An
antifouling polymer brush-like structure was fabricated by a
simple and versatile dip-coating method of sulfobetaine containing
copolymer-grafted silica nanoparticles (SiNPs) and alkyl diiodide
cross-linkers. Surface-initiated atom transfer radical copolymerization
of 3-(N-2-methacryloyloxyethyl-N,N-dimethyl)ammonatopropanesulfonate (MAPS) and N,N-dimethylaminoethyl methacrylate (DMAEMA) was carried out from initiator-immobilized
SiNPs to give poly(MAPS-co-DMAEMA)-grafted SiNPs
(MAPS/DMAEMA = 9/1, mol/mol) with diameters of 150–170 nm.
The SiNP-g-copolymer/2,2,2-trifluoroethanol solution
was dip-coated on silicon and glass substrates. Successive treatment
with 1,4-diiodobutane in methanol gave a hydrophilic cross-linked
coating film for the SiNP-g-copolymer. The cross-linked
particle brushes did not peel off from the substrate even after washing
with water in an ultrasonic cleaner despite the simple physical absorption
of the SiNP-g-copolymer on the substrate surface.
The adhesion force of the tentacle of a living barnacle cyprid on
a glass surface covered with the cross-linked SiNP-g-copolymer was directly measured by scanning probe microscopy in
seawater. The coating film exhibited extremely low adhesion to the
cypris larva in the seawater, expecting this to be an effective antifouling
property.