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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]

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]

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]

We report the synthesis of nanosized polystyrene (PSt) microspheres with good uniformity, strong absorptivity, good shear resistance and controllable size. The PSt nanofluid, entitled with a high surface adsorption of nanoparticles, can effectively reduce interfacial tension without using surfactants and alter the wettability towards a more water-wet condition. Subsequently, their fluidic properties for chemical enhanced oil recovery of PSt nanofluidic microspheres were also investigated based upon core flooding experiments, sand-pack and NMR tests. It is found that remaining oil displacement can be realized by regulating the nanofluid behavior, including wettability and interfacial tension. Moreover, deep fluid diversion could be achieved through profile control by plugging pores. All these advantages made the PSt nanofluid to be favorable for oilfield practice. [Display omitted] • Unique polystyrene (PSt) microspheres are synthesized and serve as nanofluid. • The PSt nanofluid effectively reduces interfacial tension without surfactants. • The PSt nanofluid alters the wettability towards a more water-wet condition. • The PSt nanofluid enables enhanced oil recovery. [ABSTRACT FROM AUTHOR]

Designing efficient visible light photocatalysts is targeted to improve the solar utilization to ameliorate environmental problems. Ag 10 Si 4 O 13 has great application potential due to a narrow band gap and the existence of internal electric field（spontaneous polarization electric field inside the crystal）. Here, a novel and convenient synthetic strategy based on sol-gel method and template method was proposed to fabricate 3D sponge-like hierarchical pore Ag 10 Si 4 O 13 (HPA) microblock with enhanced photocatalytic activities. The group multiple coordination is conducive to further improve the dispersion of Ag 10 Si 4 O 13 precursor around polystyrene (PS) microsphere. Weak sintering between nano-Ag 10 Si 4 O 13 particles ensured the formation of sponge skeleton structure. Compared with Ag 10 Si 4 O 13 , HPA showed enhanced separation efficiency of electron hole pairs due to the carbon doping. And the uniform and well-developed pore structures further improved the photocatalytic performance. As a result, HPA (P-5) exhibited a degradation efficiency of 98.98% at 30 min under visible light, and an excellent cycle performance were obtained. The proposed strategy provides an important reference for the preparation of easily recoverable microblock photocatalyst. [Display omitted] • Green synthesis methods, keeping synthesis and environmental impact to a low threshold. • Multi-coordination between Ag 10 Si 4 O 13 precursor and PS resulting in a 3D sponge-like hierarchical pore. • Dual function of internal electric field and C doping enhanced photogenerated carrier separation efficiency of Ag 10 Si 4 O 13. [ABSTRACT FROM AUTHOR]