• 한국재료학회지
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• 제31권11호
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• pp.593-600
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• 2021

Herein, a series of g-C₃N₄ modified Bi₂MoO₆ nanocomposites using Bi₂MoO₆ and melamine as original materials are fabricated via sintering process. For presynthesis of Bi₂MoO₆ an ultrasonic-assisted hydrothermal technique is researched. The structure and composition of the nanocomposites are characterized by Raman spectroscopy, X-ray diffraction (XRD), and high-resolution field emission scanning electron microscopy (SEM). The improved photoelectrochemical properties are studied by photocurrent density, EIS, and amperometric i-t curve analysis. It is found that the structure of Bi₂MoO₆ nanoparticles remains intact, with good dispersion status. The as-prepared g-C₃N₄/Bi₂MoO₆ nanocomposites (BMC 5-9) are selected and investigated by SEM analysis, which inhibits special morphology consisting of Bi₂MoO₆ nanoparticles and some g-C₃N₄ nanosheets. The introduction of small sized g-C₃N₄ nanosheets in sample BMC 9 is effective to improve the charge separation and transfer efficiency, resulting in enhancing of the photoelectric behavior of Bi₂MoO₆. The improved photoelectronic behavior of g-C₃N₄/Bi₂MoO₆ may be attributed to enhanced charge separation efficiency, photocurrent stability, and fast electron transport pathways for some energy applications.

• 한국유변학회:학술대회논문집
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• 한국유변학회 2001년도 Australian-Korean Rheology Conference 2001
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• pp.156.3-156
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• 2001

(No abstract, see full-text)

• 폴리머
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• 제34권4호
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• pp.294-299
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• 2010

아미노실란 처리된 점토를 제조하여, 이를 분자량이 서로 다른 폴리프로필렌(140 kg/mol과 410 kg/mol) 과 상용화제인 무수말레인산 그래프트 폴리프로필렌(50 kg/mol)과 함께 $170^{\circ}C$ 및 $190^{\circ}C$에서 용융혼합법으로 각각의 폴리프로필렌/점토 나노복합체를 제조하였다. 무수말레인산 그래프트 폴리프로필렌과 용융혼합과정에서 낮은 분자량의 폴리프로필렌은 점토 층 사이로 쉽게 침투하여 층간 거리를 58 $\AA$ 이상으로 증가시키지만, 첨가된 점토는 60~80 nm 두께의 응집체로 나노복합체 내에 분산상을 이룬다. 이와 달리 높은 분자량의 폴리프로필렌 기반 나노복합체에서는 점토는 27 $\AA$로 낮은 박리 정도를 보이며, 전반적으로 고른 점토 분산상을 형성한다. 분자 량 및 용융혼합공정의 차이에 따른 폴리프로필렌/점토 나노복합체의 미세 모폴로지 차이로 기계적 물성 및 결정 화거동이 관찰되었으며, 분자량 410(kg/mol)인 폴리프로필렌은 개질된 점토를 1~3 wt% 첨가함으로써 순수 폴 리프로필렌의 연성특성을 유지하면서 향상된 인장강도와 탄성률을 보였다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 추계학술발표대회 논문집
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• pp.6-8
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• 2004

A big boom in nanocomposites research has landed also in Japan. As a virtual 'center of excellence' in composites technology there, ACE TeC of ISTA/JAXA has led pioneering portions of nanocomposites research particularly in mechanical properties oriented applications. An overview of research activities based on nano-technologies in ACE TeC/JAXA will be given first and some remarkable results will be introduced briefly.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 춘계총회 및 연구발표회 초록집
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• pp.150.1-150
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• 2003

• 한국유변학회:학술대회논문집
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• 한국유변학회 2000년도 추계 학술발표회 논문집
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• pp.48-51
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• 2000

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.49-54
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• 2014

Background: Hydrogels are a class of polymers that can absorb water or biological fluids and swell to several times their dry volume, dependent on changes in the external environment. In recent years, hydrogels and hydrogel nanocomposites have found a variety of biomedical applications, including drug delivery and cancer treatment. The incorporation of nanoparticulates into a hydrogel matrix can result in unique material characteristics such as enhanced mechanical properties, swelling response, and capability of remote controlled actuation. Materials and Methods: In this work, synthesis of hydrogel nanocomposites containing magnetic nanoparticles are studied. At first, magnetic nanoparticles ($Fe_3O_4$) with an average size 10 nm were prepared. At second approach, thermo and pH-sensitive poly (N-isopropylacrylamide -co-methacrylic acid-co-vinyl pyrrolidone) (NIPAAm-MAA-VP) were prepared. Swelling behavior of co-polymer was studied in buffer solutions with different pH values (pH=5.8, pH=7.4) at $37^{\circ}C$. Magnetic iron oxide nanoparticles ($Fe_3O_4$) and doxorubicin were incorporated into copolymer and drug loading was studied. The release of drug, carried out at different pH and temperatures. Finally, chemical composition, magnetic properties and morphology of doxorubicin-loaded magnetic hydrogel nanocomposites were analyzed by FT- IR, vibrating sample magnetometry (VSM), scanning electron microscopy (SEM). Results: The results indicated that drug loading efficiency was increased by increasing the drug ratio to polymer. Doxorubicin was released more at $40^{\circ}C$ and in acidic pH compared to that $37^{\circ}C$ and basic pH. Conclusions: This study suggested that the poly (NIPAAm-MAA-VP) magnetic hydrogel nanocomposite could be an effective carrier for targeting drug delivery systems of anti-cancer drugs due to its temperature sensitive properties.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.550-551
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• 2012

Physically responsive field-effect transistors (physi-FETs), which are sensitive to physical stimuli, have been studied for decades. However, the primary issue of separating responses by sensing materials from interferences by other subcomponents in a FET transducer under global physical stimuli has not been completely resolved. Recent challenges of structural design and employing smart materials with a large electro-physical coupling effect for flexible physi-FETs still remain. In this article, we propose directly integrating nanocomposites of barium titanate (BT) nanoparticles (NPs) and highly crystalline poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) as gate dielectrics into flexible organic FETs to precisely separate and quantify tiny variations of remnant polarization caused by mechanical stimuli. Investigations under static stimuli resulted in first-reported giant-positive piezoelectric coefficients of d33 up to 960 pC/N, presumably due to significant contribution of the intrinsic piezoelectricity of BT NPs and P(VDF-TrFE) crystallites. This approach provides a general research direction, and not limited to physic-FETs.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.2049-2056
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• 2014

A simple method for exfoliating pristine graphite to yield mono-, bi-, and multi-layers of graphene sheets as a highly concentrated (5.25 mg/mL) and yielded solution in an organic solvent was developed. Pre-thermal treatment of pristine graphite at $900^{\circ}C$ in a sealed stainless steel bath under high pressures, followed by sonication in 1-methyl-2-pyrrolidinone solvent at elevated temperatures, produced a homogeneous, well-dispersed, and non-oxidized graphene solution with a low defect density. The electrical conductivities of the graphene sheets were very high, up to 848 S/cm. These graphene sheets were used to fabricate graphene-polyimide nanocomposites, which displayed a higher electrical conductivity (1.37 S/m) with an improved tensile strength (95 MPa). The synthesized graphene sheets and nanocomposites were characterized by transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy.

• 한국세라믹학회지
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• 제52권6호
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• pp.502-507
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• 2015

We examined the photo catalytic activity and catalytic recyclability of CdSe/graphene nanocomposites fabricated via modified hydrothermal technique. The prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX), transmission electron microscopy (TEM), Raman spectroscopic analysis, and X-ray photoelectron spectroscopy (XPS). The photocatalytic behavior was investigated through decomposition of RBB as a standard dye under visible light radiation. Our results indicate that there is significant potential for graphene based semiconductor hybrids materials to be used as photocatalysts under visible light irradiation for the degradation of organic dyes from industry effluents.