Porous beads and method of production thereof

• Main Authors: ANDREW IAN COOPER, HAIFEI ZHANG
• Format: Patent
• Language: English
• Published: 08.09.2004
• Edition: 7
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; HUMAN NECESSITIES; HYGIENE; MEDICAL OR VETERINARY SCIENCE; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PREPARATIONS FOR MEDICAL, DENTAL, OR TOILET PURPOSES; THEIR PREPARATION OR CHEMICAL WORKING-UP; WORKING-UP

Hydrophilic, porous, polymeric beads have an open-cell lattice structure providing an intrusion volume of at least 3 ml/g. For preference, the polymeric material is selected from poly(vinyl alcohol), poly(ethylene glycol), poly(vinyl pyrrolidone), poly(acrylic acid) or its sodium salt, poly(acrylamide), poly(sodium styrene sulfonate), poly(2-acrylamido-2-methyl-1-propanesulfonic acid), or polysaccharides. Dispersed throughout the bead may be a surfactant or active ingredient such as: dyes, nano-particles, pharmaceuticals, enzymes, cleaning agents, flavours, fragrances etc. The polymeric beads are prepared by a preferred method of forming an emulsion comprising an aqueous phase, an organic phase and a hydrophilic polymeric material, taking said emulsion and injecting the emulsion into a fluid which is at a temperature such that the emulsion will freeze into beads, collecting the beads and freeze drying them to remove the organic phase and generate the open-cell lattice structure.