TY - JOUR
T1 - Retarding and accelerating effects of aluminum on the growth of polysilicic acid particles
AU - Yokoyama, Takushi
AU - Takahashi, Yoko
AU - Tarutani, Toshikazu
N1 - Funding Information:
The authors are grateful to Dr. Setsuko Kinoshita, Fukuoka University, for her measurements of 27A1 NMR. This work was partially supported by a Grant-in-Aid for Scientific Research (60740414, 61740328, and 63740317) from the Ministry of Education, Science, and Culture.
PY - 1991/2
Y1 - 1991/2
N2 - Retarding and accelerating effects of aluminum on the growth of particles of polysilicic acids were studied in the pH range 7-9 at 50°C by gel chromatography, spectrophotometry, and 27Al NMR. The effects depended on the pH and aluminum concentration. The greater retarding effect was observed at lower pH, while the greater accelerating effect at higher pH. It was concluded that the retarding effect is due to the formation of a negatively charged aluminosilicate site by substitution of aluminum for 4-coordinated silicon on polysilicic acid, and that the accelerating effect is due to the formation of unidentified aluminum species, which could not be detected by 27Al NMR, on the surface of polysilicic acid.
AB - Retarding and accelerating effects of aluminum on the growth of particles of polysilicic acids were studied in the pH range 7-9 at 50°C by gel chromatography, spectrophotometry, and 27Al NMR. The effects depended on the pH and aluminum concentration. The greater retarding effect was observed at lower pH, while the greater accelerating effect at higher pH. It was concluded that the retarding effect is due to the formation of a negatively charged aluminosilicate site by substitution of aluminum for 4-coordinated silicon on polysilicic acid, and that the accelerating effect is due to the formation of unidentified aluminum species, which could not be detected by 27Al NMR, on the surface of polysilicic acid.
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U2 - 10.1016/0021-9797(91)90352-9
DO - 10.1016/0021-9797(91)90352-9
M3 - Article
AN - SCOPUS:0026107099
SN - 0021-9797
VL - 141
SP - 559
EP - 563
JO - Journal of Colloid And Interface Science
JF - Journal of Colloid And Interface Science
IS - 2
ER -