We report on the growth and characterization of onedimensional\ud
(1D) planar all-polymer photonic crystals (PhC) with\ud
high dielectric contrast (Dn50.3) prepared by spin coating using\ud
hyperbranched polyvinylsulfide polymers (HB-PVS) as high\ud
refractive index material and cellulose acetate as low refractive\ud
index material. Solution processable HB-PVS show a near ultraviolet\ud
absorption inducing an increased refractive index in the\ud
visible-near infrared (n51.68, k51000 nm). HBPVS:Cellulose\ud
Acetate Distributed Bragg Reflectors show a very clear fingerprint\ud
of the photonic band gap possessing the expected polarized\ud
dispersion properties as a function of the incidence angle.\ud
Moreover, engineered microcavities tuned on the weak fluorescence\ud
spectrum of the HB-PVS show directional fluorescence\ud
enhancement effects due to spectral redistribution of the emission\ud
oscillator strength. The combination of all these properties\ud
testifies the high optical quality of the obtained photonic structures\ud
thus indicating HB-PVS as an interesting material for the\ud
preparation of such PhC. V
We
report on the highly sensitive optical and colorimetric detection
of perfluorinated compounds in the vapor phase achieved by all-polymer
dielectric mirrors. High optical quality and uniformly distributed
Bragg reflectors were fabricated by alternating thin films of poly(
N
-vinylcarbazole) and Hyflon AD polymers as high and low
refractive index medium, respectively. A new processing procedure
has been developed to compatibilize the deposition of poly(
N
-vinylcarbazole) with the highly solvophobic Hyflon AD
polymer layers to achieve mutual processability between the two polymers
and fabricate the devices. As a proof of principle, sensing measurements
were performed using the Galden HT55 polymer as a prototype of the
perfluorinated compound. The Bragg stacks show a strong chromatic
response upon exposure to this compound, clearly detectable as both
spectral and intensity variations. Conversely, Bragg mirrors fabricated
without fluorinated polymers do not show any detectable response,
demonstrating that the Hyflon AD polymer acts as the active and selective
medium for sensing perfluorinated species. These results demonstrate
that organic dielectric mirrors containing perfluorinated polymers
can represent an innovative colorimetric monitoring system for fluorinated
compounds, suitable to improve both environmental safety and quality
of life.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.