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Design of high‐temperature, gas‐phase synthesis of hard or soft TiO 2 agglomerates
Author(s) -
Grass Robert N.,
Tsantilis Stavros,
Pratsinis Sotiris E.
Publication year - 2006
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.10739
Subject(s) - agglomerate , economies of agglomeration , coalescence (physics) , sintering , materials science , chemical engineering , dispersity , particle size , particle size distribution , particle (ecology) , mineralogy , nanotechnology , chemistry , metallurgy , composite material , polymer chemistry , geology , oceanography , physics , astrobiology , engineering
Conditions for high temperature, aerosol synthesis of titania (TiO 2 ) with controlled degree of agglomeration are identified. Accounting for simultaneous gas phase and surface reactions, coagulation and sintering during formation and growth of titania by oxidation of Ti‐tetraisopropoxide (TTIP) and TiCl 4 vapors, the evolution of the primary particle and agglomerate collision diameters is presented at nonisothermal conditions neglecting the polydispersity of the particle‐size distribution. Hard‐ or soft‐agglomerate formation is identified at the end of full coalescence and sintering, respectively. The role of surface reaction on the evolution of the agglomerate state is examined. Diagrams for the degree of hard‐agglomeration as well as the size of the primary TiO 2 particles are developed in terms of maximum process temperature, cooling rate and precursor initial molar fraction and compared with experimental data on synthesis of nonagglomerated TiO 2 . © 2005 American Institute of Chemical Engineers AIChE J, 2006