New Two-photon Polymerization Initiator Synthesis, Characterization And Properties

Based on searching and reading a great deal of literatures related two-photon absorption (TPA) materials, we have known the latest development situation in this field. The application of two-photon polymerization (TPP) in 3D microfabrication strongly attracted our eyes. We designed and synthesized eight novel TPP initiators at first time, which included carbazole and phenothiazine group with good photoelectric function. They have successfully initiated TPP reaction and realized 3D microfabrication.The main achievements in this thesis are summarized as follows:1. By designing we synthesized eight novel initiators and their structures were characterized clearly. Vilsmeier signal-formylation and bi-formylation reactions were studied in detail. Signal-aldehydes and bi-aldehydes were obtained at yield above 85%. Solid-phase Wittig reaction under room temperature was used at first time to efficiently synthesize our target compounds and the yields of four initiators are above 80%.2. Electric spectra, fluorescence spectra and their solvent effect (Lippert Equation) were studied. The eight initiators have relatively high fluorescence quantum yield (all above 50%). The relationships between fluorescence spectra in solid-phase, fluorescence lifetimes and structures also were discussed.3. Two-photon fluorescence (TPF) spectra of eight compounds in three solvents were collected under femtosecond laser pulses. Five compounds can emit blue-violet light. The TPF signals exhibit a squared dependence on the exciting laser power. The TPA coefficiency P and TPA cross-section o for our compounds at 532 nm laser pulses were determined by Z-scan technique. Meanwhile, TPA cross-section a was evaluated based on the two-state model.4. Four representative compounds successfully initiated TPP and good 3D microstructures (2 um) were obtained, which are fully content requirement of artificial crystal. Electrochemical studies prove our compounds possess relatively high electric density.