Search

There is a great demand for transparent films, membranes, or substrates in the fields of intelligent wearables, electronic skins, air filtration, and tissue engineering. Traditional materials such as glass and plastics cannot satisfy these requirements because of the lack of interconnected pores, undesirable porosity, and flexibility. Electrospun fibrous membranes offset these shortcomings because they contain small pores and have high porosity as well as outstanding flexibility. Thus, the development of transparent electrospun fibrous membranes is of great value. This work reports a simple and effective way to develop flexible and porous transparent fibrous membranes (TFMs) directly from electrospun fibrous membranes via mechanical pressing, without employing any other additives. In addition, the relationship between the transparency performance and the molecular structure of the polymers after pressing was summarized for the first time. After mechanical pressing, the membranes maintained fibrous morphology, micron-sized pores, and desired porosity. Polystyrene fibrous membranes, which exhibited excellent optical and mechanical properties, were used as a reference. The TFMs possessed high transparency (∼89% visible light transmittance at 550 nm), high porosity (10%–30%), and strong mechanical tensile strength (∼148 MPa), nearly 78 times that of the pristine electrospun fibrous membranes. Moreover, this study demonstrated that transparent and conductive membranes can be fabricated based on TFMs using vacuum-assisted filtration of silver nanowires followed by mechanical pressing. Compared with indium tin oxide films, conductive TFMs exhibited good electrical conductivities (9 Ω per square (Ω·sq−1), 78% transmittance at 550 nm) and notable mechanical performance (to bear abundant bending stresses).

As the most commonly used antipyretic and analgesic drug, paracetamol (PA) coexists with neurotransmitter dopamine (DA) in real biological samples. Their simultaneous determination is extremely important for human health, but puzzled by their mutual interference. In order to improve the conductivity, adsorption affinity, sensitivity and selectivity of TiO2-based electrochemical sensor, N-doped carbon@TiO2 double-shelled hollow sphere (H–C/N@TiO2) is designed and synthesized by simple alcoholic and hydrothermal method, using polystyrene sphere (PS) as a template. Meanwhile, TiO2 hollow spheres (H–TiO2) or N-doped carbon hollow spheres (H–C/N) are prepared by the same method. H–C/N@TiO2 hollow spheres have good conductivity, charge separation, and the highly enhanced and stable current responses for the detection of PA and DA. The detection limit and linear range are 50.0 nmol/L and 0.3–50 μmol/L for PA, 40.0 nmol/L and 0.3–50 μmol/L for DA, respectively, which are better than those of carbon-based sensors. Moreover, this electrochemical sensor with high selectivity, strong anti-interference, high reliability, and long time durability, can be used for the simultaneous detection of PA and DA in human blood serum and saliva. The high electrochemical performance of H–C/N@TiO2 is attributed to the multi-functional combination of different layers, because of good conductivity, absorption and electrons transfer ability from in-situ N-doped carbon and electrocatalytic activity from TiO2.

Copper azide with high density was successfully synthesized by in-situ reaction of nanoporous copper (NPC) precursor with HN3 gaseous. NPC with pore size of about 529 nm has been prepared by electroless plating using polystyrene (PS) as templates. The copper shells thickness of NPC was controlled by adjusting the PS loading amount. The effects of copper shell on the morphology, structure and density of copper azide were investigated. The conversion increased from 87.12% to 95.31% when copper shell thickness decrease from 100 to 50 nm. Meanwhile, the density of copper azide prepared by 529 nm NPC for 24 h was up to 2.38 g/cm3. The hollow structure of this NPC was filled by swelling of copper azide which guaranteed enough filling volume for keeping the same shape as well as improving the charge density. Moreover, HNS-IV explosive was successfully initiated by copper azide with minimum charge thickness of 0.55 mm, showing that copper azide prepared has excellent initiation performance, which has more advantages in the application of miniaturized explosive systems.

Concentration gradient and fluid shear stress (FSS) for cell microenvironment were investigated through microfluidic technology. The Darcy–Weisbach equation combined with computational fluid dynamics modeling was exploited to design the microfluidic chip, and the FSS distribution on the cell model with varying micro-channels (triangular, conical, and elliptical). The diffusion with the incompressible laminar flow model by solving the time-dependent diffusion–convection equation was applied to simulate the gradient profiles of concentration in the micro-channels. For the study of single cell in-depth, the FSS was investigated by the usage of polystyrene particles and the concentration diffusion distribution was studied by the usage of different colors of dyes. A successful agreement between model simulations and experimental data was obtained. Finally, based on the established method, the communication between individual cells was envisaged and modeled. The developed method provides valuable insights and allows to continuously improve the design of microfluidic devices for the study of single cell, the occurrence and development of tumors, and therapeutic applications.

Next-generation packaging materials are expected to have higher thermal conductivity, because the heat accumulated in high-performance electronic equipment should be removed to increase the service life of the equipment. At the same time, the dielectric loss of the material needs to be reduced to lessen signal delay and attenuation, especially for the applications under high frequency. In this work, we introduce nano-silicon carbide (SiC) and carbon nanotubes (CNTs) into the polystyrene (PS) and poly(methyl methacrylate) (PMMA) blends system. The design of two-way migration at the interface of CNTs and SiC nanoparticles is realized through the masterbatch method and processing technology control. As a result, the thermal conductivity is successfully increased up to 75%. Meanwhile, compared to the CNTs single-phase migration system, it effectively reduces the dielectric loss of the nanocomposite and optimizes the electrical insulation. This work has significant practical application value in the design of electronic device substrates and packaging materials, and provides an innovative methodology for the mesostructure design of multiphase nanocomposites.

Polystyrene (PS) is rich in plastic materials, but it produces a large amount of waste every year, causing a huge burden on the environment. Although PS plastic is the source of a common "white pollution" in daily life, it still has a high utilization value. At the same time, the flammability of PS material determines that it cannot be applicated in places where fire accidents occur frequently. As a result, its application has been greatly limited. In order to realize the efficient utilization of waste PS and broaden its scope of application, PS was modified by hyper-crosslinking in order to improve its fire-retardant performance. In this method, the PS solution with high purity was obtained by dissolving waste PS foam with 1,2-dichloroethane (DCE), and then the hyper-crosslinked polymer with high specific surface area was prepared by adding cross-linking agent formaldehyde dimethyl acetal (FDA) and a Lewis-acid catalyst ferric chloride (FeCl3). Further studies showed that the effects of the amount of cross-linking agent FDA, catalyst FeCl3 and PS on the reaction products were different. In addition, compared the as-prepared fire-retardant materials with PS foam from the aspects of flame retardancy and thermal insulation, it can be concluded that the fire-retardant performance of the materials prepared by this method has been significantly enhanced. And it is proved that this method is feasible towards the preparation of a large number of fire-retardant composite materials by using a scale-up experiment.

Facile strategy enabling the fabrication of carbon dots (CDs) with favorable performance useful for various applications is highly desirable. Here, we report the fabrication of highly fluorescent carbon dots (CDs) towards sensitive metal ion detection, brightly fluorescent printing pattern, as well as green flame retardants for synthetic polymeric materials. CDs are synthesized by solvothermal treatment of polypropylene carbonate (PPC) with ethylenediamine, and the quantum yield of CDs could increase from 30 to 86% by further adding trace of citric acid. The abundant functional groups on the surface of CDs allow CDs well incorporated into polymers to form CD-loaded polystyrene (PS) microspheres, which are employed to construct fluorescent supraballs via triphase microfluidic technique and used as “inks” for uniform fluorescent patterns. Interestingly, the resultant CDs show good flame retardancy for highly flammable polymeric foams and fibers. The CDs surpass previously reported flame-retardant additives, to show excellent combustion resistance that the addition of 20 wt% CDs causes 75% decrease in the peak of heat release rate (P-HRR) for polyurethane (PU) foams. Significantly, a molecular dynamics simulation process for PU/CDs combustion is constructed. This work may spur the preparation and application of high-performance carbon-based nanomaterials.

Heavy metal pollution poses a severe threat to the water environment. Engineering sub-10 nm active functional materials is an important approach to address the problems, and nanocomposites, developed in recent years by pore confinement always present weaken diffusion and low utilization of nanoparticles. In this study, we successfully prepared the polydopamine confined high-density sub-10 nm Sn(HPO4)2 coating for toxic lead(II) removal and its unique external coating structure and superior active sub-10 nm size achieved remarkable performances for heavy metal remediation. The hybrid sub-10 nm coating exhibits an extended acidic environment application (pH=2.0-7.0) as well as significant selectivity with a superior Kd values (9.4×104 mL/g, which is 450 times greater than that of commercial sulfonated polystyrene. Ultrafast filtrations by vacuum further validate its superior sequestration (near to 100%) to Pb and Cd ions at different concentrations (10-100 mg/L) for 2 mins. The real column application further demonstrates the remarkable capacity of 11800 kg per kg sorbents, the trace effluents with three orders (∼103) reduction to below 1 ppb (> 99.9% Pb removal) and efficient stability for several cycles. The effective performances are mainly driven by the PDA motivated external nanoparticles arrangement and strong inner-sphere complexation by small size of Sn(HPO4)2. These results set a new benchmark for removing toxic metals and the proposed approach (engineering sub-10 nm coating design) is unique for heavy metal removal.

In this study, the in situ chemical polymerization process was used to synthesize polystyrene/magnetite nanocomposite (PS-DVB/ Fe3O4). The prepared composite was characterized by XPS, SEM, XRD, HRTEM, FT-IR, and TGA technique. The XPS as an essential elemental analysis tool proved the proposed general formulae of the prepared nanocomposite (PS-DVB/ Fe3O4). FT-IR data proved the functional groups in the proposed structural formula of the prepared nanomaterials. The thermal analysis confirmed the high thermal stability of the prepared core–shell polymer. XRD results prove the crystallinity and single phase. Scanning electron microscope (SEM) and the presence of Fe2O3 and PS-DVB/Fe3O4 composite has been confirmed by HRTEM. The particle size analysis was used to determine the distribution of particle size within the polymer matrix. The adsorption potential of Tartrazine azo dye from polluted water samples onto cross-linked (PS-DVB/Fe3O4) using fixed-bed adsorption column was investigated. The adsorption capacity of Tartrazine onto PS-DVB greatly improved when Fe3O4 is added to the porous composite of PS-DVB copolymer to be 0.15 mol with removal efficiency reach 98%. In this respect, the effect of liquid flow rate, initial Tartrazine concentration, and PS-DVB/Fe3O4 bed height on the adsorption technique's breakthrough features was taken. In this work, the mass transfer model, which involved the two parameters of τ (50% breakthrough time) and k (adsorption rate constant), was suggested for discussion the effect of PS-DVB/Fe3O4on such values. It was found that the adsorption capacity Qe and τ values were decreased with the flow rate increases. The flow rate had little effect, at least for the PS-DVB/Fe3O4, on the k value. On the other hand, both Qe and τ values decreased with increasing the initial Tartrazine concentration, whereas the k value was slightly increased. We concluded that the liquid flow rate, initial Tartrazine concentration, and bed height were1mL/min, 5 M, and 7 cm, respectively. Finally, the PS-DVB/Fe3O4 was a suitable Tartrazine adsorbent using a fixed-bed adsorption column, which fitted well with the mass transfer model.

To increase the low yield and selectivity of aromatic hydrocarbons during the biomass pyrolysis process, we torrefied the biomass and then co-pyrolyzing with plastics such as high-density polyethylene (HDPE), polystyrene (PS), ethylene-vinyl acetate (EVA) and polypropylene (PP) and also single and dual catalyst layouts were investigated by Py-GC/MS. The results showed that non-catalytic fast pyrolysis (CFP) of raw bagasse (RBG) generated no aromatics. After torrefaction non-CFP of torrefied bagasse (TBG) generated low aromatic yield. Indicating that torrefaction would enhance the proportion of aromatics during the pyrolysis process. The CFP of TBG200°C and TBG240°C over ZSM-5 produced the total aromatic yield of 1.96 and 1.88 times higher, respectively, compared to non-CFP of TBG. Furthermore, the addition of plastic could increase H/Ceff. ratio of the mixture, consequently, increase the yield of aromatic compounds. Among the various torrefied-bagasse/plastic mixtures, the CFP of TBG/EVA (7:3 ratio) mixture generated the highest the total aromatic yield of 7.7 times more than the CFP of TBG alone. The dual catalyst layout could enhance the yield of aromatics hydrocarbons. The dual-catalytic co-pyrolysis of TBG200°C/plastic (1:1) ratio over USY/ZSM-5, improved the total aromatics yield by 4.33 times more than the catalytic pyrolysis of TBG200oC alone over ZSM-5 catalyst. The above results showed that the yield and selectivities of light aromatic hydrocarbons can be improved via catalytic co-pyrolysis and dual catalytic co-pyrolysis of torrefied-biomass with plastics.

The production of hydrogen (H2) from the pyrolysis–catalytic steam reforming of polyethylene, polystyrene (PS) and polyethylene terephthalate waste plastics was investigated using a two-stage reactor. The highest yield of hydrogen (125 mmol/gplastic) was obtained with PS at a catalyst temperature of 900°C and steam input weight hourly space velocity of 7.59 g/(h/gcatalyst) with a 10 wt% nickel/aluminium oxide (Ni/Al2O3) catalyst. Further investigation using PS showed that the process parameters of high catalyst temperature (900°C) and optimised steam input rate significantly increased the yield of hydrogen. Examination of several different catalysts (nickel/aluminium oxide, iron/aluminium oxide, copper/aluminium oxide, cobalt/aluminium oxide) showed that nickel/aluminium oxide had by far the highest catalytic activity and selectivity towards the yield of hydrogen.

Three-dimensional (3D) plasmonic nano-arrays can provide high surface-enhanced Raman scattering (SERS) sensitivity, good spectral uniformity and excellent reproducibility. However, it is still a challenge to develop a simple and efficient method for fabrication of 3D plasmonic nano-arrays with high SERS performance. Here we report a facile approach to construct ordered arrays of silver (Ag) nanoparticles-assembled spherical micro-cavities using polystyrene (PS) sphere template-assisted electrodeposition and post-growth. The electrodeposited small Ag nanoparticles grow into bigger stable nanoparticles during the post-growth process, which could significantly improve the SERS sensitivity. The Ag nanoparticles-assembled 3D micro-cavity array provides much more hotspots in the excitation laser beam-covered volume than the two-dimensional counterpart. The relative standard deviation (RSD) of 612 cm−1 peak of rhodamine 6G (R6G) was calculated to be 8%, and the RSD of the characteristic peak taken from substrates of different batches was less than 10%. The detectable lower concentration as low as 1 fM was achieved for an aqueous solution of R6G. Such SERS substrate also showed high sensitivity to thiram (fungicide) and paraquat (herbicide) in water with limits of detection of 0.067 nM and 2.5 nM respectively. Furthermore, it also demonstrated that SERS detection of pesticide residues on fruits can be realized, showing a potential application in rapid monitoring food safety.

Ring-like residual deposits are often observed after drying suspension droplets on surfaces. That introduces a crucial defect in practical applications, such as ink-jet printing that requires a uniform deposit. In this study, depositions after drying sessile/pendant droplets with silica/polystyrene particles were examined to identify the effect of gravitational sedimentation of particles on self-pinning and deposition pattern. The suspension droplet with larger polystyrene (or silica) particles would trigger the self-pinning at larger (or smaller) particle concentrations. The deposition pattern of pendant drops with silica particles is hill-like. This is due to the large density difference between silica and water to induce high sedimentation velocity, and the particles would precipitate and aggregate along the air–liquid interface to form a hollow shell deposit. The depositions for suspensions with bi-dispersed particles, the larger silica particles would accumulate at the bottom of the deposit due to the higher sedimentation velocity, in contrast to the well-mixed in the deposits for bi-dispersed polystyrene particles. The sedimentation and capillary flow velocities were calculated and discussed. These new findings reveal that the particle density (gravity effect) can be used to adjust the sedimentation velocity to control the deposition morphology and particle size distribution even to suppress the coffee-ring effect.

Owing to the lack of research on structure-activity relationship and interaction mechanism between unsaturated polyester resins (UPR) and flame retardants, it has been a big challenge to prepare high-efficiency flame retardants for UPR in industry. In this research, to explore structural rules of high-efficiency flame retardants, several polymeric flame retardants were synthesized with varied main-chain, side-chain, phosphorus valence states and contents of flame retardant elements. The thermal stabilities of flame retardants and UPR composites were firstly assessed. It has been found the interaction existed between flame retardants and UPR, through transesterification reaction and β scission pathway in polyester and polystyrene chains. With only 15 wt% of PCH3-S, UPR composites can reach V0 rating in UL-94. The PHRR and THR values can be maximumly decreased by 71.66 % and 77.67 %, with 20 wt% of PB-S. It has been found flame retardants with sulfone group and + 3 valence state of phosphorus in molecular backbone can release SO2 and phosphorus containing compounds in gaseous phase, which diluted fuel fragments and catalyzed H⋅ and HO⋅ radical removal. The mechanism for improved flame retardancy of UPR composites with various polymeric flame retardants were discussed in detail. Some general rules for highly efficient flame retardant UPR can be summarized: First, gaseous phase flame retardant mechanism plays the major role in improvement of flame retardant performance of UPR composites; Second, the combination of + 3 valence state of phosphorus structures, higher phosphorus contents and sulfone groups effectively improves the flame retardant efficiency of flame retardants.

Syndiotactic-polystyrene based porous polymers were obtained by polymerizations of styrene (St), 4-methyl styrene (MSt), or 4-tert-butyl styrene (BSt) and copolymerization of St/MeSt, St/BuSt, or S...

A novel nanofiber-based solid phase extraction (NFSPE) coupled with HPLC-DAD was developed for the determination of salivary histidine, a new potential index of physiological events. The treatment of the sample was based on a coupling reaction of histidine with the diazotization products of sulfanilic acid and sodium nitrite in a slightly alkaline medium, followed by NFSPE. Nanofibers comprising polystyrene and zinc acetate were used as a novel solid-phase sorbent to extract derived histidine via the chelation of Zn

The concept of back-contact device architecture for perovskite solar cells (PSCs) is a promising alternative to PSCs with the traditional sandwich-type device architecture. The most convenient and low cost method to fabricate back-contact electrodes for PSCs is using microsphere lithography as it can be performed without expensive photolithography tools and cleanroom environment. Deposition of a monolayer of polystyrene microbeads on the surface of cathode substrates (conductive transparent oxide glass substrates covered with a thin layer of SnO2) is achieved through a self-assembly process. The self-assembly process is based on electrostatic attraction forces between negatively charged microbeads and the positively charged cathode surface. The self-assembled monolayer of polystyrene microbeads is used as a sacrificial polymer mask to fabricate the anode layer on top of cathodes. The back-contact electrodes are obtained after removing the sacrificial polymer mask through a lift-off process.

The behaviours of microparticles inside a sessile droplet actuated by surface acoustic waves (SAWs) were investigated, where the SAWs produced an acoustic streaming flow and imparted an acoustic radiation force on the microparticles. The Rayleigh waves formed by a comb-like interdigital transducer were made to propagate along the surface of a LiNbO3 substrate in order to allow the manipulation of microparticles in a label-free and non-contact manner. Polystyrene microparticles were first employed to describe the behaviours inside a sessile droplet. The influence of the volume of the sessile droplet on the behaviours of the microparticles was examined by changing the contact angle of the droplet. Next, cancer cells were suspended in a sessile droplet, and the influence of contact angle on the behaviours of the cancer cells was investigated. A long gelation time was afforded by using a PEGylated fibrin gel. A primary tumour was mimicked by patterning the cancer cells to be concentrated in the middle of the sessile droplet. The non-contact manipulation property of acoustic waves was indicated to be biocompatible and enabled a structure-free platform configuration. Three-dimensional aggregated culture models were observed to make the cancer cells display an elevated expression of E-cadherin. The efficacy of the anticancer drug tirapazamine increased in the aggregated cancer cells, attributed to the low levels of oxygen in this formation of cancer cells.

The extremely increasing amount of plastic waste due to the development of human society, economics and urbanization is an emergency task that must be urgently handled in order to reduce environmental problems. Although the plastic wastes can be converted to alternative liquid fuels through pyrolysis process, the compositions in the pyrolysis oil depended on the chemical structure of raw materials and pyrolysis condition affect its quality. Thus, this research aimed to comparatively investigate the production of alternative liquid fuels obtained from mixed plastics containing polystyrene (PS)/polyethylene terephthalate (PET)/polyethylene (PE)/polypropylene (PP) at 20/5/35/40 (w/w) via non-catalytic cracking (under N2 atmosphere), non-catalytic hydrocracking (under H2 atmosphere), and catalytic hydrocracking over 10 wt% Ni/SBA-15 catalyst conducted at an atmospheric pressure and 650 °C for 1 h. The product yields and chemical compositions (paraffins, olefins, aromatics and PAHs) in the liquid products generated from these processes were investigated and also compared to ones obtained from the non-catalytic processes of each plastic. Herein, the characteristics of 10 wt% Ni/SBA-15 catalyst was analyzed by N2-adsorption/desorption, X-ray diffraction (XRD), and H2-temperature programmed reduction (H2-TPR). The results indicated that the non-catalytic processes of PS provided the highest content of oil and wax product (ca. 92 wt%). Whereas, the non-catalytic hydrocracking of the mixed plastics gave the lowest one (ca. 69 wt%). However, the catalytic hydrocracking over 10 wt% Ni/SBA-15 catalyst (2.5 – 10.0 wt% based on the mixed plastics) could suppress the cracking and yielded the higher amount of oil and wax to ca. 76–80 wt%. To consider the chemical compositions in the liquid phase, the PAHs formation was relied on the aromatic structure in the feedstocks. The liquid product derived from the non-catalytic processes of PS contained the highest amount of PAHs compounds (2622–2926 ppm) followed by the mixed plastics. When the 10 wt% Ni/SBA-15 catalyst was applied to the catalytic hydrocracking of the mixed plastics, the amount of PAHs in the liquid product decreased from 1621 ppm to ca. 1000 ppm (30 – 40% PAHs reduction) without the reduction of heating value when compared to one obtained from the non-catalytic processes.

A novel polystyrene-poly(hydroxamic acid) interpenetrating network resin (PS-PHA IPNs) was successfully synthesized by suspension polymerization and interpenetrating network technology. The effects of various experimental parameters, including pH, contact time and initial concentrations of rare earth ions on the adsorption capacity were discussed in detail. Under the condition of pH 4.0 (La3+), 1.0 (Ce3+) and 3.0 (Y3+), respectively, PS-PHA IPNs can reach equilibrium adsorption in 6 h and get maximum adsorption capacities (1.08, 1.43 and 1.36 mmol/g). The adsorption process of PS-PHA IPNs for La(III), Ce(III) and Y(III) ions can be described by liquid membrane diffusion, particle diffusion and chemical reaction. The adsorption process is a spontaneous and endothermic process and can be better simulated by Langmuir adsorption isotherm. The studies of SEM-EDS indicate that rare earth ions are adsorbed on the surface of PS-PHA IPNs. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis further prove that rare earth ions are chemisorbed on the surface of PS-PHA IPNs. These results reveal that the as-prepared PS-PHA IPNs is a promising adsorbent for adsorption of rare earth ions due to their higher adsorption capacity than other adsorbents.

The growing number of manufactured nanomaterials (MNMs) used in consumer products and industrial applications is leading to increased exposures whose consequences are not yet fully understood in terms of potential impacts on human and ecosystem health. Thus, there is an urgent need to further develop high throughput testing for hazard prediction in nanotoxicology. The zebrafish (Danio rerio) embryo has emerged as a vertebrate model organism for nanotoxicity studies, as it provides superior characteristics for microscopy-based screening and can describe the complex interactions of MNMs with a living organism. Automated microscopy coupled with image acquisition has facilitated hazard assessment of chemicals by quantification of various endpoints (e.g., mortality, malformations, hatching), an approach which we employed here to address adverse effects of a selected library of MNMs of different compositions and surface functionalities. We investigated metal and metal oxide MNMs with mean primary particle sizes of 5 to 50 nm, different chemical compositions (silica, ceria, titania, zinc oxide and silver) and various surface coatings / functionalisation, including OECD reference materials. In addition, we tested as proxies representatives for of nanoplastics polystyrene and polymethylmethacrylate nanoparticles which were surface modified by either amino- or carboxyl-groups. Our systematic analysis to establish quantitative property-activity relationships revealed a pronounced toxicity of silver and amino-modified polystyrene nanoparticles (NPs), evidenced by reduced survival and malformations. Interference with hatching, however, was the most sensitive endpoint, as zinc oxide as well as silver NPs reduced hatching already at lower concentrations (i.e., 0.5 and 1 µg/mL, respectively) and early time points (3 days post fertilization, dpf). Interestingly, carboxylated polystyrene NPs and carboxylated or amino-modified polymethylmethacrylate NPs were non-toxic, highlighting both surface modification and core chemistry of nanoplastics as key determinants of biocompatibility.

This work reports the fabrication of magnetic polymer dimers with controlled surface anisotropy. The fabrication process involves the preparation of magnetite (Fe3O4) magnetic clusters with strong magnetism, followed by their surface modification, dispersion polymerization while using them as seeds, multilayer shell formation via layer-by-layer deposition, and polymer core swelling. The interplay between the swelling and multilayer shells generates pressure inside the multilayer-deposited, magnetic polystyrene (PS) spheres, forming structurally anisotropic dimers with single PS protrusions anchored on the multilayer surfaces within minutes. The use of titania precursor and different swelling agents, along with the change in the composition of the multilayer shell, enables the introduction of different surface anisotropies, such as the surface-charge anisotropy, anisotropic hydrophilicity/hydrophobicity, and material composition anisotropy, to the dimers. The strong magnetic response of the dimers, attributed to the magnetic cluster seeds, in combination with the surface-charge and material composition anisotropies allows a rapid magnetic recovery and an excellent reusability, enabling their application to 20-cycled reduction of 4-nitrophenol (4-NP) and methylene blue (MB) without loss of catalytic activity. Furthermore, the anisotropic hydrophilicity/hydrophobicity makes the dimers potentially useful as solid surfactant to stabilize immiscible oil–water mixture.

Polystyrene is thermoformed in a viscous state at temperatures corresponding to its crystalline melting point (100–140 °C). The mechanical properties of the material change with temperature since these plastics behave viscously when temperature is increased. Findings are presented during numerical simulations, implementing a viscoelastic characterization of laminated polystyrene. A viscoelastic generalized Maxwell model with Prony series is used in the simulation to replicate the thermoforming processes. The results were verified by comparing them through experimental tensile tests at different temperatures. The good agreement between the model and experimentation allows the proper selection of operating parameters such as pressure, time and temperature of the process.

High-performance foldable metal-coated ionic polymer-metal nanocomposites (IPMNCs) with crack minimized electrode are desired for wearable electronics, energy harvesting devices, tactile sensors, structural health monitors, humidity sensors, and supercapacitor devices. However, the IPMNC shows the cracked structure that seriously decreases the performance of IPMNCs for sensors and actuators applications. To overcome the issue of the cracked metal electrode, here we propose a metal-coated hierarchical porous structured IPMNC via minimizing the cracks in the Platinum (Pt) electrode using attachment of poly(2-acrylamide-2-methyl-1-propane-sulfonic acid) (PAMPS) in poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE))/polyvinylpyrrolidone (PVP) blend. The crack-minimized Pt electrode deposition on PAMPS attached P(VDF-TrFE)/PVP-based IPMNCs showed enhanced electrical and sensing signals compared to the Nafion, ionic liquid, and polystyrene sulphonic acid-based IPMNCs. The developed IPMNCs with an optimized composition depict stable sensing signals up to 10,000 cycles. The hierarchical porous structure and the crack-minimized metal electrode on the P(VDF-TrFE)/PVP/PAMPS IPMNC can be utilized in various attractive applications such as energy harvesting, wearable electronics, humidity sensor, pulse, braille recognition, catalyst supports, bio-interfacing, and sensors.

SiO2@3COFs@CuO and SiO2@3COFs@Fe2O3 are prepared in this study. Then SiO2 and its hybrids are incorporated into PS through solution blending method. The thermal stability, mechanical performance, combustion performance and smoke density of PS and its nanocomposite are investigated. The temperature at 5 wt% weight loss and the maximum weight loss rate of PS/SiO2@3COFs@ Fe2O3 (PS 4) under air are 15 and 14 °C higher than that of neat one, respectively. The glass-transition temperature of PS/SiO2@3COFs (PS 2) is 1.5 °C lower than that of PS, which can conclude that SiO2@3COFs contributes to impact strength of PS 0. The peak heat release rate (20.8%) and total heat release (14.0%) of PS 2 decreases further compared with that of PS 0. The smoke density of PS 4 is 23.1% lower than that of neat PS. The influence of SiO2 and its nano-hybrids on the pyrolysis and combustion of PS is investigated. Incorporation of SiO2 and its nano-hybrids shows little effect on pyrolysis process of PS. However, heat resistance of PS is enhanced obviously and thermal degradation rate of PS is also decreased through incorporation of SiO2 and its nano-hybrids. The gaseous pyrolysis products (aromatic compounds and alkenyl compounds) of PS and its nanocomposite also decrease.

The research was conducted on growth and vital functions of watercress in the conditions of encapsulated mineral fertilizers treatment. The cyclic application of mineral fertilizers during three vegetation periods is simulated in this paper. Used mineral fertilizers are encapsulated on the basis of polyethylene terephthalate and polystyrene waste. It was found that the intermediate products of the polymer covering decomposition do not have a negative impact on the soil environment and the use of encapsulated fertilizers is safe for plants growing.

The dynamics of a series of soft colloids comprised of polystyrene cores with poly(N-isopropylacrylamide) (PNIPAM) coronas was investigated by diffusing wave spectroscopy (DWS). The modulus of the coronas was varied by changing the cross-link density and we were able to interpret the results within a hard-soft mapping framework. The soft, swellable particle properties were modeled using an extended Flory-Rehner theory and a Hertzian pair potential. Following volume fraction jumps, softness effects on the concentration dependence of dynamics were determined, with a ‘soft colloids make strong glass-forming liquid’-type of behavior observed close to the nominal glass transition volume fraction, φ g . Such behavior from the current systems cannot be fully explained by the osmotic deswelling model alone. However, inspired by the soft-hard mapping from Schmiedeberg et al, [Europhys. Lett. 2011, 96 (3) , 36010] we estimated effective hard-sphere diameters and achieved a successful mapping of the α-relaxation times to a master curve below φ g . Above φ g , the curves no longer collapse but show strong deviations from a Vogel-Fulcher type of divergence onto soft jamming plateaux. Our results provide evidence that osmotic deswelling itself cannot fully explain the observed dynamics. Softness also plays an important role in the dynamics of soft, concentrated colloids.

Ta3N5 has suitable band positions for visible light photocatalytic hydrogen production from water splitting. However, fast self-recombination of electrons and holes is a drawback for its low efficiency. A Ta3N5/WO3 Z-scheme was therefore considered to solve this problem. Furthermore, a nanohoneycomb (nHC) structure was designed and fabricated based on solution-based nanosphere lithography to offer higher surface area for reaction. The cell size of the nHC was controlled by using 400-, 200-, and 100-nm polystyrene nanospheres as the mask. Under visible light irradiation, the hydrogen generation rates of Ta3N5@WO3 film and Ta3N5@100-nm WO3 nHC were measured to be 4.6 and 8.1 μmol/g·h, respectively, whereas that of pure Ta3N5 nHC was negligible. With deposition of Pt cocatalyst, the hydrogen generation rates for Ta3N5@WO3 film and Ta3N5@100-nm WO3 nHC were further raised to 9.9 and 16.6 μmol/g·h, confirming the effectiveness of the structure design.

Electroconductive polystyrene (PS) composites with ideal flame-retardant properties are considered as potential electromagnetic interference (EMI) shielding materials. In this work, PS/silicon wrapped ammonium polyphosphate/multi-wall carbon nanotubes (PS/SiAPP/MWCNT) composites with segregated structure were synthesized via the methods of balling mill and hot-pressing. The obtained results revealed that the SiAPP and MWCNT were successfully introduced onto PS spheres and showed uniform distribution on the PS surface. The thermogravimetric analysis showed that PS/SiAPP/MWCNT containing 7 wt% MWCNT exhibited excellent thermal stability. Furthermore, the results of cone calorimeter test indicated that the heat release rate and total heat release of the PS/SiAPP/MWCNT containing a loading of 7 wt% MWCNT were reduced by 60.5% and 33.9%, respectively. In addition, the EMI shielding performance could reach 11 dB. Above results implied that the synergistic effect between the MWCNT and SiAPP effectively enhanced the flame retardant performance of the PS by promoting the generation of dense and continuous char layer to protect the PS from burning. The multiple reflection and adsorption are responsible for improved EMI shielding effectiveness. Therefore, segregated PS/SiAPP/MWCNT hybrid is an up-and-coming candidate for satisfactory EMI shielding materials with exceptional fire retardancy for electronic devices.

With polystyrene nanoparticles being widely used in various applications, there is a great need for deeper knowledge on the safety, fate and biological effects of these particles on both individual living organisms and the whole ecosystems. Due to this, there is a growing interest in performing ecotoxicological studies using model plastic nanoparticles, and consequently it generates an increasing number of published papers describing the negative impact on wildlife caused by such nanoparticles. Polystyrene is the most studied nanosized plastic, therefore this review focuses on research conducted with manufactured polystyrene nanoparticles. The aim of the present article is to provide a critical methodological outline of the existing ecotoxicological studies on the effects of polystyrene nanoparticles on aquatic organisms. Going through the published articles, we noted that particle characterization especially in the test medium, can be improved. The analysis also highlights the importance of purifying the polystyrene nanoparticles before studying its toxicity. Furthermore, the size characterization of such nanoparticles is underemphasized, and in future studies, authors should consider including more techniques to achieve this goal. Finally, short-term or direct exposure scenarios do not add the most environmentally relevant knowledge in terms of the toxicity caused by polystyrene nanoparticles.

In this research we tried to improve the thermal insulation efficiency of polystyrene foam by adding some natural materials. The gebrile soil was selected for several reasons, including abundance and ease of processing before the addition - There are many previous researches for soil treatment -. We have found at ratio 20%(The proportion of the soil in the compound) the coefficient of conduction is low and then rises after this percentage As for the absorption of water it increases by increasing the soil, but at this ratio the absorption is within the permissible limit according to the specifications required for the insulation materials and also compressive strength increase with the increasing of the soil ratio because of increasing of mechanical links between the polycarbonate and polystyrene particles and composite-material’s density increasing in general.

Utilizing the emulsion-forming ability of partially deacetylated chitin nanofibers, a composite with polystyrene was prepared. A partially deacetylated chitin nanofiber aqueous dispersion was added to styrene to obtain an oil in a water-type Pickering emulsion. Using the emulsion, suspension polymerization was performed to obtain polystyrene fine particles covered with chitin nanofibers. The degree of polymerization of polystyrene increased depending on the mixing ratio of chitin nanofibers. The glass transition temperature of polystyrene and the thermal decomposition temperature of the composite increased with the mixing ratio of chitin nanofibers. This composite could be molded by hot pressing, and the molded product was transparent to some extent. Since chitin nanofibers effectively reinforced polystyrene, Young’s modulus, fracture stress, and fracture strain were greatly improved. The optimum mixing ratio of chitin nanofibers for improving mechanical properties was 7%. When the composite was molded by hot pressing again, the mechanical properties did not decrease. Thus, the nanofiber reinforcement material was recyclable. Utilizing the emulsion-forming ability of partially deacetylated chitin nanofibers, a composite with polystyrene (PS) was prepared. A partially deacetylated chitin nanofiber aqueous dispersion was added to styrene to obtain an oil in a water-type Pickering emulsion. Using the emulsion, suspension polymerization was performed to obtain PS fine particles covered with chitin nanofibers. This composite could be molded by hot pressing, and the molded product was transparent to some extent. Mechanical properties of PS were greatly improved. When the composite was molded again, the mechanical properties did not decrease.

In the present work we have explored a new catalyst prepared with Algerian clay and a new method to synthesise polystyrene and poly(1,3-dioxolane). This technique consists of using Algerian modified clay (Kaolinite-H+) as a green catalyst. Kaolinite-H+ is a proton exchanged clay which is prepared through a simple exchange process. Synthesis experiments are performed in bulk. The polymerization of styrene in bulk leads to the yield of 83 % at room temperature with the reaction time of 3 h. Molecular weight of the obtained polystyrene is calculated by 1H NMR and is about 2196 g/mol. Polymerization of (1,3-dioxolane) is carried out at room temperature with the reaction time of 3 h and polymerization yield of 91 %. The calculated molecular weight of the obtained poly(1,3-dioxolane) is about 573 g/mol. The structure of the obtained polymers is confirmed by FT-IR and 1H NMR. The modified clay (Kaolinite-H+) is characterized by FT-IR, XRD and SEM analysis.

Herein we report the synthesis of polystyrene-graphene nanosheets (PS-GNs) and octadecylamine-graphene nanosheets (OA-GNs) which possessed much rougher surface and wider lamellar spacing than that of the pristine GNs. The incorporation of PS and OA into the GNs mitigated the agglomeration issues of the pristine GNs. The synthesized PS-GNs and OA-GNs were in turn applied as additives to prepare modified cement mortars which were tested for various mechanical and fluidity tests. The test results showed that PS-GNs and OA-GNs incorporation played effective roles in reinforcing compressive strength and flexural strength of modified cement mortar. The results revealed that in contrast to the physical reaction of PS-GNs with the cement mortar, the chelating reaction of OA-GNs with Ca2+ retarded the hydration process at 0–7 days of cement mortar. This study provides important findings for the preparation of PS-GNs/cement mortar and OA-GNs/cement mortar with enhanced mechanical properties for practical applications in construction industries.

While the strategy of blending commodity insulating polymers with conjugated polymers has been previously applied to modify the properties of organic field-effect transistors (OFETs), comprehensive...

Endothelial cells (EC), which line the internal surface of blood vessels, play various essential roles in controlling vascular function. The mouse is an important animal model for the study of vascular biology and cardiovascular diseases. However, the isolation of primary EC from the murine aorta is challenging because they are readily contaminated by smooth muscle cells (SMC). A previous study developed a simple method to isolate murine EC from SMC. By taking advantage of the differential sedimentation rate between the two cells, the EC was selectively enriched with collagen-coated polystyrene surfaces. Our study further improved this method by introducing a biomimetic peptide REDV (Arg-Glu-Asp-Val), which may bind specifically to EC but not to SMC or fibroblasts. Firstly, REDV-gelatin conjugate was synthesized by using the amine-to-sulfhydryl crosslinker SMCC. REDV-gelatin coating was then prepared on polystyrene surfaces, and their affinities to EC and SMC were subsequently investigated. Fluorescence microscopy and flow cytometric analysis showed that EC adhesion to the gelatin coating was significantly promoted by REDV peptide conjugation. Moreover, cell migration assay and cell viability assay also showed that the conjugation of REDV does not affect EC migration, and this coating did not show cytotoxicity against EC. This gelatin-REDV coating provides a cost-effective and straightforward tool for isolating EC from SMC, which may facilitate in vitro investigations of EC from mice.

Luminescent core–shell polymer particles carrying amino groups for covalent immobilization of enzymes were synthesized for practical applications in immunoassays. The polystyrene core particles were synthesized by miniemulsion polymerization of oil-in-water emulsion styrene droplets dissolving 2-(2-chloropropionyl)ethyl methacrylate and the europium complex emulsified with 2-methacryloyloxyethyl-N,N-dimethyl-N–n-dodecylammonium bromide. The red luminescence attributed to europium complexes embedded in the core particles was observed upon UV irradiation. The PSt-g-POEGMAx-NH2 aminated core–shell particles were prepared by surface-initiated atom transfer radical polymerization of oligo(ethylene glycol) methyl ether methacrylate (OEGMAx), followed by Gabriel synthesis. The densities of grafted chains were determined by the composition, the hydrodynamic diameters, and the fluorescence labeling method. POEGMAx-grafted chains were found to affect the dispersion stability of the particles. The nonspecific adsorption of bovine serum albumin was suppressed by the POEGMAx-grafted chains. The enzymatic activity of horseradish peroxidase covalently bound to the terminal amino groups of POEGMAx-grafted chains was evaluated by colorimetric immunosorbent assay.

Hydrophobic interaction plays an important role in numerous interfacial phenomena and biophysical and industrial processes. In this work, polystyrene (PS) was used as a model hydrophobic polymer for investigating its hydrophobic interaction with highly deformable objects (i.e., air bubbles and oil droplets) in aqueous solutions. The effects of polymer molecular weight, solvent (i.e., addition of ethanol to water), the presence of surface-active species, and hydrodynamic conditions were investigated, via direct surface force measurements using the bubble/drop probe atomic force microscopy (AFM) technique and theoretical calculations based on the Reynolds lubrication theory and augmented Young-Laplace equation by including the effect of disjoining pressure. It was found that the PS of low molecular weight (i.e., PS590 and PS810) showed slightly weaker hydrophobic interactions with air bubbles or oil droplets, as compared to glassy PS of higher molecular weight (i.e., PS1110, PS2330, PS46300, and PS1M). The hydrophobic interaction between PS and air bubbles in a 1 M NaCl aqueous solution with 10 vol % ethanol was weaker than that in the bare aqueous solution. Such effects on the hydrophobic interactions are possibly achieved by influencing the structuring/ordering of water molecules close to the hydrophobic polymer surfaces by tuning the surface chain mobility and surface roughness of polymers. It was found that the addition of three surface-active species, i.e., cetyltrimethylammonium chloride (CTAC), Pluronic F-127, and sodium dodecyl sulfate (SDS), to the aqueous media could suppress the attachment of the hydrophobic polymer and air bubbles or oil droplets, most likely caused by the additional steric repulsion due to the adsorbed surface-active species at the bubble/polymer/oil interfaces. Our results have improved the fundamental understanding of the interaction mechanisms between hydrophobic polymers and gas bubbles or oil droplets, with useful implications on developing effective methods for modulating the related interfacial interactions in many engineering applications.

In this study, polystyrene/organoclay nanocomposites were developed using two different methodologies, i.e., in-situ bulk process and solution process. A comparative analysis of the thermal and mechanical properties was carried out for the nanocomposites obtained by these two distinct methods. The in-situ bulk method resulted in nanocomposites having good exfoliation and high thermal stability, while in-situ solution method resulted in materials with good mechanical properties and high thermal stability upon intercalation of the polymer matrix into the clay galleries. Two kinds of organically modified clays were used as labeled as CTA-Mag(1CEC) and CTA-Mag(2CEC) modified by a quaternary ammonium surfactant which was cetyltrimethylammonium bromide (CTAB). Maghnite is a natural clay (in Algeria) that can act as a catalyst and an inorganic reinforcement, both. These organoclays were utilized for the synthesis of polystyrene/clay nanocomposites. The impacts of the CTA-Mag on the morphology and properties of the nanocomposites were examined. However, polystyrene/CTA-Maghnite (PS/CTA-Mag) nanocomposites were characterized by various physicochemical techniques, i.e., XRD, FTIR, TGA, and transmission electron microscopy (TEM). Gel permeation chromatography (GPC) illustrated the ability of the CTA-Mag organoclay to effectively minimize the average molecular weight of the PS particles. The greatest improvement in thermal stabilities of the nanocomposites was obtained with 5 wt% of CTA-Mag for both organoclays. The nanocomposite containing 3 wt% organoclay showed the greatest improvement in Young’s modulus, impact strength, and tensile strength. The addition of organoclay reduced the MFI value of the polystyrene nanocomposites. The measurement of Young’s modulus, shock resistance, and breaking stress enabled the evolution of the mechanical properties to be assessed.

Polymer-grafted nanoparticle (PGN) films were prepared from polystyrene (PS) grafted to rodlike cellulose nanocrystals (MxG-CNC-g-PS) with a controllable grafting density (0.03–0.25 chains/nm2) and...

The purpose of this work was to investigate the effects of polystyrene-based acidic copolymers and ionomers on the dispersion of asphaltenes in heavy oil. In the first part of the work, we studied ...

A majority of microplastics (MPs) in wastewater treatment plants are aggregated in waste activated sludge (WAS) and potentially threaten the subsequent anaerobic digestion. Meanwhile, many physical...

Total internal reflection is an optical imaging technique for nanoparticle tracking and observation employing the scattered light from an evanescent field near the interface or reference surface. Generally, the nanoparticle behavior is the three-dimensional Brownian motion in an aqueous medium. The motion can be traced by an optical microscopy, but it cannot be traced by an electron microscopy technique. In the three-dimensional nanoparticle moving position, the X and Y positions are parallel to the surface, which can be traced by the general microscopy techniques. However, the height position Z of a nanoparticle perpendicular to the surface could not be traced without the longitudinal scanning method. Here, a novel method is proposed to investigate the 3D position of nanoparticles by applying multi-wavelength evanescent fields microscopy, which has a high spatial resolution in the Z-direction without longitudinal scanning. This paper focuses on the verification of measurement in the Z-direction. A piezoelectric actuator was employed to control the nanoparticle displacement in height Z. Standard polystyrene 100 nm particles were randomly adhered on a spherical tip that connected with the piezoelectric actuator. The spherical tip was essentially made from an optical adhesive (n = 1.348) with a refractive index close to the water for decreasing the unnecessary signal from the tip-self during nanoparticle observation in the water. The proposed method could obtain the multi-wavelength scattering lights from the observed nanoparticles by an 8-bit color camera with higher than 50 frames per second recording to investigate the 3D nanoscale tracking. The X and Y positions of nanoparticles were determined by the centroid of the scattering light intensities. The height Z was determined from the logarithm ratios between the detected scattering light intensities of both wavelengths. The measurement repeatability of the absolute difference in height between nanoparticles could be measured less than ±16 nm by using the proposed method. The penetration height measurability range was approximated at 250 nm from the reference surface.

In this research, a highly sensitive and selective hydrogen gas sensor was developed based on Cu-doped SnO2. Sensing characteristics were compared based on SnO2 doped with different concentrations of Cu, and the highest sensitivity and fastest response time were shown when 3% Cu was contained. A 3D structure was formed using a polystyrene to increase the surface-to-volume ratio, which allows more oxygen molecules to bond with the surface of the SnO2 sensing material. Extremely increased sensitivity was observed as compared to the planar structure. A temperature sensor and micro-heater were integrated into the sensor, and the surface temperature was maintained constant regardless of external influences. In addition, an electronic sensor interface was developed for the efficient analysis of real-time data. The developed sensor was wire-bonded to the flexible printed circuit board (FPCB) cable and connected with the sensor interface. Sensitivity and linearity measured based on the developed sensor and interface system were analyzed as 0.286%/ppm and 0.98, respectively, which were almost similar to the results observed by a digital multimeter (DMM). This indicates that our developed sensor system can be a very promising candidate for real-time measurement and can be applied in various fields. The enhanced sensitivity of 3% doped SnO2 toward hydrogen is attributed to the huge number of oxygen vacancies in the doped sample.

Heterogeneous catalysts for fine chemical synthesis play a crucial role in establishing an efficient chemical process. Immobilization of homogeneous catalysts is an important method for the prepara...

Hierarchically porous crystalline nanoporous aerogels of syndiotactic polystyrene (sPS) received much attention because of their unique nanoporous structures along with meso- and macroporosity. Dep...