Abstract
The viscosity behaviors of rapidly curable transparent silica aerogels, such as time at the onset point and the slope of viscosity increase, are investigated as functions of target density, water and catalyst content. Results were compared with the visually measured gel time. The effects of temperature and shear rate on the onset point and rate of the viscosity increase are also investigated with the selected samples. Experimental design and result analysis were also conducted using the Design of Experiment (DOE) method, and the Arrhenius relation was applied to predict the temperature dependence of viscosity. It is found that the target density and catalyst content played more important roles in determining gelation and viscosity behavior than water content did. As the target density increased, the gel time and the onset point appeared at significantly earlier times and the slope increased more rapidly, while there existed an optimum catalyst and water content for fast gelation and desirable viscosity behaviors. The temperature dependence of the viscosity behaviors of rapidly curable transparent silica sols can be expressed by the Arrhenius relation. The onset time of viscosity increase was little affected by the shear rate at a low shear rate range of up to 1.32 s−1, and after that it linearly decreased with increasing shear rate, while the slope of viscosity increase continuously decreased with increasing shear rate. Overall, the viscosity measurement appears as a simple and reliable method for quantitatively measuring gel time, especially for the rapidly curable sol–gel process.
Similar content being viewed by others
References
Z. Zhang, Y. Tanigami, R. Terai, and H. Wakabayashi, J. Non-Cryst. Solids 189, 212 (1995).
K.Y. Jang, K. Kim, and R.S. Upadhye, J. Vac. Sci. Technol A 8, 1732 (1990).
H.S. Yang, S.Y. Choi, S.H. Hyun, H.H. Park, and J.K. Hong, J. Non-Cryst. Solids 221, 151 (1998).
S. Keysar, Y. Cohen, S. Shagal, S. Slobodiansky, and G.S. Grader, J. Sol–Gel Sci. Tech. 14, 131 (1999).
C. González, J. Gutiérrez, J. Llorens, M.I. Galán, and C. Mans, J. Non-Cryst. Sol. 147/148, 690 (1992).
J.Y. Chane-Ching and L.C. Klein, J. Am. Ceram. Soc. 71(1), 83 (1988).
J.K. Bailey, T. Nagase, S.M. Broberg, and M.L. Mecartney, J. Non-Cryst. Sol. 109, 198 (1989).
W.H. Shih and L. Pwu, J. Mater. Res. 10(11), 2808 (1995).
M.D. Sacks and R.S. Sheu, J. Non-Cryst. Sol. 92, 383 (1987).
S.Q. Zeng, A. Hunt, and R. Grief, J. Non-Cryst. Solids 225, 282 (1998).
G. Biesmans, D. Randall, E. Francais, and M. Perrut, J. Non-Cryst. Solids 225, 36 (1998).
J.K. Lee, R. Trifu, and G.L. Gould, NASA SBIR Phase I, Final Report, Contract No. NAS9-030281, July 2003.
Program Manuals of Statistica, Vol. IV Industrial Statistics, Experimental Design, StatSoft (1995), p. 4254.
R.K. Iler, The Chemistry of Silica (Wiley, New York, 1979), p. 288.
J.C. Debsikdar, Adv. Ceram. Mater. 1, 93 (1998).
V. Gottardi, M. Guglielmi, A. Bertoluzza, C. Farnano, and M.A. Morelli, J. Non-Cryst. Solids 63, 71 (1984).
M.W. Colby, A. Osaka, and J.D. Mackenzie, J. Non-Cryst. Solids 99, 129 (1988).
J.K. Lee, S.E. Solovyov, T.L. Virkler, and C.E. Scott, Rheol. Acta. 41, 567 (2002).
J.K. Lee, T.L. Virkler, and C.E. Scott, Polym. Eng. Sci. 42, 1541 (2002)
J.K. Lee, T.L. Virkler, and C.E. Scott, Polym. Eng. Sci. 42, 1840 (2002).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Lee, J.K., Gould, G.L. Viscosity Behaviors of Rapidly Curable Silica Sols. J Sol-Gel Sci Technol 34, 281–291 (2005). https://doi.org/10.1007/s10971-005-2525-4
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s10971-005-2525-4