Preceramic Polymer Routes to Amorphous and Crystalline Aluminosilicate Powders for Electrorheological Applications. I
Electrorheological (ER) fluids prepared using suspensions of amorphous and crystalline aluminosilicates in inert, nonpolar liquids are reported to exhibit good-to-exceptional ER activity.1–3 Unfortunately, the measured ER properties can vary greatly ever for compositionally similar fluids. This variation results, in part, because previous efforts to correlate ER behavior with the properties of well-defined aluminosilicates relied on commercially produced aluminosilicates. The commercial sources rarely provided a range of products (e.g. wide variety of compositions, particle sizes, etc.), or detailed quantification of powder properties (phase and chemical purity, surface area and pore size distribution, etc.). In addition, because the synthetic procedures are typically proprietary, it is not possible to identify important differences in methods of preparation. Hence, a detailed understanding of the exact mechanism(s) of ER activity as a function of individual aluminosilicate properties has been difficult-to-impossible to establish. The objectives of the work reported here are to: (1) develop a detailed and general synthetic approach to aluminosilicate powders; (2) develop protocols for characterizing their spectroscopic and physical properties, and (3) conduct preliminary ER studies to demonstrate the proof-of-principle of our chosen approach.
KeywordsPore Size Distribution Thermal Gravimetric Analysis Pyrolysis Temperature Diffuse Reflectance Infrared Fourier Transform Spectroscopy Physisorbed Water
Unable to display preview. Download preview PDF.
- 1.“Electrorheological (ER) Fluids”, A Research Needs Assessment. DOE final report for Contract No. DE-AC02-91ER30172.Google Scholar
- 3.a. D.R. Gamota, A.S. Wineman, F.E. Filisko, “Fourier Transform Analysis: Fundamental Nonlinear Dynamic Response of an Electrorheological Material,” J. Rheol., accepted, b. D.R. Gamota, B.L. Mueller, F. Filisko, patent application filed (1994).Google Scholar
- 5.a. R.M. Laine, B.L. Mueller, T. Hinklin, D. Treadwell, “One Step Synthesis of Neutral Alkoxy Silanes and Alanes from SiO2 and Al(OH)3,”submitted for publication.Google Scholar
- b.V.E. Shklover, Yu. T. Struchkov, M.G. Voronkov, Z.A. Ovchinnikova, V.P. Baryshok, Dokl. Akad. Nauk SSR. 227:1185 (1984). Chem. Abstracts, 102:37181k (1984).Google Scholar
- 6.K.Y. Blohowiak, D.R. Treadwell, B.L. Mueller, M.L. Hoppe, S. Jouppi, P. Kansal, K.W. Chew, C.L.S. Scotto, F. Babonneau, J. Kampf, R.M. Laine, “SiO2 as a Starting Material for the Synthesis of Pentacoordinate Silicon Complexes. I.,” Chem. Mater. in press (1994).Google Scholar
- 7.C.R. Bickmore, R.M. Laine, “Processing Oxynitride Powders via Fluidized Bed Ammonolysis of Large, Porous, Silica Particles,” submitted to J. Am. Ceram. Soc.Google Scholar
- 9.J.P. Olivier, W.B. Conklin, presented at 7th Int. Conf. on Surf. and Coll. Sci., Compiegne, France, (1991).Google Scholar
- 11.S. Ross, J.P. Olivier, in On Physical Adsorption, Chapter 1, Interscience, New York (1964).Google Scholar
- 13.A.W. Schubring, F. E. Filisko, “Study of the Variation of the Substitutional Atoms in Amorphous Alumino-Silicates as an Electrorheological Material,” Am. Chem. Soc. Poly. Prpts, 35:xxx (1994).Google Scholar