Electrophoretic core-shell particles having an organic pigment core and a shell with a thin metal oxide layer and a silane layer

• Main Authors: Anseth, Jay William, MacDonald, Brandon, Breen, Craig Alan
• Format: Patent
• Language: English
• Published: 02.07.2024
• Subjects: ADHESIVES; CHEMISTRY; 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; DYES; FREQUENCY-CHANGING; LAKES; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; MORDANTS; NATURAL RESINS; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES; PAINTS; PHYSICS; POLISHES; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

An electrophoretic medium comprises a plurality of core-shell particles and a non-polar fluid. The core-shell particles comprise an organic pigment particles core and a shell comprising a metal oxide layer and a silane layer. The metal oxide layer may have a thickness of 0.4 to 2 nm. It may be formed using a fluidized bed reactor by inserting the organic pigment into the reactor as a powder bed, contacting the powder bed with a gaseous stream comprising a metal oxide precursor and an inert gas, and contacting the powder bed with a gaseous stream of a reagent and an inert gas. The silane layer is formed from a silane compound comprising a first functional group, wherein the first functional group reacts with the metal oxide.