ISO 23157 discusses the determination of the silanol group content on the surface of fumed silica by reaction gas chromatographic method. Fumed silica (pyrogenic silicon dioxide) has a relatively high concentration of silanol groups formed during high-temperature flame hydrolysis and the following cooling process.
This specified property enables fumed silica to be widely used as a reinforcing filler, thickener, thixotropy-increasing, and anti-sagging additive in numerous industries, for example, silicone rubber, coating materials, adhesives, and sealants. ISO 23157 specifies a method for the determination of the silanol group content on the surface of fumed silica by the reaction gas chromatographic method.
ISO 23157 on the determination of the silanol group content on the surface of fumed silica is useful for:
The determination of the silanol group content on the surface of fumed silica is essential for both manufacturers and users to develop a high-performance, surface-modified fumed silica and improve existing products. Further, it also facilitates communication among interested parties.
In practice, methods of titration, thermogravimetry (TG), infrared spectroscopy (IR) and reaction gas chromatography can be a choice for the determination of the silanol group content on the surface of fumed silica. Among these methods, the method of reaction gas chromatography is preferred by users due to the advantage of higher sensitivity and better reproducibility.
ISO 23157 provides you with a detailed procedure for how to conduct the testing of the silanol group content on the surface of fumed silica by means of the reaction gas chromatographic method. Compared with the traditional chemical method, the method in ISO 23157 has distinct advantages in terms of lower reagent consumption, high sensitivity, good stability, and reliability.
ISO 23157