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polystyrene latex

Chunjie Xie, Teng Qiu, Jinglong Li, Heling Zhang, Xiaoyu Li, Xinlin Tuo
The direct synthesis of polymer microspheres modified by aramid nanofibers (ANF) is an interesting challenge. This work describes a simple aqueous process to prepare polystyrene (PS)/ANF composite microspheres, where the specific ANF network was "dressed" on PS. ANF was derived from the copolymerization of terephthaloyl chloride (TPC), p-phenylene diamine (PPD), and methoxypolyethylene glycol (MPEG), and could be dispersed in water stably. We applied the as-synthesized ANF as Pickering emulsifier in the o/w emulsion of styrene monomer...
July 22, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Jeongan Choi, Seung Chan Hong, Woojin Kim, Jae Hee Jung
We report a novel microfluidic technique for sampling of aerosols into liquids. The two-phase fluid, sampling air and collecting liquid, forms a stratified flow in the curved microchannel. By passing fluids through the curved region, the particles are transferred from air into the liquid phase by the particle centrifugal and drag forces. This microfluidic-based aerosol-into-liquid sampling system, called the MicroSampler, is driven by particle inertial differences. To evaluate the physical particle collection efficiency of the MicroSampler, we used standard polystyrene-latex (PSL) particles ranging in size from 0...
April 28, 2017: ACS Sensors
Alessandro Dani, Karoline Täuber, Weiyi Zhang, Helmut Schlaad, Jiayin Yuan
Porous polyelectrolyte membranes stable in a highly ionic environment are obtained by covalent crosslinking of an imidazolium-based poly(ionic liquid). The crosslinking reaction involves the UV light-induced thiol-ene (click) chemistry, and the phase separation, occurring during the crosslinking step, generates a fully interconnected porous structure in the membrane. The porosity is on the order of the micrometer scale and the membrane shows a gradient of pore size across the membrane cross-section. The membrane can separate polystyrene latex particles of different size and undergoes actuation in contact with acetone due to the asymmetric porous structure...
June 26, 2017: Macromolecular Rapid Communications
Habauka M Kwaambwa, Maja S Hellsing, Matthew J Wasbrough, Markus Bleuel, Adrian R Rennie
Studies with a model system consisting of polystyrene latex particles showed that the protein from seeds of Moringa trees adsorbs to the surface and causes flocculation as unusually dense aggregates. In this study, electrolytes sodium chloride (NaCl), ferric chloride (FeCl3) and aluminium sulfate (Al2(SO4)3) have been used to aggregate model polystyrene particles. The study augments previous work using neutron scattering on the flocculation of polystyrene latex with protein from seeds of Moringa trees that had indicated higher floc dimension, df, values as the concentration of particles increased...
May 17, 2017: Journal of Colloid and Interface Science
Ida Berts, Giovanna Fragneto, Lionel Porcar, Maja S Hellsing, Adrian R Rennie
Polysaccharides are known to modify binding of proteins at interfaces and this paper describes studies of these interactions and how they are modified by pH. Specifically, the adsorption of human serum albumin on to polystyrene latex and to silica is described, focusing on how this is affected by hyaluronan. Experiments were designed to test how such binding might be modified under relevant physiological conditions. Changes in adsorption of albumin alone and the co-adsorption of albumin and hyaluronan are driven by electrostatic interactions...
May 17, 2017: Journal of Colloid and Interface Science
Xiongwei Wang, Peiyi Wu
Rational distribution and orientation of boron nitride nanosheets (BNNSs) are very significant for a polymer/BNNS composite to obtain a high thermal conductivity at low filler content. In this paper, a high-performance thermal interface material based on exfoliated BNNSs and polystyrene (PS) microspheres was fabricated by latex blending and subsequent compression molding. In this case, BNNSs and PS microspheres first self-assembled to form the complex microspheres via strong electrostatic interactions between them...
June 1, 2017: ACS Applied Materials & Interfaces
Soheyl Tadjiki, Manuel David Montaño, Shoeleh Assemi, Angela Barber, James Ranville, Ronald Beckett
A methodology has been developed to measure nanoparticle mass and density, by combining centrifugal field-flow fractionation (CeFFF; more commonly called sedimentation FFF or SdFFF) and transmission electron microscopy (TEM). Particle effective mass obtained from CeFFF retention data and particle size obtained from the TEM images were used to calculate the nanoparticle density. The method was initially applied to measure the density of monodispersed polystyrene latex nanoparticles. Measured densities for latex nanoparticles of 160-300 nm in diameter were in the range of 1041-1063 kg m(-3) with standard deviations of 0...
June 6, 2017: Analytical Chemistry
Chao Zhang, Dingqu Wang, Rong Zhu, Wenming Yang, Peng Jiang
Counting and sizing of polydisperse airborne nanoparticles have attracted most attentions owing to increasing widespread presence of airborne engineered nanoparticles or ultrafine particles. Here we report a miniature aerosol sensor to detect particle size distribution of polydisperse ultrafine particles based on ion diffusion charging and electrical detection. The aerosol sensor comprises a couple of planar electrodes printed on two circuit boards assembled in parallel, where charging, precipitation and measurement sections are integrated into one chip, which can detect aerosol particle size in of 30-500 nm, number concentration in range of 5 × 10²-10⁷ /cm³...
April 22, 2017: Sensors
Weixiong Zhao, Xuezhe Xu, Bo Fang, Qilei Zhang, Xiaodong Qian, Shuo Wang, Pan Liu, Weijun Zhang, Zhenzhu Wang, Dong Liu, Yinbo Huang, Dean S Venables, Weidong Chen
We report on the development of a blue light-emitting-diode-based incoherent broad-band cavity-enhanced absorption spectroscopy (IBBCEAS) instrument for the measurement of the aerosol extinction coefficient at λ=461  nm. With an effective absorption path length of 2.8 km, an optimum detection limit of 0.05  Mm<sup>-1</sup> (5×10<sup>-10</sup>  cm<sup>-1</sup>) was achieved with an averaging time of 84 s. The baseline drift of the developed spectrometer was about ±0...
April 10, 2017: Applied Optics
Zheng Xing, Siok-Wei Tay, Yeap Hung Ng, Liang Hong
This study starts with the synthesis of silica hollow spheres (HSs) by utilizing in situ synthesized polystyrene (PS) microspheres as the template for the deposition of a silica (SiO2) shell, followed by a slow gasification step in air to remove the PS core. The size of HS and the thickness of the porous SiO2 shell are tuned by varying the synthesis conditions of the PS latex and those of the sol-gel deposition, respectively. Various HS powder samples are characterized by ultraviolet-visible-near infrared (UV-vis-NIR) spectroscopy to determine their diffuse reflectance...
April 21, 2017: ACS Applied Materials & Interfaces
Vesta Kohlmeier, George C Dragan, Erwin W Karg, Jürgen Schnelle-Kreis, Dietmar Breuer, Patricia B C Forbes, Egmont R Rohwer, Ralf Zimmermann
During many measurements it is important to account for possible changes in the gas-particle distribution of aerosols containing semi-volatile organic compounds (SVOCs). If denuders are combined with currently used personal air samplers, a simultaneous differential sampling of the gas and particle phase is possible. Here we analysed the transmission efficiency of denuders based on multi-channel silicone rubber traps (setup: 9 cm long glass liner (ID 4 mm), containing 22 parallel silicone rubber tubes (55 mm long, ID 0...
May 24, 2017: Environmental Science. Processes & Impacts
Shengnan Peng, Dan Wu, Zhi Ge, Meiping Tong, Hyunjung Kim
The effects of graphene oxide (GO) on the transport and deposition behaviors of colloids with different sizes in packed quartz sand were investigated in both NaCl (10 and 50 mM) and CaCl2 solutions (1 and 5 mM) at pH 6. Fluorescent carboxylate-modified polystyrene latex microspheres (CMLs) with size ranging from 0.2 to 2 μm were utilized as model colloids. Both breakthrough curves and retained profiles of colloids in the presence and absence of GO in suspensions under all examined solution conditions were analyzed...
March 30, 2017: Environmental Pollution
N Ashwin K Bharadwaj, Jin Gu Kang, Marta C Hatzell, Kenneth S Schweizer, Paul V Braun, Randy H Ewoldt
Typical colloid-polymer composites have particle diameters much larger than the polymer mesh size, but successful integration of smaller colloids into a large-mesh network could allow for the realization of new colloidal states of spatial organization and faster colloid motion which can allow the possibility of switchable re-configuration of colloids or more dramatic stimuli-responsive property changes. Experimental realization of such composites requires solving non-trivial materials selection and fabrication challenges; key questions include composition regime maps of successful composites, the resulting structure and colloidal contact network, and the mechanical properties, in particular the ability to form a network and retain strain stiffening in the presence of colloids...
January 26, 2017: Soft Matter
Hua Zou, Xia Wang
This paper presents a more general method to prepare silica-coated polystyrene (PS) particles with minimal excess silica by adsorption, highlighting the role of poly(N-vinylpyrrolidone) (PVP). The method is based on the addition of small silica nanoparticles onto submicrometer-sized near-monodisperse polymer latex particles under the conditions of monolayer silica coverage of the latex surface. Either a cationic or an anionic initiator could be used in the PVP-involved emulsion polymerization to prepare PS particles, and the adsorption was conducted successfully either under acidic or basic conditions...
February 3, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Fabiano Palmeira Gonçalves, Gutemberg Alves, Vladi Oliveira Guimarães, Marco Antônio Gallito, Felipe Oliveira, Míriam Zaccaro Scelza
Bis-acryl resins are used for temporary dental restorations and have shown advantages over other materials. The aim of this work was to evaluate the in vitro cytotoxicity of two bis-acryl composite resins (Protemp 4 and Luxatemp Star), obtained at 1, 7 and 40 days after mixing the resin components, using a standardized assay employing human primary cells closely related to oral tissues. Human gingival fibroblast cell cultures were exposed for 24 h to either bis-acryl composite resins, polystyrene beads (negative control) and latex (positive control) extracts obtained after incubation by the different periods, at 37 °C under 5% CO2...
September 2016: Brazilian Dental Journal
Cheuk Ka Poon, Owen Tang, Xin-Ming Chen, Byung Kim, Matthias Hartlieb, Carol A Pollock, Brian S Hawkett, Sébastien Perrier
The authors report the preparation of a novel range of functional polyacrylamide stabilized polystyrene nanoparticles, obtained by surfactant-free reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization, their fluorescent tagging, cellular uptake, and biodistribution. The authors show the versatility of the RAFT emulsion process for the design of functional nanoparticles of well-defined size that can be used as drug delivery vectors. Functionalization with a fluorescent tag offers a useful visualization tool for tracing, localization, and clearance studies of these carriers in biological models...
December 14, 2016: Macromolecular Bioscience
Paulina Żeliszewska, Monika Wasilewska, Zbigniew Adamczyk
The adsorption of mouse monoclonal immunoglobulin G (IgG) on negatively charged polystyrene microparticles was studied by the laser Doppler velocimetry (LDV) electrophoretic mobility measurements. The dependence of the electrophoretic mobility of microparticles on the IgG concentration in the suspension was determined for different ionic strengths and pHs (3.5, 7.4). The increase in the electrophoretic mobility was quantitatively interpreted in terms of the 3D electrokinetic model. The maximum coverage of IgG on latex was determined by the depletion method aided by AFM imaging...
March 15, 2017: Journal of Colloid and Interface Science
Anetta Härtlova, Julien Peltier, Orsolya Bilkei-Gorzo, Matthias Trost
Phagocytosis plays an essential role in the immune system for the defense against invading microorganisms and the clearing of apoptotic cells. After internalization, the newly formed phagosome is constantly remodeled by fusion with early endosomes, late endosomes, and lysosomes. These changes ultimately deliver the engulfed material into the terminal degradative compartments known as phagolysosomes. However, defective phagosome maturation can result in inflammatory or autoimmune disease depending on the type of phagosome cargo...
2017: Methods in Molecular Biology
Astha Garg, Charles A Cartier, Kyle J M Bishop, Darrell Velegol
The zeta potential of a particle characterizes its motion in an electric field and is often thought to be negligible at high ionic strength (several moles per liter) due to thinning of the electrical double layer (EDL). Here, we describe zeta potential measurements on polystyrene latex (PSL) particles at monovalent salt concentrations up to saturation (∼5 M NaCl) using electrophoresis in sinusoidal electric fields and high-speed video microscopy. Our measurements reveal that the zeta potential remains finite at even the highest concentrations...
November 15, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Hamza Al-Shehri, Tommy S Horozov, Vesselin N Paunov
We prepared model porous composite supra-particles and investigated the effect of the initial infused fluid phase on their attachment at the liquid-fluid interface. We used a simple method for fabrication of millimetre-sized spherical porous supra-particles from much smaller monodisperse latex microparticles as building blocks by evaporation of a polystyrene sulphate latex suspension on a hot super-hydrophobic surface. We annealed the dried supra-particles at the polymer's glass transition temperature to fuse partially their latex particle building blocks...
October 12, 2016: Soft Matter
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