TY - JOUR
T1 - The pH Dependence on the Formation Process of Tungsten Oxide Gel
AU - Kuboyama, Keiichi
AU - Hara, Kazuhiro
AU - Okabe, Hirotaka
AU - Matsushige, Kazumi
PY - 1993
Y1 - 1993
N2 - In order to investigate the pH-effect on gelation process of tungstic acid, the simultaneous measurements of transmitted-light intensities were carried out for specimens with several different-pH values (pH=1.3~1.6), prepared by adding different amounts of NaOH aqueous solution into ion-exchanged tungstic acid. The transmitted-light intensity decreased faster, as the pH-value of the specimen became lower. Moreover, it was found that the transmitted-light intensities of the different-pH specimens showed a unique time dependence when the observation time was scaled by T1/2 (the time when the transmitted-light intensity became the middle value of the initial and the final intensity). This result indicates that, though the light-scattering mechanism in tungstic acid might change during gelation process, the mechanism of gelation process itself is same irrespective of pH-values. In addition, the critical pH value for the gelation was extrapolated to be 1.71 from T1/2 vs. pH value curve.
AB - In order to investigate the pH-effect on gelation process of tungstic acid, the simultaneous measurements of transmitted-light intensities were carried out for specimens with several different-pH values (pH=1.3~1.6), prepared by adding different amounts of NaOH aqueous solution into ion-exchanged tungstic acid. The transmitted-light intensity decreased faster, as the pH-value of the specimen became lower. Moreover, it was found that the transmitted-light intensities of the different-pH specimens showed a unique time dependence when the observation time was scaled by T1/2 (the time when the transmitted-light intensity became the middle value of the initial and the final intensity). This result indicates that, though the light-scattering mechanism in tungstic acid might change during gelation process, the mechanism of gelation process itself is same irrespective of pH-values. In addition, the critical pH value for the gelation was extrapolated to be 1.71 from T1/2 vs. pH value curve.
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U2 - 10.1143/JPSJ.62.357
DO - 10.1143/JPSJ.62.357
M3 - Article
AN - SCOPUS:21144483295
VL - 62
SP - 357
EP - 361
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
SN - 0031-9015
IS - 1
ER -