Equilibrium and nonequilibrium nanoscale ordering of polystyrene- b -poly( n,n ′-diethylaminoethyl methacrylate), a block copolymer carrying tertiary amine functional groups

Poly(styrene)-b-poly(N,N′-diethylaminoethyl methacrylate) (PS-b-PDEAEM) block copolymer was synthesized by RAFT free-radical polymerization using a trithiocarbonate type of chain transfer agent (CTA). Several block copolymer compositions were achieved maintaining low polydispersities by using PS as macro-CTA in the first step. Thin films of PS60%-b-PDEAEM40% were deposited over mica substrate, and its equilibrium and nonequilibrium nanostructures were studied. Lamellar (equilibrium), bicontinuous (nonequilibrium) and detached nanoflakes (nonequilibrium), were obtained by using different annealing methods. Mixing nanocomposites of gold nanoparticles/PDEAEM in the block copolymer resulted in the formation of toroidal nanostructures confining gold nanoparticles to the core of those nanostructures. The same toroidal nanostructure was achieved by different annealing methods, including irradiation with UV light for 15 min. Electron micrographs show clearly this different type of arrays.