Hydrophilic sponges based on 2-hydroxyethyl methacrylate. I. effect of monomer mixture composition on the pore size

1993 ◽  
Vol 32 (3) ◽  
pp. 221-232 ◽  
Author(s):  
Traian V. Chirila ◽  
Yi-Chi Chen ◽  
Brendon J. Griffin ◽  
Ian J. Constable
Keyword(s):  
Pore Size ◽  
Mixture Composition ◽  
Hydroxyethyl Methacrylate ◽  
Monomer Mixture

Distribution of chemical composition of statistical copolymers from the conversion dependences of copolymer or residual monomer mixture composition

1986 ◽  
Vol 19 (6) ◽  
pp. 1575-1580 ◽  
Author(s):  
Jaroslav Stejskal ◽  
Pavel Kratochvil ◽  
Dagmar Strakova ◽  
Ondrej Prochazka
Keyword(s):  
Chemical Composition ◽  
Mixture Composition ◽  
Monomer Mixture ◽  
Residual Monomer

Influence of the Monomer Mixture Composition on Acrylate Membrane Properties

2000 ◽  
Vol 352 ◽  
pp. 201-206
Author(s):  
A. Nastasović ◽  
V. Laninović ◽  
M. Stanković
Keyword(s):  
Mixture Composition ◽  
Membrane Properties ◽  
Monomer Mixture

scholarly journals Diffusion of drugs in hydrogels based on (meth)acrylates, poly(alkylene glycol) (meth)acrylates and itaconic acid

2012 ◽  
Vol 66 (6) ◽  
pp. 823-829 ◽  
Author(s):  
Marija Babic ◽  
Jovana Jovasevic ◽  
Jovanka Filipovic ◽  
Simonida Tomic
Keyword(s):  
Drug Release ◽  
Pore Size ◽  
Itaconic Acid ◽  
Hydroxyethyl Methacrylate ◽  
Release Process ◽  
In Vitro Drug Release ◽  
Ionic Groups ◽  
Variable Content ◽  
Alkylene Glycol

The aim of this paper is to propose equations for the diffusion of drugs for investigated drug/hydrogel systems using the parameters affecting the transport of drug through poly(2-hydroxyethyl methacrylate/itaconic acid) (P(HEMA/IA)), poly(2-hydroxyethyl acrylate/itaconic acid) (P(HEA/IA)), and poly(2-hydroxyethyl methacrylate/poly(alkylene glycol) (meth)acrylates) (P(HEMA/BIS)) copolymeric hydrogels. Different monomer types, as well as the variable content of some components in hydrogel composition (the amount of ionizable comonomer (IA) and different type of nonionic poly(alkylene glycol) (meth)acrylates), ultimately defined the pore size available for drug diffusion. The hydrogels synthesized ranged from nonporous to microporous, based on the classification in accordance to the pore size, and could be classified as hydrogels that contain ionic groups and hydrogels without ionic groups. The drugs selected for this study are bronchodilators-theophylline (TPH), fenethylline hydrochloride (FE), and antibiotic-cephalexin (CEX). Results of in vitro drug release tests defined the release systems based on the drug type, as well as the type of hydrogel used. The diffusion coefficient of drugs and the restriction coefficient, , defined as the ratio of solute to ?pore? radius (rs/r? ) that describes the ease of drug release from the gels, were used as factors that govern the release process.

Release and Diffusion Studies of Hydrogels Based on Itaconic Acid

2007 ◽  
Vol 555 ◽  
pp. 441-446 ◽  
Author(s):  
M.M. Mićić ◽  
S.Lj. Tomić ◽  
J.M. Filipović ◽  
E. Suljovrujić
Keyword(s):  
Pore Size ◽  
Itaconic Acid ◽  
Drug Transport ◽  
Diffusion Equations ◽  
Hydroxyethyl Methacrylate ◽  
Drug Molecules ◽  
Release Studies ◽  
Diffusion Studies ◽  
Gentamicin Sulphate ◽  
And Diffusion

Controlled release studies of drugs (theophylline (TH), fenethylline hydrochloride (FE) and gentamicin sulphate (GS)) from pH sensitive poly(2-hydroxyethyl methacrylate/itaconic acid) (P(HEMA/IA)) hydrogels obtained by gamma irradiation were carried out to investigate transport phenomena. Drug behavior and release profiles were analyzed using the restriction coefficient combining the influence of network structure and the size of the drug on release and transport properties. The results demonstrated that the ratio of drug radius to polymer pore size and drugpolymer interactions were dominant factors in hindering the diffusion process. The diffusivity of a drug through the hydrogels decreases with the size of the drug molecules and with the decrease in gel pore size. The diffusion equations for used drugs explain drug transport in hydrogels.

scholarly journals Pore-size distributions of cationic 2-hydroxyethyl methacrylate (HEMA) hydrogels

1995 ◽  
Vol 3 (1) ◽  
pp. 29-45 ◽  
Author(s):  
Dieter H. Walther ◽  
Garrett H. Sin ◽  
Harvey W. Blanch ◽  
John M. Prausnitz
Keyword(s):  
Pore Size ◽  
Size Distributions ◽  
Hydroxyethyl Methacrylate ◽  
Pore Size Distributions

Macroporous Hydrogels Based on 2-Hydroxyethyl Methacrylate. Part 1. Copolymers of 2-Hydroxyethyl Methacrylate with Methacrylic Acid

2003 ◽  
Vol 68 (4) ◽  
pp. 812-822 ◽  
Author(s):  
Martin Přádný ◽  
Petr Lesný ◽  
Jindřich Fiala ◽  
Jiří Vacík ◽  
Miroslav Šlouf ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sodium Chloride ◽  
Pore Size ◽  
Methacrylic Acid ◽  
Unit Volume ◽  
Hydroxyethyl Methacrylate ◽  
Diffusion Parameters ◽  
And Diffusion ◽  
Scanning Electron

A series of macroporous crosslinked copolymers of 2-hydroxyethyl methacrylate (HEMA) with methacrylic acid (MA) was prepared in the presence of fractionated particles of sodium chloride. The hydrogels were characterized by the number of pores in unit volume, the pore size, the water content in pores and diffusion parameters. The structure of the hydrogels was followed by confocal and scanning electron microscopy.

Transfer Technique for Electron Microscopy of Membrance Filter Samples

1974 ◽  
Vol 32 ◽  
pp. 554-555
Author(s):  
Lawrence W. Ortiz ◽  
Bonnie L. Isom
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Pore Size ◽  
Membrane Filters ◽  
Size Dependent

A procedure is described for the quantitative transfer of fibers and particulates collected on membrane filters to electron microscope (EM) grids. Various Millipore MF filters (Millipore AA, HA, GS, and VM; 0.8, 0.45, 0.22 and 0.05 μm mean pore size) have been used with success. Observed particle losses have not been size dependent and have not exceeded 10%. With fibers (glass or asbestos) as the collected media this observed loss is approximately 3%.

The microstructure of functionalized poLyacrylonitrile beads for bioseparations

1990 ◽  
Vol 48 (4) ◽  
pp. 1094-1095
Author(s):  
Eduardo A. Kamenetzky ◽  
David A. Ley
Keyword(s):  
Aqueous Solution ◽  
Affinity Chromatography ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Surface Coverage ◽  
Vacuum Impregnation ◽  
Thin Sections ◽  
Selective Staining ◽  
Low Viscosity ◽  
Diamond Knife

The microstructure of polyacrylonitrile (PAN) beads for affinity chromatography bioseparations was studied by TEM of stained ultramicrotomed thin-sections. Microstructural aspects such as overall pore size distribution, the distribution of pores within the beads, and surface coverage of functionalized beads affect performance properties. Stereological methods are used to quantify the internal structure of these chromatographic supports. Details of the process for making the PAN beads are given elsewhere. TEM specimens were obtained by vacuum impregnation with a low-viscosity epoxy and sectioning with a diamond knife. The beads can be observed unstained. However, different surface functionalities can be made evident by selective staining. Amide surface coverage was studied by staining in vapor of a 0.5.% RuO4 aqueous solution for 1 h. RuO4 does not stain PAN but stains, amongst many others, polymers containing an amide moiety.

Sign in / Sign up

Export Citation Format

Share Document