2-STEP CHEMICAL-VAPOR SURFACE MODIFICATION OF POROUS-GLASS WITH FLUOROALKYL-FUNCTIONAL SILANES

Surface porous glass substrates were exposed to heptadecafluorodecyl-trichlorosilane (HFTS) vapor followed by the treatment with trifluoropropyl-trichlorosilane (TFTS). The resistance of the monolayer to liquid H2O was found to be better than those of the samples treated with the respective reagents, i.e., HFTS or TFTS. The coverage with the molecules in the pores were estimated from the analyses of the reflection spectra having a minimum in the visible range. These results reasonably explain the superior resistance to H2O of the sample treated with HFTS (Ist step) and TFTS (2nd step).