Aerogel mechanical characterization

Zirconia is a very interesting material in ceramic industry, with exceptional electrical, thermal (Chap. 23), and mechanical properties (Chap. 22 Mechanical characterization of aerogels) allowing its use in fuel cells, thermal barrier coatings, oxygen sensors, and many other high-temperature applications. In all these applications, this material is doped with other oxides to stabilize the tetragonal or cubic phase at low temperatures. 

Figure 13.3. A. Mechanical characterization by a short beam 3-point bending (see inset) of polyurea-crosslinked silica aerogel monoliths and their noncrosslinked (native) counterparts a, 0.63 gcm b, 0.44 gcm c, 0.38 gcm , and d, 0.28 gcm . Native samples do not register in the load-force scale shown. B. Cumulative data. Dark blue triangles and the dark blue line concern two-step aerogels made by acid-catalyzed hydrolysis and base-catalyzed gelation. All other samples use one-step base-catalyzed silica with different isocyanates. Multiple lines for crosslinked samples correspond to different di- and tri-isocyanate crosslinkers.

Katti A, Shimpi N, Roy S, Lu H, Fahrizio E F, Dass A, Capadona L A, Leventis N (2006) Chemical, physical and mechanical characterization of isocyanate-crosslinked amine-modified silica aerogels. Chem Mater 18 285-296... 

Katti, A., N. Shimpi, S. Roy, H. Lu, E.F. Fabrizio, A. Dass, L.A. Capadona, and N. Leventis. 2006. Chemical, physical, and mechanical characterization of isocyanate cross-Linked amine-modified silica aerogels. Chemistry of Materials 18(2) 285-296. 

As explained previously by Lu et al. [215], there are standard testing methods and equipment that can be employed for reinforced aerogel materiak such as polymer cross-linked ones (X-aerogek), although their standard mechanical characterization does not exist. Flexural tests are carried out in three-point bending mode, normally leading to failure imder tensile bending stresses in... 

Luo H, Churu G, Fabrizio EF, Scbnobrich J, Hobbs A, Dass A, Mulik S, Zhang Y, Grady BP, Capecelatro A, et al (2008) Synthesis and characterization of the physical, chemical and mechanical properties of isocyanate-crosslinked vanadia aerogels. J Sol-Gel Sci Technol 48 113-134... 

In an altogether different approach to improve the mechanics and introduce superhydrophobic properties, in this chapter, we are presenting work on the synthesis of flexible and superhydrophobic silica aerogels derived from methyltrimethoxysilane (MTMS) and methyltriethoxysilane (MTES) precursors and their usability as efficient sorbents for oil and hydrocarbons [18, 19]. The main objective of this chapter is to provide an overview of synthesis, characterization, and most promising areas of applications. 

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