Preparation of capsules

• Main Authors: CHEBIYAM RAJESH, WHITESIDES THOMAS H, STEINER MICHAEL L, MANNING JEREMY J, WALLS MICHAEL D, VALIANATOS PETER J
• Format: Patent
• Language: English
• Published: 14.04.2015
• Subjects: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; COMPOSITIONS BASED THEREON; CONVEYING; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; HANDLING THIN OR FILAMENTARY MATERIAL; MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGINGARTICLES OR MATERIALS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; ORGANIC MACROMOLECULAR COMPOUNDS; PACKING; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PHYSICS; STORING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; THEIR PREPARATION OR CHEMICAL WORKING-UP; THEIR RELEVANT APPARATUS; TRANSPORTING; UNPACKING

Prior art processes for producing protein-based capsules (for example, capsules for use in electrophoretic media) tend to be wasteful because they produce many capsules outside the desired size range, which is typically about 20 to 50 μm. Capsule size distribution and yields can be improved by either (a) emulsifying a water-immiscible phase in a preformed coacervate of the protein; or (b) using a limited coalescence process with colloidal alumina as the surface-active particulate material.