• Carbon letters
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• v.11 no.2
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• pp.90-95
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• 2010

Carbon materials such as graphite and graphene exhibit high electrical conductivity. We examined the electrical conductivity of synthetic and natural graphene powders after the chemical reduction of synthetic and natural graphite oxide from synthetic and natural graphite. The trend of electrical conductivity of both graphene (synthetic and natural) was compared with different graphite materials (synthetic, natural, and expanded) and carbon nanotubes (CNTs) under compression from 0.3 to 60 MPa. We found that synthetic graphene showed a marked increment in electrical conductivity compared to natural graphene. Interestingly, the total increment in electrical conductivity was greater for denser graphite; however, an opposite behavior was observed in nanocarbon materials such as graphene and CNTs, probably due to the differing layer arrangement of nanocarbon materials.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.230-233
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• 2003

New photopolymers were designed and prepared using the photosensitive polymer binders. The photochemical reaction of the photosensitive polymer binder was studied by virtue of UV absorption and infrared spectroscopy. The holographic gratings were successfully fabricated in these photopolymer film samples by conventional optical interference method. We also investigated the effect of photocrosslink in the polymer binder on the diffraction behavior of the photopolymer. The dynamic behaviors of the grating formation were studied with the change of exposure intensity in terms of the diffraction efficiency. Particularly, we focused our efforts to observe the variation of the diffraction efficiency during post UV curing process.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.1025-1032
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• 2008

(4,5-Dichloro-6-oxo-6H-pyridazin-1-yl)phosphoric acid diethyl ester (3a) are efficient and selective coupling agents for the amidation of carboxylic acids. Amidation of aliphatic and aromatic carboxylic acids with aliphatic and aromatic amines using 3a under mild condition gave chemoselectively the corresponding amides in good to excellent yield. Three protected-dipeptides were also synthesized from N-BOC-Phe and O-Me-amino acid hydrochlorides using 3a under mild condition.

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.163.3-164
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• 2000

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2819-2821
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• 2013

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.1
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• pp.54-61
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• 2000

Covering rate, visual rating and sod development were evaluated under three natural fiber materials with Phragmites spp. when over a plastic sheet. The results were as follows. (1) The last covering rate was high on jute net, coir mat and on Miscanthus sacchariflorus, respectively while the early covering rate was high on coir mat and on Miscanthus sinensis+perennial ryegrass. (2) The early growth was good on perennial ryegrass but the covering rate gradually turned poor because of summer drought. (3) Sod was highly developed on Phragmites japonica, Miscanthus sacchariflorus and Miscanthus sinensis compared with other species and mixtures. (4) The covering rate and visual rating were high on natural fiber materials such as coir mat and jute net when compared with on natural fiber materials such as none treatment plots. (5) The natural fibers materials on Phragmites spp. and Miscanthus spp. were effect on sod establishment. Sod coir mat was highly established. (6) The carpet-type sod was best developed on the coir mat.

• Proceedings of the Korean Magnestics Society Conference
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• 2015.05a
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• pp.30-31
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• 2015

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3848-3851
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• 2010

• Proceedings of the Korean Magnestics Society Conference
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• 2015.11a
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• pp.98-98
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• 2015

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3810-3816
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• 2012

Here we report our recent result of a new semiconductor material, which has an asymmetric structure. The synthesized molecules consist of anthracene and thiophene connected by bridged ethylene and substituted with hexyl or dodecyl groups as pendants. The semiconductors were synthesized using a McMurry coupling reaction between anthracene-2-carbaldehyde and corresponding 5-hexyl(or dodecyl)thiophene-2-carbaldehyde. A first investigation of synthesized asymmetry AVHT (9a) and AVDT (9b) for the physical properties showed that they have high oxidation potential and thermal stability. The devices prepared by using AVHT (9a) and AVDT (9b) showed the mobility of $2.6{\times}10^{-2}cm^2/Vs$ and $4.4{\times}10^{-3}cm^2/Vs$, respectively, in solution processed OTFTs.