Infrared evidence for two isolated silanol species on activated silicas

摘要: Infrared spectroscopy has been used to study the OH stretching vibration of isolated silanol groups on an aerosil and a precipitated silica which have activated under vacuum at 450, 600 or 800°C. When 450°C samples are cooled −191°C, normally asymmetric peak splits into two components having maximum near 3750 3746 cm −1 for silica, respectively, shoulder 3738