Multifunctional Sol-Gel Nanocomposite Coatings for Aerospace, Energy, and Strategic Applications: Challenges and Perspectives

Sol-gel technique is a wet chemical synthesis procedure involving the hydrolysis of either a fully hydrolyzable metal/silicon alkoxide or an organically modified silane followed by condensation and polymerization reactions. Through this method, ceramics, glasses, and hybrid nanocomposite materials of high purity and homogeneity can be produced than when obtained through conventional processes that involve high-temperature treatment conditions. Sol-gel-derived hybrid nanocomposite coatings combine the interesting properties such as flexibility, hardness, etc. drawn from an organic polymer and an inorganic glass and hence are of great interest for aerospace, energy, and defense applications, due to their distinct advantages. Varied functionalities like corrosion protection, antireflection, scratch resistance, antibacterial, water/oil repellant, erosion resistant, and antistatic are possible to be obtained using this technique. Sol-gel nanocomposite films on appropriate substrates are also capable of being used as sensors for detecting chemical/biological warfare agents as well as for sensing ionizing radiation in the environment. Despite many advantages of this technique, there are still certain challenges that need to be circumvented in order to fully harness the potential of the coatings derived from this process. This chapter mainly focuses on the potential applications of sol-gel nanocomposite coatings for aerospace, energy, and strategic sectors, where challenges in using them for applications and future perspectives on how they can be mitigated are discussed.