads to blocking the timber surface from penetration. Such a mechanism underlying the effect of protective coating is likely the factor in the process adjustment, due to which the integrity of the object is preserved. Thus, a polymer shell was created on the surface of the sample, significantly reducing the penetration of microorganisms inside the timber, while the loss of timber mass during biodestruction did not exceed 2.5 %. Therefore, there are grounds to assert the possibility of targeted control over the processes of timber bio-penetration by using coatings capable of forming a protective film on the surface of the material

Synthesis of Fe3O4@Zn-BDC nanocomposite for the removal of MB from aqueous solution

Coordination polymers (CPs) are a significant platform for dye adsorption. Designing Fe3O4@CP nanocomposites as easy-recoverable adsorbents could facilitate their recycling. In this research, a core-shell Fe3O4@CP nanocomposite was prepared for methylene blue (MB) adsorption and removal from aqueous solutions. The obtained nanocomposite consists of Fe3O4 core and coordination polymer shell constructed from Zn2+ and benzene-1,4-dicarboxylic acid (H2-BDC) which formed with layer-by-layer assembly. The formation of the core-shell nanostructure was approved with various physicochemical techniques. The microscopy results confirmed a core-shell nanostructure for Fe3O4@CP nanocomposite that shell thickness is about 5–7 nm. The adsorption experiments indicated that Fe3O4@CP nanocomposite not only adsorbed more than 86% of MB only after 2 min, it significantly could be separated magnetically and reused without evident loss of adsorption efficiency after four cycles.

Hybrid Inorganic-Organic Core-Shell Nanodrug Systems in Targeted Photodynamic Therapy of Cancer.

Hybrid inorganic-organic core-shell nanoparticles (CSNPs) are an emerging paradigm of nanodrug carriers in the targeted photodynamic therapy (TPDT) of cancer. Typically, metallic cores and organic polymer shells are used due to their submicron sizes and high surface to volume ratio of the metallic nanoparticles (NPs), combined with enhances solubility, stability, and absorption sites of the organic polymer shell. As such, the high loading capacity of therapeutic agents such as cancer specific ligands and photosensitizer (PS) agents is achieved with desired colloidal stability, drug circulation, and subcellular localization of the PS agents at the cancer site. This review highlights the synthesis methods, characterization techniques, and applications of hybrid inorganic-organic CSNPs as loading platforms of therapeutic agents for use in TPDT. In addition, cell death pathways and the mechanisms of action that hybrid inorganic-organic core-shell nanodrug systems follow in TPDT are also reviewed. Nanodrug systems with cancer specific properties are able to localize within the solid tumor through the enhanced permeability effect (EPR) and bind with affinity to receptors on the cancer cell surfaces, thus improving the efficacy of short-lived cytotoxic singlet oxygen. This ability by nanodrug systems together with their mechanism of action during cell death forms the core basis of this review and will be discussed with an overview of successful strategies that have been reported in the literature.

The Core–Shell Structure, Not Sugar, Drives the Thermal Stabilization of Single-Enzyme Nanoparticles

Trehalose is widely assumed to be the most effective sugar for protein stabilization, but exactly how unique the structure is and the mechanism by which it works are still debated. Herein, we use a polyion complex micelle approach to control the position of trehalose relative to the surface of glucose oxidase within cross-linked and non-cross-linked single-enzyme nanoparticles (SENs). The distribution and density of trehalose molecules in the shell can be tuned by changing the structure of the underlying polymer, poly(N-[3-(dimethylamino)propyl] acrylamide (PDMAPA). SENs in which the trehalose is replaced with sucrose and acrylamide are prepared as well for comparison. Isothermal titration calorimetry, dynamic light scattering, and asymmetric flow field-flow fraction in combination with multiangle light scattering reveal that two to six polymers bind to the enzyme. Binding either trehalose or sucrose close to the enzyme surface has very little effect on the thermal stability of the enzyme. By contrast, encapsulation of the enzyme within a cross-linked polymer shell significantly enhances its thermal stability and increases the unfolding temperature from 70.3 °C to 84.8 °C. Further improvements (up to 92.8 °C) can be seen when trehalose is built into this shell. Our data indicate that the structural confinement of the enzyme is a far more important driver in its thermal stability than the location of any sugar.

Plasma‐Assisted Deposition of TiO2 3D Nanomembranes: Selective Wetting, Superomniphobicity, and Self‐Cleaning

AbstractFabrication of tunable wetting surfaces is sought for the last years given its importance on energy, biomaterials and antimicrobials, water purification, microfluidics, and smart surfaces. Liquid management on surfaces mainly depends on the control at the micro‐ and nanoscale of both roughness and chemical composition. Herein, the combination of a soft‐template method and plasma‐enhanced chemical vapor deposition is presented for the synthesis of TiO2 nanofibers on porous substrates such as cellulose and stainless‐steel membranes. The protocol, carried out under mild conditions, produces 3D nanomembranes with superhydrophobicity and oleophilicity that are tested as microliter water/oil filters. Photoactivation of TiO2 by UV illumination provides a straightforward approach for wetting tunability that converts the surface into amphiphilic. A final chemical modification of the TiO2 nanofibers by embedding them in an elastomeric polymeric shell and by fluorine‐based grafting opens the path toward the formation of superomniphobic and self‐cleaning surfaces with long‐lasting lifetimes. Thus, a reliable procedure is demonstrated for the fabrication of TiO2 nanofibers, which allows the modification of porous supports and provides an innovative route for the development of 3D nanomembranes with under design wetting. This protocol is extendable to alternative metal oxides, metals, and core@shell nanoarchitectures with potential multifunctionalities.

Layer-by-Layer-Stabilized Plasmonic Gold-Silver Nanoparticles on TiO2: Towards Stable Solar Active Photocatalysts.

To broaden the activity window of TiO2, a broadband plasmonic photocatalyst has been designed and optimized. This plasmonic ‘rainbow’ photocatalyst consists of TiO2 modified with gold–silver composite nanoparticles of various sizes and compositions, thus inducing a broadband interaction with polychromatic solar light. However, these nanoparticles are inherently unstable, especially due to the use of silver. Hence, in this study the application of the layer-by-layer technique is introduced to create a protective polymer shell around the metal cores with a very high degree of control. Various TiO2 species (pure anatase, PC500, and P25) were loaded with different plasmonic metal loadings (0–2 wt %) in order to identify the most solar active composite materials. The prepared plasmonic photocatalysts were tested towards stearic acid degradation under simulated sunlight. From all materials tested, P25 + 2 wt % of plasmonic ‘rainbow’ nanoparticles proved to be the most promising (56% more efficient compared to pristine P25) and was also identified as the most cost-effective. Further, 2 wt % of layer-by-layer-stabilized ‘rainbow’ nanoparticles were loaded on P25. These layer-by-layer-stabilized metals showed superior stability under a heated oxidative atmosphere, as well as in a salt solution. Finally, the activity of the composite was almost completely retained after 1 month of aging, while the nonstabilized equivalent lost 34% of its initial activity. This work shows for the first time the synergetic application of a plasmonic ‘rainbow’ concept and the layer-by-layer stabilization technique, resulting in a promising solar active, and long-term stable photocatalyst.

Preparation of core‐shell microporous organic polymer‐coated silica microspheres for chromatographic separation and N‐glycopeptides enrichment

Through a "one-pot" strategy, a layer of microporous organic polymer was coated onto the surface of monodisperse amino-functionalized silica microsphere via amino-aldehyde condensation reaction with core-shell structure. The change in chemical structure of material before and after modification was determined by Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. Due to existence of a large number of amino and aldehyde groups in microporous organic polymer shell, the water contact angle decreased from 56.8° (silica microspheres) to 34.7° (microporous organic polymer-coated silica microspheres). Based on these properties, microporous organic polymer-coated silica microspheres were employed as the stationary phase for capillary liquid chromatography and successfully offered baseline separation of polar small molecules. Additionally, the material could also be served as the sorbent of hydrophilic interaction chromatography to enrich glycopeptides from human serum digest. A total of 470 unique N-glycopeptides and 342 N-glycosylation sites mapped to 112 N-glycosylated proteins were unambiguously identified from 2μL of human serum, exhibiting a promising application prospect of microporous organic polymer-coated silica microspheres in the pretreatment of proteomics samples.

Roles of aqueous additives in the mass transfer process of water molecules in water/oil/water double emulsion droplets

Finding suitable aqueous additives to inhibit the mass transfer of water molecules in double emulsion droplets is beneficial for improving the surface quality of polymer shells. In this work, fluorobenzene/aqueous systems with polyvinyl alcohol (PVA) molecules and electrolyte ions were constructed by molecular dynamics simulation, which are typical water/oil (W/O) systems in actual fabrication processes of polymer shells. The interfacial mass transfer coefficients and equilibrium water solubility in fluorobenzene of various W/O systems were calculated by fitting the dissolution curves with a classical mass transfer model. The effects of polyvinyl alcohol additives on the diffusion process of water molecules at the fluorobenzene/water interface were investigated from the perspectives of thermodynamics and microscopic interface morphology. Furthermore, to avoid the inner surface defects of polymer shells caused by electrolyte ions osmosis, 1,3-butanediol molecules were proposed to replace ions as aqueous solutes, which also inhibited the diffusion of water molecules to fluorobenzene membrane.

Hemoglobin microbubbles for in vivo blood oxygen level dependent imaging: Boldly moving beyond MRI

Microbubbles are gas-filled, micron-sized particles stabilized by lipid, protein, or polymer shells. They scatter ultrasound energy efficiently due to their compressible gas cores, making them excellent blood pool contrast agents in ultrasound imaging. In this project, we have developed a novel oxygen-sensitive hemoglobin-shell microbubble designed to acoustically detect blood oxygen levels in vivo. We hypothesized that structural changes in the hemoglobin in response to varying oxygen levels will alter the mechanical properties of the bubble shell, resulting in detectable changes in the bubble acoustic signature. In this project, we have (1) optimized the hemoglobin bubble formulation for in vivo circulation, (2) demonstrated that the hemoglobin shell is still responsive to oxygen after formulation, and (3) characterized the acoustic response of the microbubbles at varying oxygen levels. Our preliminary results show a strong correlation between the oxygen concentration in the solution and the acoustic response of bubbles, suggesting that they would serve as excellent oxygen sensors. If successful, in vivo sensing of oxygen levels would have numerous benefits, including evaluating the hypoxic regions in tumors and in the brain, among other blood-oxygen-level-dependent (BOLD) imaging applications.

Ionic liquids filled hybrid capsules by harnessing interfacial imine chemistry of Janus nanosheets stabilized pickering emulsion for removal of chlorophenols

Ionic liquids filled hybrid capsules (C-IL) hold promise as extraction medium to remove phenolic endocrine disruptors (PEDs), which are priority pollutants because of their high persistence and toxicity. Nonetheless, preparation of uniformly sized C-IL has stand out as the major drawback for their use on adsorption applications. In this work, Janus graphene oxide (J-GO) nanosheets stabilized Pickering emulsion incorporated with interfacial imine chemistry were used for synthesis of polymer shell encapsulated 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6), and then as-prepared hybrid capsules (C-IL/W) were considered as a novel material for 3,4,5-trichlorophenol (3,4,5-TCP) capture. Uniformly sized C-IL/W (180 μm in diameter) had high IL content of 90 wt%, and its shell thickness from quick interfacial imine chemistry in situ is about 2.0 to 2.5 μm. Benefiting from the strong hydrogen bonding and π-π conjugation of the two aromatic rings with loaded [BMIM]PF6, the maximum adsorption capacity calculated from Langmuir model was 6775 mg g−1 at 25 °C for 3,4,5-TCP. Through the principal component analysis (PCA), the facts that chlorine substituent such as its number and location posed a significant influence on the PEDs extraction efficiency were confirmed, which followed the order: 2-chlorophenol (2-CP) < 2,6-dichlorophenol (2,6-DCP) < 2,4-dichlorophenol (2,4-DCP) < 3,4,5-TCP. The hydrophobicity and steric hindrance upon [BMIM]PF6 were the main factors affecting the extraction performance. After three regeneration cycles, the adsorption capacity of capsules towards 3,4,5-TCP was 79% of the first cycle, and the desorption efficiency was still above 90%. The results not only demonstrated an important method to design C-IL for PEDs removal, but also suggested the possible mechanism for chlorophenols extraction.

Bispecific prodrug nanoparticles circumventing multiple immune resistance mechanisms for promoting cancer immunotherapy

Cancer immunotherapy is impaired by the intrinsic and adaptive immune resistance. Herein, a bispecific prodrug nanoparticle was engineered for circumventing immune evasion of the tumor cells by targeting multiple immune resistance mechanisms. A disulfide bond-linked bispecific prodrug of NLG919 and JQ1 (namely NJ) was synthesized and self-assembled into a prodrug nanoparticle, which was subsequently coated with a photosensitizer-modified and tumor acidity-activatable diblock copolymer PHP for tumor-specific delivery of NJ. Upon tumor accumulation via passive tumor targeting, the polymeric shell was detached for facilitating intracellular uptake of the bispecific prodrug. NJ was then activated inside the tumor cells for releasing JQ1 and NLG919 via glutathione-mediated cleavage of the disulfide bond. JQ1 is a bromodomain-containing protein 4 inhibitor for abolishing interferon gamma-triggered expression of programmed death ligand 1. In contrast, NLG919 suppresses indoleamine-2,3-dioxygenase 1-mediated tryptophan consumption in the tumor microenvironment, which thus restores robust antitumor immune responses. Photodynamic therapy (PDT) was performed to elicit antitumor immunogenicity by triggering immunogenic cell death of the tumor cells. The combination of PDT and the bispecific prodrug nanoparticle might represent a novel strategy for blockading multiple immune evasion pathways and improving cancer immunotherapy.

Current views on the pharmacological correction of iron deficiency conditions in gynecological practice

The review considers features of iron and folic acid (FA) pharmacokinetics, which affect the effective micronutrient support: molecular mechanisms of absorption and distribution, homeostatic processes of maintaining plasma vitamin and mineral levels by the feedback mechanism, including by regulating the deposition. An important characteristic of ferrokinetics is the presence of unique iron exporter ferroportin which is controlled by a family of iron regulatory proteins. Systemic ferrotherapy and oral rout of iron delivery are distinguished. In general, parenteral iron preparation complexes consist of Fe(III) oxide/hydroxide core stabilized by a carbohydrate polymer shell. Once entering the bloodstream, iron complexes are absorbed by resident macrophages of the reticuloendothelial system of the liver, spleen and bone marrow. Systemic Fe(III) preparations are prodrugs, the active part of which, i.e. iron is released in the lysosomal matrix of phagocytes. Oral iron preparations are divided into those containing bivalent (ferrous) and trivalent (ferric) iron. The article discusses factors determining the differences in the absorption of oral ferrous and ferric iron preparation, the spectrum of side effects, as well as key pharmaceutical approaches to increase the tolerance and adherence of ferrotherapy. These include using preparations containing Fe(II) organic compounds that have a lower dissociation rate than inorganic iron salts as well as slowing down the release of the active Fe(II) pharmaceutical substance from the drug. The review pays special attention to folates as iron synergists and examines the features of FA pharmacokinetics, the molecular basis of synergism, and substantiates the use of combined iron and FA preparations.

Iron Oxide/Polymer Core-Shell Nanomaterials with Star-like Behavior.

Embedding nanoparticles (NPs) with organic shells is a way to control their aggregation behavior. Using polymers allows reaching relatively high shell thicknesses but suffers from the difficulty of obtaining regular hybrid objects at gram scale. Here, we describe a three-step synthesis in which multi-gram NP batches are first obtained by thermal decomposition, prior to their covalent grafting by an atom transfer radical polymerization (ATRP) initiator and to the controlled growing of the polymer shell. Specifically, non-aggregated iron oxide NPs with a core principally composed of γ-Fe2O3 (maghemite) and either polystyrene (PS) or polymethyl methacrylate (PMMA) shell were elaborated. The oxide cores of about 13 nm diameter were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS). After the polymerization, the overall diameter reached 60 nm, as shown by small-angle neutron scattering (SANS). The behavior in solution as well as rheological properties in the molten state of the polymeric shell resemble those of star polymers. Strategies to further improve the screening of NP cores with the polymer shells are discussed.

NIR-light triggered dual-cascade targeting core-shell nanoparticles enhanced photodynamic therapy and immunotherapy

Cell and organelle targeting of nanomedicines are two cascade processes that lead to drug internalization and subsequent enrichment on the final target. However, it is still challenging to achieve dual-cascade targeting (DCT) with high spatiotemporal precision and efficiency via sequential activation of nanomedicine. Herein, we developed DCT core-shell nanoparticles triggered by near infrared (NIR) light for optimized photodynamic therapy (PDT) and immunotherapy. To obtain the DCT core-shell nanoparticles, an aggregation induced emission (AIE) monomer (7) with two hydroxyl groups was first synthesized. Thereafter, two core polymers with either reactive oxygen species (ROS) generation or mitochondrial targeting ability, and a shell polymer with cell surface targeting were synthesized. Assembly of the core polymers and subsequent coating with the shell polymer formed DCT core-shell nanoparticles (NP4). After NP4 were i.v. injected into mice, they were efficiently accumulated at tumor sites. Upon NIR light irradiation, NP4 induced robust ROS generation with concomitant detachment of negative shell polymers with polyethylene glycol (PEG), resulting in charge reversal and the positively charged core nanoparticles for mitochondrial targeting. Subsequently, ROS generated in mitochondria upon continuous light irradiation killed cancer cells via PDT. In addition, PDT induced immunogenic cell death (ICD), thus activating adaptive immunity. This work provided a novel strategy for nanoparticles with DCT capacity to maximize the effectiveness of combined photodynamic and immunotherapy.

Development of a dual capsule self‐healing silicone composite using silicone chemistry and poly(melamine‐urea‐formaldehyde) shells

AbstractThis study aims to develop microcapsules that can be used as room‐temperature self‐healing agents in silicone‐based matrices. A telechelic reactive silanol‐terminated polydimethylsiloxane (PDMS) as the healing agent, was selected to ensure the homogeneity of the polymeric matrix and encapsulated in poly(melamine‐urea‐formaldehyde) shells through an in‐situ emulsion polymerization technique. To catalyze the polycondensation reaction of the healing agent, dibutyltin dilaurate (DBTL) was encapsulated within the same type of polymeric shell. The synthesized microcapsules were characterized using Fourier‐transform infrared spectrometry, optical microscopy, scanning electron microscopy (SEM), and differential scanning calorimetry. The analyses confirmed that the spherical microcapsules with an average size of 56 μm for PDMS‐MUF microcapsules and 42 μm for DBTL‐MUF microcapsules, with a shell wall thickness of 100–200 nm, and good thermal stability were formed. Therefore, the two‐component self‐healing silicone composite was successfully developed using 10:1.2 wt% PDMS: DBTL microcapsules within the silicone matrix. SEM showed the self‐healing ability of the silicone matrix by observing the successful healing of microcracks at room temperature. Tensile and trouser tear tests were adopted to assess the self‐healing performance of the elastomeric matrix, showing the self‐healing efficiencies of 67% and 55%, respectively.

Expandable crosslinked polymer coatings on silicon nanoparticle anode toward high-rate and long-cycle-life lithium-ion battery

Porous and electrically conductive coating on silicon nanoparticles (Si NPs) anode can mitigate the volume expansion during charging or discharging in Li-ion battery (LIB) while conventional protection coating process resulted in non-uniform polymer shell which show low volumetric or areal capacities. Here, we demonstrated that ultra-thin polyacrylonitrile layer can be formed conformally by emulsion-assisted coating process and cross-linked on Si NPs (Si@x-PAN) producing stable and expandable polymer shell which showed a highly stable long-term cycling ability. Areal and specific capacities of Si@x-PAN were an ∼ 2 mAh/cm2 and a 2000 mAh/g, respectively. Importantly, we found that capacity decay was only 5 % after 100 cycles and>75 % of capacity was retained even after 1000 cycles (0.5C/0.5C) with the help of a uniform Li-ion current around the Si NPs during continuous charging and discharging. To our knowledge, this long-term stability at reasonable loading levels is one of the highest levels of performance in pure Si anode systems.

Building effective core/shell polymer nanoparticles for epoxy composite toughening based on Hansen solubility parameters

Abstract Particles have been demonstrated to toughen epoxy resins, especially for fiber-reinforced epoxy composites, and core/shell particles are one of them. It is known that not all particles toughen the same but most evaluations are through experimentation, and few studies have been conducted to accurately predict the particles’ toughening effect or guide the design of effective particles. In this study, efforts were made to find the control factors of core/shell particles, primarily interfacial compatibility and degree of dispersion, and how to predict them. Nanocomposites were fabricated by incorporating core/shell nanoparticles having various shell polymer compositions, especially their polarities. Their compatibility was estimated using a novel quantitative approach via adopting the theory of Hansen solubility parameters (HSP), in which the HSP of core/shell nanoparticles and the epoxy matrix were experimentally determined and compared. It was found that the HSP distance was a good predictor for particle dispersion and interfacial interaction. Particles having a small HSP distance (R a) to the epoxy resin, represented by the polybutylacrylate core/polymethyl methacrylate shell particle having the smallest R a of 0.50, indicated a uniform dispersion and strong interfacial bonding with the matrix and yielded outstanding toughening performance. In contrast, polybutylacrylate core/polyacrylonitrile shell particle having the largest HSP distance (6.56) formed aggregates and exhibited low interfacial interaction, leading to poor toughness. It was also demonstrated that HSP can provide an effective strategy to facilitate the design of effective core/shell nanoparticles for epoxy toughening.

Preparation and Properties of Thermally Expandable Microspheres for Foam Coating

A type of thermally expandable microspheres (TEMs) for foam coating was prepared by suspension polymerization with acrylonitrile (AN), methyl methacrylate (MMA), vinyl acetate (VAC) as shell polymer monomers and i-pentane as core foaming agent. The effects of an aqueous additive (Sodium Chloride, NaCl) on the size and distribution of TEMs, and the effects of crosslinking degree, i-pentane dosage and monomer mass ratio on the expansion property, expansion temperature and solvent-resistance of TEMs were investigated. The results showed that when the dosage of NaCl was close to the saturation solubility (30%), the dosage of crosslinking agent and alkane were about 0.09% and 7.4%, and the mass ratio of AN/MMA/VAC w rm distribution and good solvent resistance, the expansion diameter ratio was 5 times under 110~120 C, which meets the application requirements for foam coating of leather or synthetic leather.