Polystyrene Tweaked To Emit Light
12 June 2008, 10:44
Categories: polymers smt-luminescent-light-emit
(a) Fluorescent image of blue (left) and white (right) light-emitting PS particles dispersed in water. The particles have the diameter of 1.5 μm. The samples were excited with a mercury-xenon lamp with the wavelength range of 355 – 375 nm.
(b) Fluorescent microscope image of blue and white luminescent PS particles on a Si substrate.
(c) Assembly of luminescent nanowires. The lateral width of the nanowires is 200nm and the length of the nanowires is 12 µm.
(d) Array of luminescent nanowires aligned on a silicon substrate. The nanowires have a lateral width of 200nm and a length of 5 µm.
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Researchers at the Korea Advanced Institute of Science and Technology (KAIST) have discovered that non-luminescent polystyrene can be converted into a luminescent organic material whose emitting color can be tuned from deep blue to white by electron irradiation. The researchers found that the organic polymers emitted visible light when excited by ultraviolet light, and that polystyrene exhibited significant light emission when irradiated. The self-assembled polystyrene nanostructures allow the fabrication of diverse and complex luminescent nanoarchitectures, whereby a surface can be functionalized to respond to chemical, biological, electronic, and optical stimuli. Additionally, by irradiating select areas with an electron beam, luminescent nanopatterns can be easily be achieved.
“We have presented a strategy to obtain luminescent nanoarchitectures based on a simple one-step electron irradiation process,” said Dr. Sung Oh Cho. “Electron irradiation produces light-emitting materials from non-luminescent polymers while simultaneously patterning the polymer to form nanostructures. Our top-down irradiation strategy, through combination with bottom-up approaches for precursor preparation or through direct electron-beam writing, provides a powerful tool to fabricate desired complex luminescent nanoarchitectures and nanopatterns.”
Posted by: The Editors
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