According to the experimental procedure an exact volume

Using this band intensity, a simple method for the estimation of FRAX597 powders and surface areas of films has been devised [33], under the assumption of a constant isolated OH group density. Not all of the isolated OH groups were substituted in the course of our experiment, as indicated by the presence of very low intensity bands at 3746 cm−1 (Fig. 3). The intensity of the band for w/w APTMS larger than 19.88% seemed to be steady, meaning that the integrated intensity of this band could also be used for the purpose.