Fluorescent Property Of Sulfonated Acetone-Formaldehyde Condensate And Its Application As Dopant Of Poly(3,4-ethylenedioxythiophene)

Sulfonated acetone-formaldehyde(SAF),one of the high-effective aliphatic water-reducing agents,has been widely studied and applied in the construction industry owing to its excellent dispersing capacity,simple preparation and inexpensive reactants.However,the theoretical and applied study of SAF was just limited on industrial dispersant fields during the last 30 years since it was firstly developed.In order to broaden the researches of SAF,this thesis firstly discovers and systematically studies its unconventional fluorescence,and uses it as the dopant of conductive poly(3,4-ethylenedioxythiophene)(PEDOT)for the application on high-performance organic light-emitting diode(OLED).The yellow-green fluorescence of SAF aqueous solution is firstly discovered in this study,and we introduce cluster-induced emission of carbonyl groups mechanism to expound the origin of the fluorescence considering its linear unconjugated aliphatic structure.According to this mechanism,arylation modification is made on SAF structure for enhancing their molecular aggregation effects.Successfully,NSPAF and t-SPAF with enhanced fluorescence and different emission colors are prepared.It is proved that SAF and SPAFs possess obvious aggregation-enhanced emission(AEE)through the experiment of adding poor solvent for molecular aggregation.The fluorescent materials with AIE effect are widely studied and applied in the fields of fluorescent probes,cell imaging and organic optoelectronic devices due to their unique fluorescent property at high concentration even solid state.Therefore,this study about the unconventional fluorescence of SAF not only broadens its research areas,also provides a convenient route for designing water-soluble AIE molecules.Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is the common used hole transporting material in organic optoelectronic devices as its outstanding optical and electrical properties.However,there are some drawbacks such as strong acidity,structural inhomogeneity and relatively low conductivity,which tremendously limit its wide applications.Considering the unique structure and excellent dispersing capacity of SAF,we firstly applies it as the dopant of PEDOT and successfully prepared black-blue PEDOT:SAF aqueous dispersion,and its mass dopant ratio is 1:2.By comparison with the commercial PEDOT:PSS,PEDOT:SAF shows superior properties including excellent dispersing stability,lower acidity,higher conductivity and work function.Moreover,using PEDOT:SAF as the hole injecting layer(HIL)in a blue phosphorescent organic light-emitting diode(PHOLED),this device achieves extremely lower turn-on voltage,higher efficiency and lifetime comparing to the traditional PEDOT:PSS-based device.These results indicate the application potential of SAF on the dopant of conductive polymer like PEDOT and organic optoelectronic devices.This study on the unconventional fluorescence of SAF and the performance of PEDOT:SAF greatly broader the application fields of SAF,and it is significant for both of basic and application researches.What's more,the inexpensive reactants,simple preparation and eco-friendly property of SAF make it has bright application prospective in the fields of fluorescence and conductive polymer.