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In recent years, a large number of microplastics (MPs) appeared in the aquatic environment, causing serious pollution. In order to study the influence of MP concentrations on freshwater zooplankton, polystyrene microspheres (PS) of 0.5 μm were used in this study as experimental reagents, and Moina macrocopa, which was dominant zooplankton in the Pearl River Basin of China, was selected as the experimental object. The experiment was divided into four treatment groups plus a control group, and it was conducted for 15 days. The treatment groups had MP concentrations of 10, 10², 10³ and 104 pieces/mL. The survival time, reproduction rate, the total offspring, and the time of first pregnancy of Moina macrocopa were counted every day, and the intrinsic growth rate, generation time, and net reproduction rate were calculated. The results showed that the survival time of Moina macrocopa decreased with the increase of the MP concentration, and the MP concentration had more influence on the reproduction rate. Except for the 10 pieces/mL treatment group, no reproduction occurred in other treatment groups, and the reproduction rate gradually decreased with the increase of age. The life table showed that only the control group and the 10 pieces/mL treatment group had an intrinsic growth rate, and the intrinsic growth rate of the treatment group was far lower than that of the control group. Our experimental results provide basic data and a theoretical basis for further understanding the toxic effects of MPs on freshwater zooplankton. [ABSTRACT FROM AUTHOR]

In confocal Raman microscopy, depth profiling is a key application that enables analysis of the structural and chemical composition and size of three-dimensional (3D) transparent objects. However, the precise interpretation of a probed sample's Raman depth profile measurement can be significantly affected by both its size and surrounding objects. This study provides a more comprehensive understanding of the observed optical effects at the interface between polymer spheres and different substrates. Ray- and wave-optical simulations support our results. We derive a correction factor that, depending on the instrumental configuration, allows us to determine the nominal dimensions of the scanned objects more accurately from Raman depth profiles. Our studies support the need for careful consideration when employing depth profiling in confocal Raman microscopy for nondestructive, quantitative tomography of 3D objects. Graphical Abstract This is a visual representation of the abstract. [ABSTRACT FROM AUTHOR]

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To enhance the color saturation of the amorphous photonic crystal (APC) coating composed of polystyrene (PS) microparticles, MXene nanosheets were deposited on the surface of the PS microparticles through strong electrostatic attraction. Three distinct colored APC coatings were achieved using Mayer rod-coating methods, employing PS microparticles of varying sizes. The intrinsic black nature of MXenes results in these coatings exhibiting high brightness of structural colors under ambient lighting conditions. Additionally, the three distinct colored APC coatings demonstrate high color saturation and low angular dependence. The thermal stability and flame retardancy of PS and PS@MXene microparticles with different MXene content were investigated. PS@MXene microparticles (three different diameters) containing 5 wt% MXene exhibited char residues of 11.0, 8.7, and 6.7 wt% at 700 °C during decomposition, whereas pure PS microparticles showed a char residue of <1.7 wt%. The peak heat release rate and total heat release of the PS@MXene microparticles were lower than those of pure PS, as characterized by a microscale combustion calorimeter. Furthermore, crack-free APC coatings on a black polyurethane substrate were successfully prepared using the Mayer rod-coating method, assisted by polyacrylic acid and ethylene glycol. The APC coatings containing PS@MXene microparticles with 5 wt% MXene, deposited on the surface of the polyurethane film, demonstrated shielding performances of approximately 20 dB. This work presents a straightforward and environmentally friendly method for constructing multifunctional APC coatings. • Amorphous photonic crystal (APC) composed of MXene-coated polystyrene was prepared. • APC coating composed of MXene-coated polystyrene presented high color saturation. • The existence of MXene in APC coating improved the flame retardancy of polystyrene. • The MXene endowed the APC coating with electromagnetic interference shielding. [ABSTRACT FROM AUTHOR]

Development of a multiplexed and sensitive biosensing platform is a priority for public health security. We report a micropore resistance counting platform based on polystyrene microsphere size-based encoding and Clostridium butyricum Argonaute (CbAgo) decoding for multiplexed and ultrasensitive detection. Initially, we constructed a target DNA-modified polystyrene microsphere coding system based on micropore resistance counting. Subsequently, the precise recognition and cleavage capabilities of the guide DNA-activated CbAgo protein enable the decoding of the encoded microsphere system. Changes in the concentration of polystyrene microspheres are presented as a signal readout. The platform demonstrated excellent performance in multiplexed detection of three mycotoxins (with a sensitivity range over 4 orders of magnitude reaching the pg/mL level) and two inflammatory markers at pg/mL. Combining precise enzyme cleavage by CbAgo with micropore resistance counting, the developed platform is a multiplexed and highly sensitive detection tool with wide-ranging potential in applications such as clinical diagnosis, food safety inspection, and environmental monitoring.

The reconstruction of the three-dimensional (3D) morphology of polymeric microsphere layers based on confocal Raman microscopy was studied. Refraction of the Raman laser beam at the curved surface of the spheres broadens the focus volume inside the sphere. Compared to planar layers, the focus gets trapped inside the spheres such that the measured depth profiles are shifted and broadened. Additionally, the Raman signal of the underlying substrate is already observed for nominal focus positions above the microsphere layer. The results are successfully modeled with ray-optical simulations that allow for a clear understanding of the relevant mechanisms that lead to the generation of the Raman signals in the complex three-dimensional structures. Graphical Abstract [ABSTRACT FROM AUTHOR]

With the increasing difficulty in exploitation of low-permeability, high water content and other unconventional reservoirs, a new kind of proppants that possess not only ultra-light weight and high strength and but also hydrophobic performances have attracted more and more interests. Here, this kind of proppants were designed and prepared successfully in the form of polymer microspheres. What's more is that the polymer microspheres (named O-MSDBs) showing high strength and stable hydrophobicity were prepared by a one-step suspension polymerization between styrene, divinyl benzene and γ-methacryloxypropyl-trimethoxy silane accompanying with the formation of silica through sol–gel process. When compared with reported ultra-lightweight proppants (ULWPs), the O-MSDBs not only perform better in ultra-lightweight (0.9917 g·cm−3) and are comparable in high strength (low crushing ratio of 0.89–2.53% at 55–69 MPa), but also show new hydrophobic function. The water contact angle on the surface of O-MSDBs is 140.7° that keeps about more than 80% after mechanical abrasion or acid dissolution. The one-step facile preparation method and brilliant performances make O-MSDBs very promising to large-scale preparation and widely applied in fracturing technology as proppants. [ABSTRACT FROM AUTHOR]

A fiber-optic temperature sensor based on fiber tip polystyrene microsphere is proposed. The sensor structure can be formed simply by placing and fixing a polystyrene microsphere on the center of an optical fiber tip. Since polystyrene has a much larger thermal expansivity, the structure can be used for high-sensitive temperature measurement. By the illuminating of the sensor with a broadband light source and through the optical Fabry-Perot interference between the front and back surfaces of the polystyrene microsphere, the optical phase difference (OPD) or wavelength shift can be used for the extraction of temperature. Temperature measurement experiment shows that, using a fiber probe polystyrene microsphere temperature sensor with a spherical diameter of about 91.7 µm, a high OPD-temperature sensitivity of about −0.617 96 nm/°C and a good linearity of 0.991 6 were achieved in a temperature range of 20°C–70°C. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman scattering (SERS) technique can increase the Raman signals of the analytes owing to the electric field enhancements on the nanostructures. The strong light intensity, called photonic nanojet, can be formed at the backlight of the dielectric microstructures. Recently, some researchers have applied the photonic nanojets in SERS. In this paper, a layer of synthesized low-cost polystyrene microspheres with the average of small particle size of 4.26 μm and high refractive index 1.5875 was prepared by dispersion polymerization method and coating on metal nanopillars SERS substrates using air-water interfacial floating method, and it was applied to improve the Raman signal sensitivity of kinetin (6-furfurylaminopurine) which is one kind of plant growth regulators and can function an effective compound for improving plant stress tolerance. The Raman intensity increased from 841 to 4449 for the Raman shift at 1327 cm−1, about 5.29 times stronger. The SERS experiments using the kinetin of ultralow concentrations are measured and it shows that femto Molar can be measured. The numerical simulations indicated that the enhancement factor was about 4 times for plane wave illumination and 3.1 times for focused Gaussian beam. It has considerable potential for different analytes in sensing applications. [ABSTRACT FROM AUTHOR]

Through liquid phase deposition (LPD) of TiO2 photocatalyst films on an 800 nm polystyrene (PS) microsphere template, this study prepared a porous, LPD-TiO2 hollow layer (HL) with high specific surface area. An aqueous solution of ammonium hexafluorotitanate mixed with boric acid was used to prepare a TiO2 photocatalyst film. The effects of H3BO3 concentration and PS microsphere solid content on the surface morphology, film composition, and photocatalytic property of the films were investigated. The findings revealed that the LPD-TiO2 hollow film prepared using 0.6 M H3BO3 and a substrate containing 0.4 wt% PS microspheres had higher specific surface area and hydrophilicity than a LPD-TiO2 dense layer (DL). Such properties considerably increase the degradation efficiency of a photocatalyst film. After 6 h, the degradation achieved by the LPD-TiO2 hollow layer prepared using a substrate with PS microsphere concentration of 0.4 wt% was 90.7%, whereas that achieved by the dense LPD-TiO2 was only 64.7%. Moreover, the porous, hollow LPD-TiO2 film exhibited excellent photocatalytic performance and may be widely applied to environmental purification in the future. [ABSTRACT FROM AUTHOR]

Graphical abstract Here we develop a facile approach for the assembly of functional nanocomposite of reduced graphene oxide@ceria nanoparticles on the polystyrene microspheres, which exhibit excellent photocatalytic activity and reusability towards the degradation of methylene blue. Abstract Herein we report a facile two-step synthetic strategy for fabricating the ternary polystyrene/reduced graphene oxide/ceria (PS/RGO@CeO 2) nanocomposite particles for the first time through the self-assembly of the RGO on the surface of PS microsphere (PS/RGO) and then the attachment of CeO 2 nanoparticles (NPs) onto the as-prepared PS/RGO nanocomposite particles. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetric analysis have been employed to characterize the morphology and composition of the as-prepared samples. The size and mass loading of resulting CeO 2 NPs on the PS/RGO nanocomposite particles are easily tunable. Furthermore, the photocatalytic performance of as-prepared ternary nanocomposite particles towards the degradation of methylene blue is investigated. Notably, the PS/RGO@CeO 2 nanocomposite particles have high photocatalytic activity due to the synergistic effect between the CeO 2 NPs and RGO in such a unique structure, and moreover, they also exhibit high stability in a recyclable manner. Therefore, it can be expected that our ternary nanocomposite particles are an attractive photocatalyst candidate for various photocatalytic applications. [ABSTRACT FROM AUTHOR]

Therapeutic effects of adult stem-cell transplantations are limited by poor cell-retention in target organs, and a reduced potential for optimal cell differentiation compared to embryonic stem cells. However, contemporary studies have indicated heterogeneity within adult stem-cell pools, and a novel culturing technique may address these limitations by selecting those for cell proliferation which are highly functional. Here, we report the preservation of stemness in human adipose-derived stem cells (hASCs) by using microgravity conditions combined with microspheres in a stirred suspension. The cells were bound to microspheres (100−300 μm) and cultured using a wave-stirring shaker. One-week cultures using polystyrene and collagen microspheres increased the proportions of SSEA-3(+) hASCs 4.4- and 4.3-fold (2.7- and 2.9-fold increases in their numbers), respectively, compared to normal culture conditions. These cultured hASCs expressed higher levels of pluripotent markers (OCT4, SOX2, NANOG, MYC, and KLF), and had improved abilities for proliferation, colony formation, network formation, and multiple-mesenchymal differentiation. We believe that this novel culturing method may further enhance regenerative therapies using hASCs.

In this work, new optical properties of composites based on polystyrene (PS) microspheres and graphene oxide (GO) are reported. The radical polymerization of styrene in the presence of benzoyl peroxide, pentane and GO induces the appearance of new ester groups in the PS macromolecular chains remarked through an increase in the absorbance of the infrared (IR) band at 1743 cm−1. The decrease in the GO concentration in the PS/GO composites mass from 5 wt.% to 0.5 wt.% induces a diminution in the intensities of the D and G Raman bands of GO simultaneous with a down-shift of the D band from 1351 to 1322 cm−1. These variations correlated with the covalent functionalization of the GO layers with PS. For the first time, the photoluminescent (PL) properties of PS/GO composites are reported. The PS microspheres are characterized by a PL band at 397 nm. Through increasing the GO sheets’ concentration in the PS/GO composite mass from 0.5 wt.% to 5 wt.%, a PS PL quenching process is reported. In addition, in the presence of ultraviolet A (UVA) light, a photo-degradation process of the PS/GO composite having the GO concentration equal to 5 wt.% is demonstrated by the PL studies.

The discharge of microplastics into aquatic environment poses the potential threat to the hydrocoles and human health. The fate and transport of microplastics in aqueous solutions are significantly influenced by water chemistry. In this study, the effect of water chemistry (i.e., pH, foreign salts and humic acid) on the surface charge and aggregation of polystyrene microsphere in aqueous solutions was conducted by batch, zeta potentials, hydrodynamic diameters, FT-IR and XPS analysis. Compared to Na + and K + , the lower negative zeta potentials and larger hydrodynamic diameters of polystyrene microspheres after introduction of Mg 2+ were observed within a wide range of pH (2.0–11.0) and ionic strength (IS, 0.01–500 mmol/L). No effect of Cl − , HCO 3 – and SO 4 2− on the zeta potentials and hydrodynamic diameters of polystyrene microspheres was observed at low IS concentrations (<5 mmol/L), whereas the zeta potentials and hydrodynamic diameters of polystyrene microspheres after addition of SO 4 2− were higher than that of Cl − and HCO 3 – at high IS concentrations (>10 mmol/L). The zeta potentials of polystyrene microspheres after HA addition were decreased at pH 2.0–11.0, whereas the lower hydrodynamic diameters were observed at pH < 4.0. According to FT-IR and XPS analysis, the change in surface properties of polystyrene microspheres after addition of hydrated Mg 2+ and HA was attributed to surface electrostatic and/or steric repulsions. These investigations are crucial for understanding the effect of water chemistry on colloidal stability of microplastics in aquatic environment. [ABSTRACT FROM AUTHOR]

A magnetic cation-exchange resin (MCER) was prepared by copolymerization of oleic acid-grafted magnetite with styrene, divinylbenzene (DVB), and triallylisocyanurate (TAIC) for removing Cd(II) from wastewater. A non-magnetic cation-exchange polystyrene resin (CEPR) was also prepared as a reference. Structural and morphological analyses revealed that the MCER and CEPR were mesoporous microspheres; the MCER contained about 25% Fe3O4. The influence of temperature, pH, contact time, and the initial concentration of Cd(II) on the adsorption of Cd(II) was investigated. The maximum adsorption capacity of the MCER reached 88.56 mg/g, which was achieved at 343 K using a Cd(II) initial concentration of 200 mg/L. The adsorption processes attained equilibrium within 120 min for the MCER and 300 min for the CEPR, and were well described by a pseudo-second-order kinetic model. Furthermore, the equilibrium adsorption data fitted the Freundlich isotherm model better than the Langmuir model. The superior magnetic response and regeneration of the MCER make it a good candidate as an adsorbent for removing Cd(II) from wastewater. [ABSTRACT FROM AUTHOR]

We report the surface modification of polystyrene microsphere by ozone treatment. The effects of the ozone treatment on the surface properties of polystyrene microsphere are probed using a series of measurements, including Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy(XPS), scanning electron microscope(SEM), fluorescence microscope. As a result of above measurements, the surface of the sample contains a large number of carboxyl and hydroxy (mainly -COOH) groups. In addition, the polystyrene microsphere successfully connected with amino quantum dots which demonstrates the existence of functional groups. A major conclusion that can be drawn from the results and analysis described in this work is that the ozone treatment provides a feasible method for surface modification of polystyrene microsphere in the use of biological testing. The method is simple and universal, and the operation is simple and convenient to modify the carboxyl group. [ABSTRACT FROM AUTHOR]

Polystyrene microspheres (PSMs) with diameters of 5 μm and 10 μm are prepared on garnet by a self-assembly method. The pressure generated by quartz sheet/PSM/garnet/graphite is measured by a resistance strain sensor as a function of the external direct current (DC) voltage. The surface morphology of the PSMs are observed by optical microscopy. The polarization properties of the linearly and circularly polarized laser beams with a wavelength of 1550 nm reflected from the different PSMs are researched by a Thorlabs PAX 5710 IR3 Polarization Analyzing System as a function of the external DC voltage. The results show that the PSMs with different sizes can be damaged when the external pressure exceeds its critical value of 3.0 MPa, but the critical DC voltages are different. The optical polarization properties of the circularly polarized laser beam can be changed with the external DC voltage, whereas the linearly polarized laser beam cannot be changed. [ABSTRACT FROM AUTHOR]

Using PS colloidal spheres as the template, 3DOM Ag/CeO 2 -ZrO 2 was synthesized by the sol–gel combined with the decompression filling method, which showed a good crystal structure with an orderly, open, transparent macroporous structure, and with a large specific surface area. The synergy of SPR effect and Z-scheme of Ag on 3DOM Ag/CeO 2 -ZrO 2 can evidently enhance the photocatalytic degradation and water splitting performance. [Display omitted] • Using PS colloidal spheres as the template, 3DOM Ag/CeO 2 -ZrO 2 was synthesized by the sol–gel combined with the decompression filling method. • 3DOM Ag/CeO2-ZrO2 showed a good crystal structure with an especial structure, and with a large specific surface area. • The synergy of SPR effect and Z-scheme of Ag on 3DOM Ag/CeO2-ZrO2 evidently enhanced the photocatalytic performance. • 3DOM Ag/CeO 2 -ZrO 2 showed preferably activities during multimode photocatalytic degradation and water splitting into hydrogen experiments. Using polystyrene spheres (PS) as a template, a kind of three-dimensionally ordered macroporous (3DOM) Ag/CeO 2 -ZrO 2 material was synthesized by the sol–gel combined with the decompression filling method. A series of characterization methods, such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (UV–vis/DRS), Scanning electron microscopy (SEM), High-resolution transmission electron microscopy (HR-TEM), and N 2 adsorption–desorption measurements were used to study its composition, structure, morphology, and surface physicochemical properties. The synthesized composite material 3DOM Ag/CeO 2 -ZrO 2 shows a good crystal structure, open and transparent arrangement in a three-dimensional space. Meanwhile, compared with the sample without PS treatment, the composite material has a smaller band gap energy value, which means under the excitation of light, it is easier to produce electron–hole pairs and enables to absorb more reactive molecules on the surface of the catalyst, thus improving the photocatalytic performance of the composite. And after loading Ag metal on the composite, the light absorption of the catalyst is extended to the visible region by the surface plasmon resonance effect (SPR), resulting in promoting the absorption efficiency of light. During multimode photocatalytic degradation experiments of Congo Red (CR), 3DOM Ag/CeO 2 -ZrO 2 composite exhibited an excellent photocatalytic performance. Under ultraviolet light, its catalytic performance was much better than that of both commercial catalyst P25 and the sample without loading Ag. At the same time, in the photocatalytic hydrogen evolution experiment, 3DOM Ag/CeO 2 -ZrO 2 showed a stronger ability of water splitting into hydrogen, whose hydrogen yield (53 μmol in 8 h) was about 4 times than that of P25, indicating 3DOM Ag/CeO 2 -ZrO 2 had the ability of photodegradation and photolysis of water. In addition, superoxide free radical (O 2 −), hydroxyl radical (OH), and hole (h+) were considered as main reactive groups in the photocatalytic process according to capture experimental results. Moreover, the transfer effect of Ag as Z-Scheme in the photocatalytic reaction was speculated as well. [ABSTRACT FROM AUTHOR]

Herein we present a facile approach to the attachment of ceria nanoparticles (CeO 2 NPs) onto polystyrene (PS) microspheres in a one-step process based on the decrease in total Gibbs free energy of colloidal system. This synthetic method has the advantage of eliminating the complex surface functionalizations or modifications of support microsphere, which are usually necessary in the established synthesis of polymer-supported CeO 2 NPs. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetry have been employed to characterize the as-prepared PS/CeO 2 composite particles. The size and amount of CeO 2 NPs deposited on the surface of PS microspheres can be easily controlled by changing the concentration of Ce(NO 3 ) 3 ·6H 2 O and reaction temperature. Furthermore, the resultant PS/CeO 2 composite particles are tested for catalytic degradation of methyl orange (MO) in the presence of hydrogen peroxide (H 2 O 2 ). Significantly, these composite particles are proved to be an efficient catalyst for catalyzing the oxidation degradation of MO and also show good stability in a recyclable manner. [ABSTRACT FROM AUTHOR]

The study aimed to evaluate the differentiation ability of intravitreally injected rat bone marrow-derived mesenchymal stem cells (rBM-MSCs) to retinal ganglion-like cells in a polystyrene microsphere induced rat glaucoma model. The glaucoma rat model was generated via intracameral injection of 7 microliter polystyrene microspheres. Green fluorescence protein-labeled (GFP) rBM-MSCs were transplanted intravitreally at or after induction of ocular hypertension (OHT), depending on the groups. By the end of the fourth week, flat-mount retinal dissection was performed, and labeled against Brn3a, CD90, GFAP, CD11b, Vimentin, and localization of GFP positive rBM-MSCs was used for evaluation through immunofluorescence staining and to count differentiated retinal cells by flow cytometry. From 34 male Wistar albino rats, 56 eyes were investigated. Flow cytometry revealed significantly increased CD90 and Brn3a positive cells in glaucoma induced and with rBM-MSC injected groups compared to control(P = 0.006 and P = 0.003 respectively), sham-operated (P = 0.007 and P < 0.001 respectively), and only rBM-MSCs injected groups (P = 0.002 and P = 0.009 respectively). Immunofluorescence microscopy revealed differentiation of GFP labeled stem cells to various retinal cells, including ganglion-like cells. rBM-MSCs were observable in ganglion cells, inner and outer nuclear retinal layers in rBM-MSCs injected eyes. Intravitreally transplanted rBM-MSCs differentiated into retinal cells, including ganglion-like cells, which successfully created a glaucoma model damaged with polystyrene microspheres. Promisingly, MSCs may have a role in neuro-protection and neuro-regeneration treatment of glaucoma in the future. • Intravitreally injected rBM-MSCs to retinal ganglion-like cells • The frequency of Brn3a+GFP+ and CD11b+GFP+ cells notably increased in the G-MSC • MSCs promise hope for glaucoma as neuro-regeneration therapies. • NFP immunohistochemistry shows enlarged axonal fibers with intense staining. • GFAP immunohistochemistry demonstrated glial hypertrophy with increased expression in glial cells of the optic nerve. [ABSTRACT FROM AUTHOR]

Iron carbonyl polymer microspheres for simultaneously high-speed adsorption and desorption of dye-emulsified micelles with frequency manipulation under an alternating electric field. [Display omitted] • Iron carbonyl polymers are incorporated into polystyrene microspheres (PMs) as adsorbents of iron carbonyl PMs. • Iron carbonyl PMs exhibits the significant enhancement of adsorption capacity of dye-emulsified micells (DEM). • Applying an alternating electric field (AEF) causes the electric dipoles on both iron carbonyl PMs and DEMs. • The adsorption rate is enhanced with the electric dipoles under an AEF at 150 kHz due to the particle assembling. • The desorption rate is improved under an AEF at 1 MHz due to the dipole relaxing. Developing a versatile methodology for high-speed water purification is critical for environmental and water source protection. Traditional adsorption and desorption were determined based on the concentration gradients. Herein, a versatile methodology is reported based on the simple application of an alternating electric field (AEF) on a system including dye-emulsified micelles (DEM) and adsorbents that simultaneously exhibit high-speed adsorption and desorption of DEM by frequency manipulation. Iron carbonyl polymers are incorporated into polystyrene microspheres (PMs) to generate iron carbonyl polystyrene microspheres (ICPMs) as adsorbents, which can vary the affinity with DEM and dielectric properties simultaneously. Both the DEM and microspheres were polarized under the AEF and generated electric dipole moments that could rapidly assemble the DEM and microspheres. Compared with the adsorption through the concentration gradient, the adsorption rate of DEM was enhanced significantly in the presence of an AEF of 20 V at 150 kHz of frequency because of the effect of particle assembly. At 1000 kHz of frequency, the alternative high-speed change between electrostatic attraction and repulsion hindered the adsorption of the dyes, which could also enhance the desorption rate. The ICPMs could be recycled 10 times within 20 min with frequency manipulation in the presence of AEF. This versatile methodology could provide novel insights into the development of high-speed water purification techniques. [ABSTRACT FROM AUTHOR]

The monodisperse polystyrene (PS) microspheres were prepared by dispersion polymerization. The rheological properties of shear thickening fluid (STF) based on PS microspheres dispersing in polyethylene glycol with different concentrations were studied through the steady and oscillatory shear at different temperatures, respectively. All suspensions successively present the first shear thinning, the shear thickening, and the second shear thinning. The experimental results indicate that the shear thickening behavior of STF is controlled by the concentration of PS microspheres and temperature, as changed from continuous shear thickening (CST) to discontinuous shear thickening (DST) with increasing solid content or decreasing temperature. The STF is affected by shear rate, temperature, and the viscosity of the dispersed medium, and it is reversible absolutely and presents transient response ability. Both CST and DST behave as dilatancy. The PS microsphere aggregations formed under shear stress may result in the shear thickening in STFs. [ABSTRACT FROM AUTHOR]

In this work, polystyrene microspheres (PSMS) and PSMS-based polymer nanocomposites have been prepared. PSMS were first synthesized by dispersion polymerization of styrene monomer. The microsphere-coated-multi-walled carbon nanotube (PSMS/MWCNT) nanocomposite was prepared by incorporating MWCNT into PSMS matrix. Aniline monomer was then introduced by means of in situ oxidative polymerization (PANI) route to PSMS, MWCNT, and PSMS/MWCNT. Fourier transform infrared spectroscopy depicted the composite formation of PANI and MWCNT with PSMS matrix. PANI polymer was successfully polymerized in PSMS matrix and on carbon nanotube walls. According to scanning electron microscopy, all nanocomposites exhibited core-shell morphology. Glass transition temperature (Tg) of PSMS/PANI, PANI/MWCNT, and PSMS/PANI/MWCNT were found as 245℃, 287℃, and 289℃, while maximum decomposition temperature (Tmax) was 387℃, 575℃, and 580℃, respectively. Tetrahydrofuran was shown to be a suitable solvent for dispersing the nanocomposite. Toluene can also be used as suitable solvent for these nanocomposites. X-ray diffraction analysis depicted amorphous form of PSMS; however, PANI and MWCNT reduced the amorphous nature of the microspheres. PANI/MWCNT showed the highest crystallinity among all nanocomposites. Moreover, PSMS/PANI/MWCNT nanocomposite revealed electromagnetic interference shielding effectiveness of ∼23.2 dB. [ABSTRACT FROM AUTHOR]

Aflatoxin M 1 (AFM 1) contamination poses a serious threat to human health globally. Hence, it is necessary to develop reliable and ultrasensitive methods for the determination of AFM 1 residue in food products at low levels. In this study, a novel polystyrene microsphere-mediated optical sensing (PSM-OS) strategy was constructed to solve the problems of low sensitivity and susceptibility to interference from the matrix in AFM 1 determination. Polystyrene (PS) microspheres have the advantages of low cost, high stability, and controllable particle size. They can be useful optical signal probes for qualitative and quantitative analyses attributed to the fact that they have strong ultraviolet–visible (UV–vis) characteristic absorption peaks. Briefly, magnetic nanoparticles were modified with the complex of bovine serum protein and AFM 1 (MNP 150 -BSA-AFM 1), and biotinylated antibodies of AFM 1 (AFM 1 -Ab-Bio). Meanwhile, PS microspheres were also functionalized with streptavidin (SA-PS 950). In the presence of AFM 1 , a competitive immune reaction was triggered leading to the changes in AFM 1 -Ab-Bio concentrations on the surface of MNP 150 -BSA-AFM 1. The complex of MNP 150 -BSA-AFM 1 -Ab-Bio binds with SA-PS 950 to form the immune complexes due to the special binding of biotin and streptavidin. The remaining SA-PS 950 in the supernatant was determined by UV–Vis spectrophotometer after magnetic separation, which positively correlated with the concentration of AFM 1. This strategy allows for ultrasensitive determination of AFM 1 with limits of detection as low as 3.2 pg/mL. It was also successfully validated for AFM 1 determination in milk samples, and a high consistency was found with the chemiluminescence immunoassay. Overall, the proposed PSM-OS strategy can be used for the rapid, ultrasensitive, and convenient determination of AFM 1 , as well as other biochemical analytes. [Display omitted] • A novel, ultrasensitive, and facile optical immunoassay enables AFM 1 determination. • PS microspheres with high stability and low cost were used as signaling probes. • This novel PSM-OS strategy is simple to use and enabled the AFM 1 analysis in milk. [ABSTRACT FROM AUTHOR]

In this study, we develop a superhydrophobic coating on an aluminum alloy plate, and the related weatherability and applications are investigated. The superhydrophobic coating consisting of polystyrene microspheres (PS) with polydimethylsiloxane (PDMS) is prepared by a facile and effective one-step spraying method. The as-prepared PS/PDMS coating possesses good repellency to several kinds of liquid droplets and has a high water contact angle of ∼158° and a low sliding angle of ∼5.9°. The surface morphologies and chemical composition of the PS/PDMS coating are investigated by SEM, EDS, and LSM. The thermal stability, rainwater immersion, self-cleaning, and anti-icing of the PS/PDMS coating are evaluated. The freezing-delay time of 7 μL water droplets on the PS/PDMS coating is 34 s longer than that of the uncoated-Al surface at − 15 ℃. The average icing speed of the PS/PDMS coating is also much lower than that of the uncoated-Al surface. This PS/PDMS coating is suitable for industrial applications as it can be easily scaled up to create uniform superhydrophobic surfaces. [Display omitted] [ABSTRACT FROM AUTHOR]

Polystyrene microsphere (emulsion polymerization) was grafted on pure multiwalled carbon nanotube and amine-modified multiwalled carbon nanotube. Silver nanoparticle was also decorated on nanotube using chemical reduction (dimethylformamide). Amine-modified multiwalled carbon nanotube secures better silver attachment on nanotube wall. Polystyrene/Ag–amine-modified multiwalled carbon nanotube depicted fine dispersion in polymer latex due to modification. The 10% decomposition temperature and maximum degradation temperature of polystyrene/Ag–amine-modified multiwalled carbon nanotube was increased to 352 and 424°C. Antibacterial properties of nanocomposite were studied against respiratory track demolishing Gram-positiveStaphylococcus aureusbacteria and two Gram-negative bacteria (Escherichia coliandPseudomonas aeruginosa). Ag nanoparticle was found responsible to potential death rate of microbes. [ABSTRACT FROM AUTHOR]

Novel polystyrene microsphere (PSMS)-based PSMS/Si and polystyrene/silica nanoparticle/multi-walled carbon nanotube (PS/Si/MWCNT) nanocomposite has been prepared using in situ sol-gel and chemical amalgamation methods. Aniline monomer was introduced by in situ route to form PSMS/PANI, PSMS/PANI/Si and PSMS/PANI/Si/MWCNT nanocomposite. FESEM of nanocomposite indicated core-shell spherical and tubular morphology. Glass transition temperature (Tg) and maximum decomposition temperature (Tmax) of PSMS/PANI/Si/MWCNT nanocomposite were found as 295°C and 524°C, respectively, which were higher than the PSMS/PANI (Tg= 245°C; Tmax= 387°C) and PSMS/PANI/Si (Tg= 257°C; Tmax= 388°C) nanocomposite. For nanocomposite dispersion, tetrahydrofuran was studied as fine solvent. XRD depicted amorphous nature of PSMS/Si and PSMS/PANI/Si; however MWCNT reduced amorphous character of PSMS/PANI/Si/MWCNT. Electromagnetic interference (EMI) shielding effectiveness improved from 0.1 dB (PSMS) to 12.3 dB (PSMS/PANI/Si) to 24.5 dB (PSMS/PANI/Si/MWCNT). The increase in EMI shielding effectiveness was also observed with variation in log of conductivity from −14 mho m−1(PSMA) to 1.17 mho m−1(PSMS/PANI/Si/MWCNT). [ABSTRACT FROM AUTHOR]

Particle shape is one of the most important parameters that can influence the characteristics and properties of dispersion systems. In this study, we have developed a straightforward and facile method to generate oblate spheroidal particles via a film squeezing process. Representative methods so far developed to prepare oblate spheroidal particles, such as film blowing and mechanical stretching based on a biaxial process, have serious problems, including being difficult methods to adopt, very low yield, and non-uniform particle size. Our film squeezing process involves simply squeezing a sandwiched array comprised of an arbitrarily shaped film with embedded polymer spheres between two identical circular elastomeric sheets, on the basis that homogeneous deformation is possible in the mid-plane of simple squeeze flow. This method utilizes a unified uniaxial process for producing both prolate and oblate spheroidal particles. The advantages of the method are easier access, much higher yield, and more uniform sizes and shapes than previously reported methods. This process can be helpful for the fundamental studies utilizing oblate spheroidal particles with controlled geometries. [ABSTRACT FROM AUTHOR]

Herein we develop a facile and controllable strategy for the preparation of composite particles composed of polystyrene (PS) microspheres decorated with gold nanoparticles (AuNPs) through Pickering emulsion template. The oil-in-water Pickering emulsion is prepared using unmodified citrate-stabilized AuNPs and toluene solution of unfunctionalized PS as stabilizer and dispersion phase, respectively. After the evaporation of toluene from the Pickering emulsion, the AuNP-coated PS composite particles are obtained. The resultant AuNP-coated PS composite particles have been characterized extensively by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and energy dispersive X-ray spectroscopy. Significantly, our method enables easy and effective control over the size and surface coverage of AuNPs on the surface of PS microspheres. Furthermore, the proposed method does not only allow the easy deposition of other noble metal (Ag, Pt, and Pd) nanoparticles onto the surface of PS microspheres but also can be directly applicable to the employed PS polymers derived from different approaches. In addition, the AuNP-coated PS composite particles as an example exhibited excellent catalytic activity and recyclability in the reduction of rhodamine B by NaBH 4 . [ABSTRACT FROM AUTHOR]