pH-Induced antireflection coatings derived from hydrogen-bonding-directed multilayer films.
Hydrogen-bonding-directed layer-by-layer assembled films, based on polystyrene-block-poly(acrylic acid) (PS-b-PAA) block copolymer micelles and poly(4-vinylpyridine) (P4VP), were successfully fabricated in methanol. Varying the PAA content in the PS-b-PAA micelles afforded control over the film growth properties, especially the multilayer film thickness. Interestingly, antireflection films with refractive indices that could be tuned between 1.58 and 1.28 were obtained by treatment with an aqueous HCl solution (pH 2.27), and the transmittance obtained was as high as 98.4%. In acid solution, the pyridine group was protonated, destroying the hydrogen bonding between P4VP and PAA. A concomitant pH-induced polymer reorganization in the multilayers resulted in a porous honeycomb-like texture on the substrate.
Lu
Yingxi
Y
Department of Chemical Engineering, Polymer Research Institute, Pohang University of Science and Technology, Pohang 790-784, Korea.
Choi
Yeon Joo
YJ
Lim
Ho Sun
HS
Kwak
Donghoon
D
Shim
Chiyeoung
C
Lee
Seung Goo
SG
Cho
Kilwon
K