• Title/Summary/Keyword: Nanoparticulates

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

  • Kwon, Hyung-Jun;Jung, Dae-Hyuk;Song, Jin-Woo;Jang, Seung-Hyun;Kim, Bum-Seok;Kwon, Yong-Hee;Cho, Sung-Dong;Sohn, Hong-Lae
    • Journal of Sensor Science and Technology
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    • v.15 no.5
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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.
    • Proceedings of the Korea Environmental Mutagen Society Conference
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    • 2005.05a
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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
    • Journal of the Korean Ceramic Society
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    • v.53 no.1
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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.

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

  • Jung, Yo-Han;Lee, Jang-Woo;Yoo, Young-Tai
    • Polymer(Korea)
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    • v.36 no.4
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    • pp.434-439
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    • 2012
  • To improve the performance of ionic polymer-metal composite (IPMC) actuators, Nafion films sandwiched with Nafion/conducting nanoparticulate electrospun webs were used as polymer electrolytes of IPMC. Multiwalled carbon nanotube (MWNT) and silver were the conducting nanoparticulates and the nanoparticles dispersed in a Nafion solution were electrospun. IPMCs with the Nafion/conducting nanoparticulate electrospun webs displayed improved displacements, response rates, and blocking forces. MWNT was superior to silver in terms of displacement and blocking force, and the webs without the conducting fillers also caused enhanced performances compared with the conventional IPMCs. These improvements were attributed to an elevated electrolyte flux through highly porous interlayers and capacitance induced by well dispersed conducting fillers, and low interfacial resistance between electrolyte and electrodes.

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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    • v.15 no.1
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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.