An optical waveguide study on the nanopore formation in block copolymer/homopolymer thin films by selective solvent swelling.
Thin films of mixtures of asymmetric poly(styrene-block-methyl methacrylate) (PS-b-PMMA) diblock copolymers and PMMA homopolymers with cylindrical PMMA microdomains oriented normal to the substrate surface were used to couple optical modes in the Kretschmann configuration, and their optical properties were investigated by optical waveguide spectroscopy (OWS). The nanopore formation in the block copolymer (BCP) waveguide layer via selective solvent swelling and subsequent reannealing was monitored in terms of shifts in the coupling mode angles. The sequential swelling/reannealing of the initial mixture film resulted in a number of discrete or partially interconnected pores instead of cylindrical pores with a high aspect ratio. The simultaneous processes occurring inside and on top of the BCP waveguide layer were discerned independently with high selectivity for p- and s-polarization.
Kim
Dong Ha
DH
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany. dhkim@ewha.ac.kr
Lau
King Hang Aaron
KH
Joo
Wonchul
W
Peng
Juan
J
Jeong
Unyong
U
Hawker
Craig J
CJ
Kim
Jin Kon
JK
Russell
Thomas P
TP
Knoll
Wolfgang
W
D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry*; D055095:Optics and Photonics; D010316:Particle Size; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D016062:Porosity; D012680:Sensitivity and Specificity; D012997:Solvents / Q000737:chemistry; D013057:Spectrum Analysis / Q000379:methods
D008567:Membranes, Artificial; D011137:Polystyrenes; D012997:Solvents; C522519:poly(styrene-block-methyl methacrylate); D019904:Polymethyl Methacrylate