| Novel D-?-A Chromophore containing polymer materials afforded the great possible for frontier research of large-area and flexible devices,due to its unique chemical structure,excellent film forming ability and remarkable electrical and optical properties.This kind of promising materials has attracted a widespread attention in the field of nonlinear optical,electrical memory,optical data storage,opto-electronic information,because of the potential application.Designing and preparing the novel high-performance D-?-A chromophore containing polymer materials to investigate the unique optical and electrical properties of the materials is the research hotspot in the opto-electronics research field.We prepare the novel D-?-A Chromophore containing polymer materials,in order to develop the novel materials with high thermal stability and outstanding electrical/optical properties,understand the relationship between the chemical structure and the performance of the materials,and also to solve the fundamental problem in the opto-electronics materials synthesis,such as the low yield of acceptor,the complicated synthesis procedure,and so on.In our study,we design and synthesis a series of novel D-?-A Chromophore containing polymers,including host-guest system,covalent bond system(side-chain polymer)and supramolecular system.Through covalent bond,hydrogen bond or simple blending by solution process,we combine the D-?-A chromophore possessing the electro-optical properties with the polymer materials,and also study the synthesis method of these novel materials and the synthesis reaction mechanism in these processes.By designing the molecule of chromophore and choosing the reasonable synthetic approaches,the optical and electrical properties of novel D-?-A chromophore containing polymer materials are enhanced.Novel D-?-A chromophores containing polymer were used to fabricate the devices.The performance of the devices and the relationship between the chemical structure of the novel D-?-A chromophore containing polymer and the devices performance was studied comprehensively.The details of the dissertation are as follows:(1)Two novel second order nonlinear optical(NLO)chromophores,compound 7 and compound 8,based on N,N-diethylaniline as donors,verbenone based tetraene as bridge,and 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (CH3-TCF)or tricyanofuran(TCF)derivatives with dendritic moiety as acceptor have been synthesized.The chemical structure of these novel chromophores has been investigated and characterized systematically through nuclear magnetic resonance spectrum(NMR),high resolution mass spectrometry(HRMS),ion trap mass spectrometer(MS).The ground-state structure and molecular polarization of chromophores as revealed by UV-vis-NIR absorption measurement.Compared with compound 7,after introducing dendritic derivative steric hindrance groups into the acceptor,chromophores Compound 8(Td=273°C)had good thermal stabilities with high thermal decomposition temperatures which were 33 °C higher than chromophore Compound 7(Td=240°C).The bulky dendritic moiety linked by short C-C bond is closer to the TCF acceptor,which is most polar part in the chromophore,compared to conventional isolation groups.In the host-guest polymer system,this unique structure has advantage to minimize the dipole-dipole interactions between the chromophores,prevent the antiparallel packing and improve the poling efficiency and EO performance.The TCF(tricyanofuran)derivative is very important acceptor in the electro-optic field.However,the complicated synthesis procedures and the low yield of the TCF impede the development of the novel structure of TCF.We use the advanced Focused Microwave-Assisted Synthesis to improve the yield of the novel TCF,and also study the influence of dendritic group to the ring closure reaction of TCF.More important,through design and synthesis the novel dendritic ?-ketol,using this ?-ketol with unique structure the novel dendritic TCF derivatives was prepared through the ring closure reaction.This is new synthetic route for preparing the dendritic TCF derivatives.This part of our work about dendritic TCF acceptor is innovative and distinctive,and the specific chemical structure of dendritic TCF derivatives attracts a great amount of attention in the frontier research of electro-optic.Besides,we use the(1S)-(-)-verbenone in the bridge,because the(1S)-(-)-verbenone-based tetraene bridge has more planar molecular structure for more effective conjugation pathway in comparison with the isophorone-based bridge.The bicyclic system of the(1S)-(-)-verbenone can rigidly lock the conformations of polyene chains and also can improve the glass-forming ability.The(1S)-(-)-verbenone-based tetraene bridge is a new type bridge,and there is less research about the properties of chromophore based on this bridge with different donor-acceptor strength.These properties include polarity,hyperpolarizability and charge-transfer resonance forms.The charge-transfer resonance forms,optical and electrical properties of the chromophores based on(1S)-(-)-verbenone with dialkylaminophenyl donor,and CH3-TCF acceptor or the new dendritic TCF acceptor were systematically studied.(2)We have designed and synthesized two novel azobenzene functionalized poly(aryl ether)s(PAE-azo-X),which possess the electrical memory properties,from a new azobenzene monomer(ENDAF,dialkylamino as donor)via nucleophilic aromatic substitution polycondensation.This direct polymerization approach via azobenzene monomer have the advantages of controlling the distribution and amount of the azobenzene chromophores in the polymer.Both of the polymers showed very good thermal stability and excellent solubility for future application in the electronics industry.These polymers were fabricated as films by simple spin-coating and both of them were then prepared as sandwich memory devices.PAE-azo-1 and PAE-azo-2 exhibit write-once-read-many-times(WORM)type memory behavior,and possess the low operation voltage below-3.0V.The memory mechanism has been investigated through UV-vis optical absorption spectrum,the cyclic voltammetry(CV)and the DFT(density functional theory)molecular simulation method.These novel polymers are p type materials.Compared novel monomer(ENDAF)with model compounds(PM-1 and PM-2),we found that the charge carriers mainly transport on conjugated azobenzene moiety.After the polymerization,the components of chain have influence on the HOMO and LUMO energy level of materials.These obtained results indicate that the novel azobenzene functionalized poly(aryl ether)s(PAE-azo-X)is a promising candidate for low power consumption and high performance materials for data-storage.(3)This study reports the fabrication and characterization of polymer resistive switching memory devices fabricated from poly(ether sulfone)s(PES),containing carboxylic functional groups for hydrogen bonding with disperse red 1(DR1),which possess the electrical memory property.This PES-Based Supramolecular polymer material has the advantage of tuning the content and kinds of azobenzene in the polymer film.The PES-Based Supramolecular memory devices exhibited write-once read-many-times(WORM)type memory effects,with low switching threshold voltages and high ON/OFF current ratios for low power consumption materials.Through tuning the content of DR1 moieties in PES,the device performance parameters,including the turn-on voltage,were tuned accordingly.A possible switching mechanism based on the charge transfer interaction and charge trapping mechanism was proposed through molecular simulation,optical absorption and cyclic voltammetry.These results render the PES-Based Supramolecular polymer materials are promising components for high-performance memory devices. |
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