Preparation Of Polystyrene Research Articles

Novel polystyrene‐based light diffusing materials: Introduction of magnesium hydroxide to enhance scattering range and thermal conductivity

AbstractIn high‐power lighting, large‐screen display, and other practical application scenarios, Light diffusing materials (LDMs) with favorable thermal conductivity are desired to assist in heat dissipation. In this paper, platy magnesium hydroxide (pMH) and mesoporous spherical magnesium hydroxide (sMH) were introduced as scattering particles for the first time to prepare polystyrene (PS)‐based LDMs. The limited refractive index mismatch allowed MH to be filled in large quantities with less sacrifice of light transmission performance. Owing to the complex surface morphology and large specific surface area, sMH possesses stronger scattering capability, and its combination addition with pMH could effectively increase scattering range. Meanwhile, an effective filler network was constructed with the combined use of pMH and sMH, and thus enhanced the thermal conductivity of the composites. Additionally, PS/pMH‐sMH composites exhibited higher thermal stability. This study expands the auxiliary thermal management capability of light diffusion materials and presents a new application possibility for MH as scattering particles.Highlights A new application possibility for Magnesium hydroxide as scattering particles. Light transmittance degradation of PS/MH at high filler loadings was mitigated by RI matching. Complex surface morphology endowed sMH with strong scattering capability. Optimal filling ratio of pMH to sMH was tested for better scattering performance. Extended scattering range, improved TC and thermal stability was achieved.

Preparation of polystyrene and silane-modified nano-silica superhydrophobic and superoleophilic three-dimensional composite fiber membranes for efficient oil absorption and oil-water separation

Oily solid waste and wastewater are two kinds of contaminants that seriously endanger the environment and the general public. Recently, superhydrophobic and superoleophilic materials have attracted extensive attention owing to their exceptional oil-water separation capabilities. In this study, we demonstrated a simple, low-cost, and high-economic efficiency method to prepare nanosilica (SiO2) from dye diatomite filter aid waste (DDW) and silanize it with octadecyltrichlorosilane (OTS) to form hydrophobic nanosilica (hSiO2) by solution impregnation. Polystyrene/hydrophobic nanosilica (PS/hSiO2) composite fiber membranes with a rough surface and low surface energy were prepared by electrospinning. The prepared PS/hSiO2 water contact angle can reach 166.6°, showing superhydrophobicity and excellent adsorption capacity for various common oils. The maximum oil absorption capacity for transformer oil can reach 136.4 g/g. Importantly, the oil absorption process of the nanocomposite is selective, fast, and efficient, and it can be used for the purification of oil-contaminated water. In addition, it also demonstrates remarkable durability and stability in strong acid and alkali solutions. This strategy of making oil-water separation materials from solid waste may offer a straightforward, cost-effective, and environmentally sustainable option for the treatment of solid waste, industrial oil wastewater treatment, and marine oil spill cleanup.

Third order nonlinearity and optical power limiting studies of PS/ZnO nanocomposite foils for photonic applications

The present work focuses on the preparation of Polystyrene (PS) and PS/ZnO nanocomposite foils by solution casting method and study their structural and nonlinear optical (NLO) characterizations. The Zinc Oxide (ZnO) nanoparticles were synthesized by Sol-gel method. Structural analysis of the prepared nanocomposite foils was carried out by x-ray diffraction (XRD) with an estimated average crystallite size of 27.33 nm. UV–vis-NIR spectra reveal that the nanocomposite foils are transparent in the visible region. FESEM micrographs show the surface morphology of the prepared nanocomposite foils. Energy Dispersive x-ray Spectroscopy (EDX) of the prepared foils confirmed the compositional and spatial distribution of the elements. The NLO properties such as nonlinear absorption coefficient (β), nonlinear index of refraction (n2), and third-order nonlinear susceptibility were investigated by Z-scan technique at a wavelength of 532 nm and 200 mW with field intensity The values of β were found to bein the order of ∼ 10−7 cm W−1, n2 in the order of ∼10−12 cm2 W−1 and in the range 4.99 × 10−7– 38.7 × 10−7e.s.u. Further, the optical power limiting threshold was calculated to be 3.646 KW cm−2 for 8 wt % of PS/ZnO nanocomposite foil which is a better candidate to act as an optical limiter. The figure of merit has also been determined that establishes the suitability of nanocomposite foils for optical limiting and/or optical switching applications in the visible region.

Use of polypyrrole-polystyrene membranes for extracting DNA from plant tissues

We describe the preparation of a membrane composed of polypyrrole-polystyrene (PPy-PS) and its application in DNA extraction. We adopted the electrospinning technique to prepare polystyrene (PS) membranes, which we used as substrates for incorporating polypyrrole chains through an in situ chemical procedure. As a model system, we initially investigated the use of PPy-PS membranes for the extraction of salmon sperm DNA from aqueous solutions. These studies have shown that the PPy-PS membrane has a maximum adsorption capacity of 236.0 mg of DNA per gram of PPy after 30 min of exposure to a DNA solution (100 mg/L). We incorporated the PPy-PS membranes into centrifugation columns, which we used to carry out experiments for extracting and purification of DNA from curly lettuce leaves. The protocol was initially optimized by first examining the most appropriate concentration of the three components of the lysis buffer (Tris/HCl, NaCl, and EDTA-Na). We then investigated the most adequate volumes of the concentrated surfactant solution (SDS 20%) and that used in the protein and polysaccharide precipitation step (5 M potassium acetate, pH 6.3), factors that directly influence the quality and quantity of the fraction of DNA obtained. For curly lettuce leaves, both in their mature and young stages, the yield and purity of the DNA purified using the PPy-PS membrane were comparable to those obtained using a commercial kit. In both cases, the collected DNA samples presented excellent integrity and quality. These results are suggestive that these composite membranes are competitive with the commercial kits available for the extraction and purification of DNA from plants.

Preparation and Mnuplation of Silver Nanostructure with Plasmon Activity By a Simple Method

Introduction: One of metal fine particles’ applications is Surface Enhanced Raman Scattering; SERS) with their surface plasmon resonance. It is usually performed on the substrates which have gold or silver clusters on their surface. It can be enhanced at the gap between two clusters much more than at the surface of a cluster. However, this enhancement at the gap of clusters was limited because these clusters were usually placed on the plate substrate. Placed these nanoparticles on the surface of the larger particles, the enhanced point can be moved on any place.In this study, we tried to prepare polystyrene (PS) particles which have smaller metal particles deposited by the electroplating on their surface. Experimental: PS beads (<1.0 μm) were used as template particles. The PS dispersion in 50 % ethanol aqueous solution was put on indium tin oxide coated glass substrate to form the colloidal crystalline template.The flash electroplating was performed with DC power supply with 1 – 10 V in aqueous solutions containing silver ions. After rinsed with distilled water, the particles were observed by scanning electron microscopy.Photoabsorption spectrum of Ag deposited samples were measured for evaluation of LSPR. Results and Discussions: SEM images of Ag electroplated with 3 V for 5 s in 0.001 M AgNO3 aqueous solution on the template by 1.0 μm PS beads were shown in Fig. 1. With lower voltage, 1 V, less Ag clusters were generated. With higher voltage, the clusters were rapidly grown and covered the PS beads’ surface so that it is not found the gap between the clusters. Same tendency was found the results with more concentrated silver solution. It is suggested that the optimal condition for placing Ag clusters on the PS beads was the electroplating with 3 or 5 V. It is also indicated that the Ag particles’ size can be controlled by the applied DC voltage and applied period of electrodeposition. In addition, the Ag cluster induced photoabsorption with surface plasmon resonance (SPR) around 480 nm region. The photoabsorption was observed particularly strongly in the brushy structure (using 1.0 μm PS beads and 5 V applied), and it was shown that it was due to the strong electromagnetic field derived from the nanogap structure in the Ag clusters. This also shows that SPR is localized. We have succeeded in preparing the localized surface plasmon resonance (LSPR) active structure and found that its optical properties can be controlled using a very simple method with an electroplating process. These results suggest that one of the possibilities of the helpful to high sensitivity the sensor using the surface enhanced method (Raman, IR, photoluminescence (PL) and more). Acknowledgement: This work was supported by JSPS KAKENHI Grant Number JP19K05191. Figure 1

Polystyrene-b-poly(acrylic acid) nanospheres for the synthesis of size-controlled cobalt nanoparticles encapsulated inside hollow carbon spheres

Metal particle agglomeration is known to be one of the factors responsible for the reduction in catalytic activity (even selectivity) when metal particles are supported on carbon. In this study, an approach using functional groups attached to a polymeric support was used to reduce metal agglomeration. Herein, we report on the preparation of polystyrene (PS) (d = 350 nm) and asymmetric polystyrene-b-poly(acrylic acid) (PS-b-PAA) nanospheres (8% and 12% PAA loadings; d = 274 nm and 343 nm) to make cobalt/polymer complexes. The CoxOy nanoparticles were supported on the PS and PS-b-PAA templates (5%, 10% and 15% Co loading), and then the CoxOy/template was coated with resorcinol–formaldehyde (RF). Thermal removal of the templates and annealing of the RF at 600 °C for 2 h gave the CoxOy@HCS materials. At a nominal Co loading of 5%, the PS template produced CoxOy@HCS materials that contained small Co particles (6.1 nm) while at higher Co loadings (10%, 15%) large and irregularly shaped Co nanoparticles (d > 20 nm) were formed. In contrast, PS-b-PAA gave CoxOy@HCS with small, highly dispersed Co nanoparticles (d < 10 nm) at loadings between 5 and 15%. The three polymeric nanospheres and the CoxOy/polymer and CoxOy@HCS materials were all characterized using SEM, TEM, TGA and FTIR spectroscopy. The use of functionalized polymer templates thus allows small Co particles to be easily transferred from the template to the RF to give CoxOy@HCS, even when using high-temperature (600 °C) synthesis conditions.

In situ polymerization of styrene\u2013clay nanocomposites and their properties

This work focuses on the preparation and characterization of polystyrene/organoclay nanocomposites. The effects of the nature of the organoclays and the method of preparation were studied in order to evaluate their morphological, thermal and mechanical properties. X-ray diffraction (SAXS), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning and transmission electron microscopy (SEM, TEM), atomic force microscope (AFM) were used to determine the characteristics of the resulting materials. Initially, cetyltrimethylammonium bromide was used as an organomodifier to modify the clay to form an organic clay. After that, polystyrene/organoclay nanocomposites were synthesized by an in situ mass polymerization process in which styrene was polymerized in the presence of different proportions of organoclay ranging from 1 to 15% by weight. The results obtained confirm the intercalation of cetyltrimethylammonium bromide (CTA) surfactant in the clay layers, while the nanocomposites obtained showed morphologies in which the exfoliated forms were obtained. Nanocomposites showed a significant improvement in thermal stability compared to unmodified polystyrene. The highlighting of the modification was examined by mechanical tests (shock, traction). The Charpy impact test showed an increase in impact resilience, and this is mainly due to a better interfacial adhesion of the matrix. The tensile test showed an improvement in stiffness.Graphic abstractThe preparation of polystyrene–clay nanocomposites containing various amounts of organoclays ranging from 1 to 15% using the mass polymerization technique has shown the positive effect of the introduction of a cetyltrimethylammonium bromide surfactant chain on the thermal stability of the nanocomposites. Exfoliated morphologies were obtained for the majority of the prepared nanocomposites. A structure, surface and thermal property relationship was established based on TGA, XRD and TEM/SEM analyses.

Electrical and Structural Properties of Polystyrene/Graphite Composite by Direct Mixing Method

Melt mixing method was used in the preparation of Polystyrene (PS)/graphite composite with different graphite weight %.The electrical and structural properties of the composite were studied using Keithley two-point probe and GBC EMMA X-ray diffractometer (XRD) respectively. The result showed that the electrical conductivity of the composites was improved as the weight percentage of graphite content increases but the percolation threshold was observed at 0.10wt%. The conductivity of the composites was also observed to increase at higher temperatures. The structural result showed that the amorphous structure of polystyrene was converted to crystalline as the weight% of the graphite increases which influences the degree of crystallinity. Keywords: polymer, graphite, composite, percolation threshold, electrical conductivity DOI : 10.7176/APTA/81-03 Publication date: December 31 st 2019

Polystyrene Nanocomposites Reinforced with Novel Dumbbell-Shaped Phenyl-POSSs: Synthesis and Thermal Characterization.

Two series of novel dumbbell-shaped polyhedral oligomeric silsesquioxanes (POSSs), fully functionalized with phenyl groups at the corner of the silicon cages, were used to prepare polystyrene (PS) nanocomposites through the method of in situ polymerization. The percentage of the molecular filler reinforcement was set as 5% w/w of POSS and was checked by 1H-NMR spectroscopy. The obtained nanocomposites were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Thermal and morphological properties were evaluated and compared among the nanocomposites obtained using the two different series of dumbbell-shaped POSSs and with the net PS. The thermal parameters for the prepared nanocomposites were very high when compared with those of neat PS, and they evidenced significant differences when an aliphatic or aromatic bridge was used to link the silicon cages. SEM analysis results allow us to hypothesize a justification for the different resistance to thermal degradation showed by the two series of molecular reinforcement.

Fabrication of nanoclay gel composite: A novel nanoclay masterbatch approach to nanocomposite preparation via melt extrusion process

The objective of this research was to fabricate a novel nanoclay masterbatch containing polymer‐intercalated in nanoclay with comparable degree of interlayer expansion, flowability, and high thermal stability. It is ready to use for preparing polymer/clay nanocomposites by melt extrusion. The nanoclay masterbatch was efficiently prepared in one‐step via a new approach called nanoclay gel. The nanoclay gels were successfully prepared at different original nanoclay concentrations ranging from low to high clay loading (10%, 20%, and 30% w/v) in cooperation with polyethylene glycol (PEG) at various PEG loadings (weight ratios of nanoclay/PEG 1/1, ½, and 1/3) and kappa carrageenan (KC), a thermolytic hydrogel at a fixed minimum concentration. X‐ray diffraction (XRD) results revealed that the intercalation of PEG molecules expanded silicate basal spacing up to 17–18 A° even at high percentage of nanoclay (dry content about 24–49 wt%). Scanning electron microscope (SEM) revealed the denser packing of clay layers in accordance to an increase in density of the dry nanoclay gel with increment of original nanoclay loadings. An increase of PEG content exhibited better flow ability as seen by increasing melt flow index. Thermal decomposition of the nanoclay gels was up to 380°C; by using the dry nanoclay gels to prepare polystyrene (PS)/clay nanocomposites via melt extrusion. The morphological results showed that the exfoliated structures were achieved. The mechanical and thermal stability properties were significantly enhanced. The appearing color of PS/clay nanocomposites prepared from nanoclay gel was bright pale‐yellow without evidence of thermal degradation. POLYM. COMPOS., 40:2751–2767, 2019. © 2018 Society of Plastics Engineers

One-pot preparation of surface-functionalized barium titanate nanoparticles for high-K polystyrene composite films prepared via floating method

An advanced and inexpensive one-pot method to prepare polystyrene (PS)–barium titanate (BT) films by solution mixing is reported. The process was developed to obtain free-standing films with an increased dielectric constant (e′). Since PS is soluble in apolar solvents, BT nanoparticles (BT-NPs) were surface-modified with palmitic acid (PAc) and embedded within the polymer matrix without affecting homogeneity and smoothness of the composite. The films were prepared by floating method consisting in dropping BT-NPs dispersed in PS/toluene solution on the water surface. After the evaporation of toluene, smooth, free-standing and thermally stable films were obtained with a markedly higher e′ compared to the neat PS. PAc modification improved the dispersion of BT-NPs in the apolar phase and prevented their diffusion into the aqueous phase during the toluene evaporation. The proposed film-forming technique makes it possible to modulate the thickness and shape of the films by selecting the quantity and concentration of the organic phase and using various templates, thus opening up a broad range of applications.

聚苯乙烯荧光乳液的制备及其性能研究

聚苯乙烯荧光乳液的制备及其性能研究

Nanoaramid Dressed Latex Particles: The Direct Synthesis via Pickering Emulsion Polymerization.

The direct synthesis of polymer microspheres modified by aramid nanofibers (ANFs) is an interesting challenge. This work describes a simple aqueous process to prepare polystyrene (PS)/ANF composite microspheres, where the specific ANF network was "dressed" on PS. ANF was derived from the copolymerization of terephthaloyl chloride, p-phenylene diamine, and methoxypolyethylene glycol and could be dispersed in water stably. We applied the as-synthesized ANF as a Pickering emulsifier in the o/w emulsion of styrene monomer. Radical polymerization was subsequently initiated in the Pickering emulsion system. The combination of ANF with polymer spheres was revealed by scanning electron microscopy (SEM) and thermal gravity analysis. The role of ANF in the monomer emulsion as well as in the polymerization was studied through SEM, optical microscopy, optical stability analyzer, and pulse nuclear magnetic resonance combined with the polymerization kinetic analysis. Moreover, we investigated the effects of other synthesis parameters, such as monomer type, monomer content, pH value, and salt concentration.

Melt extrusion of polystyrene reinforced with cellulose nanocrystals modified using poly[(styrene)-co-(2-ethylhexyl acrylate)] latex particles

Non-covalent modification of cellulose nanocrystals (CNC) was performed using a water based method with laboratory prepared statistical copolymer, viz. poly [(styrene)-co-(2-ethylhexyl acrylate)], by ionic interactions. The thermal, functional and morphological properties of modified CNC were characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Their hydrophobic nature was investigated by contact angle measurements. These nanoparticles were used to prepare polystyrene (PS) nanocomposites by twin-screw extrusion. The thermomechanical performance of the ensuing composites was examined by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The morphology of the materials was also studied using scanning electron microscopy (SEM).

A UV-Cleavable Bottlebrush Polymer with o-Nitrobenzyl-Linked Side Chains.

An ultraviolet (UV)-cleavable bottlebrush polymer is synthesized using the "grafting-onto" strategy by combining living radical polymerization and copper-catalyzed azide-alkyne cycloaddition (CuAAC). In this approach, reversible addition-fragmentation chain transfer polymerization is used to prepare a poly(methylacrylate) backbone with azide side groups, while atom transfer radical polymerization is employed to prepare polystyrene (PS) side chains end-functionalized with o-nitrobenzyl (UV-cleavable) propargyl groups. CuAAC is then used to graft PS side chains onto the polymer backbone, producing the corresponding bottlebrush polymers with UV-cleavable PS side chains. The formation of the bottlebrush polymer is characterized by 1 H nuclear magnetic resonance spectroscopy, gel permeation chromatography (GPC), and Fourier transform infrared spectroscopy. The cleavage behavior of the bottlebrush polymer is monitored in tetrahydrofuran solution under UV irradiation by GPC and viscosity measurements.

Polystyrene-based Hollow Microsphere Synthesized by \u03b3-ray Irradiation-assisted Polymerization and Self-Assembly and Its Application in Detection of Ionizing Radiation

To simply and multitudinously synthesize hollow microspheres in a pure system is important for relevant research and application. Here, a simple and novel one-pot synthetic strategy to prepare polystyrene (PS) hollow microspheres via irradiation-assisted free-radical polymerizing and self-assembly (IFPS) approach under γ-ray irradiation with no additives introduced into the system is presented. And PS/2,5-Diphenyloxazole (PPO) fluorescent microspheres have been prepared successfully by IFPS reaction, which can be used as scintillators for the detection of ionizing radiation. A linear relationship between emitted luminescence and dose-activity in water is obtained, which suggests that composite microspheres could be used as liquid scintillation in specific environment.

HPMA-based block copolymers promote differential drug delivery kinetics for hydrophobic and amphiphilic molecules

We describe a method how polymeric nanoparticles stabilized with (2-hydroxypropyl)methacrylamide (HPMA)-based block copolymers are used as drug delivery systems for a fast release of hydrophobic and a controlled release of an amphiphilic molecule. The versatile method of the miniemulsion solvent-evaporation technique was used to prepare polystyrene (PS) as well as poly-d/l-lactide (PDLLA) nanoparticles. Covalently bound or physically adsorbed fluorescent dyes labeled the particles’ core and their block copolymer corona. Confocal laser scanning microscopy (CLSM) in combination with flow cytometry measurements were applied to demonstrate the burst release of a fluorescent hydrophobic drug model without the necessity of nanoparticle uptake. In addition, CLSM studies and quantitative calculations using the image processing program Volocity® show the intracellular detachment of the amphiphilic block copolymer from the particles’ core after uptake. Our findings offer the possibility to combine the advantages of a fast release for hydrophobic and a controlled release for an amphiphilic molecule therefore pointing to the possibility to a ‘multi-step and multi-site’ targeting by one nanocarrier. Statement of SignificanceWe describe thoroughly how different components of a nanocarrier end up in cells. This enables different cargos of a nanocarrier having a consecutive release and delivery of distinct components. Most interestingly we demonstrate individual kinetics of distinct components of such a system: first the release of a fluorescent hydrophobic drug model at contact with the cell membrane without the necessity of nanoparticle uptake. Secondly, the intracellular detachment of the amphiphilic block copolymer from the particles’ core after uptake occurs. This offers the possibility to combine the advantages of a fast release for a hydrophobic substance at the time of interaction of the nanoparticle with the cell surface and a controlled release for an amphiphilic molecule later on therefore pointing to the possibility to a ‘multi-step and multisite’ targeting by one nanocarrier. We therefore feel that this could be used for many cellular systems where the combined and orchestrated delivery of components is prerequisite in order to obtain the highest efficiency.

Versatile method via reversible addition-fragmentation transfer polymerization for synthesis of poly styrene/ZnO-nanocomposite

Reversible addition-fragmentation chain transfer (RAFT) polymerization enables the synthesis of controlled architectures for a wide-variety of polymers with defined end and pendant functionalities using mild conditions. A simple synthetic route for the preparation of polystyrene (PS)/ZnO nanocomposite with well-defined structure is demonstrated. ZnO nanoparticles were synthesized by homogeneous precipitation. To reduce the aggregation among ZnO nanoparticles, an effective surface modification method was proposed by grafting polystyrene onto the ZnO particles. The surface of ZnO nanoparticles was firstly treated with a 4-cyano-4-[(4-methoxyphenyl carbon thiol) solfanylvaleric acid] coupling RAFT agent in the presence of THF as a solvent at 65°C. A carboxylic group in raft agent attached to ZnO nanoparticles by the esterification reaction with the hydroxyl groups on the ZnO particle surface. Then, RAFT polymerization of styrene was subsequently conducted to graft PS onto the exterior surface of ZnO nanoparticles by new RAFT agent 4-cyano-4-[(4-methoxyphenyl carbon thiol) solfanylvaleric acid]. The obtained nanocomposite was characterized by Fourier transform infrared spectroscopy (FT-IR), thermo gravimetric (TGA), transmission electron microscopy (TEM), and X-ray powder diffraction (XRD). POLYM. ENG. SCI., 56:187–195, 2016. © 2015 Society of Plastics Engineers

Preparation of Polystyrene Microspheres/PEG-PCL-PEG Hydrogel Composite for Soft Tissue Augmentation

Preparation of Polystyrene Microspheres/PEG-PCL-PEG Hydrogel Composite for Soft Tissue Augmentation

Superhydrophobic Surface Enhanced Raman Scattering Sensing using Janus Particle Arrays Realized by Site-Specific Electrochemical Growth.

Site-specific electrochemical deposition is used to prepare polystyrene (PS)-Ag Janus particle arrays with superhydrophobic properties. The analyte molecules can be significantly enriched using the superhydrophobic property of the PS-Ag Janus particle array before SERS detections, enabling an extremely sensitive detection of molecules in a highly diluted solution (e.g., femtomolar level). This superhydrophobic surface enhanced Raman scattering sensing concept described here is of critical significance in biosensing and bioanalysis. Most importantly, the site-specific electrochemical growth method we developed here is a versatile approach that can be used to prepare Janus particle arrays with different properties for various applications.