Novel self-assembled molecular aggregates formed by fluoroalkyl end-capped oligomers and their application

Preparation of Fluoroalkyl End-Capped Vinyltrimethoxysilane Oligomeric Silica Nanocomposites Containing Gluconamide Units Possessing Highly Oleophobic/Superhydrophobic, Highly Oleophobic/Superhydrophilic, and Superoleophilic/Superhydrophobic Characteristics on the Modified Surfaces

“…N-(3-triethoxysilylpropyl)gluconamide [Glu-Si(OEt) 3 ] was purchased from AZmax. Co. (Chiba, Tokyo).…”

“…A typical procedure for the preparation of nanocomposites is as follows: To methanol solution (5.0 mL) containing fluoroalkylated vinyltrimethoxysilane oligomer [200 mg; R F -(CH 2 CHSi(OMe) 3 ) n -R F ; R F = CF(CF 3 )OC 3 F 7 ; M n = 730 (R F -(VM) n -R F )] was added 50 wt % Glu-Si(OEt) 3 ethanol solution (1400 mg). The mixture was stirred with a magnetic stirring bar at room temperature for 30 min.…”

“…To methanol solution (5.0 mL) containing R F -(VM) n -R F oligomer (200 mg) was added 50 wt % Glu-Si(OEt) 3 ethanol solution (700 mg) and 25% aqueous ammonia solution (1.0 mL). The mixture was stirred with a magnetic stirring bar at room temperature for 5 h. The glass plates (18 × 18 mm 2 pieces) were dipped into this methanol solution at room temperature and left for 1 min.…”

“…However, such studies have been very limited so far. In our fluoroalkyl end-capped oligomers, especially, two fluoroalkyl end-capped vinyltrimethoxysilane oligomer [R F -(CH 2 -CHSi(OMe) 3 ) n -R F ] can undergo the sol-gel reaction under alkaline conditions to afford the corresponding fluorinated oligomeric silica nanoparticles [R F -(CH 2 -CHSiO 3/2 ) n -R F ] [22]. These fluorinated oligomeric silica nanoparticles have been also applied to the surface modification of glass to supply the superhydrophobic characteristic (water contact angle value: 180 degrees) with the oleophobic property [22].…”

“…From these findings, it is highly suggested that the composite reactions of our present fluorinated vinyltrimethoxysilane oligomer with the gluconamide derivatives should lead the obtained composites to the creation of the unique surface characteristics imparted by not only longer fluoroalkyl groups, but also the gluconamide units. Here we report that two fluoroalkyl end-capped vinyltrimethoxysilane oligomers [R F -(CH 2 -CHSi(OMe) 3 ) n -R F ] can undergo the sol-gel reaction in the presence of N-(3-triethoxysilylpropyl)gluconamide [Glu-Si(OEt) 3 ] under alkaline conditions to afford the corresponding fluorinated oligomeric silica nanocomposites containing gluconamide units [R F -(VM-SiO 3/2 ) n -R F /Glu-SiO 3/2 ]. The modified surfaces treated with these obtained nanocomposites can provide the unique wettability states such as the highly oleophobic/superhydrophobic, highly oleophobic/superhydrophilic, and superoleophilic/superhydrophobic characteristics.…”