Polystyrene Emulsion Research Articles

Effects of an Amphiphilic Micelle of Diblock Copolymer on Water Adsorption of Cement Paste

To reduce the inhibiting effects of polystyrene-based emulsion on the hydration process and strength development of cementitious materials, an amphiphilic diblock copolymer polystyrene-block-poly(acrylic acid) (PS-b-PAA) was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization and demonstrated in cement paste system for improving the resistance to water absorption without significantly reducing 28-day compressive strength. Firstly, the dissolved PS-b-PAA was added into water, and it quickly self-assembled into amphiphilic 80 nm-sized micelles with hydrophobic polystyrene-based core and hydrophilic poly(acrylic acid)-based shell. The improved dispersion compared to that of polystyrene emulsion may minimize the inhibiting effects on strength development, as the effects of PS-b-PAA micelle as hydrophobic admixtures on rheological properties, compressive strength, water absorption, hydration process, and pore structure of 28-day cement pastes were subsequently investigated. In comparison with the control sample, the saturated water absorption amount of cement pastes with 0.4% PS-b-PAA was reduced by 20%, and the 28-day compressive strength was merely reduced by 2.5%. Besides, the significantly increased hydrophobicity instead of slightly decreased porosity of cement paste with PS-b-PAA may contribute more to the reduced water adsorption characteristics. The study based on prepared PS-b-PAA micelle suggested a promising alternative strategy for fabricating polystyrene-modified concrete with reduced water absorption and unaffected compressive strength.

Synthesis of Nano-ZnO Composite Polystyrene Acrylic Emulsion and Its Application in Chinese Painting Pigments

With the continuous development of coating technology and environmental protection concepts, coating has become an indispensable item in the field of architecture and industry. Styrene acrylic emulsion as a new type of waterborne paint has attracted much attention since its emergence. Its functional modification is the focus of research, but the research results have not been ideal. To further improve the performance of styrene acrylic emulsion, nano-ZnO composite polystyrene emulsion was synthesized by emulsion polymerization, and its properties were analyzed. Aiming at the problem that nanopigments are prone to agglomeration, corresponding solutions are proposed, and the stability of nano-coatings is preliminarily studied. The inherent culture and essence of traditional culture and art is the wealth of realizing the unique nationalization and internationalization of design works. There is a lot of artistic quintessence in traditional Chinese painting art that can be used for reference to visual communication design. Through in-depth understanding and learning of Chinese painting theory and techniques, designers’ aesthetic abilities and innovation abilities can be qualitatively improved. First of all, the emulsion polymerization was carried out by semicontinuous method. The composite polystyrene emulsion containing different content of nano-ZnO was successfully prepared, which was recorded as N, Z, Z15, Z25, and Z35, respectively. The properties of the emulsion were determined, and the solid content, monomer conversion, viscosity, water absorption, and bacteriostatic effect of the emulsion were determined. The experimental results show that the solid content of emulsion Z15 (nano-ZnO content is 15%) reaches the highest value of 43.5%. The content of monomer in the emulsion affects the solid content, but the higher the monomer content, the better the solid content. The highest monomer conversion of Z15 was 86.4% at 80°C. The monomer conversion increased with the increase of polymerization temperature and tended to be stable after reaching the highest value. In the absence of nano-ZnO, the viscosity of the emulsion is the highest, and the viscosity of the emulsion decreases with the increase of the content of nano-ZnO monomer. Z35 (when the content of nano-ZnO is 35%) is the highest, which is 18.91%. The water absorption increases with the increase of nano-ZnO content. The content of nano-ZnO in the emulsion increased, the MIC value became smaller, and the bacteriostatic effect became better and better. This indicates that nano-ZnO composite polystyrene emulsion has good monomer conversion, super water resistance, and bacteriostatic effect, but its viscosity is relatively poor.

Newsprint microcrystalline fibers reinforced styrene butadiene rubber as a low thermal conducting material: Effect of electron beam irradiation and fiber content

AbstractThe present study focuses on utilizing polystyrene emulsion treated newsprint microcrystalline fibers (NPMCF). These treated fibers were then added to styrene‐butadiene rubber (SBR) at different concentrations, namely, 3, 6, 9, and 12 phr (part per hundred part of rubber). Mixing of ingredients was carried out on a rubber roll mill and afterward molded as a thin film on a hot press, then, exposed to electron beam irradiation doses up to 200 kGy so as to enhance the treatment of the composites. Mechanical properties of the composites, such as tensile strength, elongation at break, tensile modulus, and cross‐link density were enhanced by adding the treated fiber to SBR and by irradiation, and this enhancement was obtained at 6 phr fiber at 100 kGy. Measurements of scanning electron microscopy (SEM) proved the adhesion of the treated fibers to SBR. The thermal conductivity was measured for the prepared composites as a function of electron beam irradiation and fiber content. It was found that the thermal conductivity decreases according to fiber loading (up to 6 phr fiber) and irradiation dose.

One-step multiple structure modulations on sodium vanadyl phosphate@carbon towards ultra-stable high rate sodium storage

• A template-assisted sol–gel strategy is proposed for multi-structure engineering of NVP@C cathode material. • Simultaneous realizations of pore constructing, nanosizing and carbon compositing can be achieved in one step. • Pore structure of NVP@C can be tuned by adjusting the diameter of PS nanospheres. • A novel mesoporous-macroporous structure can be realized due to the demulsification of PS emulsion. • The mesoporous-macroporous NVP@C exhibits extraordinary rate capability and cycling stability at high rate. Na 3 V 2 (PO 4 ) 3 (NVP) is recognized as a promising sodium ion battery (SIB) cathode material due to its high working potential and robust three-dimensional framework. However, the poor intrinsic electronic conductivity and huge volume change during sodium ion insertion/desertion process hinder its further applications, which makes its structure modulations highly desirable. Herein, a facile template-assisted sol–gel strategy is developed to realize multiple structure modulations of NVP@C in one-step. With citric acid as chelating agent and polystyrene (PS) nanospheres as template, the realization of nanosizing NVP particles, hybridizing NVP particle with carbon material and constructing pore structure on NVP@C can be facially achieved. More importantly, the pore structure can be tuned by the diameter of used PS nanospheres. When the diameter of PS nanospheres is down to 70 nm, the corresponding 70-PS NVP possesses a hierarchically mesoporous-macroporous structure due to the demulsification effect, which can shorten the ion diffusion pathway, increase the contact surface area between the electrolyte and active material, improve the diffusion kinetics and buffer the volume change. Benefiting from the above superiority, the sample exhibits an extraordinary rate capability and a prominent cycling stability at high rate (104 mAh g −1 after 5000 cycles at 50C), which surpass most of the recently reported SIB cathode materials. This work opens a facile revenue for boosting the electrochemical performance of electrode materials through characteristic pore construction, nanosizing and integration with carbonaceous materials.

Bimetallic PdCo Nanoparticles Loaded in Amine Modified Polyacrylonitrile Hollow Spheres as Efficient Catalysts for Formic Acid Dehydrogenation

Polyacrylonitrile hollow nanospheres (HPAN), derived from the polymerization of acrylonitrile in the presence of polystyrene emulsion (as template), were modified by surface amination with ethylenediamine (EDA), and then used as support for loading Pd or PdCo nanoparticles (NPs). The resultant bimetallic catalyst (named PdCo0.2/EDA-HPAN) can efficiently catalyze the additive-free dehydrogenation of formic acid with very high activity, selectivity and recyclability, showing turnover frequencies (TOF) of 4990 h−1 at 333 K and 915 h−1 at 303 K, respectively. The abundant surface amino groups and cyano group as well as the hollow structure of the support offer a suitable environment for achieving high dispersion of the Pd-based NPs on the surface of EDA-HPAN, thus generating ultra-small bimetallic NPs (bellow 1.0 nm) with high stability. The addition of a small portion of Co may adjust the electronic state of Pd species to a certain extent, which can further improve their capability for the dehydrogenation of formic acid. In addition, the surface amino groups may also play an important role in synergistically activating formic acid to generate formate, thus leading to efficient conversion of formic acid to hydrogen at mild conditions.

Aqueous phase properties on governing particle coagulation and mechanism nucleation in one-step emulsion polymerization of styrene

As is well known, changing continuous phase properties has a great influence on the nucleation mechanism and particle size, and the addition of electrolytes or alcohol is the main mean to control the properties of solution phase. In this study, a series of experiments about polystyrene emulsion polymerization were produced by adding K2CO3 and alcohols in different types and contents, so as to study the essential reasons for the influence of solution phase properties on the growth process of particles and the synergistic effect between electrolytes and alcohols. In the presence of methanol-water polymerization systems, the particle size of polystyrene latex particles was enlarged obviously with the increase of methanol content when 0.6 wt% K2CO3 was contained, but there are no significant changes for the particle size with 0.1 wt% K2CO3. For the alcohols with different chain lengths, the particle diameters as follows: Dpropanol (212.6 nm) > Dethanol (123.1 nm) > Dmethanol (90.75 nm). They indicate that adding alcohol to the solution could promote particle coagulation by reducing dielectric constant of the continuous phase. As a result, the polystyrene latex particles with large-scale particle size can be acquired using controlling particle coagulation by changing aqueous phase composition.

Role of Osmotic Pressure for the Formation of Sub-micrometer-Sized, Hollow Polystyrene Particles by Heat Treatment in Aqueous Dispersed Systems †.

In a previous article, it was reported that a rather amount of sulfate end-groups as initiator fragment were buried in the inside of polystyrene (PS) particles, which were synthesized by emulsion polymerization with potassium persulfate initiator and nonionic emulsifier and operated to absorb water from the aqueous medium, resulting in hollow particles, when the PS emulsion was treated at higher temperature than the glass transition temperature of PS. In this article, it was clarified that the water absorption is based on the osmotic pressure between the outside (aqueous medium) and inside of the PS particles due to the buried sulfate end-groups.

Natural Halloysites-Based Janus Platelet Surfactants for the Formation of Pickering Emulsion and Enhanced Oil Recovery

Janus colloidal surfactants with opposing wettabilities are receiving attention for their practical application in industry. Combining the advantages of molecular surfactants and particle-stabilized Pickering emulsions, Janus colloidal surfactants generate remarkably stable emulsions. Here we report a straightforward and cost-efficient strategy to develop Janus nanoplate surfactants (JNPS) from an aluminosilicate nanoclay, halloysite, by stepwise surface modification, including an innovative selective surface modification step. Such colloidal surfactants are found to be able to stabilize Pickering emulsions of different oil/water systems. The microstructural characterization of solidified polystyrene emulsions indicates that the emulsion interface is evenly covered by JNPS. The phase behaviors of water/oil emulsion generated by these novel platelet surfactants were also investigated. Furthermore, we demonstrate the application of JNPS for enhanced oil recovery with a microfluidic flooding test, showing a dramatic increase of oil recovery ratio. This research provides important insights for the design and synthesis of two-dimensional Janus colloidal surfactants, which could be utilized in biomedical, food and mining industries, especially for circumstances where high salinity and high temperature are involved.

Surface-Functionalized Polystyrene Latexes Using Itaconate-Based Surfmers

Itaconic acid was readily transformed to a series of amphiphilic diesters via stepwise esterification of itaconic anhydride; the diesters carry one alkyl (cetyl or octyl) group and either a PEG, glyceryl, or dopamine segment. These diesters were used as surfmers for the preparation of polystyrene (PS) emulsions, with the expectation that the surface of the emulsion particles would carry PEG, glyceryl or dopamine units. NMR spectroscopic studies revealed that the surfmers were covalently incorporated into the polystyrene chains; furthermore, NMR tube polymerization experiments also confirmed that when the PEG surfmer was used, the PEG segments are indeed present on the surface of the emulsion particles. The size of the PEGlyated PS emulsions was readily varied from 35 to 140 nm by changing the mole fraction of surfmer used. In the case of the glyceryl and dopamine carrying surfmers, anoctyl unit was used as the hydrophobic segment to ensure appropriate hydrophobic-hydrophilic balance; it was noticed that significantly larger mole fractions of the surfmers were required (15-20 mol %) to generate stable emulsions with particle sizes of about 150 nm. The PS emulsions carrying dopamine units on the surface were found to adhere to glass surfaces; thus suggesting that such "sticky" emulsion particles could be used to functionalize different types of surfaces. Finally, itaconate diesters bearing cetyl and perfluorooctyl segments were also prepared and shown to copolymerize with styrene to generate fluoroalkyl-enriched PS copolymers; these were used to generate hydrophobic coatings, with water contact angles of over 120°. Thus, itaconate-based surfmers are readily accessible alternatives for the preparation of emulsions with tailored size and surface functionality.

Preparation of stable poly(methacrylic acid)-b-polystyrene emulsion by emulsifier-free emulsion iodine transfer polymerization (emulsion ITP) with self-assembly nucleation

Emulsifier-free emulsion iodine transfer polymerization (emulsion ITP) of styrene with self-assembly nucleation was successfully carried out with some living features for the first time as follows. Firstly, poly(methacrylic acid) (PMAA; degree of polymerization, 37)-iodide (PMAA37-I) as a macro chain transfer agent was synthesized by solution reversible chain transfer catalyzed polymerization (solution RTCP) with 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) as an initiator, iodoform as a chain transfer agent and germanium iodide as a catalyst in dioxane at 40 °C. A dioxane solution of PMAA37-I and styrene were added stepwisely under stirring into an aqueous solution (pH∼9), and then emulsion ITP was initiated by adding 4,4′-azobis(4-cyanopentanoic acid) at 60 °C with stirring at 500 rpm. Stable polystyrene emulsion was obtained without coagulation. At 100% conversion, the number-average diameter was 223 nm. Number-average molecular weight (Mn) increased linearly with conversion, which were well closed to theoretical Mn and molecular weight distribution at 100% conversion was comparatively narrow (Mw/Mn∼2.1).

Controlled-release drug carriers based mesoporous silica spheres with hierarchical hollow/nano structure

Mesoporous silica spheres with hierarchical hollow/nano structure (MSSH-H/N) have been successfully prepared by a template-guided approach, in which cetyltrimethyl ammonium bromide (CTAB) and polystyrene (PS) emulsion was used as the template of mesopores and hollow core, respectively. A consecutive template mechanism and the formation of the hierarchical hollow/nano structure were proposed on basis of the combined characterizations including transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction patterns (XRD) and nitrogen sorption analysis, which showed that the hierarchical structure is composed of mesoporous hollow SiO2 spheres and discrete mesoporous SiO2 nanoparticles coating on the shell. Ibuprofen (IBU) was chosen as a drug model in delivery and release experiments, and these MSSH-H/N samples exhibited higher drug loading capacity, desired low initial IBU release rate and typical two-phase drug release behavior compared with conventional single-structure (single-shelled) hollow mesoporous silica spheres due to their unique hierarchical hollow/nano structure.

Hydrophilic Modification of Multi-Walled Carbon Nanotube for Building Photonic Crystals with Enhanced Color Visibility and Mechanical Strength.

Low color visibility and poor mechanical strength of polystyrene (PS) photonic crystal films have been the main shortcomings for the potential applications in paints or displays. This paper presents a simple method to fabricate PS/MWCNTs (multi-walled carbon nanotubes) composite photonic crystal films with enhanced color visibility and mechanical strength. First, MWCNTs was modified through radical addition reaction by aniline 2,5-double sulfonic acid diazonium salt to generate hydrophilic surface and good water dispersity. Then the MWCNTs dispersion was blended with PS emulsion to form homogeneous PS/MWCNTs emulsion mixtures and fabricate composite films through thermal-assisted method. The obtained films exhibit high color visibility under natural light and improved mechanical strength owing to the light-adsorption property and crosslinking effect of MWCNTs. The utilization of MWCNTs in improving the properties of photonic crystals is significant for various applications, such as in paints and displays.

Study of Organic/Inorganic Hybrid Nanoparticles in Sizing Agents for Mechanism and Effect of Fiber Adhesion

This paper stated the preparation of nano-modified polyacrylic acid sizing agents by adding self-made hybridized nano-TiO2(titanium dioxide)/PSt(Polystyrene) and nano-SiO2(silica dioxide)/PSt emulsion respectively into self-made polyacrylic acid sizing agents which called SW. Influences of two kinds of nano hybrid particles in nano-modified SW with different dosages on the strength of sizing yarns and mechanisms of increasing adhesion were analyzed. Experimental results showed that: 1. when two kinds of nano particles’ weight was about 1.1% of SW solid content, adhesion force of nano-modified sizing agents with Terylene/Cotton(T/C)fibers will reach the maximum,while when the weight of nano particles were less than 1.1% or more than 1.1%, the adhesion force between sizes and (T/C)fibers increased obviously or declined evidently; 2. scanning electronic microscope(SEM) photograph of roving chips displayed that fibers’ surface were completely covered by smooth size film and many hybrid nanoparticles between macromolecules of sizes, thus engendering huge bonding force between sizes and fibers, and increasing the slip resistance between fibers.

The preparation of hollow silica spheres with mesoporous shell via polystyrene emulsion latex template and the investigation of ascorbic acid release behavior

In this study, the emulsifier-free polymerization was employed to prepare polystyrene (PS) latex particles. When the styrene conversion of 80 % was reached, appropriate amounts of methacryl oxypropyl trimethoxy silane (MPS) and divinylbenzene (DVB) were added to the emulsion solution. Emulsion particle surfaces bear silanol functional groups that facilitate the rapid reaction with silica precursor solution, which is formed through the hydrolysis of tetraethyl orthosilicate (TEOS) and silanol groups of MPS on the emulsion surface. Consequently, a core-shell structure with PS core and silica shell structure was developed. Using extraction and calcination to remove the central polystyrene core, a hollow glass sphere with porous shell structure was obtained. Finally, ascorbic acid was placed and encapsulated in these hollow glass spheres, as inspected by SEM and carbon element mapping images, to examine their controlled release behavior. The cumulative release percentage was analyzed using the Higuchi model, a zero-order model, and a first-order model for kinetic study of release behavior. Results show that the zero order and first order models describe the release kinetics of ascorbic acid equally well for hollow glass spheres.

Numerical Simulation of Optically-Induced Dielectrophoresis Using a Voltage-Transformation-Ratio Model

Optically-induced dielectrophoresis (ODEP) has been extensively used for the manipulation and separation of cells, beads and micro-droplets in microfluidic devices. With this approach, non-uniform electric fields induced by light projected on a photoconductive layer can be used to generate attractive or repulsive forces on dielectric materials. Then, moving these light patterns can be used for the manipulation of particles in the microfluidic devices. This study reports on the results from numerical simulation of the ODEP platform using a new model based on a voltage transformation ratio, which takes the effective electrical voltage into consideration. Results showed that the numerical simulation was in reasonably agreement with experimental data for the manipulation of polystyrene beads and emulsion droplets, with a coefficient of variation less than 6.2% (n = 3). The proposed model can be applied to simulations of the ODEP force and may provide a reliable tool for estimating induced dielectrophoretic forces and electric fields, which is crucial for microfluidic applications.

Heterocoagulation으로 제조된 PBA/PS/Si 블렌드의 압력가소성

Baroplastic poly(butyl acrylate) (PBA)/polystyrene (PS) blends were prepared by mixing PBA and PS emulsions synthesized by cationic and anionic surfactant, respectively. Interestingly, the heterocoagulation of nanoparticles have found to be affected strongly by emulsion concentration but the blends have been prepared with almost same compositions regardless of the amount of reactants. Utilizing this method, PBA/PS/Si hybrid nano-blends were prepared successfully via electrostatic attraction forces between PBA, PS and silica nanoparticles. The hybrid nano-blend having 2 or 5 wt% of silica was then processed to a semi-transparent film at under 13.8 MPa for 10 min, which showed 3.0 MPa of tensile strength and 25 MPa of elastic modulus. Therefore, the heterocoagulation technique can be used for preparing baroplastics with uniform compositions of polymer and silica nanoparticles.

Waste newsprint fibers for the reinforcement of radiation‐cured (styrene‐butadiene rubber)‐based composites. Part ii characterization and thermal properties

AbstractWaste newsprint fibers were used as reinforcing fillers in composite materials based on a styrene‐butadiene rubber matrix. Surface modification of the fibers was carried out by polystyrene emulsion treatment, and copolymerization with the rubber matrix was done by a radiation technique. Characterization of the modified surfaces and the adhesion between the treated newsprint paper fibers and the rubber matrix involved a variety of techniques, including X‐ray diffraction, FTIR spectroscopy and differential scanning calorimetry, which revealed that the surface modification did occur and that it affected adhesion between the treated fibers and the rubber matrix upon irradiation. Thermogravimetric analysis indicated that the thermal stability of the fibers was enhanced by the treatment and that the thermal stability of irradiated composites was increased by the addition of treated newsprint fiber. © 2012 Society of Plastics Engineers.

Facile method to prepare Pd/Polystyrene composite microspheres and investigation on their catalytic properties

Nano-sized Pd/polystyrene composite nanoparticles were prepared via surfactant-free emulsion polymerization. The as-prepared composite particles were used as a catalyst for Suzuki reaction, and they showed excellent catalytic properties in the conversion and recyclability. First, polystyrene (PS) latex particles bearing carboxyl groups on the surfaces were synthesized via one-stage surfactant-free emulsion polymerization employing acrylic acid as the functional monomer. Thus, made the PS particles negatively charged and could attract positively charged Pd2+ ions. By adding PdCl2 solution to this functional polystyrene emulsion, Pd2+ ions were attached to the surfaces and reduced to zero valent particles by the reducing agent, NaBH4. Nano-sized Pd/PS composite particles could be synthesized via this facile method. The amount of the functional monomers, the Pd2+ content and the amount of the initiator played important roles to the final morphologies of the composite particles. The resulting composite microspheres were observed by TEM. Furthermore, catalytic properties of the as-prepared Pd/PS composite particles were studied via Suzuki reaction, and the results were characterized by FTIR and 1H-NMR. The Pd/PS composite particles showed excellent conversion and could be recycled easily for reuse. After each round of Suzuki reaction, the Pd/PS composite particles could be separated just by filtration, the conversion still remained as high as 70.2 %, even when used 5 times.

Waste newsprint fibers for reinforcement of radiation-cured styrene butadiene rubber-based composites - Part I: Mechanical and physical properties

In this study, waste newsprint paper fiber was treated by polystyrene emulsion and included as a filler in styrene butadiene rubber. Then, the composites were subjected to electron beam irradiation at different irradiation doses, and follow-up was done on the effect of irradiation dose and fiber concentration on mechanical and physical properties of prepared composites. The results indicated that the mechanical properties like tensile strength, elongation at break, stiffness, and toughness were enhanced by the increase of radiation and fiber content. Also, the physical properties like soluble fraction, swelling ratio, and volume fraction of rubber in swollen gel were enhanced by the increase of radiation and fiber content. On the other hand, scanning electron microscope (SEM) results confirmed that adhesion was situated between fiber and rubber matrix.

Preparation and Performance of Ordered Porous TiO2 Film Doped with Gd3+

An organic template of polystyrene colloidal crystals was fabricated through dip-coating in a polystyrene emulsion. Based on the template, an ordered porous TiO2 film doped with Gd3+ was deposited on a conductive glass. x-ray diffractometry (XRD), scanning electron microscopy (SEM), UV-vis spectroscopy were used to characterize the structures and properties of the film. The as-produced film was used as an electrode in dye-sensitized solar cells with a sandwich structure. XRD showed that anatase TiO2 was obtained. SEM images clearly demonstrated that these films had an ordered porous structure, mainly in a hexagonal orientation. UV-vis spectroscopy revealed that the absorption was improved in both the ultraviolet and the visible areas. Under simulated solar illumination, a short circuit current of 0.618 mA and an open circuit voltage of 0.538 V were attained, which were better than the performances of only a TiO2 film electrode and an ordered porous TiO2 film electrode.