• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1341-1342
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• 2007

Poly-ether-sulphone (PES) 기판위에 열처리 공정을 거친 HgTe 나노입자를 이용하여 플렉시블 투명 박막 트랜지스터를 제작하였다. 활성층으로 사용된 HgTe 나노입자층은 UV/ozone 처리로 친수성화 된 PES 기판위에 스핀코팅으로 형성되었다. 제작된 박막 트랜지스터는 전형적인 p형 트랜지스터 특성을 보여주었으며, PES 기판에 스트레인을 가하지 않은 상태에서는 164의 전류점멸비와 1.6 $cm^{2}/Vs$ 의 전하 이동도가 계산되었고, PES 기판에 2.0%의 스트레인을 인가하였을 때에는 266의 전류점멸비와 1.0 $cm^2/Vs$ 의 전하 이동도가 계산되었다.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.56-57
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• 2003

포토 폴리머를 광 소자 재료로 이용할 경우 경제성 및 다른 수동 광 소자와의 집적이 가능하므로 최근 들어 많은 관심의 대상이 되고 있다. 특히, 포토 폴리머는 광 소자로서 가격 경쟁력을 높일 수 있으므로 차세대 광 소자 매질로서의 가능성이 매우 높다. 또한, 포토 폴리머는 고감도, 간단한 실시간 처리, 저렴한 가격 등의 이점 때문에 광굴절 결정보다 홀로 그래픽 저장기술 응용에 손쉽게 적용할 수 있다. (중략)

• Membrane and Water Treatment
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• v.14 no.4
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• pp.175-180
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• 2023

Mixed matrix membranes (MMMs) can be a promising alternative for the solution of dye removal from coloured effluents. Polymeric membranes are widely used due to their good film-forming ability, flexibility, separation properties, and cost. However, they have low mechanical, chemical, and thermal resistances. Moreover, the fouling of polymeric membranes is high because of their hydrophobic nature. Hence, there is an increasing interest in organic-inorganic hybrid membranes as a new-generation membrane material. It has been shown that carbon nanotubes have the potential to increase the material properties of polymers with their low density, high strength, hardness, and exceptional aspect ratio. In this work, carbon nanotubes blended MMMs were prepared and methyl orange removal efficiency of them was investigated. Compared to the bare membranes, MMMs showed not only increased hydrophilicity, water content, and pure water flux but also increased methyl orange rejection and flux recovery

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.1
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• pp.143-150
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• 1997

The electrical properties of polysilicon thin films implanted with $B_2H_6$ diluted in $H_2$ as dopant source using ion mass doping technique and the effect of radiation damage on the dopant activation behavior were investigated. Comparing the SIMS profiles of boron in polysilicon films with that obtained from computer simulation using TRIM92 the most probable ion species were $B_2H_x\;^+$(x＝1, 2, 3‥‥) type molecular ions. As a result of the Implantation of energetic massive ions, a continuous amorphized layer was created in polysilicon films where the fraction of amorphized layer varied with doping time. This amorphization comes from the fact that mass separation of implanting species is not employed in this ion mass doping technique. In the dopant activation behavior, reverse annealing phenomenon appeared in the intermediate annealing temperature range for a severely damaged specimen. The experimental result showed that the off-state current of the p-channel polysilicon thin film transistor is dependent on the degree of radiation damage.

• Korean Journal of Materials Research
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• v.3 no.4
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• pp.319-326
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• 1993

The effects of $SnO_2$ crystallite size on the powder characteristics, the resistance in air and the sensitivity to 0.5 vol % $H_2$, CO-air mixture were observed. The size of SnO, powder was controlled by calcining temperature variation ($500^{\circ}C$ ~$1100^{\circ}C$) of $\alpha$-stannic acid fabricated from $SnCl_4 \cdot xH_2O$. Its crystallite size. evaluated from TEM image, was in the range of 8-54nm. With the reduction of crystallite size, the adsoption peak of $H_2O$ on FTIR curve became more clear while the lattice parameters were invariable. As the crystallite size decreased, with elements of thick film, the temperatures showing a minimum resistance in air and a maximum sensitivity to H, gas reduced. The temperature variations were assigned to the changes of activation energy of the active adsorbates, and it was suggested that the decrease of activation energy can be one of the reasons for the' sensitivity increase with the' fine powder.

• Journal of Pharmaceutical Investigation
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• v.35 no.6
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• pp.411-416
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• 2005

The aim of the present work was to prepare the nanosuspension of inorganic pigment which shows light reflection and scattering as efficient sunscreen. The zinc oxide (ZnO) was chosen as an inorganic pigment, and high pressure homogenizer and bead mill have been used for the preparation of nanosuspension. The ZnO nanosuspensions were characterized by particle size, in vitro sun protection factor (SPF) and UV transmittance. ZnO nanosuspension prepared by bead mill showed the average diameter of $119{\pm}4\;nm$, resulting in the high value of SPF $(28.74{\pm}2.06,\;n=20)$, while that prepared by high pressure homogenizer showed the average diameter of $751{\pm}32\;nm$ with the relative lower value of SPF $(21.38{\pm}1.94\;n=20)$. In addition, the film of ZnO nanosuspension prepared by bead mill was showed a high visible ray (VIS) transmittance, indicating a high transparency. In conclusion, a physically stable ZnO nanosuspension in cyclomethicone was successfully prepared using bead mill for the suitable sunscreen preparations.

• Korean Journal of Materials Research
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• v.2 no.6
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• pp.417-427
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• 1992

Silicon ion implantation was performed to LPCVD amorphous Si films and the low temperature annealing process followed with various conditions to find the optimal physical properties by studying recrystallization behavior. The uniformity of the recrystallized films was inspected by optical microscopy and for this purpose, new KOH: (IPA) : $H_2$O: $K_2$C${r_2}{O_7}$, etchant was developed. XRD and TEM results showed that the crystallites were grown as a form of dendrite with (111) preferred orientation, and the grain size was increased with dose concentration. The maximum grain size was obtained when the 3${\times}{10^{15}}$c$m^2$ implanted amorphous Si film was recrystallized at 55 $0^{\circ}C$for more than 40 hrs and at this condition the grain size was 3.2${\mu}$m.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.735-740
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• 2002

In order to improve the anti-fogging property of polymer films, organic-inorganic hybrid coating solutions which have good hydrophilic property and transmission in the range of visible light were synthesized by the sol-gel method. The coating solutions were prepared by adding glycidoxypropyl trimethoxysilane(GPS) to a colloidal silica(15 nm) suspension(Ludox). GPS as silane coupling agent forms strong bonds to the colloidal silica and surrounding polymer matrix and links two different materials together. Solutions prepared by addition of GPS at the acidic condition resulted in coatings that were less prone to cracking, while those at the basic condition caused coatings with more cracking. These resulted in better hydrophilic property and transmission in the range of visible light for the solution prepared at the acidic condition(pH 2). Compared with coatings under acidic conditions, coatings prepared at basic conditions showed worse hydrophilic property and transmission in the range of visible light.

• Journal of Adhesion and Interface
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• v.20 no.4
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• pp.146-154
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• 2019

In this study, alkoxysilane-functionalized amphiphilic polymer (AFAP), which have hydrophilic segment and hydrophobic segment functionalized by alkoxysilane group at the same backbone, was synthesized and used as a dispersant and control agent for reaction rate in the preparation of colloidally stable organic-inorganic (O-I) hybrid sols. After reaction with fluorosilane compounds, fluorinated O-I hybrid sols were prepared and coated onto glass substrate to form hydrophobic O-I hybrid coating films through low-temperature curing process. Surface hardness and hydrophobicity of cured coating films were varied with type of solvent and composition of AFAP and fluorinated alkoxysilane compounds. At appropriate solvent and composition of fluorinated alkoxysilane compounds, O-I hybrid coating film having high transparency and surface hardness could be prepared, which could be applicable to cover window of solar cell and displays.

• Korean Chemical Engineering Research
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• v.45 no.4
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• pp.364-371
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• 2007

Effects of continuous oil phase on silver halide nanoparticles were investigated where nanoparticles were prepared using two different types of water-in-oil(W/O) microemulsions containing silver and halide, respectively. Phase behavior experiments for ternary systems containing AOT surfactant, hydrocarbon oil and aqueous solution of an inorganic salt showed that the region of one phase W/O microemulsion was found to be broadened with an increase in the alkyl chain length of a hydrocarbon mainly due to an increase in hydrophilic nature of a surfactant. With the information of phase behavior experiments, silver halide nanoparticles were prepared using different AOT-based microemulsion systems and photomicrographs obtained by transmission electron microscopy indicated that about 10 nm size particles of relatively spherical shape were obtained. It has been found that an increase in alkyl chain length of a hydrocarbon results in a decrease in particle size because of higher intermicellar exchange rate among microemulsion drops. The average particle size was also found to increase with the inorganic salt composition of initial aqueous solution.