• 제목/요약/키워드: Nanoparticulates

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에너지 전달을 이용한 Polymetalloles의 응집에 의해 유도되는 광발광성의 증가 (Aggregation-induced photoluminescence enhancement of polymetalloles by energy migration)

  • 권형준;정대혁;송진우;장승현;김범석;권용희;조성동;손홍래
    • 센서학회지
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    • 제15권5호
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    • pp.303-308
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    • 2006
  • Aggregation-induced emissions of polymetalloles have been investigated since they are very attractive in their possible optoelectronic applications such as P-LED's and Sensors. Size of nanoparticulates was measured by using scanning electron micrograph and was about 200-300 nm. Phenylmethylpolysilane (PMPS) and polymetalloles emit the light at 360 nm and 520 nm, respectively. However, the aggregates of polymetallole containing PMPS exhibit an enhanced emission band at 520 nm, indicating that the energy transfer occurs from PMPS to polymetalloles in aggregates. Emission intensity of PMPS/polymetallole nanoparticulates at 520 nm increases depending on the aliquot of PMPS.

Impact of Nanoparticulates on Respiratory Health Effects

  • Warheit David B.
    • 한국환경성돌연변이발암원학회:학술대회논문집
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    • 한국환경성돌연변이발암원학회 2005년도 춘계 국제심포지엄 및 학술대회
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    • pp.40-50
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    • 2005
  • [ $\cdot$ ] Risk is a product of Hazard and Exposure $\cdot$ Cannot assume that nanomaterials are the same as their bulk counterpart $\cdot$ Each particle-type should be tested on a casse-by-case basis

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Effect of the Si-C Powder Prepared by Mechanical Alloying on the Densification of Silicon Carbide Powder

  • Yoon, Bola;Lee, Sea-Hoon;Lee, Heesoo;Hwang, Geumchan;Kim, Byungsook
    • 한국세라믹학회지
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    • 제53권1호
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    • pp.99-104
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    • 2016
  • High purity Si-C (99.999%) powder prepared by mechanical alloying was added to a commercial SiC powder as a sintering additive. Reaction bonded silicon carbide balls and jars with high purity (99.98%) were used for the mechanical alloying. As a result, the purity of the sintered Si-C was higher than 99.99%. When sintered at $2200^{\circ}C$ under 50 MPa pressure for 1 h, SiC containing 10 wt% of high purity Si-C showed a relative density of 95.3%, similar to the relative density of commercial SiC (95%). However, the relative density of SiC decreased to 90.6% without the additive when the applied pressure decreased to 40 MPa. In contrast, the relative density was nearly unaffected by the decrease of the pressure when using the Si-C additive. Therefore, the addition of Si-C powder promoted the densification of SiC above $2000^{\circ}C$ under 40 MPa pressure.

나피온/전도성 나노입자 전기방사 웹을 이용한 고성능 이온성 고분자-금속 복합체 구동기의 제조 (High-Performance Ionic Polymer-Metal Composite Actuators Based on Nafion/Conducting Nanoparticulate Electrospun Webs)

  • 정요한;이장우;유영태
    • 폴리머
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    • 제36권4호
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    • pp.434-439
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    • 2012
  • 이온성 고분자-금속 복합체(ionic polymer-metal composite, IPMC) 구동기의 구동성능 향상을 위해 전기방사를 통해 제조된 나피온/전도성 나노입자 웹을 나피온 필름의 양면에 접합시켜 전해질막을 개질하였다. 전도성 나노입자는 다층탄소나노튜브(multiwalled carbon nanotube, MWNT)와 은 나노입자가 사용되었으며, 이를 각각 나피온 용액에 분산시켜 전기방사하였다. 개질된 IPMC는 향상된 구동변위, 응답속도 및 구동력을 나타내었으며 은 나노입자에 비해 MWNT가 더욱 뛰어난 구동변위와 구동력을 유도하였고, 전도성 나노입자가 포함되지 않은 전기방사 웹을 적용한 경우에도 성능향상이 관찰되었다. 제조된 IPMC의 우수한 구동성능은 전기방사 웹의 다공성에 의한 전해액 이동의 용이성, 고분산된 전도성 나노입자에 의해 유도된 높은 전기용량 및 낮은 전극 저항 때문인 것으로 분석되었다.

Physicochemical Characteristics of Fe3O4 Magnetic Nanocomposites Based on Poly(N-isopropylacrylamide) for Anti-cancer Drug Delivery

  • Davaran, Soodabeh;Alimirzalu, Samira;Nejati-Koshki, Kazem;Nasrabadi, Hamid Tayefi;Akbarzadeh, Abolfazl;Khandaghi, Amir Ahmad;Abbasian, Mojtaba;Alimohammadi, Somayeh
    • 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.