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Particle Size Control and Dependence on Precursor pH: Synthesis Uniform Submicrometer Zinc Aluminate Particles
Author(s) -
Chen ZhiZhan,
Shi ErWei,
Zheng YanQing,
Li WenJun,
Xiao Bing,
Zhuang JiYong,
Tang LianAn
Publication year - 2005
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2004.00017.x
Subject(s) - particle size , dissolution , aluminate , zinc , reactivity (psychology) , base (topology) , hydrothermal synthesis , chemistry , particle (ecology) , inorganic chemistry , hydrothermal circulation , mineralogy , nuclear chemistry , chemical engineering , materials science , metallurgy , organic chemistry , engineering , medicine , mathematical analysis , alternative medicine , mathematics , oceanography , pathology , cement , geology
Zinc aluminate (ZnAl 2 O 4 ) particles have been synthesized by the hydrothermal method using NH 3 ·H 2 O as a pH adjustment mineralizer. Experimental results showed that ZnAl 2 O 4 particle size was dependent on the precursor pH, and could be controlled through pH adjustment. It was 5.5, 11.5, and 27 nm when the precursor pH was 8.2, 9.3, and 10.5, respectively. On the other hand, the particle size distribution changed broader with increase in pH. These differences were attributable to the different NH 3 ·H 2 O function. NH 3 ·H 2 O was mainly used as a base at lower pH (<9.0), while its complex function predominated at higher one (>9.5). From thermodynamic viewpoint, the rate‐limiting steps were dissolution of Al(OH) 3 and γ‐AlO(OH) to Al(OH) 4 − at lower and higher pH, respectively. The newly formed γ‐AlO(OH) with high reactivity was the critical factor in the synthesis of bimodal particles. Higher temperature treatment of γ‐AlO(OH) could decrease the reactivity, and could be used as an aluminum source for synthesis uniform ZnAl 2 O 4 particles.