ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The progressive development of primary arrays of straight and curved cracks during the drying of thin films of aqueous silica sol-gel is investigated experimentally by direct observations using light microscopy. Three main test configurations are used to generate a range of drying profiles in the sol-gel: (i) films between a glass plate and a flexible glass cover slip; (ii) films between two glass plates held apart by a rigid spacer, and; (iii) uncovered films on a glass plate. Cracks in the primary arrays grow normal to the iso-concentration water profiles. The arrays of primary cracks observed in basalt lava flows and described by Spry (J. Geol. Soc. Aust. 8 (1962) 191) i.e. parallel straight columns, chevrons, rosettes, fans, inverted fans and basins, are reproduced in the pseudo two-dimensional films of sol-gel. The development of both primary and secondary cracking patterns is strongly dependent on the constraints associated with the bonding of the sol-gel to the glass and the subsequent splitting of the gel-glass interfaces.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004793731308
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