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Polyvinylcarbazole was discovered by the chemists Walter Reppe (1892-1969), Ernst Keyssner and Eugen Dorrer and patented by I.G. Farben in the USA in 1937. [4] [1] PVK was the first polymer whose photoconductivity was known.
Upon exposure to γ-irradiation, N-vinylcarbazole undergoes solid-state polymerisation. [ 5 ] It is produced by the vinylation of carbazole with acetylene in the presence of base.
Further blurring the lines, a substance may emit light by one, two, or all three mechanisms depending on the material and excitation conditions. [ further explanation needed ] [ 11 ] When the stored energy becomes locked in by the spin of the atomic electrons , a triplet state can occur, slowing the emission of light, sometimes by several ...
Time-resolved photoluminescence (TRPL) is a method where the sample is excited with a light pulse and then the decay in photoluminescence with respect to time is measured. This technique is useful for measuring the minority carrier lifetime of III-V semiconductors like gallium arsenide ( GaAs ).
Living cationic polymerization is a living polymerization technique involving cationic propagating species. [1] [2] It enables the synthesis of very well defined polymers (low molar mass distribution) and of polymers with unusual architecture such as star polymers and block copolymers and living cationic polymerization is therefore as such of commercial and academic interest.
This is the photoluminescence of two very similarly structured polyfluorene derivatives. The one on the left (purple) is a copolymerization of a fluorene derivative, benzene and oxadiazole molecules and the one on the right (light green) has the structure directly below this image.
PVDF may be synthesized from the gaseous vinylidene fluoride (VDF) monomer by a free-radical (or controlled-radical) polymerization process. This may be followed by processes such as melt casting, or processing from a solution (e.g. solution casting, spin coating, and film casting). Langmuir–Blodgett films have also been made.
Poly(p-phenylene vinylene) (PPV, or polyphenylene vinylene) is a conducting polymer of the rigid-rod polymer family. PPV is the only polymer of this type that can be processed into a highly ordered crystalline thin film. PPV and its derivatives are electrically conducting upon doping.