• ETRI Journal
• /
• v.25 no.4
• /
• pp.253-257
• /
• 2003

This study investigated the photochromic properties and characterization of acetyl-substituted diarylethene (DAMBTF6)-doped fluoroacrylates media for holographic storage. For the rewritable holographic recording media, we prepared photochromic polymer films using an acrylate matrix by simple photocuring methods. Switching light sources from a visible (532 nm) to an ultraviolet (365 nm) produced transparent films that changed from pale yellow to red. Holographic recording was performed on the photochromic films by two interfering collimated plane wave beams. Excitation with a visible or ultraviolet light completely erased the records, and the film was rewritable either by 532 nm laser or by 325 nm laser within 2 seconds. Images were recorded onto a pixelated spatial light modulator with rectangular pixel apertures and reconstructed on the photochromic films to show recovery of the original images with high resolution.

• Korean Journal of Materials Research
• /
• v.9 no.5
• /
• pp.473-477
• /
• 1999

Xerographic properties of double-layer photoconductor doped with 4-butyl-4'-methoxyazobenzene (BMAB) as charge-carrier transport material were investigated. BMAB can undergo reversible trans-cis isomerization by light with appropriate wavelength. In the results of measured surface voltage properties for photoconductor doped with BMAB, TNF: BMAB(4-wt%) sample with trans form showed the lowest dark decay, the lowest residual voltage, and the highest sensitivity among cis form. The trans isomer of BMAB has ordering orientation because the molecule possesses a rodlike shape, while the cis isomer has random orientation due to its bent shape. Therefore the molecular arrangement of trans form enhanced charge-carrier transport mobility.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.18 no.6
• /
• pp.499-505
• /
• 2005

We compared the effects of a representative aromatic acid amplifier, 2-hydroxy-2'-tosylory biphenyl, doped in poly(tort-butyl methacrylate) (PTBMA), poly (tetrahydropyranylmethacrylate) (pTHPMh) or poly[tert-butoxycarbonyloxystyrene) (pTBOCST) resin film as acid labile polymer in view of thermal stability and photosensitivity enhancement. The acid amplifier was stable up to 60 min in pTBMA and pTBOCST film and up to 10 min in pTHPMA film at $120^{\circ}C$. pTBMA and pTHPMA film doped with the acid amplifier showed 9 times and 3 times higher photosensitivity, respectively. But pTBOCST film showed a negligible photosensitivity enhancement. Photosensitivity enhancement and thermal stability of the acid amplifier were found to be affected by the resin.

• Polymer(Korea)
• /
• v.35 no.6
• /
• pp.543-547
• /
• 2011

A study has been done to enhance the mechanical properties and processability of electrically conductive polyaniline(PANI) without the polymer's structural alternation. Functionalized acid doped PANI (PANI-DBSA) was prepared by an emulsion polymerization, and dodecylbenzenesulfonic acid (DBSA) played both roles of surfactant and dopant. Also, PANI-DBSA was solution cast blended with high impact polystyrene (HIPS) to produce PANI-DBSA/HIPS blend film. The structure and electrical properties of the conducting polymer blends were observed through UV-vis and FTIR/ATR spectroscopy. A study of the blend was carried by focusing on observation of mechanical and electrical properties based on dispersibility and changes in polymer morphology. The conductivity of the blends was increased by increasing the content of PANI-DBSA, and the sudden increase of conductivity to $3.5{\times}10^{-4}$ S/cm was observed even under a low content of 9 wt%. There was a strong association of continuous network formation with percolation and conductivity in the conducting polymer blends.

• Korean Chemical Engineering Research
• /
• v.54 no.1
• /
• pp.36-43
• /
• 2016

Hydrosilylation reactions of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl butyrate catalyzed by Karstedt's, $H_2PtCl_6$ and Pt/C catalyst were studied and 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane was obtained. The reaction order, activation energies and rate constants were determined. Ringopening polymerization of 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane in the presence of $CaF_2$, LiF, KF and anhydrous potassium hydroxide in $60-70^{\circ}C$ temperature range was carried out and methylsiloxane oligomers with regular arrangement of propyl butyrate pendant groups were obtained. The synthesized products were studied by FTIR and NMR spectroscopy. The polysiloxanes were characterized by wide-angle X-ray, gel-permeation chromatography and DSC analyses. Via sol-gel processes of oligomers doped with lithium trifluoromethylsulfonate or lithium bis (trifluoromethylsulfonyl)imide, solid polymer electrolyte membranes were obtained. The dependences of ionic conductivity of obtained polyelectrolytes on temperature and salt concentration were investigated, and it was shown that electric conductivity of the polymer electrolyte membranes at room temperature changed in the range $3.5{\times}10^{-4}{\sim}6.4{\times}10^{-7}S/cm$.

• Journal of the Korean Chemical Society
• /
• v.41 no.3
• /
• pp.144-149
• /
• 1997

Organic electroluminescence devices(ELD) were fabricated using by molecularly doped method with N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine(TPD) as a hole transport agent, squarylium dye as an emitting agent, and side chain liquid crystalline polymer(MCH) as matrix for TPD. An indium-tin-oxide(ITO) coated glass and an Mg electrode were used as the hole and the electron injecting electrode, respectively. The highest stability of ELD was obtained by spin coating method using dichloroethane as a solvent at a polymer/TPD concentration of 0.005 wt%. For the EL cell with ITO/polymer-TPD/SQ dye/Mg structure, we achieved light red luminescence at a current of 102 mA/$cm^2$ with an applied voltage of 23 V.

• Polymer(Korea)
• /
• v.39 no.2
• /
• pp.225-234
• /
• 2015

In this study, we proposed to synthesize thermally stable, soluble and conjugated Schiff base polymer (SbP). For this reason, a specific molecule namely 4,4'-thiodiphenol which has sulfur and oxygen bridge in its structure was used to synthesize bi-functional monomers. Bi-functional amino and carbonyl monomers namely 4,4'-[thio-bis(4,1-phenyleneoxy)] dianiline (DIA) and 4,4'-[thiobis(4,1-phenyleneoxy)]dibenzaldehyde (DIB) were prepared from the elimination reaction of 4,4'-thiodiphenol with 4-iodonitrobenzene and 4-iodobenzaldehyde, respectively. The structures of products were confirmed by elemental analysis, FTIR, $^1H$ NMR and $^{13}C$ NMR techniques. The molecular weight distribution parameters of SbP were determined by size exclusion chromatography (SEC). The synthesized SbP was characterized by solubility tests, TG-DTA and DSC. Also, conductivity values of SbP and SbP-iodine complex were determined from their solid conductivity measurements. The conductivity measurements of doped and undoped SbP were carried out by Keithley 2400 electrometer at room temperature and atmospheric pressure, which were calculated via four-point probe technique. When iodine was used as a doping agent, the conductivity of SbP was observed to be increased. Optical band gap ($E_g$) of SbP was also calculated by using UV-Vis spectroscopy. It should be stressed that SbP was a semiconductor which had a potential in electronic and optoelectronic applications, with fairly low band gap. SbP was found to be thermally stable up to $300^{\circ}C$. The char of SbP was observed 29.86% at $1000^{\circ}C$.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.13 no.2
• /
• pp.33-45
• /
• 1995

1, 4-Diketo-3, 6-diphenyl-pyrrolo-[3, 4c]-pyrrole(abbriviated DPP) is a new heterocyclic pigment of red color whose chlorinated derivative is now on the market. DDP was synthesized from benzonitrile and diethylsuccinate. Pariser-parr-pople(PPP) molecular orbital calculations have been carried out on the DPP in other to study spectroscopically the DPP chromophore on deprotonation.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.838-841
• /
• 2006

Orientational alignment patterns proved that they are very useful for realizing diverse properties of liquid crystals. Here we tried to produce the patterns combining interfered laser light and double irradiations. A photo-isomerizable polymer doped with azo dye, which induce uniform liquid crystal alignment to the uniform laser irradiation, was used as the alignment layer. Double irradiations into two orthogonal directions brought the orientation patterns similar to the checkerboard. It indicates the possibility of bistability on those patterns.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.22 no.2
• /
• pp.179-198
• /
• 2004

Organic electroluminescent devices are light-emitting diodes in which the active materials consist entirely of organic materials. Recently, many fluorescent organic materials have been reported and the study on synthesis and application of new organic light-emitting materials has been demanded. This paper reports the optical and electrical characteristics of OLEDs using novel polymers containing biphenyl structure. First, Optical properties of novel light-emitting biphenyl derivatives doped with poly(9-vinyl carbazole)(PVK) and emitted blue, bluish green color, which is attributed to the overlap area between PL spectrum of host(PVK) and absorption spectra of guests(polymer). This is correspondent with F$\"{o}$rster energy transfer process in the blends. And, OLED devices were fabricated using poly (3,4-ethylenedioxy thiophene) (PEDOT) as a hole injection material and tris-(8-hydroxyquinoline) aluminum ($Alq_3$) as an electron transporting material. EL devices fabricated as ITO/PEDOT/PVK doped with biphenyl derivatives/$Alq_3$/Li:Al and I-V-L chatacteristics and emitting efficiency of EL devices were examined. Finally, the drift mobility of PVK doped with biphenyl derivatives and $Alq_3$ were measured by TOF technique varying applied electric field. EL efficiency was increased as the ratio of hole mobility of PVK doped with biphenyl derivatives and electron mobility of $Alq_3$ was close to one.