Applications on Coatings and Other Advanced Materials

Several available FTIR techniques such as attenuated total reflection [5-7] have been utilized for coatings hardened on a metal surface, diffuse reflectance [8] for ultra-thin films, and transmittance [9, 10] for clear or transparent coatings. The FTIR is useful for determining parameters such as residual porosity and molecular bonding. If used in concert with a microscope, excellent spatial resolution can be obtained. Hasik et al. [11] studied a polysiloxane-silsesquioxane system with FTIR spectroscopy while developing SiCO ceramic. The authors noticed the transformation in vibration bands, in their material, as a function of chemical compositions and temperature. A quartz crystal microbalance and reflection-absorption infrared spectroscopy (RAIR) was used to study silane reaction over oxidized aluminum surface [12]. 

Rapid kinetics or in-situ observation of the curing reaction mechanism using time-resolved FTIR spectroscopy [13] can provide valuable information about the volume collapse or hardening route in the complex ceramer network. The residual porosity V in the coating structure can be determined by FTIR analysis using the following equation [14]  

x and a (1.0 x 10 cm for dense silica film) are the film thickness and the absorption coefficient of the dense film, respectively, while x and a are the film thickness and the absorption coefficient of a porous film A is absorbance. 

Silane Compounds FTIR peak assignments (cm ) Raman peak assignments (cm ) 

stretch asymmetric stretch v. symmetric stretch v, out-of-plane stretch v, in-plane stretch 6 asymmetric bending 6 symmetric bending 6. deformation (bend, twist or rock) co. wagging p/r, rocking r, in-plane-rocl r, out-of-plane rock T, torsion t. twist p. in-plane-bend y. out-of plane bend, ip, in-plane  

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