Modified amorphous oxide surfaces chemically

In another study, the so-called sohd-liquid-solid (SLS) technique was used to prepare a silicon oxide nanofiber surface [64]. The amorphous sihcon oxide nanofibers shown in Fig. 10b were made by heating a silicon substrate coated with a thin gold layer at 1100°C for 3 h in a lutrogen atmosphere in contrast to the previous example, no additional source of silicon materials was used in this case. As before, the nanofiber growth starts at the interface of the Au/Si alloy droplet and the Si substrate and is maintained by the diffusion of the Si atoms from the substrate to the interface [65]. The surface was then UV/ozone-treated to generate surface hydroxyl groups that were subsequently reacted with perfluorodecyltrichlorosilane. The chemically modified nanofiber surface exhibited a WCA of 152°. 

Chemical vapor deposition (CVD) of some organic compounds was examined to control the porosity and surface function of active carbon fiber (ACF). In this system, the deposition takes place only on the pore wall of the ACF, when the precursor organic compound and deposition temperature around 700 C were selected carefully. The surface of the ACF was modified by carbon derived from heterocyclic compounds (pyridine, pyrrole, furan and thiophene) through CVD. The moderately activated ACF modified by pyridine, pyrrole and thiophene showed molecular sieving activity, that modified by furan did not. Only fiiran was decomposed at this temperature. Thermal stability is a key factor to get molecular sieving performance after CVD. Pyridine produced amorphous carbon within the pore, which appears to maintain the pyridine ring structure, creates basic sites over the surface of the ACF. Thus catalytic oxidation of SOx over ACF of high surface area was accelerated. 

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