• Journal of the Society of Naval Architects of Korea
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• v.40 no.1
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• pp.55-62
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• 2003

This study has investigated physical and chemical properties of FRP waste, has manufactured polymer cement mortar using a crushed waste with sand and has evaluated its capability to develop the economical waste recycling technology. The study has investigated tension strength, hardness test and impact test as physical properties and also thermogravimetric characteristics and analyzed infrared spectroscope as chemical properties. Then the study has manufactured polymer cement mortar and has analyzed how the FRP waste fine aggregate replacement ratio has an effect on compression strength. Noticing admixture can complement strength drop occurred by the FRP waste fine aggregate replacement, the study examined an optimum rate of admixture addition and its reaction through electron microscope photos.

• Polymer(Korea)
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• v.38 no.4
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• pp.464-470
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• 2014

A chemo-mechanical method was used to prepare lignin-containing cellulose nanofibrils(L-CNF) from unbleached woodpulps dispersed uniformly in an organic solvent. L-CNF/PLA composites were obtained by solvent casting method. The effects of L-CNF concentration on the composite performances were characterized by tensile test machine, contact angle machine, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). The tensile test results indicated that the tensile strength and elongation-at-break increased by 50.6% and 31.8% compared with pure PLA. The contact angle of PLA composites decreased from $79.3^{\circ}$ to $68.9^{\circ}$. The FTIR analysis successfully showed that L-CNF had formed intermolecular hydrogen bonding with PLA matrix.

• Journal of the Korean Ceramic Society
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• v.54 no.4
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• pp.298-302
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• 2017

To investigate the influence of alkaline impurity K content on bubbles of quartz glass, samples were prepared based on $SiO_2$ sand with differing amounts of potassium hydroxide solution added by electric fusion. Bubble properties such as number, diameter and bubble fraction were determined using a stereoscopic microscope. The results of the observations indicated that an alkaline impurity content of 100 ppm had a good effect on bubble decline in quartz glass. The effect on OH was investigated by FTIR(Fourier transform infrared spectroscopy).

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.859-862
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• 2003

Well-aligned multiwall carbon nanotubes (MWCNTs) were prepared at low temperature of 400 $^{\circ}C$ by utilizing a radio frequency plasma-enhanced chemical vapor deposition (rf-PECVD) system. The MWCNTs were treated by an external rf plasma source and an ultra-violet laser in order to modify structural defect of carbon nanotube and to ablate possible contamination on carbon nanotube surface. Structural properties of carbon nanotubes were investigated by using a scanning electron microscopy (SEM), Raman spectroscopy, Fourier transformer Infrared spectroscopy (FTIR) and transmission electron microscope (TEM). In addition, the emission properties of the MWNTs were measured for the application of field emission display (FED) in near future. Various post treatments were found to improve the field emission property of carbon nanotubes.

• Preventive Nutrition and Food Science
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• v.6 no.2
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• pp.112-116
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• 2001

Oxidized potato starch/polyethylene (PE) cast films were prepared with different percentages of linear low density PE (LLDPE), oxidized potato starch and prooxidant. For the determination of biodegradability of the films, lignocellulose-degrading Streptomyces viridosporus T7A (ATCC 39115) was used. Films were chemically disinfected and incubated with S. viridosporus by shaking at 100 rpm at 37$^{\circ}C$ for eight weeks. Hydroxyl indices of the films by Fourier-Transform Infrared Spectroscopy, mechanical Properties of the films by Instron and film morphology by scanning electron microscope (SEM) were measured. The hydroxyl index of the film containing the oxidized potato starch incubated with S. viridosporus T7A was higher than that of the corresponding control. All the films containing 5% and 10% oxidized starch showed a decrease of tensile strength on the films after incubation when the corresponding uninoculated film was compared. In the oxidized starch/PE film incubated with S. viridosporus T7A, partial destruction of starch and PE was examined by SEM.

• Fibers and Polymers
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• v.7 no.3
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• pp.235-240
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• 2006

Polyacrylonitrile (PAN) fiber was grafted with casein after alkaline hydrolysis and chlorination reactions of the original fiber. The structures and morphologies of the casein grafted fiber were characterized by Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), and scanning electron microscope (SEM). Moisture absorption, specific electric resistance, water retention value, and mechanical properties were also investigated. The results showed that casein was grafted onto the surface of the PAN fiber and the grafted PAN fiber presented better hygroscopicity compared with the untreated fiber. With proper tensile strength, the modified fiber could still meet the requirement for wearing. A mechanism was proposed to explain the deposit of casein on the synthetic acrylic fiber.

• Carbon letters
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• v.21
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• pp.74-80
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• 2017

A highly facile and eco-friendly green synthesis of Annona squamosa (custard apple) leaf extract reduced graphene oxide (CRG) nanosheets was achieved by the reduction of graphene oxide (GO). The as-prepared CRG was characterized with X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-Vis), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopic techniques. Removal of oxygen containing moieties from the GO was confirmed by UV-Vis, FT-IR and XPS spectroscopic data. The XRD and Raman data further confirmed the formation of the CRG. TEM images showed the sheet structure of the synthesized CRG. These results show that the phytochemicals present in custard apple leaf extract act as excellent reducing agents. The CRG showed good dispersion in water.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2680-2686
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• 2009

The synthesis of a novel superabsorbent hydrogel with natural hybrid backbone via graft copolymerization of acrylamide (AAm) onto kappa-carrageenan (kC, as a polysaccharide) and gelatin (as a protein) under classic thermal conditions is described. The Taguchi method as a strong experimental design tool was used for synthesis optimization. A series of hydrogels were synthesized by proposed conditions of Qualitek-4 Software. Considering the results of 9 trials according to analysis of variance (ANOVA), optimum conditions were proposed. The swelling behavior of optimum hydrogel was measured in various solutions with pH values ranging from 1 to 13. In addition, swelling kinetics, swelling in various organic solvents, various salt solutions and On–Off switching behavior were investigated. The hydrogel formation was confirmed by Fourier transform infrared spectroscopy (FTIR) and thermogravimetrical analysis (TGA). Surface morphology of the synthesized hydrogels was assessed by scanning electron microscope (SEM).

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.149-153
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• 2013

The chemical functionalization of carboxylated multi-walled carbon nanotubes (MWCNT-COOH) by creatinine (MWCNT-Amide) and latter modification with 2-aminobenzophenone for producing 1-methyl-9-phenyl-1H-imidazo[4,5-b]quinolin-2-amine (MWCNT-quino) have been investigated. All products were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscope, elemental analysis, thermogravimetric analysis, derivative thermogravimetric and cellular investigations. The interesting point is that MWCNT-quino can be homogeneously dispersed in dimethylformamide and to some extent in ethyl alcohol without sonication. Also, MTT assay was used to examine the behavior of cell proliferation after 48 h of cell culture experiments. Cellular results showed high toxicity of MWCNT-quino on the cancer cells. These functionalizations have been chosen due to active sites of carbonyl and methylene groups in MWCNT-Amide and the creating quinoline derivative on the MWCNTs for future application.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1536-1537
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• 2007

본 논문은 당뇨병의 지표 물질인 glucose의 농도를 극미량의 시료를 사용하여 정량할 수 있는 방법을 개발하기 위해 organic/inorganic 네트웍에 의해 안정화된 나노입자 효소를 이용하여 초소형 효소 전극을 개발하였다. 전극은 실리콘 웨이퍼상에 반도체 공정을 이용하여 마이크로 크기의 금 박막 전극을 제작하였다, Organic/Inorganic 물질과 함께 합성된 glucose oxidase 나노입자는 20nm 크기로 투과형 전자현미경 (Transmission Electron Microscope:TEM)으로 관찰하고, 푸리에변환 적외선분광법(Fourier transform infrared spectrophotometer : FTIR) 을 이용하여 분석하였고, 전극 특성을 알아보기 위해 Potentiostat/Galvanostat을 사용하여 전기 화학 실험을 하였다. 제작된 전극은 시간대 전류법으로 glucose의 농도에 따른 감도를 측정하였다. 실험결과에 따라 전극의 표면에서 발생하는 전류는 glucose의 농도에 비례함을 알 수 있었다. 또한 순환 전압전류법을 통하여 감도를 측정하였다.