indeed, the observed –OH peak occurred despite extensive drying of silicified fibers for 24 h at 25 °C in vacuum. Peaks corresponding to various groups in silk fibroin were also presented in the region of 1,200–2,000 cm−1, indicating very little or no change in pure silk and silk/TMOS nanofibers. - See more at: http://www.mdpi.com/2077-0375/1/4/275/htm#sthash.lXCwdE4b.dpuf