Journal of Emerging Trends in Engineering and Applied Sciences: Research Areas

Article Title: Thermal Analysis of the Modified and Unmodified Silica Gels to Estimate their Applicability as Stationary Phase in Gas Chromatography
by Ashraf Yehia El-Naggar

Abstract:
The prepared and surface modified silica gels were subjected to thermal analysis via thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The modification methods are calcinations at 5oo oC and 1000 oC, hydrothermal treatment, silylation, coating with polymer and bonded with polymer, these modicications are used to improve silica surfaces for using as good solid stationary phase or good solid support in gas chromatography. Temperature is an important factor affecting the life and efficiency of stationary phase and therefore affecting the efficiency of gas chromatographic separation. All the modified silica samples are more thermally stable compared with parent silica. SiC and double treated silica (SiCHT and SiCS) showed the high stabilities and lowest weight loss among the all modified solids. With respect to coating with polymer, SiBo25% is more stable than SiCo25% which has the same polymer content and it is evident that SiCCo10% is the most stable silica sample compared with the other coated and bonded silica samples. Our goal of this work is study the changes that occurs for silica gel surfaces in order to assess the maximum recommended temperature for using these materials as stationary phases in gas chromatography.

Keywords: silica gels, thermogravimetric analysis, differential thermal analysis, stationary phases, gas chromatographic analysis.

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