• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1532-1534
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• 2008

Aquesous carbon nanotubes (CNTs) solutions were prepared using SDS (sodium dodecyl sulfonate) and NADDBS (sodium dodecylbenzene sulfonate). Our inks are found to have the viscosity of 1-2 cps. In addition, the surface tension of inks inversely decreased with increasing surfactant concentration and then saturated at critical micelle concentration (CMC). The low surface tension at CMC gave rise to lower contact angles on Indium layers, resulting in larger printable feature sizes. In the fabrication of cold cathode, jet-printing is feasible to modify and scale up the cathode structures. These feasibilities could contribute jet-printing method to be more adaptable for making large-area cold cathodes.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 1999년도 Pre-symposium of the 10th ISWPC Recent Advances in Paper Science and Technology
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• pp.343-348
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• 1999

Presence of small amount of old newspapers printed with waterbased flexographic inks leads to a significant loss of brightness of the deinked pulp by flotation process. Recently there has been an increased interests in employing neutral deinking processes to solve the problems associated with waterbased flexo ink. A comparative experimental study was performed to evaluate the efficiency of neutral deinking and conventional alkaline deinking for ONP furnishes contaminated with flexo ink. Effects of the deinking processes on pulp quality and white water characteristics were examined. It was shown that neutral deinking would provide significant improvement in brightness, yield, and freeness as compared with conventional alkaline deinking. Three was no increase change in brightness when OMG was added in the furnish up to 20%, and it was attributed to the redeposition of flexo inks on chemical pulp fibers.

• 한국인쇄학회지
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• 제19권1호
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• pp.42-54
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• 2001

The combination of a silicone surfaced plate and high viscosity ink produced a waterless printing system that worked well, but had limitation. The limitation was that this system was restricted to relatively short run lengths. In the waterless printing process, the press tended to heat up rapidly. Heat in turn, broke down the resins in the inks, causing them to become more fluid. When the ink is heated, the viscosity will drop, the ink will become too liquid and the plate will no longer be able to resist it. The ink will adhere to the non-print portions of the plate, and will print as a very fine mist or speckle pattern in the non-image area. On the other hand, when the ink gets too cold, viscosity will increase until ink transfer is impeded. This study carried otu to investigate the effect of temperature variations of the inks on the print quality in waterless lithography and to examine the adaptability of waterless lithography to conventional offset press without cooling system.

• 한국물환경학회지
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• 제22권6호
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• pp.996-1003
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• 2006

The absorption characteristics of powdered activated carbon doped by transition-metal nanoparticles were investigated to enhance the remove efficiencies of $TCOD_{Mn}$ and Color from the flexo-inks wastewater. According to the adsorption dynamics of PAC and MPAC, the optimal dosage of activated-carbon adsorbents was 3 g/L under the reaction conditions of pH6.0, 30 mill of reaction time, 240 rpm of mixing intensity. The removal efficiencies by the optimal dosages were maximized as 19% $TCOD_{Mn}$, 57% Color for PAC and 88% $TCOD_{Mn}$, 95% Color for MPAC. Freundlich indexes of isotherm absorption were estimated as follows: i) For PAC, k=-8.11, 1/n=2.98, r=0.91 in the raw water, and k=0.14, b/n=0.75, r=0.96 in the biological treatment water, ii) For MPAC, k=2.69, 1/n=0.21, r=0.80 in the raw water, and k=0.74, 1/n=1.17, r=0.95 in the biological treatment water. MPAC (Powdered activated carbon doped by transition-metal nanoaprticles) was very effective in the removal of organics from the raw water and biological treatment water, as Freundlich indexes of 1/n for both types of water were estimated less than 2.0.

• Tissue Engineering and Regenerative Medicine
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• 제15권6호
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• pp.761-769
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• 2018

BACKGROUND: Bioprinting has recently appeared as a powerful tool for building complex tissue and organ structures. However, the application of bioprinting to regenerative medicine has limitations, due to the restricted choices of bio-ink for cytocompatible cell encapsulation and the integrity of the fabricated structures. METHODS: In this study, we developed hybrid bio-inks based on acrylated hyaluronic acid (HA) for immobilizing bio-active peptides and tyramine-conjugated hyaluronic acids for fast gelation. RESULTS: Conventional acrylated HA-based hydrogels have a gelation time of more than 30 min, whereas hybrid bio-ink has been rapidly gelated within 200 s. Fibroblast cells cultured in this hybrid bio-ink up to 7 days showed >90% viability. As a guidance cue for stem cell differentiation, we immobilized four different bio-active peptides: BMP-7-derived peptides (BMP-7D) and osteopontin for osteogenesis, and substance-P (SP) and Ac-SDKP (SDKP) for angiogenesis. Mesenchymal stem cells cultured in these hybrid bio-inks showed the highest angiogenic and osteogenic activity cultured in bio-ink immobilized with a SP or BMP-7D peptide. This bio-ink was loaded in a three-dimensional (3D) bioprinting device showing reproducible printing features. CONCLUSION: We have developed bio-inks that combine biochemical and mechanical cues. Biochemical cues were able to regulate differentiation of cells, and mechanical cues enabled printing structuring. This multi-functional bio-ink can be used for complex tissue engineering and regenerative medicine.

• 한국재료학회지
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• 제25권12호
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• pp.719-726
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• 2015

For a decade, solution-processed functional materials and various printing technologies have attracted increasingly the significant interest in realizing low-cost flexible electronics. In this study, Cu nanoparticles are synthesized via the chemical reduction of Cu ions under inert atmosphere. To prevent interparticle agglomeration and surface oxidation, oleic acid is incorporated as a surface capping molecule and hydrazine is used as a reducing agent. To endow water-compatibility, the surface of synthesized Cu nanoparticles is modified by a mixture of carboxyl-terminated anionic polyelectrolyte and polyoxylethylene oleylamine ether. For reducing the surface tension and the evaporation rate of aqueous Cu nanoparticle inks, the solvent composition of Cu nanoparticle ink is designed as DI water:2-methoxy ethanol:glycerol:ethylene glycol = 50:20:5:25 wt%. The effects of poly(styrene-co-maleic acid) as an adhesion promoter(AP) on rheology of aqueous Cu nanoparticle inks and adhesion of Cu pattern printed on polyimid films are investigated. The 40 wt% aqueous Cu nanoparticle inks with 0.5 wt% of Poly(styrene-co-maleic acid) show the "Newtonian flow" and has a low viscosity under $10mPa{\cdots}S$, which is applicable to inkjet printing. The Cu patterns with a linewidth of $50{\sim}60{\mu}m$ are successfully fabricated. With the addition of Poly(styrene-co-maleic acid), the adhesion of printed Cu patterns on polyimid films is superior to those of patterns prepared from Poly(styrene-co-maleic acid)-free inks. The resistivities of Cu films are measured to be $10{\sim}15{\mu}{\Omega}{\cdot}cm$ at annealing temperature of $300^{\circ}C$.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.193-194
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• 2008

$Orgacon^{TM}$ products, based on the conducting polymer PEDOT/PSS, are very promising materials in cost-effective R2R production of large area electronics. This presentation will show both the progress in the surface resistance/VLT and progress in the stability (T/R.H. and light stability). A new generation of films, coating formulations and inks will be presented.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2009년도 춘계학술발표회 논문집
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• pp.75-85
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• 2009

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 추계총회 및 연구발표회 초록집
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• pp.175.1-175
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• 2003

• 한국의상디자인학회지
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• 제12권2호
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• pp.67-73
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• 2010

Whole process of textile printing is made by computer and it remarkably improves environment problem. This digital textile printing is becoming next step environment friendly textile printing method. But, still now range of textile possible for digital textile printing is limited, and also color analysis according to fiber types is not completed. The ink printed on the fabrics through DTP printer can be absorbed and fixed into textile without any blots by pre-treatment using suitable media solution for fabrics types. The chemical formulation of media solution used in the pre-treatment process varies according to the types of textiles and inks for DTP products. First, I studied reference books or articles about color analysis of digital textile printing. Second, I recorded pre-process, printing, post-process and coloring of silk, wool, nylon at same condition. After that, I analyzed $L^*\;a^*\;b^*$, Total K/S, ${\Delta}E$ and studied color intensity and coloring. According to this study, I suggested particular textile special for coloring and manual for affective coloring control. It showed that the performance of the digital printing on the Silk, Wool and Nylon blend fabrics treated by the media solution developed in this study was better than the one treated by the previous media solution for each single inks.