Showing papers on "Self-healing hydrogels published in 1972"

Method for preparation of biocompatible and biofunctional materials and product thereof

Abstract: A METHOD FOR THE PREPARATION OF BIOCOMPATIBLE AND BIOFUNCTIONAL SURFACES IS PROVIDED BIOCOMPATIBLE AND ATI N GRAFTING A REACTABLE COMPOUND SELECTED FROM THE GROU CONSISTING OF POLYMERS AND COPOLYMERS ONTO AN INERT UP POL MERIC SUBSTRATE AND THEREAFTER CHEMICALLY BONDING A BIOLOGICALLY ACTIBE MOLECULE TO THE REATABLE COMPOUND SPECIFIC EMBODMENTS INCLUDE CHEMICALLY BONDING OF HUMAN SERUM ALBUMIN HEPARIN, STREPTOKINASE, PROSTAGLANDIN E-1 AND MIXTURES THEREOF TO HYDROGELS OF VARYING COMPOSITIONS WITH OR WITHOUT "ARM" SUC AS E-AMINO CAPROIC MOLECULE OR CHEMICAL "ARM" SUCAN INTERMEDIATE SMALLER ACID OR 1,4 DIAMINO BUTANE, THE HYDROGELS HAING BEEN PREVIOUSLY RADIATION-GRAFTED TO TOUGH INERT POLYMERIC SUBSTRATE. A HIGHLY SYNERGISTIC EFFECT IS ACHIEVED FOR HYDROGELS CONTAINING HIGH WATER CONTENT E.G., ABOVE ABOUT 55% WHEN THE CHEMICALLY BONDING OF THE BIOLOGICALLY ACTIVE MOLECULE IS CARRIED OUT VIA AN INTERMEDIATE SMALLER MOLECULE OR CHEMICALL ARM. FOR THIN FILM SUBSTRATES HAVING RAIATION-GRAFTED THERETO HYDROGELS WITH -CO2 PENDANT FUNCTIONAL GROUPS WHICH ARE ACTIVATED WITH A CARBODIIMIDE SOLUTION A QUICK WASH OF THE THIN FILM WITH ICE WATER IS REQUIRED TO EFFECT SUBSEQUENT CHEMICAL BONDING OF THE BIOLOGICALLY ACTIVE MOLECULES TO THE ACTIVATED SURFACE. THE SAME TECHNIQUE IS ALSO REQUIRED WHERE A CHEMICAL ARM IS EMPLOYED WHICH HAS -CO2H PENDANT FUNCTIONAL GROUPS.

Hydrogels from radiation crosslinked blends of hydrophilic polymers and fillers

Abstract: Particulate, Free-Flowing, Insoluble Swellable Polymers are provided which are comprised of a mixture of an insoluble, swellable hydrogel and inert filler The mixtures are freeflowing powders or granules which can absorb many times their weight of water and hence are useful as a soil amendment

Interaction of urea with poly(2‐hydroxyethyl methacrylate) hydrogels

Abstract: The interaction of poly(2-hydroxyethyl methacrylate) [poly(HEMA)] and other similar hydrogels with dilute urea solution has been studied by a variety of techniques, including swelling experiments, fluorescence quenching, near infrared spectroscopy and fundamental band infrared spectroscopy. The results obtained indicate that the anomalous swelling behavior of poly(HEMA) gels in the presence of such dilute urea solutions is probably not due to the disruption of a secondary hydrophobic bond structure as has been generally believed. Although poly(HEMA) gels do contain sites that can participate in hydrophobic bonding, the evidence gathered indicates that dilute urea solutions have no effect on such bonds. A plausible model that does fit all the data involves the interaction of urea with a secondary structure composed of hydrogen-bonded hydroxyl groups, stabilized by the exclusion of water molecules from the regions containing the bonds.

Process for the manufacture of substantially spherical, silica-containing hydrogels

Abstract: Substantially spherical, silica-containing hydrogels are prepared by spraying droplets of silica hydrosols (obtained by reacting alkaline silica-containing raw materials with acidic solutions) into a gaseous medium and allowing the droplets to solidify while falling freely. The reaction for the formation of silica hydrosol is carried out by introducing the acidic solution at the upstream end of a continuous-flow mixing zone and adding the silica-containing raw material at a series of points distributed along the downstream path.

Studies on Alumino-Silicate Hydrogel—Part IV: Cation Exchange Study in the Synthetic Hydrogel

Abstract: Synthetic hydrogels possessing very high cation exchange capacity were prepared and values comparable to those of organic exchanger were obtained. The factors affecting the CEC and selectivity have been studied.

Studies on Alkali Alumino-Silicate Hydrogel—Part III: Physico-Chemical Characteristics of the Synthetic Hydrogels

Abstract: The alkali alumino-silicate hydrogels, synthesised from alkali silicate and aluminate by wet interaction have been processed and purified. The physico-chemical properties of the samples have been studied with respect to their homogeneity and suitability as an industrial cation exchanger.