• Restorative Dentistry and Endodontics
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• v.13 no.1
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• pp.151-158
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• 1988

The purpose of this study was to evaluate the effect of canal filling methods and post-space preparation time on the apical seal of endodontically treated teeth. Seventy-six single-rooted human teeth were divided into 6 groups and each tooth was obturated and prepared post-space according to the purpose of this study. After all specimens were immersed in Indian ink, decalcified and cleared, the degree of dye penetration into the root canals observed by magnifying glass (X20) and measured by caliper. The results were as follows: 1. In the thermatic condensation, no significant difference in ink penetration occured when the post-spaces were created immediately after obturation or when they were made a week later. 2. In the lateral condensation, no significant difference in ink penetration existed between teeth whose post-space were prepared immediately or delayed. 3. In comparison of experimental groups and control groups, no significant difference showed when the groups were obturated with McSpadden compactor but when the teeth were laterally condensed, the experimental groups showed less ink penetration than controls. 4. Thermatic condensed teeth with McSpadden compactor were less ink penetration thn laterally condensed teeth.

• Korean Journal of Materials Research
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• v.16 no.7
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• pp.422-429
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• 2006

Studies were performed on preparation of organic-inorganic hybrid silica dye in a dispersing ink system. The silica was subjected to surface modification using 3-aminopropyltrimethoxysilane (APTMS) in order to promote the chemical reactivity of the raw silica. On the surfaces of the aminosilane-functionalised silica, red vinylsulfone-containing azo dye was adsorbed. The dye was found to have chemically reacted with the aminosilane-grafted silica surface, which was proven by FT-IR spectra. Studies on morphology and microstructure were performed employing scanning electron microscopy. The SEM micrographs and particle size distributions showed that a homogeneous pigment can be obtained employing silica as a core. Particle size distribution was also examined using the technique of dynamic light scattering. The ensuing pigment was subjected to various physicochemical evaluation such as inkjet property, storage stability, color change as inkjet ink using printer, spectrophotometric, microscopic techniques. Studies on hybrid dyes from the silica surface demonstrated that, in general, stable pigments for inkjet dispersion ink were obtained.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1466-1468
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• 2009

The preparation method of copper nanopowder by dry process for conductive ink was investigated. Inert gas condensation method was used to synthesize copper nanopowder. The produced powders was spherical and sized 10~100nm flowing the conditions. The results showed that input voltage and evaporation rate is critical variables for nano-sized copper powder.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.831-836
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• 2013

Platinized counter electrode is common in most of the dye sensitized solar cell (DSSC) researches because of its high catalytic activity and corrosion stability against iodine in the electrolyte. Platinum (Pt) film coating on fluorine doped tin oxide (FTO) glass surface by using alcoholic solution of hexachloroplatinic acid ($H_2PtCl_6$), paste containing Pt precursors or sputtering are widely used techniques. This paper presents a novel application of Pt ink containing nanoparticles for making platinized counter electrode for DSSC. The characteristics of Pt films coated on FTO glass surface by different chemical methods were compared along with the performance parameters of the DSSCs made by using the films as counter electrodes. The samples coated with Pt inks were sintered at $300^{\circ}C$ for 30 minutes whereas Pt-film and Pt-paste were sintered at $400^{\circ}C$ for 30 minutes. The Pt ink diluted in n-hexane was found to a promising candidate for the preparation of platinized counter electrode. The ink may also be applicable for DSSC on flexible substrates after optimization its sintering temperature.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.914-916
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• 2009

Using gelatin and acacia as wall and electronic ink as core substance, microcapsules were prepared by complex coacervation to fabricate a flexible electronic paper display. In order to obtain the microcapsules in a narrow dispersed distribution, we focus on the interfacial tension between the hydrophobic electrophoretic ink and an aqueous polyelectrolyte solution, through controlling sodium dodecyl sulphate (SDS) concentration and stirring rate. The existence of anionic surfactant of SDS not only decreases the droplet diameters, but also reduces the diameter size distribution. And, as the stirring rate is increased, the average size of microcapsule is also decreased.

• Korean Journal of Materials Research
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• v.16 no.10
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• pp.599-605
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• 2006

N-(3-triethoxysilylpropyl)-1,4-diaminoanthrquinone-2,3-dicarboximide (TESP-DADI), an organic blue pigment, has been prepared and incorporated into silica solid matrix reacting triethyl orthosilicate (TEOS) via sol-gel method. Morphology and microstructure of resulting hybrid pigment were studied employing SEM and TEM. The micrographs and particle size distributions showed that uniform pigment can be obtained employing TEOS-based sol-gel method forming silica core. Particle size distribution of dispersed pigment in water was examined using the technique of dynamic light scattering. The ensuing pigment dispersion ink was subjected to various physicochemical evaluation such as viscosity, surface tension, inkjet stability, storage stability, and color change as inkjet ink using spectrophotometric, and microscopic techniques.

• Journal of Adhesion and Interface
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• v.14 no.4
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• pp.167-174
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• 2013

In this study, Ultraviolet (UV) curable urethane acrylates for ink binder was prepared by reaction of IPDI, polyether polyol and HEA. The UV curing behavior of compositions with HEA/PETA ratio on UV irradiation time was investigated by FT-IR spectrophotometer, probe tack tester and Photo-DSC. Conversion % and gel content were increased with increasing UV irradiation time, but probe tack was decreased. Storage modulus, tensile strength and decomposition temperature were increased as PETA content increased. In case of HEA/PETA ratio was 30/70, adhesion property of UV-cured composition on PMMA sheet was excellent.

• Journal of Electrochemical Science and Technology
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• v.12 no.1
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• pp.146-158
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• 2021

This paper reports the preparation of an ink-jet printed flexible electrochromic device based on a water-soluble viologen-functionalized dendrimer. Polyamidoamine (PAMAM) dendrimers were modified with different concentrations of 1-1 bis(propylamine)-4,4'-bipyridylium dibromides to obtain solution-processable electrochromic materials (K1/2 and K1). FTIR, NMR, and elemental analyses are used to characterize synthesized viologens. Moreover, their electrochemical properties were investigated using cyclic voltammetry in an electrolyte solution consisting of 0.1 M HCl to find the optimum viologens. The low-cost ink-jet printer was used to print the prepared water-soluble electrochromic inks onto the ITO coated PET substrate to form desired transparent patterns. The electrolyte was applied on the printed electrochromic ink to make a sandwich with another ITO coated PET to prepare the electrochromic devices (ECD). By applying an electrical potential (0 to -2 V), the transparent ECD's color changed from colorless to blue. The color changes for the optimum ECD (K1), which had more viologen units on the dendrimer, was accompanied by an optical contrast of 47% and 311.5 ㎠C-1 coloration efficiency at 600 nm.

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.194-194
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• 2005

• Macromolecular Research
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• v.17 no.1
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• pp.2-4
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• 2009