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polystyrene latex

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...
November 27, 2016: 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
Vesselin N Paunov, Hamza Al-Shehri, Tommy S Horozov
We developed and tested a theoretical model for the attachment of fluid-infused porous supra-particles to a fluid-liquid interface. We considered the wetting behaviour of agglomerated clusters of particles, typical of powdered materials dispersed in a liquid, as well as of the adsorption of liquid-infused colloidosomes at the liquid-fluid interface. The free energy of attachment of a composite spherical porous supra-particle made from much smaller aggregated spherical particles to the oil-water interface was calculated...
September 29, 2016: Physical Chemistry Chemical Physics: PCCP
Hongyan Cao, Libin Zhang, Lili Wu, Xiang Zheng Kong
Heterocoagulation of colloid particles with opposite surface charge has been used for the preparation of composite microspheres with specifically designed suprastructure, such as those with raspberry-like surface morphology and core-shell microspheres, which are difficult to achieve through other techniques. Here we report our investigation on the heterocoagulation of cationic polystyrene (PS) particles with anionic poly(methyl methacrylate) (PMMA) particles by a novel technique, i.e., by following online the evolution of the light transmittance in the process with practically no disturbance of the dispersion and no post-treatment for the samples...
October 12, 2016: ACS Applied Materials & Interfaces
Jani Tuoriniemi, Beatriz Moreira, Gulnara Safina
The capabilities of surface plasmon resonance (SPR) for characterization of colloidal particles were evaluated for 100, 300, and 460 nm nominal diameter polystyrene (PS) latexes. First the accuracy of measuring the effective refractive index (neff) of turbid colloids using SPR was quantified. It was concluded that for submicrometer sized PS particles the accuracy is limited by the reproducibility between replicate injections of samples. An SPR method was developed for obtaining the particle mean diameter (dpart) and the particle number concentration (cp) by fitting the measured neff of polystyrene (PS) colloids diluted in series with theoretical values calculated using the coherent scattering theory (CST)...
October 4, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Pascal Pratte, Stéphane Cosandey, Catherine Goujon-Ginglinger
CONTEXT: Knowledge of the droplet size distribution of inhalable aerosols is important to predict aerosol deposition yield at various respiratory tract locations in human. Optical methodologies are usually preferred over the multi-stage cascade impactor for high-throughput measurements of aerosol particle/droplet size distributions. OBJECTIVE: Evaluate the Laser Aerosol Spectrometer technology based on Polystyrene Sphere Latex (PSL) calibration curve applied for the experimental determination of droplet size distributions in the diameter range typical of commercial e-cigarette aerosols (147-1361 nm)...
October 2016: Inhalation Toxicology
Samy Rengasamy, Ronald Shaffer, Brandon Williams, Sarah Smit
NIOSH published a Federal Register Notice to explore the possibility of incorporating FDA required filtration tests for surgical masks (SMs) in the 42 CFR Part 84 respirator certification process. There have been no published studies comparing the filtration efficiency test methods used for NIOSH certification of N95 filtering facepiece respirators (N95 FFRs) with those used by the FDA for clearance of SMs. To address this issue, filtration efficiencies of "N95 FFRs" including six N95 FFR models and three surgical N95 FFR models, and three SM models were measured using the NIOSH NaCl aerosol test method, and FDA required particulate filtration efficiency (PFE) and bacterial filtration efficiency (BFE) methods, and viral filtration efficiency (VFE) method...
February 2017: Journal of Occupational and Environmental Hygiene
Kabindra M Shakya, Alyssa Noyes, Randa Kallin, Richard E Peltier
Inexpensive cloth masks are widely used in developing countries to protect from particulate pollution albeit limited data on their efficacy exists. This study examined the efficiency of four types of masks (three types of cloth masks and one type of surgical mask) commonly worn in the developing world. Five monodispersed aerosol sphere size (30, 100, and 500 nm, and 1 and 2.5 μm) and diluted whole diesel exhaust was used to assess facemask performance. Among the three cloth mask types, a cloth mask with an exhaust valve performed best with filtration efficiency of 80-90% for the measured polystyrene latex (PSL) particle sizes...
August 17, 2016: Journal of Exposure Science & Environmental Epidemiology
Zenamarkos Bantie Sendekie, Arthur Gaveau, Rob G H Lammertink, Patrice Bacchin
Clogging of channels by complex systems such as mixtures of colloidal and biological particles is commonly encountered in different applications. In this work, we analyze and compare the clogging mechanisms and dynamics by pure and mixture suspensions of polystyrene latex particles and Escherichia coli by coupling fluorescent microscopic observation and dynamic permeability measurements in microfluidic filters. Pure particles filtration leads to arches and deposit formation in the upstream side of the microfilter while pure bacteria form streamers in the downstream zone...
2016: Scientific Reports
Isleine P Caldas, Miriam Z Scelza, Marco A Gallito, Gutemberg Alves, Licínio Silva
AIMS: The aim of this study is to evaluate the in vitro response of human gingival fibroblasts in primary cultures to two materials for temporary relining of dentures: Temporary Soft (TDV, Brazil) and Trusoft (Bosworth, USA) for 24 hours, 7 and 30 days by using a multi-parametric analysis. MATERIALS AND METHODS: Each material sample (TDV, TS, Polystyrene, Latex) was prepared and incubated in a culture medium for 1, 7, and 30 days at 37°C. Human gingival fibroblasts were exposed to the extracts and cell viability was evaluated by a multi-parametric assay, which allowed sequential analysis of mitochondrial activity (XTT), membrane integrity [neutral red (NR)], and cell density [crystal violet dye exclusion (CVDE)] in the same cells...
June 1, 2016: Journal of Contemporary Dental Practice
Shuang Guo, Bai-Ling Qiu, Chen-Qi Zhu, Ya-Ya Gao Yang, Di Wu, Qi-Hui Liang, Nan-Yin Han
Gravitational field-flow fractionation (GrFFF) is a useful technique for separation and characterization for micrometer-sized particles. Elution behavior of micrometer-sized particles in GrFFF was researched in this study. Particles in GrFFF channel are subject to hydrodynamic lift forces (HLF), fluid inertial forces and gravity, which drive them to different velocities by carrier flow, resulting in a size-based separation. Effects of ionic strength, flow rate and viscosity as well as methanol were investigated using polystyrene latex beads as model particles...
September 15, 2016: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Ljiljana Palangetic, Kirill Feldman, Raphael Schaller, Romana Kalt, Walter R Caseri, Jan Vermant
This work revisits the synthesis of the colloidal particles most commonly used for making model near hard suspensions or as building blocks of model colloidal gels, i.e. sterically stabilised poly(methyl methacrylate) (PMMA) particles. The synthesis of these particles is notoriously hard to control and generally the problems are ascribed to the difficulty in synthesising the graft stabiliser (PMMA-g-PHSA). In the present work, it is shown that for improving the reliability of the synthesis as a whole, control over the polycondensation of the 12-polyhydroxystearic acid is the key...
July 14, 2016: Faraday Discussions
Lu Wang, Mingwang Pan, Shaofeng Song, Lei Zhu, Jinfeng Yuan, Gang Liu
Herein, we demonstrate a facile approach to prepare anisotropic poly(tert-butyl acrylate)/polystyrene (PtBA/PS) composite particles with controllable morphologies by soap-free seeded emulsion polymerization (SSEP). In the first step, noncrosslinked PtBA seeds with self-stabilizing polar functional groups (e.g., ester groups and radicals) are synthesized by soap-free emulsion polymerization. During the subsequent SSEP of styrene (St), PS bulges are nucleated on the PtBA seeds due to the microphase separation confined in the latex particles...
August 9, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Manigandan Sabapathy, Yogesh Shelke, Madivala G Basavaraj, Ethayaraja Mani
Non-spherical patchy particles are potential candidates as building blocks for the design of target colloidal structures via spontaneous self-organization. We report a facile scheme to synthesize non-spherical particles with patchy electrostatic interactions. In this method, charged spherical latex particles such as polystyrene (PS) are deformed unequally at an oil-water interface due to heating and partial swelling. The spherical particles then evolve into non-spherical shapes such as 'acorn-like' and 'idly-like'...
July 6, 2016: Soft Matter
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