Preparation of Monodisperse Polystyrenes with High Molecular Weights

Preparation of Large Monodisperse Vesicles

Preparation of monodisperse vesicles is important both for research purposes and for practical applications. While the extrusion of vesicles through small pores (approximately 100 nm in diameter) results in relatively uniform populations of vesicles, extrusion to larger sizes results in very heterogeneous populations of vesicles. Here we report a simple method for preparing large monodisperse m...

Revisiting molecular weight distribution of polystyrenes using adsorption high-performance thin-layer chromatography

A repeatable separation of polystyrenes according to MW, from 1920 to 520000 u.m.a, has been obtained under adsorption conditions using a method that comprises the use of Lichrospher HPTLC plates, and a controlled, isocratic elution with a 78:22 (v/v) mixture of cyclohexane (Cy)-tetrahydrofuran (THF). Likewise, UV-densitometric quantification of polystyrenes in mixtures can be achieved, by an i...

Preparation of monodisperse multilayer vesicles of controlled size and high encapsulation ratio

The effect of shear on lyotropic lamellar phases is studied by light scattering and microscopic observations. We found that in a certain range of shear rate the lamellar phase organizes itself into spherical multilayer vesicles of well controlled size. The size is shown to vary as the inverse of the square root of the shear rate. A simple explanation in terms of a balance between shear stress a...

Surface Adsorption of Polyethylene Glycol and Polyvinyl Alcohol with Variable Molecular Weights on Zinc Oxide Nanoparticles

Preparation of Monodisperse Melamine-Formaldehyde Microspheres via Dispersed Polycondensation

We have successfully synthesized relatively monodisperse and cross-linked melamine-formaldehyde (MF) microspheres by dispersed polycondensation and subsequent pH adjustment with serum replacement cleaning. The average particle sizes ( : weight-average and : number-average), the polydispersity index ( ), the number of particles Np, and the gel content of the M-F microspheres were observed by var...