Synthesis And Fluorescence Properties Of Side-chain Modified Organosilicon Polymers By Hydrosilylation Method

To realize full-color organic light-emitting diode(OLED)displays,three primary colors of red,green and blue light-emitting materials which have high performance are required.Blue light-emitting materials are still a significant bottleneck for OLED,owing to its face common problems in luminescence efficiency,stability and film-forming ability,etc.Therefore,it is of great significance to prepare blue light-emitting materials with high performance.In this thesis,anthryl side-chain modified organosilicon polymers were synthesized by hydrosilylation method.Their fluorescence properties and thermal stability were studied in detail.The orbital energy level distribution of polycarbosilane(PCS)with the side-chain modified by aryl group was carried out by theoretical calculation.The main subjects and results are summarized as follows:Firstly,aluminum-containing polycarbosilane(PACS)was prepared by the reaction of PCS and aluminum acetylacetonate(Al(acac)3)at 310 ℃.Then,anthryl side-chain modified PCS and PACS(VAn/PCS and VAn/PACS)were prepared by hydrosilylation reaction,using PCS or PACS with 9-vinyl anthracene as the raw materials respectively.FTIR and 1H NMR indicates that the samples exist anthryl,and the formation of Si-CH2-CH2-anthryl structural units which expand the conjugated system.Secondly,fluorescence properties of the anthryl side-chain modified PCS and PACS were characterized by photoluminescence(PL)spectroscopy,fluorescence quantum yield and thermogravimetric(TG)analysis.Results reveal that the samples possess strong fluorescence emission performance and excellent thermal stability,owing to the expansion of the conjugated system and greate relative molecular mass.Their fluorescence emission intensity are enhanced and the maximum fluorescence emission wavelength positions(λmax=433 nm)are redshift.Furthermore,VAn/PCS samples have high fluorescence quantum yield(Φ about 95.0%).In addition,the samples processed by ultraviolet(UV)radiation and oxidation curing were measured by PL spectroscopy.They still have good fluorescence emission performance with a few reduction in fluorescence emission intensity.These results reveal that the anthryl side-chain modified PCS and PACS have excellent UV resistance and good oxidation resistance performance.Finally,effect of the introduction of side-chain aryl groups on PCS band gap was also studied.The theoretical calculation results reveal that the introduction of side-chain aryl groups show a decrease of the band gap as compared to PCS,and the decrease degree increased with the rise of the number of benzene rings.These conclusions are also in consistent with the experimental redshifted trend of VAn/PCS(λmax=433 nm)to PCS(λmax=394 nm).