• Journal of the Korean Vacuum Society
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• v.10 no.2
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• pp.241-246
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• 2001

Single or dual ion implantations were performed onto the transparent polyethylene terephthalate(PET) sheet, and the surface hardness and the light transmittance in the visual-UV range were examined. Nanoindentation showed that the surface hardness was the highest at about 50 nm depth from the surface and was increased by about 3 times when nitrogen ions were implanted with energy and dose of 90 keV and $1\times10^{15}\textrm{/cm}^2$ respectively. When dual ions such as He+N and N+C ions were implanted into PET, the hardness was increased even more than the case only N ions were implanted. Especially, when PET were implanted with N+C dual ions, the surface hardness of PET increased 5 times more as compared to when implanted with N ions alone. The light at the 550 nm wavelength(visual range) transmitted more than 85%, which is close to that of as-received PET, and at the wavelength below 300 nm(UV range) the rays were absorbed more than 95% as traveling through the sheet. implying that there are processing parameters which the ion implanted PET maintains the transparency and absorbs the UV rays. It can be considered that the increase in the hardness of polymeric materials is attributed to not only cross linking but also forming hard inclusions such as hard C-N compounds, as evidenced by the formation of the highest hardness when both N and C ions are implanted onto PET.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.67-68
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• 2012

• Proceedings of the Korean Fiber Society Conference
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• 1986.06a
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• pp.44-45
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• 1986

• Proceedings of the Korean Fiber Society Conference
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• 1987.06b
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• pp.20-20
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• 1987

• Proceedings of the Korean Fiber Society Conference
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• 1990.06b
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• pp.50-50
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• 1990

• Journal of Adhesion and Interface
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• v.3 no.3
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• pp.22-29
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• 2002

UV curable coating system described here consists of double layers, namely under layer and top laser coatings. The former consists of organic-inorganic conductive materials and the latter consists of multifunctional acrylates. Transparent double layer coatings were prepared on the transparent substrates i.e. PMMA, PC, PET etc. by the wet and wet coating procedure. Their surface resistances and film properties were measured as a function of the top layer thickness and relative humidity. As the thickness of the top layer was less than $10{\mu}m$, the surface resistance in the range of $10^8{\sim}10^{10}{\Omega}/cm^2$ was obtained. The surface properties of the two-layer coating were remarkably improved compared with the single layer coating. The effects of migration of conducting materials on the film properties of multilayer coating were investigated by using contact angle and Fourier transform infrared/attenuated total reflection(FT-IR/ATR). It was found that the migration of dopant(dodecyl benzenesulfonic acid, DBSA) molecules were occurred from film-substrate interface to film-air interface in the organic conductive coating system but not in the inorganic one.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.5
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• pp.191-195
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• 2023

Three-layer nano-coated films in applications for the back cover of mobile cellular phones were prepared utilizing a roll-to-roll continuous process. By introducing a coating layer with a ceramic/metal/ceramic three-layer structure, the inherent reflective properties of the metals were maintained while electrically insulating properties were maintained. The thickness of the composite coating layer on a large area PET film with a length of 1,500 nm and width of 500 nm was less than 60 nm, and a uniform thickness was maintained in all areas. The transmittance according to the wavelength range (240~1600 nm) of the nanocoating film gradually increases as the wavelength increases, and is about 48 % at 1,000 nm, which is within the infrared region, and about 35.5 % at 550 nm, which is within the visible region. These results meet the required level of coated backcover (< 40 %).

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.176.2-176.2
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• 2014

In this work, we demonstrated that the fabrication of flexible graphene-based chemical sensor with heaters by soft lithographic patterning method [1]. First, monolayer and multilayer graphene were prepared by thermal chemical vapor deposition transferred onto SiO2 / Si substrate in order to fabrication of patterned-sensor and -heater. Second, patterned-monolayer and multilayer graphene were detached through soft lithography process, which was transferred on top and bottom sides of PET film. Third, Au / Ti (Thickness : 100/30 nm) electrodes were deposited end of the patterned-graphene line by sputtering system. Finally, we measured sensor properties through injection of NO2 and CO2 gas on different temperature with voltage change of graphene heater.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.6
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• pp.500-504
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• 2020

Heating films were prepared with composites of poly (methyl methacrylate) and conductive graphite. The as-prepared composite was deposited on a PET film and then fabricated using a bar coater to produce a film with uniform thickness. Copper electrodes were attached to both ends of the as-prepared film, and the heating characteristics of the film were analyzed while applying a DC voltage. The electrical conductivity and heating temperature of the heating films depended on the size, structure, content, and the dispersion characteristics of the graphite in the composite. The thermal energy was adjusted by controlling the electrical energy, based on the Joule heating theory. The electrical resistance of the film was altered in proportion to Ohm's law, and the heating temperature was changed according to the structure of the film (interelectrode spacing or electrode length) and the conductive graphite content. When the content of conductive graphite in the film increases, the electrical resistance decreases, and the heating temperature increases; however, there is no significant change above a certain content (50%).

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.203-203
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• 2012

The SWCNTs network are formed on various plastic substrates such as poly(ethylene terephthalate) (PET), polyimide (PI) and soda lime glass using roll-to-roll printing and spray process. Selective patterning of carbon nanotubes film on transparent substrates was performed using a femtosecond laser. This process has many advantages because it is performed without chemicals and is easily applied to large-area patterning. It could also control the transparency and conductivity of CNT film by selective removal of CNTs. Furthermore, selective cutting of carbon nanotube using a femtosecond laser does not cause any phase change in the CNTs, as usually shown in focused ion beam irradiation of the CNTs. The patterned SWCNT films on transparent substrate can be used electrode layer for touch panels of flexible or flat panel display instead indium tin oxide (ITO) film.