Showing papers on "Polystyrene published in 2019"
TL;DR: In this paper, a method that extracts plastics magnetically, taking advantage of their hydrophobic surface to magnetize the plastics, allowing magnetic recovery, was developed and applied to a simple method, which recovered 92% of 10-20 μm polyethylene and polystyrene beads and 93% of > 1 mm MPs (polyethylene, polyylene terephthalate, poly styrene, polyurethane, polyvinyl chloride and polypropylene) from seawater.
Abstract: Separating microplastics (MPs) from environmental samples is challenging, but necessary to determine their environmental prevalence. Current methods are not standardized across environmental sample type, and it is unclear how well they recover smaller sized MPs. In response, we developed a method that extracts plastics magnetically, taking advantage of their hydrophobic surface to magnetize the plastics. We created hydrophobic Fe nanoparticles that bind to plastic, allowing magnetic recovery. With this principle applied to a simple method, we recovered 92% of 10–20 μm polyethylene and polystyrene beads and 93% of >1 mm MPs (polyethylene, polyethylene terephthalate, polystyrene, polyurethane, polyvinyl chloride, and polypropylene) from seawater. We also recovered 84% and 78% of MPs (polyethylene, polystyrene, polyurethane, polyvinyl chloride, and polypropylene) ranging from 200 μm to 1 mm from freshwater and sediments, respectively. Overall, the procedure is efficient for various sizes, polymer types, and ...
180 citations
12 Mar 2019
TL;DR: In this article, the authors studied the products formed by the mechanical breakdown of two commonly used polystyrene products, takeaway coffee cup lids and expanded poly styrene foam, and characterized the breakdown products using seven different methods and found nanoparticles with different shapes and negative or nearly neutral surface charges.
Abstract: Large amounts of plastics are released into the environment every day. These released plastics have a clearly documented negative effect on wildlife. Much research attention has been given to large plastic pieces and microplastics. However, if the breakdown of plastics is a continous process, eventually nanoplastics will be produced. Nanoplastics will affect wildlife differently from larger plastic pieces. We have studied the products formed by the mechanical breakdown of two commonly used polystyrene products, takeaway coffee cup lids and expanded polystyrene foam. After breakdown using a food processor, we characterized the breakdown products using seven different methods and found nanosized polystyrene particles with different shapes and negative or nearly neutral surface charges. These results clearly demonstrate that daily-use polystyrene products can break down into nanoparticles. Model polystyrene particles with different sizes and surface modifications have previously been shown to have different negative effects on wildlife. This indicates that breakdown nanoparticles might have the potential to cause cocktail effects in nature.
155 citations
TL;DR: In this paper, the use of binder-free bentonite clay pellets as a catalyst in the pyrolysis process of polystyrene, polypropylene, polyethylene, low density polyethylenes and high density polymethylene, was investigated at a bench scale to produce useful fuel products.
Abstract: Catalytic pyrolysis of waste plastics using low cost binder-free pelletized bentonite clay has been investigated to yield pyrolysis oils as drop-in replacements for commercial liquid fuels such as diesel and gasohol 91. Pyrolysis of four waste plastics, polystyrene, polypropylene, low density polyethylene and high density polyethylene, was achieved at a bench scale (1 kg per batch) to produce useful fuel products. Importantly, the addition of binder-free bentonite clay pellets successfully yielded liquid based fuels with increased calorific values and lower viscosity for all plastic wastes. This larger scale pyrolysis study demonstrated that use of a catalyst in powder form can lead to significant pressure drops in the catalyst column, thus slowing the process (more than 1 hour). Importantly, the use of catalyst pellets eliminated the pressure drop and reduced pyrolysis processing time to only 10 minutes for 1 kg of plastic waste. The pyrolysis oil composition from polystyrene consists of 95% aromatic hydrocarbons, while in contrast, those from polypropylene, low density polyethylene and high density polyethylene, were dominated by aliphatic hydrocarbons, as confirmed by GC-MS. FTIR analysis demonstrated that low density polyethylene and high density polyethylene oils had functional groups that were consistent with those of commercial diesel (96% similarity match). In contrast, pyrolysis-oils from polystyrene demonstrated chemical and physical properties similar to those of gasohol 91. In both cases no wax formation was observed when using the bentonite clay pellets as a catalyst in the pyrolysis process, which was attributed to the high acidity of the bentonite catalyst (low SiO2 : Al2O3 ratio), thus making it more active in cracking waxes compared to the less acidic heterogeneous catalysts reported in the literature. Pyrolysis-oil from the catalytic treatment of polystyrene resulted in greater engine power, comparable engine temperature, and lower carbon monoxide (CO) and carbon dioxide (CO2) emissions, as compared to those of uncatalysed oils and commercial fuel in a gasoline engine. Pyrolysis-oils from all other polymers demonstrated comparable performance to diesel in engine power tests. The application of inexpensive and widely available bentonite clay in pyrolysis could significantly aid in repurposing plastic wastes.
144 citations
TL;DR: In this paper, acid-catalyzed Friedel-Crafts alkylation of the polystyrene block of poly(ethylene-co-butylene)-b-polystyrene (SEBS) was used.
Abstract: Elastomeric anion exchange membranes (AEMs) were prepared by acid-catalyzed Friedel–Crafts alkylation of the polystyrene block of polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) using...
134 citations
TL;DR: This paper showed that polystyrene is completely photochemically oxidized and showed that it can be oxidized to polycarbonate polyethylene (PEG) polycarbonates.
Abstract: Numerous international governmental agencies that steer policy assume that polystyrene persists in the environment for millennia. Here, we show that polystyrene is completely photochemically oxidiz...
132 citations
TL;DR: It is found that the novel phenomenon that the liquid products of HIPS plastic were mainly toluene and ethylbenzene rather than styrene, which was a product of polystyrene.
78 citations
TL;DR: In this paper, a facile method to microencapsulate phase change materials (PCMs) within a shell is proposed, which is one of the most feasible methods to explore their applications for thermal energy storage.
Abstract: Microcapsulation of phase change materials (PCMs) within a shell is one of the most feasible methods to explore their applications for thermal energy storage. Here, a facile method to microencapsul...
72 citations
TL;DR: This work demonstrates a convenient method for the preparation of cost-effective and high-performance electrode material for electric capacitor and provides a potential way to recycle polystyrene waste into high-valued product in large-scale with disposing of polymeric waste to alleviate environmental concerns.
72 citations
TL;DR: A universal method to grow polymers on MOF surfaces with well-defined thickness, sequence and functionality.
Abstract: We report a generalizable approach to construct MOF@polymer functional composites through surface-initiated atom transfer radical polymerization (SI-ATRP). Unlike conventional SI-ATRP that requires covalent pre-anchoring of the initiating group on substrate surfaces, in our approach, a rationally designed random copolymer (RCP) macroinitiator first self-assembles on MOF surfaces through inter-chain hydrogen bond crosslinking. Subsequent polymerization in the presence of a crosslinking monomer covalently threads these polymer chains into a robust network, physically confining the MOF particle inside the polymer shell. We demonstrated the universality of this approach by growing various polymers on five MOFs of different metals (Zr, Zn, Co, Al, and Cr) with complete control over shell thickness, functionality and layer sequence while still retaining the inherent porosity of the MOFs. Moreover, the wettability of UiO-66 can be continuously tuned from superhydrophilic to superhydrophobic simply through judicious monomer(s) selection. We also demonstrated that a 7 nm polystyrene shell can effectively shield UiO-66 particles against 1 M H2SO4 and 1 M NaOH at elevated temperature, enabling their potential application in demanding chemical environments.
66 citations
TL;DR: In this article, a co-pyrolysis of grape seeds and polystyrene was conducted in a fixed-bed reactor, followed by an analysis of the organic phase for possible further application as a drop-in fuel.
60 citations
TL;DR: In this article, a novel hydrophobic material based on 9-octadecenoic acid grafted graphene (POG) for oil/water separation was presented, which has the potential to be utilized to clean up oil spills or to remove oil contaminants from water for cleaner production of produced water.
TL;DR: In this article, a triblock copolymer polystyrene-poly(ethylene glycol)-polystyrene (PS-PEG-PS) is synthesized and investigated as solid polymer electrolyte.
TL;DR: In this paper, polystyrene (PS)/poly(methyl methacrylate) (PMMA)/multiwalled carbon nanotube (MWCNT) blends are prepared using six different processing techniques to investigate the effect of processing technique.
Abstract: Polystyrene (PS)/poly(methyl methacrylate) (PMMA)/multiwalled carbon nanotube (MWCNT) blends are prepared using six different processing techniques to investigate the effect of processing technique...
TL;DR: Polymeric multicompartment nanoparticles (MCNs) of μ-ABC miktoarm star polymers composed of poly(N,N-dimethylacrylamide) (PDMA), poly(butyl methacrylate) (PBMA), and polystyrene (PS) were synthesized.
Abstract: Polymeric multicompartment nanoparticles (MCNs) of μ-ABC miktoarm star polymers composed of poly(N,N-dimethylacrylamide) (PDMA), poly(butyl methacrylate) (PBMA), and polystyrene (PS) were synthesiz...
TL;DR: In this paper, hollow mesoporous silicate nanoparticles using TEOS precursors in the presence of polystyrene template were synthesized using an alcohol-based chemical system and the addition of CTAB surfactant.
TL;DR: Porphyrin fibers appeared smoother and thinner and were more resistive at lower temperature, but became much more conductive when temperature increased to 60–70 °C, which seemed further confirmation of the key role of such a macromolecule in the VOC (volatile organic compound) adsorption.
Abstract: Structural and functional properties of polymer composites based on carbon nanomaterials are so attractive that they have become a big challenge in chemical sensors investigation. In the present study, a thin nanofibrous layer, comprising two insulating polymers (polystyrene (PS) and polyhydroxibutyrate (PHB)), a known percentage of nanofillers of mesoporous graphitized carbon (MGC) and a free-base tetraphenylporphyrin, was deposited onto an Interdigitated Electrode (IDE) by electrospinning technology. The potentials of the working temperature to drive both the sensitivity and the selectivity of the chemical sensor were studied and described. The effects of the porphyrin combination with the composite graphene⁻polymer system appeared evident when nanofibrous layers, with and without porphyrin, were compared for their morphology and electrical and sensing parameters. Porphyrin fibers appeared smoother and thinner and were more resistive at lower temperature, but became much more conductive when temperature increased to 60⁻70 °C. Both adsorption and diffusion of chemicals seemed ruled by porphyrin according its combination inside the composite fiber, since the response rates dramatically increased (toluene and acetic acid). Finally, the opposite effect of the working temperature on the sensitivity of the porphyrin-doped fibers (i.e., increasing) and the porphyrin-free fibers (i.e., decreasing) seemed further confirmation of the key role of such a macromolecule in the VOC (volatile organic compound) adsorption.
TL;DR: In this paper, the glass transition temperature (Tg) for a series of highly purified cyclic polystyrene (c-PS) samples with molecular weight (MW) varying from 3300 to 13,400 was investigated.
TL;DR: In this paper, the surface modification of titanium dioxide in aqueous dispersions of specially tailor-made periodic acrylic acid/isobutylene copolymers, poly(acrylic acid)/polystyrene graft copolymer, and hydrophobically modified polyethyleneoxide urethane by ultrasonic treatment was studied.
Abstract: The surface modification of titanium dioxide in aqueous dispersions of specially tailor-made periodic acrylic acid/isobutylene copolymers, poly(acrylic acid)/polystyrene graft copolymers, and hydrophobically modified polyethyleneoxide urethane by ultrasonic treatment was studied. The pigment surface modification by the above copolymers was comparatively investigated regarding conventional adsorption as contrasted to an ultrasonic treatment assisted procedure. The course and efficiency of the polymer adsorption onto the pigment surface was quantified by electrokinetic sonic amplitude measurements. The higher efficiency of the pigment surface coating by the copolymers as achieved by ultrasonic treatment varies with the copolymer architecture and is a consequence of ultrasonically induced pigment surface activation.
TL;DR: In this article, aryl-ether free polystyrene (PS) was employed as polymer backbone and functionalized with alkaline stable N-cyclic quaternary ammonium (QA) cations via click chemistry.
TL;DR: In this paper, pyrolysis of waste polystyrene was investigated in the presence of a mixed metal oxide (Nix=0.5Cu1-xO) under inert conditions in a pyrolynsis chamber.
Abstract: In this study, pyrolysis of waste polystyrene was investigated in the presence of a mixed metal oxide (Nix=0.5Cu1–xO) under inert conditions in a pyrolysis chamber. The pyrolysis products were coll...
TL;DR: In this paper, a catalytic conversion of polystyrene over ultra-stable Y zeolites (USY) was conducted to directionally produce benzene and ethylbenzene.
TL;DR: In this article, the authors investigated the recyclability of virgin nanocellulose (NC) films and found that the recycled films retained approximately 70% of the strength of the virgin films.
TL;DR: In this paper, a review of suspension polymerization for the synthesis of polystyrene cross-linked with divinylbenzene copolymer is presented, where the effect of various synthesis parameters (agitation speed, temperature, initiator, cross-linker and diluent) on particle surface morphology, particle size and distribution, surface area and cross-linking density was reviewed and their application as catalyst support for various oxidation reactions.
Abstract: Various heterogeneous polymerization techniques such as suspension, emulsion, dispersion, precipitation and seeded are employed for the synthesis of a wide variety of porous polymer particles. In present review, suspension polymerization technique is highlighted in detail with control of particle size, advantages and its applications. The aim of the review is to understand the basics of suspension polymerization for the synthesis of polystyrene cross-linked with divinylbenzene copolymer. Also, the effect of various synthesis parameters (agitation speed, temperature, initiator, cross-linker and diluent) on particle surface morphology, particle size and distribution, surface area and cross-linking density was reviewed and their application as catalyst support for various oxidation reactions.
TL;DR: A methodology that uses click chemistry to assemble different sizes of polystyrene beads and magnetic nanoparticles to prepare versatile magnetic probes for the broad-range bioassays with high sensitivity is reported.
Abstract: Magnetic relaxation switching assays with a broad and tunable detection range can greatly improve current magnetic sensors for biochemical detections, but it remains challenging in terms of the limited detection range and low sensitivity. Herein, we report a methodology that uses click chemistry to assemble different sizes of polystyrene beads and magnetic nanoparticles to prepare versatile magnetic probes for broad-range bioassays with high sensitivity. Small magnetic nanoparticles can be controllably assembled on different sizes of polystyrene beads to form core-satellite structures, acting as broad-range probes that enable the magnetic relaxation switching assays with high sensitivity because different sizes of polystyrene beads can conjugate different numbers of small magnetic nanoparticles. On the basis of click chemistry, we assemble polystyrene beads and magnetic nanoparticles to develop a biosensing technique for analyzing three different antibiotics, with a high sensitivity and a tunable detection range from pg/mL to μg/mL.
TL;DR: A nucleation-growth model has been proposed to describe the morphology evolution and verification was offered by computer simulation, and the key discovery is that nanoparticle morphology can be kinetically controlled by diffusion of the protrusions on the seed particles.
TL;DR: In many applications, polymeric foams (such as expanded polystyrene or expanded polypropylene) are used for protection from impacts as discussed by the authors, and standard design requires the foam to maximize the energy absorpt...
Abstract: In many applications, polymeric foams (such as expanded polystyrene or expanded polypropylene) are used for protection from impacts. Standard design requires the foam to maximize the energy absorpt...
TL;DR: In this paper, the effect of CO2-philic additives (PDMS and PVAc) on the diffusion of supercritical CO2 into and out of polystyrene (PS) was investigated via experiments and dissipative particle dynamics simulations.
Abstract: The introduction of suitable CO2-philic additives, enabling high CO2 concentration retained in the polymer matrix, might be a promising strategy to obtain foams with small cell size and large volume expansion ratio. The effect of molecular weight (Mn) (2000–17000 g/mol) of CO2-philic additives (PDMS and PVAc) on the diffusion of supercritical CO2 into and out of polystyrene (PS) was investigated via experiments and dissipative particle dynamics simulations. The CO2 diffusion coefficient increased with the presence of additives especially with PDMS (2000 g/mol, from 1.2 × 10−9 m2/s to 2.8 × 10−9 m2/s). Meanwhile, the saturation solubility of CO2 increase with the incorporation additives. Compared with high Mn additives, the slower CO2 desorption rate with additives with Mn of 2000 g/mol enabled higher amount of CO2 retained in PS, resulting in higher cell density. The incorporation of PDMS (2000 g/mol) decreased the cell size (from 11.67 to 7.57 μ m) and increased volume expansion ratio of PS foams.
TL;DR: The environmental applicability of the fabricated PS/CNT membranes in treating oil-contaminated water is shown, showing superior hydrophobicity and selective oil absorption at 0.5 wt.% of CNT concentration.
Abstract: Carbon-based materials are outstanding candidates for oil spill clean-ups due to their superhydrophobicity, high surface area, chemical inertness, low density, recyclability, and selectivity. The current work deals with the fabrication of membrane oil absorbents based on carbon nanotube (CNT) reinforced polystyrene (PS) nanocomposites by electrospinning technique. The spun membranes are also irradiated with the gamma radiation to induce enough crosslinks and thus good polymer-filler interactions. The structural, morphological, and surface properties in addition to the oil/water separation efficiency were investigated by varying the concentration of CNT and the dose of γ-irradiation. Fabricated nanofiber membranes show superior hydrophobicity and selective oil absorption at 0.5 wt.% of CNT concentration. The best mechanical properties are also obtained at this particular concentration and at 15 KGy optimum γ-irradiation dosage. The gamma irradiated PS/0.5 wt.% CNT membrane also exhibits good antibacterial effects against the bacteria, Escherichia coli, in the form of bacterial inhibition rings around the membranes. The present study thus shows the environmental applicability of the fabricated PS/CNT membranes in treating oil-contaminated water.
31 Jan 2019
TL;DR: In this paper, the shape memory properties of polystyrene block poly styrene (SEBS) were quantitatively investigated under uniaxial tension using a dynamic mechanical analyzer and manual stretching.
Abstract: This work demonstrates that neat polystyrene-block-poly(ethylene-co-butylene)-block-poly styrene (SEBS) displays thermally responsive shape memory properties. The shape memory properties were quantitatively investigated under uniaxial tension using a dynamic mechanical analyzer and manual stretching. The shape memory properties of SEBS were found to depend on both the molecular weight of the polymer and on the shape programming conditions, including the programming temperature, applied strain, and annealing time at elevated temperature under load. The shape memory mechanism is proposed to be a result of partial stress relaxation of the block copolymer network under load and the formation of a second network with a lower glass transition temperature. This second network counterbalances the initially stretched network producing fixity and weakens first on heating, allowing recovery. Due to the unique mechanism of shape memory where the secondary network is generated from the initial network, achieving highe...
TL;DR: A series of copper foams with superhydrophobicity and superoleophilicity were chemically etched using 10 mg mL−1 FeCl3/HCl solution with consequent ultrasonication, followed by the subsequent modification of four sulfhydryl compounds to provide a simple and practical combinational method for the solution of oil spill.
Abstract: Membrane-based metal substrates with special surface wettability have been applied widely for oil/water separation. In this work, a series of copper foams with superhydrophobicity and superoleophilicity were chemically etched using 10 mg mL-1 FeCl3/HCl solution with consequent ultrasonication, followed by the subsequent modification of four sulfhydryl compounds. A water contact angle of 158° and a sliding angle lower than 5° were achieved for the copper foam modified using 10 mM n-octadecanethiol solution in ethanol. In addition, the interaction mechanism was initially investigated, indicating the coordination between copper atoms with vacant orbital and sulfur atoms with lone pair electrons. In addition, the polymeric fibers were electrospun through the dissolution of polystyrene in a good solvent of chlorobenzene, and a nonsolvent of dimethyl sulfoxide. Oil absorption and collection over the water surface were carried out by the miniature boat made out of copper foam, a string bag of as-spun PS fibers with high oil absorption capacity, or the porous boat embedded with the as-spun fibers, respectively. The findings might provide a simple and practical combinational method for the solution of oil spill.