Surface Of Polystyrene Spheres Research Articles

Seed polymerization of tetraethyl orthosilicate in the presence of anionic and cationic polystyrene colloidal spheres

Kinetic analyses are made for the seed polymerization of tetraethyl orthosilicate (TEOS) in the presence of anionic and cationic polystyrene colloidal sphere seeds by turbidity and dynamic light-scattering measurements. Transmission-electron microscopy pictures of the spheres formed are also used. The seed polymerization of TEOS is difficult to take place on the surface of anionic polystyrene spheres (44–212 nm in diameter). On the other hand, the reaction proceeds easily on the cationic polystyrene spheres. Hairy and soft surfaces of polystyrene spheres will disturb the seed polymerization. Furthermore, the electrostatic attraction between the anionic hydrolytic products of TEOS molecules and cationic polystyrene spheres plays an important role for the seed polymerization.

DETERMINATION OF SINGLE-STRANDED DNA THROUGH ITS HYBRIDIZATION WITH COMPLEMENTARY PROBES COUPLED ON THE SURFACES OF CARBOXYLATE POLYSTYRENE SPHERES

A sensitive assay of single-stranded DNA in samples, labeled with a Texas Red (Tex) on its 5′-terminus, was proposed through hybridization interaction with its complementary probes coupled on the surfaces of carboxylate polystyrene spheres of 10-μm in diameter. In a phosphorus buffer solution (pH 6.8) of ionic strength higher than 0.15 mol/L, the hybridization interaction of the complementary DNA samples with the 20-mer DNA probes connected on the surfaces of polystyrene spheres can reach equilibrium about 55 min, and follows a second order reaction with the hybridization constant being 103 levels. Samples of complementary DNA in the range of 0.5–4.0 × 10−9 mol/L can be detected with the limit of determination 4.8 × 10−10 mol/L (3σ), but more useful linear range is 4.0–16.0 × 10−9 mol/L, which can be expressed with the linear regression equation of ΔF = −9.1+ 2.5 × 109 c DNA-Tex (r = 0.9982).

12] Polyacrolein microspheres: Preparation and characteristics

Publisher Summary This chapter discusses the preparation and characteristics of polyacrolein (PA). Preparation of polyacrolein microspheres by means of ionizing radiation and preparation of polyacrolein-activated hybrid beads by radiation grafting are discussed. Molecular structures and chemical analyses of PA microspheres are presented. Polyacrolein can be grafted onto preformed microspheres to activate the surface of the preformed microsphere while retaining their original shape. Binding of antibodies to PA microspheres and PA-activated hybrid beads are presented. Acrolein grafting completely changed the binding characteristics of the 11.1-μm compact polystyrene (PS) microspheres. Radiation grafting of PA onto the surfaces of PS spheres, however, allows covalent bonds to be formed with immunoglobulins and will permit four times as much protein to be bound per sphere. The specific labeling of sheep red blood cells (SRBC) with a variety of polymeric spheres of various size and composition after PA is radiation grafted on their surface indicates the scope of this system as a cell marker.