[Study of the deactivation of the organic-inorganic hybrid sol-gel coatings on stainless steel tubes].
The organic-inorganic hybrid sol-gel coatings used as deactivating substance for stainless steel tubes in gas chromatography have been prepared by dynamic processing of the sol-gel solution produced by hydrolysis and polycondensation of methyltriethoxysilane and tetraethoxysilane under acidic conditions. The chromatographic behavior of the coatings was studied by GC at different aging temperatures. The experimental results indicate that the active sites on the inner surface of the stainless steel tubes have been shielded effectively by the coatings and the coatings also have the ability to separate hydrocarbons. If the coatings were aged only at 250 degrees C, the hydrocarbons with the number of carbon under 12 can be separated with perfect baseline. Compared with the results obtained from the untreated stainless steel tubes the adsorbent activation of the treated stainless steel tubes has decreased greatly. It is also found that when the aging temperature was increased, the action between the coatings and the samples was enhanced, mainly produced by the porous structure of the coatings. This phenomenon is also discussed using the tailing factors.
Han
Jiang-Hua
JH
Research Institute of Petroleum Processing, China Petroleum & Chemical Corporation, Beijing 100083, China.
Yang
Hai-Ying
HY