Defect-free nanoporous thin films from ABC triblock copolymers.
The self-assembly of triblock copolymers of poly(ethylene oxide-b-methyl methacrylate-b-styrene) (PEO-b-PMMA-b-PS), where PS is the major component and PMMA and PEO are minor components, provides a robust route to highly ordered, nanoporous arrays with cylindrical pores of 10-15 nm that show promise in block copolymer lithography. These ABC triblock copolymers were synthesized by controlled living radical polymerization, and after solvent annealing, thin films showing defect-free cylindrical microdomains were obtained. The key to the successful generation of highly regular, porous thin films is the use of PMMA as a photodegradable mid-block which leads to nanoporous structures with an unprecedented degree of lateral order. The power of using a triblock copolymer when compared to a traditional diblock copolymer is evidenced by the ability to exploit and combine the advantages of two separate diblock copolymer systems, the high degree of lateral ordering inherent in PS-b-PEO diblocks plus the facile degradability of PS-b-PMMA diblock copolymer systems, while negating the corresponding disadvantages, poor degradability in PS-b-PEO systems and no long-range order for PS-b-PMMA diblocks.
Bang
Joona
J
Department of Chemical and Biological Engineering, Korea University, Seoul 136-713, Republic of Korea.
Kim
Seung Hyun
SH
Drockenmuller
Eric
E
Misner
Matthew J
MJ
Russell
Thomas P
TP
Hawker
Craig J
CJ
D001672:Biocompatible Materials / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008956:Models, Chemical; D036103:Nanotechnology; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis*; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D016062:Porosity; D013499:Surface Properties
D001672:Biocompatible Materials; D011108:Polymers; D011137:Polystyrenes; D011092:Polyethylene Glycols; D019904:Polymethyl Methacrylate