Design and Synthesis of Various Perylene Diimide (PDI)-based Materials and the Study of Their Photo- and Electro-chemical Properties : Introduction to Perylene Diimide and Its Derivatives/Electrochomism of Layer-by-Layer Self-assembled Multilayer Film Composed of Perylenediimide-Viologen Dyad/Self-Assembly of Perylene Diimide Derivatives Containing Pyrrole Pendants/Stabilization of Self-assembled Perylene Diimide-derived Nanoparticles by Photo-crosslinking
- 주제(키워드) perylene diimide , electrochromism , nano wire , hallow vesicle
- 발행기관 서강대학교 일반대학원
- 지도교수 문봉진
- 발행년도 2010
- 학위수여년월 2010. 8
- 학위명 박사
- 학과 및 전공 일반대학원 화학과
- 실제URI http://www.dcollection.net/handler/sogang/000000046182
- 본문언어 영어
초록/요약
Perylene diimide (PDI) having viologens at both ends (PDI-2V) was synthesized for using in an electrochromic device (ECD). It was not feasible to fabricate an ECD by conventional spin-coating or deposition method because PDI-2V was an ionic compound. Therefore, an ECD was fabricated by layer-by layer (LBL) type self-assembly of PDI-2V with PEDOT/PSS. The intensity of the spectra linearly increased as the number of bilayers increased, which implies that the LBL formation of the film was efficient. In the cyclic voltammograms of a 10 bilayer film fabricated on an ITO glass, the peak currents linearly increased as the scan rates were increased, which is the typical phenomenon appearing in an adsorbed system in the electrode and this proves that the bilayer has a good absorbent in the redox system. In a single type electrochromic experiment, the PDI-2V showed three stage color change, red, blue, and purple, under the reduction potential. In addition, a dual type electrochromic device was fabricated with P3HT spin-coated ITO as a counter electrode. When -2.2 V was applied to the electrochromic device, it turned from red to purple color due to the reduction state of PDI and viologen.
more초록/요약
In this experiment, we found a new way to form PDI (perylene diimide) nano-wire. When a spin-coated PDI film on a glass substrate was immersed in co-solvent (CH3CN/H2O=13/1), PDI nano-wires with a dimension of ~100 nmⅹ200 nm were formed by dynamic solvation and self-assembly equilibrium. The solvent composition was chosen so that the films could not be dissolved away but be swollen for self-assembly of the molecules. The absorption intensity of PDI film after dipping for 12 h in the co-solvent was reduced than before dipping, which was ascribed to the partial dissolving of PDI molecules in the co-solvent. The increase of absorption spectrum at shorter wavelength was observed due to light scattering by the nanostructures. PDI derivatives having pendant pyrroles, PDI-2Py and PDI-4Py, were also subjected to the similar experimental conditions, but these derivatives did not form nano-wire. The reasons for the difference were deduced from DSC data. PDI-2Py and PDI-4Py exhibited much higher melting points compared to PDI and the phenomenon may be attributed to the interference of the intermolecular interaction between PDIs by pyrroles. The self-assembly of PDI was also dynamically observed by XRD as a function of solvent annealing time. A freshly spin casted PDI film showed a broad diffraction peak at 2θ = 5.3 ° was and it gradually disappeared after 1h of dipping in co-solvent and then two new sharp peaks at 2θ = 4.5 ° and 4.9 ° emerged. The results of this experiments implies that new lattice structures were formed through the self-assembly.
more초록/요약
PDI (perylene diimide) derivatives PDI-1, PDI-2, and PDI-3 having pyrroles at bay site 1, 6, 7, and 12 position of PDI were synthesized by condensation reaction of perylene dianhydride with aniline 6 or 10-nonadecanamine 7. The self-assembly of PDI-1, PDI-2, PDI-3 solutions in THF/H2O at various ratios were investigated. Their UV/vis spectra were red shifted and the intensity of PL spectra were decreased with decrease of THF content. Their phenomenon was due to the aggregation of each material. The shapes and sizes of PDI-1 in 5% THF were found to be spherical nano-particles with about 500 nm diameters through SEM or TEM. On the other hand, PDI-2 formed hallow vesicles with a diameter of ~180 nm under the same conditions which was due to amphiphilic structure of PDI-2. The PDI-2 particles in 2% THF were also investigated by dynamic light scattering (DLS) measurements. The size distribution of the particles obtained by DLS measurement was consistent with the results from SEM and TEM analyses of PDI-2. PDI-3 having two hydrophilic substituents at imide position of PDI formed spherical particles with the diameter of about 100 nm. Patterning of PDI-2 hollow vesicles on a glass substrate was also demonstrated under visible light (> 600 nm) with a photo-mask. The PDI-2 vesicle patterned glass substrate was investigated by SEM and fluorescence microscopy.
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