PLASMA SYNTHESIS OF TITANIUM DIOXIDE NANOPOWDER AND POWDER DOPING AND SURFACE MODIFICATION PROCESS

• Main Authors: JUREWICZ, JERZY W, NESSIM, CHRISTINE A. ABDEL MESSIH, BOULOS, MAHER I
• Format: Patent
• Language: English; French
• Published: 31.10.2002
• Edition: 7
• Subjects: ADHESIVES; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSESC01D OR C01F; COMPOUNDS THEREOF; DYES; INORGANIC CHEMISTRY; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; NON-METALLIC ELEMENTS; PAINTS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; POLISHES; PREPARATION OF CARBON BLACK; THEIR RELEVANT APPARATUS; TRANSPORTING; TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS,TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES

A process and apparatus for the synthesis of metal oxide nanopowder from a metal compound vapour is presented. In particular a process and apparatus fo r the synthesis of TIO~2 nanopowder from TICI~4 is disclosed. The metal compou nd vapour is reacted with an oxidising gas in an electrically induced RF frequency plasma thus forming a metal oxide vapour. The metal oxide vapour i s rapidly cooled using a highly turbulent gas quench zone which quickly halts the particle growth process, yielding a substantial reduction in the size of metal oxide particles formed. The metal compound vapour can also be reacted with a doping agent to create a doped metal oxide nanopowder. Additionally, a process and apparatus for the inline synthesis of a coated metal oxide is disclosed wherein the metal oxide particles are coated with a surface agent after being cooled in a highly turbulent gas quench zone.