Composite Polymer Particles Research Articles

Novel Magnetically Doped Epoxide Functional Cross-linked Hydrophobic Poly(lauryl methacrylate) Composite Polymer Particles for Removal of As(III) from Aqueous Solution

Superparamagnetic iron oxide nanoparticles have been found suitable as adsorbent materials for the removal of As(III) from aqueous solution. In this investigation, the usefulness of magnetically doped epoxide functional cross-linked poly(lauryl methacrylate) (PLMA) composite polymer particles as an adsorbent bed for the removal of As(III) ions has been evaluated. The epoxide functional composite polymer particles are prepared by seeded polymerization of glycidyl methacrylate (GMA) in the presence of cross-linked poly(LMA-divinylbenzene), P(LMA-DVB), seed particles. The surface of prepared composite polymer particles is finally doped with Fe3O4 nanoparticles. The epoxide functional magnetic composite polymer particles have been named as P(LMA-DVB)/PGMA/Fe3O4. A pH and contact time dependent adsorption behavior of As(III) is observed on P(LMA-DVB)/PGMA/Fe3O4 composite polymer particles. The equilibrium (qe) reached after 180 min and a highest removal efficiency of 57.98% is attained at pH 5.0. The adsorptio...

Synthesis of composite polymer particles with carbon nanotubes and evaluation of their mechanical properties

In the present study, a method for synthesizing composite polymer particles with multi-wall carbon nanotubes (MWCNTs) was developed, and the particles’ mechanical properties were evaluated. First, the surfaces of MWCNTs were modified by acids to increase their hydrophilicity, resulting in surface-active MWCNTs. Then, a Pickering emulsion was formed using liquid benzyl methacrylate monomer and the surface-active MWCNTs. The surface charge of the surface-active MWCNTs greatly influenced the surface coverage and size of the composite particles. Furthermore, when untreated MWCNTs were added to the monomer phase, surface coverage of the resulting particles was enhanced because MWCNTs on the surface of the particles interacted with MWCNTs incorporated inside the particles, thus preventing the surface-active MWCNTs on the surface from being released into the bulk. As a result, the mechanical properties of the composite polymer particles were successfully improved because the incorporated MWCNTs worked well as fillers.

Magnetite loaded cross-linked polystyrene composite particles prepared by modified suspension polymerization and their potential use as adsorbent for arsenic(III)

Magnetic particles have attracted much interest because they can be easily guided under the influence of magnetic field and are considered suitable in biomedical as well as in separation technology. In this work, magnetite (Fe3O4) loaded cross-linked polystyrene (PS) composite particles are prepared by a novel suspension polymerization of styrene and divinylbenzene (DVB) in presence of nanosized iron oxide (Fe3O4) particles dispersed in n-octane. The structure and surface properties are systematically characterized using FTIR, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and thermogravimetric analyses (TGA). The morphology and surface structure reveal that Fe3O4 nanoparticles are mostly dispersed within the P(S-DVB) copolymer layer. Finally the applicability of Fe3O4/P(S-DVB) composite polymer particles as adsorbent for toxic element like trivalent arsenic (As) has been investigated. Fe3O4/P(S-DVB) composite polymer particles exhibited good sorption efficiency compared to reference P(S-DVB) copolymer particles.

Композиционные полимерные суспензии со сложной морфологией частиц

The review is dedicated to the synthesis of composite polymer suspensions with complex particle morphology. Authors attempted to summarize effects of polymerization conditions on particle morphology. The significance of further investigations in the field of composite polymer suspensions synthesis was shown. The main aspects of different monomers emulsion homopolymerization, affecting the polymer particle morphology, such as polymerization topochemistry, free energy of particle formation, the kind of monomer and others were discussed. The determination methods of polymer particles phase structure may be shown to be classified as direct and indirect. The most frequently used investigation methods of suspension particles morphology viz electron microscopy, soap titration technique and film forming were described. General techniques of composite polymer particle synthesis, such as emulsion copolymerization and seed polymerization, were given and considered in detail. Advantages and disadvantages of each method were listed. Determination of particle morphology, using thermodynamic approach, was discussed. Obtained composite polymer particles were found to be classified into two large groups: non-uniform composite gradient particles and heterophase particles.

Analysis of production parameters of single-lap bonds adhesive bonded with composites based on aluminium filler

In the area of bonding of sheets of metals, mainly in construction of transport and agricultural machines, single-lap bonds are used. In manufacturing corporations focused on bonding of the metal sheets the technologies such as riveting, welding and adhesive bonding are particularly used. These methods are frequently combined. The aim of the research was the evaluation of lap length of alloy AlCu4Mg adhesively bonded using two component epoxy adhesive, which is commonly used in construction of machines and its modification based in addition of filler in form of aluminium microparticles. The secondary aim of the research was to ascertain the influence of microparticle volume of aluminium filler on mechanical properties of polymer particle composite. Strength of adhesively bonded joint depends on the thickness of the bonded material. Strength of the adhesively bonded joint is dependent on the lapping length of adhesively bonded material. The highest values of strength of adhesively bonded joint were reached with the coefficient of the proportional length 0.27 ± 0.01. The assumption about negative effect of filler on tensile strength during the experiments was not confirmed.

A novel projection based electro-stereolithography (PES) process for production of 3D polymer-particle composite objects

PurposePolymer-particle composites, which have demonstrated wide applications ranging from energy harvesting and storage, biomedical applications, electronics and environmental sensing to aerospace applications, have been investigated for decades. However, fabricating polymer-particle composites with controlled distribution of particles in polymer continues to be a fundamental challenge. As to date, a few additive manufacturing (AM) technologies can fabricate composites, however, with a limited choice of materials or limited dispersion control. Against this background, this research investigated a hybrid polymer-particle composite manufacturing process, projection electro-stereolithography (PES) process, which integrates electrostatic deposition and projection based stereolithography (SL) technologies.Design/methodology/approachIn PES process, a photoconductive film collects charged particles in the regions illuminated by light. Then, collected particles are transferred from the film to a polymer layer with defined patterns. Lastly, a digital mask is used to pattern the light irradiation of the digital micromirror device chip, selectively curing the photopolymer liquid resin and particles of that layer. By transferring particles from the photoconductive film to the photopolymer in a projection-based SL system, multi-material composites with locally controlled dispersions could be produced. A proof-of-concept PES testbed was developed. Various test cases have been performed to verify the feasibility and effectiveness of the developed approach.FindingsChallenges in this novel AM process, including process design, particle patterning and transferring, are addressed in this paper. It is found that particles can be transferred to a layer of partially cured resin completely and accurately, by using the stamping approach. The transferring rate is related to stamping force and degree of conversion of the recipient layer. The developed hybrid process can fabricate polymer-particle composites with arbitrary dispersion pattern, unlimited printable height and complicated geometries.Originality/valueAlthough an electrostatic deposition process has been investigated as a 3D printing technology for many years, it is the first attempt to integrate it with projection SL for fabricating multi-material polymer composite components. The novel hybrid process offers unique benefits including local dispersion control, arbitrary filling patterns, wide range of materials, unlimited printable height and arbitrary complicated geometries.

Preparation of Polymer Composite Particles by Phase Separation Followed by Suspension Polymerization

The novel method for preparing the polymer composite particles has been developed. It was tried to prepare polymer composite particles composed of polystyrene and carbon black with the phase separation method followed by suspension polymerization. In order to prepare the polymer composite particles with the more uniform diameter, the styrene monomer droplets containing carbon black were formed with phase separation emulsification in which ethyl alcohol and water were used as the good solvent and the poor solvent for styrene monomer, respectively. In the experiment, the surfactant species and their concentrations, the pouring velocity of water and the weight ratio of carbon black to styrene monomer were mainly changed. Water was poured at the given pouring velocity into ethyl alcohol in which styrene monomer and an initiator were dissolved and carbon black was dispersed beforehand. The spherical polymer composite particles containing carbon black were prepared with Tween 20 and Tween 80 of nonionic surfactants and the irregular polymer composite particles were prepared with PVA, SDS and Kotamine. The diameters of polymer composite particles increased with the pouring velocity of water and with the weight ratio of carbon black to styrene monomer.

Preparation of Highly Cross-linked Magnetic Polymer Composite Particles and Application in the Separation of Arsenic from Water

Iron oxide magnetic particles have become a promising research field in separation technology because of their easy separation by external magnetic field and can be applied for the removal of toxic metals from waste water. Highly cross-linked Fe3O4/P(S-DVB) particles were prepared in this research by suspension polymerization of styrene (S) and divinylbenzene (DVB) in presence of nanosized Fe3O4 particles. At first Fe3O4 nanoparticles were prepared by co-precipitation of Fe2+ and Fe3+ from their alkaline aqueous solution. To stabilize the magnetic particles, the surface of the particles was modified with oleic acid. The morphology and surface structure were characterized by Fourier Transform IR(FTIR), Transmission Electron Microscope (TEM), Scanning Electron Microscope(SEM), and light microscope.The adsorption behavior of As(III) on composite polymer particles was evaluated and a comparative study with reference copolymer particles revealed that composite polymer particles possessed better adsorption capacity.

Cumulative effect of hydrophobic PLMA and surface epoxide groups in composite polymer particles on adsorption behavior of congo red and direct red-75

Industrial application of hydrophobic materials is numerous particularly as adsorption beads to remove organic pollutants. In this research combined effect of hydrophobicity and reactive epoxide group on the adsorption behavior of dye molecules by composite polymer particles was investigated. Lauryl methacrylate (LMA) a poor water soluble long chain vinyl monomer is commercially available. Polystyrene/poly(LMA-divinyl benzene) or PS/P(LMA-DVB) composite seed particles were first prepared by slightly modified activated swelling of micron-sized PS seed particles utilizing either water or water-ethanol dispersion medium. The influence of poly(vinyl alcohol) (PVA) as steric stabilizer on the size and size distribution was evaluated. The poor solubility of LMA in the continuous phase hindered the homogeneous swelling of PS particles even in the presence of ethanol (5% w/w) and resulted in fairly polydispersed PS/P(LMA-DVB) composite seed particles. The composite seed particles were then functionalized with epoxide group by seeded polymerization of glycidyl methacrylate (GMA) to produce PS/P(LMA-DVB)/PGMA composite polymer particles. The epoxide functionalized PS/P(LMA-DVB)/PGMA composite polymer particles were used to adsorb two kinds of azo dyes, congo red (CR) and direct red-75 (DR-75). The effects of initial dye concentration at 303 and 323K on adsorption behavior were investigated and the adsorption was explained by adsorption isotherms. Temperature dependent adsorption measurements were also carried out at identical initial dye concentration. The adsorption results showed that inclusion of reactive epoxide group on/near the surface of hydrophobic PS/P(LMA-DVB) composite seed particles improved the adsorption capacity of dye molecules.

Morphological change of thermosensitive imidazolium‐based poly(ionic liquid)/poly(phenylethylmethacrylate) composite particles

Composite particles comprising poly(2‐phenylethyl methacrylate) (PPhEMA) and imidazolium‐based poly(ionic liquid)s were prepared by suspension polymerization of 1‐vinyl‐3‐ethylimidazolium bis(trifluoromethanesulfonyl)amide as an ionic liquid monomer with dissolved PPhEMA. Not only PPhEMA exhibits lower critical solution temperature (LCST) behavior in 1‐vinyl‐3‐ethylimidazolium bis(trifluoromethanesulfonyl)amide but also the polymer blend in the bulk state exhibited LCST behavior. However, the composite polymer particles obtained after polymerization at 70°C maintained a homogeneous inner structure after heat treatment as the polymerization temperature was greater than the LCST in this system due to the formation of a cross‐linked structure during polymerization. When the composite particles were prepared by suspension polymerization at 30°C, their inner morphology changed from homogeneous to phase separated during the subsequent heat treatment. Moreover, the morphology transformation of the composite particles was dependent on the PPhEMA molecular weight. Copyright © 2016 John Wiley & Sons, Ltd.

Photocatalytic and magnetic titanium dioxide/polystyrene/magnetite composite hybrid polymer particles

Novel multifunctional titanium dioxide (TiO2)/polystyrene/magnetite composite hybrid polymer particle dispersions with TiO2 nanoparticles in the surface and magnetite nanoparticles encapsulated inside the polymer matrix were produced by Pickering miniemulsion polymerization in one single step. Whereas TiO2 nanoparticles were used to impart photocatalytic functionality and colloidal stability, magnetite nanoparticles were incorporated to allow an easy extraction for recovery and reuse of the composite multifunctional particles. The morphology of the composite particles was assessed by scanning transition electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDX). The paramagnetism of the particles was analyzed using a SQUID magnetometer and their photocatalytic activity was assessed by degrading methylene blue (MB) solutions under UV light and by recovering and reusing of the particles in five consecutive cycles. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016

Computationally Guided Assembly of Oriented Nanocubes by Modulating Grafted Polymer-Surface Interactions.

The bottom-up fabrication of ordered and oriented colloidal nanoparticle assemblies is critical for engineering functional nanomaterials beyond conventional polymer-particle composites. Here, we probe the influence of polymer surface ligands on the self-orientation of shaped metal nanoparticles for the formation of nanojunctions. We examine how polymer graft-surface interactions dictate Ag nanocube orientation into either edge-edge or face-face nanojunctions. Specifically, we investigate the effect of end-functionalized polymer grafts on nanocube assembly outcomes, such as interparticle angle and interparticle distance. Our assembly results can be directly mapped onto our theoretical phase diagrams for nanocube orientation, enabling correlation of experimental variables (such as graft length and metal binding strength) with computational parameters. These results represent an important step toward unifying modeling and experimental approaches to understanding nanoparticle-polymer self-assembly.

4-Vinylpyridine–Trimethylolpropane Trimethacrylate Composite Polymer Particles and Their Application as Adsorbents

The study describes the synthesis of microspheres of 4-vinylpyridine (4VP) and trimethylolpropane trimethacrylate (TRIM) with uniform diameters. Polymeric 4VP–TRIM microspheres were prepared by seed polymerization, using polystyrene beads as a shape template. Following polymerization, microspheres with average diameters of 10.2, 8.5 and 5.6 μm and coefficient of variation of approximately 7% were obtained. By changing the molar ratio of co-monomers, it was possible to prepare 4VP–TRIM materials with developed porous structure and specific surface area of up to 355 m2/g. 4VP–TRIM microspheres were synthesized with the intention to use them as polymeric stationary phases in high-performance liquid chromatography (HPLC). The Smith method was used to evaluate the chromatographic properties of polymeric packing. Using two retention index scales (alkylbenzenes and alkyl aryl ketones), the retention indices of test compounds with different chemical characters were calculated. Toluene had the highest retention in...

Fabrication of composite polymer particles by stabilizer-free seeded polymerization

This paper reports the fabrication of polymer composite particles through stabilizer-free seeded polymerization. Various monomers were polymerized in the presence of submicron sodium styrene sulfunate-functionalized polystyrene seed particles without using swelling agent, emulsifier, or stabilizer. It was found that stable monodisperse composite particles are obtained even without using any ionic comonomer provided that the used monomer is nonpolar enough to facilitate swelling of the seeds. Utilizing the proposed method, copolymerization of styrene/divinyl benzene was successfully performed, resulting in highly crosslinked composite particles. Interestingly, Janus amphiphilic particles were achieved after the extraction of polystyrene by toluene from the particles. Overall, it is demonstrated that the proposed approach can be adopted as a facile and green process for the fabrication of various composite Janus particles.

Process Control in Microreactors

Process Control in Microreactors

Encapsulation of multiple large spherical silica nanoparticles in hollow spherical silica shells

Here we present the results of a stepwise synthesis of multiple large silica nanoparticles encapsulated in hollow, micron sized silica shells for future display applications. In the first step, 200-nm diameter silica nanoparticles were modified with 3-(trimethoxysilyl) propylmethacrylate (MPS) coupling agent. These nanoparticles were then embedded in micron-sized polystyrene particles synthesized through dispersion polymerization. To form silica shells on the polymer composite particles, tetraethylorthosilicate (TEOS) was added with cetyltrimethylammonium bromide (CTAB) surfactant. These three steps resulted in the formation of silica shell-covered solid polystyrene particles, each containing multiple silica nanoparticles. In the last step, polystyrene content was removed via calcination to achieve a multiple-silica-core-in-hollow-silica-shell composite structure. Dynamic light scattering (DLS) analysis and transmission electron microscopy (TEM) confirmed the core/shell morphology of the composite structure.

Poly(styrene–isoprene–butadiene- g -SAN) graft copolymers: Size-controllable synthesis and their toughening properties

The poly(styrene–isoprene–butadiene) (PSIB) latexes with large particle diameters were synthesized in a seed-emulsion polymerization or followed by agglomerating with amphiphilic block copolymers, and their granularity uniformities were also investigated through the determination of PSIB grain-size distribution. Resultant PSIB latexes were functionalized with styrene–acrylonitrile random copolymers (SAN) which the chemical graft modification had been investigated as well. The large particle diameter of PSIB latex via a seed-emulsion polymerization showed a continuous and normal distribution, which was improved greatly with the dosages of emulsifier and seed-emulsion concentration. A bimodal PSIB latex with large-sized particles were also prepared by the agglomerating process with a hydrophilic polymer of poly(butylacrylate-methacrylic) acid after the radical emulsion polymerization and was greatly affected with addition of poly(butylacrylate-methacrylic) acid. Moreover, the higher value of graft yield of SAN copolymer onto PSIB latex was observed as compared to the PB latex and the following factors controlled the grafting degree of the particles: (i) the composition of monomers; (ii) the initiator's content; (iii) the conditions for grafting copolymerization. Poly(styrene–isoprene–butadiene-g-SAN) graft copolymers (PSIB-g-SAN) were blended with SAN resins and their toughening properties were tested respectively. The effects of the composite polymer particles and the properties of PSIB-g-SAN particles were also discussed.

Poly(divinylbenzene-alt-maleic anhydride) nanoparticles as a novel stabilizer for Pickering polymerization of styrene

Poly(divinylbenzene-alt-maleic anhydride) nanoparticles with a narrow distribution and a diameter of 30 nm act as novel stabilizers in the Pickering emulsion polymerization of styrene. The hydrolyzed PDMNPs with NaHCO3 aqueous solution exhibited a very effective emulsification performance and a remarkably high emulsification efficiency. Raspberry-like PDMNPs/PS composite polymer particles have been successfully fabricated via copolymerization of pendant vinyl groups of PDMNPs with styrene.

Fabrication of Monodisperse Bowl-like Carbon Nanoparticles with Controlled Porous Structure

Abstract Bowl-like carbon particles with a controlled morphology and porous structure were synthesized via carbonization of the post-treated polymer composite particles. The obtained bowl-like carbon particles had a uniform, monodisperse and mesoporous structure with a narrow pore size distribution. The pH value in the post-treatment process played an important role in the formation of the bowl-like morphology and had a remarkable influence on the pore structure, which can control the morphology and pore structure of the carbon particles.

Spontaneous formation of silica–polymer composite particles by simple co-precipitation process

Organic–inorganic composite microparticle having interior nanostructures is one of the promising materials for creating a novel class of functional materials. In this paper, we show a simple co-precipitation method for silica nanoparticles and polymer composite particles by mixing water with water dispersed silica nanoparticles into tetrahydrofran THF solution of amino-terminated poly(butadiene) (PB) and evaporation of THF. High loading of inorganic nanoparticles into polymer particles was achieved and this high loading of inorganic nanoparticles was also an advantage for creating highly porous polymer particles by removal of inorganic part with HF. Interior structures of composite particles can be controlled by phase-separation of polymers.