Fluoroalkyl end-capped N-(1,1-dimethyl-3-oxobutyl)acrylamide oligomer [R F -(DOBAA) n -R F ] in silica nanocomposite can exhibit a nonflammability, even after calcination at 800 1C, through the formation of ammonium hexafluorosilicate during nanocomposite reactions. In contrast, the lack of formation of ammonium hexafluorosilicate during the usual composite reactions affords a flammable behavior for the R F -(DOBAA) n -R F oligomer in silica nanocomposite. Ammonium hexafluorosilicate is formed as a result of the dehydrofluorination of amido protons [-C(¼O)NH-] in R F -(DOBAA) n -R F oligomer, with fluorine atoms in the oligomers catalyzed by both ammonia and silica nanoparticles in the composite reactions. In contrast, the lack of dehydrofluorination in the nanocomposite reaction under acidic conditions affords the usual flammable behavior for the oligomer.

We succeeded in observing the similar solid‐state NMR spectra (1H‐magic‐angle spinning NMR spectra) of fluoroalkyl end‐capped N‐(1,1‐dimethyl‐3‐oxobutyl)acrylamide oligomer [RF‐(DOBAA)n‐RF]/silica gel nanocomposite before and even after calcinations at 800°C. This finding suggests that RF‐(DOBAA)n‐RF oligomer in RF‐(DOBAA)n‐RF/silica gel nanocomposite can afford a nonflammable characteristic to exhibit no weight loss behavior even at 800°C under atmospheric conditions. In addition, we had good oleo‐ and hydrophobic characteristics on the modified glass surface treated with RF‐(DOBAA)n‐RF/silica gel nanocomposite even after calcination at 800°C as well as those before calcinations. Especially, RF‐(DOBAA)n‐RF/silica gel nanocomposite‐encapsulated cetylpyridinium chloride (CPC) possessing no weight loss characteristic even at 800°C exhibited a clear UV–vis absorption band around 260 nm related to the presence of CPC before and even after calcinations at 800°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

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A variety of fluoroalkyl end-capped oligomers/silver nanocomposites were prepared by the reactions of silver ions with poly(methylhydrosiloxane) in the presence of fluoroalkyl end-capped N,N-dimethylacrylamide oligomer, N-(1,1-dimethyl-3-oxobutyl)acrylamide oligomer, N,N-dimethylacrylamide cooligomer containing poly(dimethylsiloxane) segments in organic media such as toluene and 1,2dichloroethane. These fluorinated oligomers/silver nanocomposites thus obtained were found to exhibit clear plasmon absorption bands around 420 nm related to the formation of silver nanoparticles. In particular, these composites could display narrow plasmon absorptions around 420 nm in toluene by the addition of trioctylamine (TOA). On the other hand, the corresponding non-fluorinated N-(1,1dimethyl-3-oxobutyl)acrylamide oligomer was not able to afford such a plasmon absorption under similar conditions. These fluorinated oligomers/silver nanocomposites in organic media have been found to be stable for more than 10 days. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) measurements showed that silver nanoparticles could be effectively encapsulated into fluorinated oligomeric aggregate cores to afford colloidal stable fluorinated oligomers/silver nanocomposites. Fluorinated oligomers/silver nanocomposites were also applied to the surface modification of traditional organic polymers such as polystyrene (PSt) and poly(methyl methacrylate) (PMMA) to exhibit not only a good oleophobicity imparted by fluorine but also a higher surface antibacterial activity related to the silver nanoparticles on their surface.