Application Of Chromatography Technology In OLED Materials Production Process

Organic light-emitting diode(OLED)has been a research hotspot in the flat panel display field in recent years.Organic electroluminescent materials are the key components in OLED,and the material purity has a great influence on the luminous efficiency and lifetime of the devices.Therefore,the material purity is one of the most important factors to consider.The purity of OLED materials is typically chracterized by high performance liquid chromatography(HPLC).Due to the polar functional group in common arylboronic acid and aromatic amine OLED intermediate materials,they interact with the stationary phase during HPLC analysis and retain,which makes them difficult to be accuratedly examined.This thesis optimizes the chracterazation methods for several common aromatic amines and arylboronic acid materials,and provides an avialable solution for the characterization of the intermediates OLED materials,which are important for the optimization of the OLED materials and devices.First,the chromatographic chracterization methods of commonly used arylboronic acid based OLED materials are studied.Due to the boric acid groups in common arylboronic acid OLED intermediate materials,they interact with the stationary phase during HPLC analysis and retain,which seriously affects the chromatographic chracterization results.In this thesis,the commonly used materials such as 4-(1-naphthyl)phenylboronic acid and 4-boronic acid trianiline have been optimized for detection wavelength,detector,solvent,column and mobile phase.And compare thechracterization results of 4-(1-naphthyl)phenylboronic acid by three mobile phase additives such as acetic acid,trifluoroacetic acid,and ionic liquid.Finally,thechracterization method of 1-ethyl-3 methyl-imidazolium tetrafluoroborate as mobile phase additive isestablished.Under this condition,the chromatogram of 4-(1-naphthyl)phenylboronic acid is sharp and symmetric,the tailing factor is 1.135,the detection limit is 1.69×10-9 g/mL.The test result is nearly one percentage point accurate compared to unoptimized method.Further synthesiz the blue light material 9-(2-naphthyl)-10-[4-(1-naphthyl)phenyl]anthracene using two batches of 4-(1-naphthyl)phenylboronic acid material with 1.0%difference in purity,and testthe quantum yield of the blue light material.The results show that there are significant differences between the two batches of products.Therefore,it is of great significance to optimize the detection methods of commonly used arylboronic acid OLED intermediate materials for quality control of the OLED devices.Second,the chromatographic chracterization methods of commonly used aromatic amine OLED materials are studied.The aromatic amine OLED materials contain-NH2/-NH groups,not only react with residual silicon hydroxy groups on the column,but also will interact with common mobile phases such as methanol and acetonitrile,which makes them difficult to be accuratedly examined.However,the existing chracterization method only uses the results of the UV detector to evaluate the chracterization method,and the presence of the sample in the mobile phase cannot be discriminated.In this thesis,the morphologies of OLED materials such as 9,9-dimethyl-2-aminoanthraquinone in the mobile phase are identified by LC/MS.And the common chracterization methods for aromatic amines are compared.Finally,establish a chromatographic chracterization method using a methanol aqueous system containing ammonia as the mobile phase.This study has important significance for the accurate determination of purity and impurity content of aromatic amine OLED materials.Related patent has been accepted.