Polystyrene latex spheres

Radko, SP Chrambach, A, Electrophoretic Migration of Submicron Polystyrene Latex Spheres in Solutions of Linear Polyacrylamide, Macromolecules 32, 2617, 1999. 

Our experiments are typically carried out at DNA concentrations of 20-50 /ig/ml with 1 ethidium per 300 bp, so that depolarization by excitation transfer is negligible.(18) The sample is excited with 575-nm light, and the fluorescence is detected at 630, 640, or 645 nm. Less than one fluorescent photon is detected for every 100 laser shots. The instrument response function e(t) is determined using 575-nm incident light scattered from a suspension of polystyrene latex spheres. 

FIG. 2.1 Sedimentation field flow fractionation (SdFFF) (a) an illustration of the concentration profile and elutant velocity profile in an FFF chamber and (b) a schematic representation of an SdFFF apparatus and of the separation of particles in the flow channel. A typical fractionation obtained through SdFFF using a polydispersed suspension of polystyrene latex spheres is also shown. (Adapted from Giddings 1991.)... 

Single-particle optical analyzers are especially useful for continuous measurement of particles of uniform physical properties. However, as discussed earlier, uncertainties develop in the measurement of particle clouds that are heterogeneous in composition because the refractive index may vary from particle to particle. Thus, in making atmospheric aerosol measurements, workers have assumed an average refractive index characteristic of the mixture to estimate a calibration curve or have reported data in terms of the equivalent particle diameter for a standard aerosol, such as suspended polystyrene latex spheres. 

FIG. 11 Potential energy profiles for 15.0 fjm polystyrene latex spheres interacting with a glass plate at ionic strengths of 0.07,0.14,0.30, and 0.90 mM. Curves and data points have been successively shifted by 2 kT for clarity. (From Ref. 63.)... 

Monodisperse polystyrene (latex) spheres having a radius value in the range 30-100 run with a standard deviation of 8% or less characterizing the size uniformity. Such samples can be obtained from Duke Scientific Corp. as 3000 Series Nanospheres (www. dukescientific.com), Polymer Laboratories as PL-Latex Plain White (www.polymerlabs. com), and Polysciences, Inc., as Nanobead Traceable Size Standards (www.polysciences. com). 

Calibration of optical devices is most frequently performed using polystyrene latex spheres that can be generated from dilute aqueous suspensions and dried before measurement. The ASTM developed a standard for the use of reticles, or disks, that can be placed in the path of the beam of a laser diffraction device for the purpose of calibration. Some manufacturers maintain that their instmments... 

Frinha, J.P.S. d Oliveira, J.M.R. Martinoho, J.M. Xu, R. Winnik, M.A. Structure in tethered chains polymeric micelles and chains anchored on polystyrene latex spheres. Langmuir 1998, 14, 2291-2296. 

M.A. (2000) Electrochemical deposition of macroporous platinum, palladium and cobalt films using polystyrene latex sphere templates. Chemical Communications, 1671-1672. 

This form is employed in aero.sol technology to characterize panicles that are nearly monodisperse such as the polystyrene latex spheres used in laboratory. studies and in instrument calibration. The value of dp can be calculated using the moment equation (1.15). In integrating, it is necessary to set a lower limit airfj, 0 and to assume that the distribution... 

In his experiment., Dahneke studied the bouncing of polystyrene latex spheres about 1 aem in diameter from polished quartz and other surfaces. Using a laser light source, he measured the velocities of the incident and reflected particles. The velocity of the incident particles was controlled by means of a deceleration chamber. 

Schmitz KS, Lu M, Gauntt J. Influence of ionic strength on the diffusion of polystyrene latex spheres, bovine serum albumin, and polynucleosomes. J Chem Phys 1983 78 5059-5066. 

ETS particles behave quite differently from MSS particles in terms of human retention. Unlike MSS, the retention of ETS in the lung is not affected by evaporative transfer and cloud effects. Instead, ETS retention is influenced mainly by particle size. Theoretical calculations indicate that the percentage retention of particles equivalent in size to ETS particles should vary between 10% and 20%. A value within the theoretical range was obtained Hiller et al. from studies with human mouth-breathing volunteer nonsmokers who orally inhaled polystyrene latex spheres of particle sizes similar to those of diluted sidestream smoke (1654a) and five volunteers who inhaled a tobacco smoke defined as sidestream smoke at a concentration similar to that encountered indoors with smokers present (1654b), estimated the percentage retention of the smoke to be 11%. 

Replicas of these slides were prepared immediately after the contact angle measurements were completed. Saturated monolayers were expected to be stable, but rearrangement in incomplete monolayers, or in monolayers incorporating appreciable amounts of solvent, was considered a definite possibility [2]. Just before the specimen was placed in the evaporator, a water suspension of polystyrene latex spheres of about 0.09-micron diameter was sprayed onto the monolayered surface with a nebulizer. The presence of a sphere in the micrograph allows quick differentiation between holes in a nearly complete film and islands of acid molecules rising above the substrate surface. The spheres... 

We selected Gregory s expression because it predicts potentials intermediate between those predicted by expressions based on exact constant-charge and exact constant-potential assumptions. This corresponds with observations of Visser (30), who demonstrated that the experimental adhesion force variation for polystyrene latex spheres on cellophane as a function of ionic strength is intermediate between force variation calculated with the DLVO approach and these two limiting assumptions. 

Eor a sphere, the conditions of the RDGA might not be matched because the refractive index of the sphere could be substantially different from that of the suspension medium. If so, P( ) should be calculated by Mie s theory. This is the case of PS (polystyrene) latex spheres in water. 

Caruso et al. [69] reported the preparation of negatively charged polystyrene latex particles (640 nm diameter) armored with a nanocomposite multilayer of Si02 nanoparticles (Ludox TM-40 26 4nm diameter) and poly(diallyldimethyl-ammonium chloride) (PDADMAC). These two components were sequentially adsorbed onto the surface of the polystyrene latex spheres (see Fig. 11), after adsorption of a precursor polyelectrolyte multilayer film of PDADMAC/... 

Fig. 28 TEM images of (a) the polystyrene latex spheres used as the core and (b) the same particles coated with a thin 25 nm titania shell, (c) SEM image of hollow titania spheres obtained by calcination of the polystyrene/Ti02 core-shell particles at 600°C under ain (d) Eidaiged TEM view of some hollow titania particles showing the small anatase crystallites that compose the sheU. Reproduced from [231] with permission of the American Chemical Society...

Such a "self-beating experiment on biologically interesting molecules was first published by Dubin et al. (14), who made measurements of bovine serum albumin, ovalbumin, lysozyme, and polystyrene latex spheres. They also studied tobacco mosaic virus and DNA and found that the nonsphericity of these molecules leads to deviations from the Lenentzian spectrum. A theoretica] analysis by Pecoia (IS), which predicts angular-dependent, multi-Lorentzian spectra, can be used to obtain shape information of such molecules. 

These materials also serve as models of the block-copolymer thermoplastic elastomers. In this case, post-curing of the continuous elastomer phase was required to attain normal rubber behavior. However, the polybutadiene portion is not covalently bonded to the polystyrene latex spheres. 

Figure 10.25. Tensile strength data for Kraton 101 (SBS triblock polymer) ( ) compared with those for an SBR vulcanizate containing 25% by volume of 350-A polystyrene latex spheres (O) (Morton and Healy, 1968) and SBR vulcanizate reinforced with 30% by weight HAF carbon black filler ( ). (Morton and Healy, 1968 Smith, 1970.)...

---