• Title/Summary/Keyword: nanocapsules

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Characterization and Electrical Conductivity of Carbon-Coated Metallic (Ni, Cu, Sn) Nanocapsules

  • Wang, Dong Xing;Shah, Asif;Zhou, Lei;Zhang, Xue Feng;Liu, Chun Jing;Huang, Hao;Dong, Xing Long
    • Applied Microscopy
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    • v.45 no.4
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    • pp.236-241
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    • 2015
  • Carbon-coated Ni, Cu and Sn nanocapsules were investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM) and a four-point probe device. All of these nanocapsules were prepared by an arc-discharge method, in which the bulk metals were evaporated under methane ($CH_4$) atmosphere. Three pure metals (Ni, Cu, Sn) were typically diverse in formation of the carbon encapsulated nanoparticles and their different mechanisms were investigated. It was indicated that a thick carbon layers formed on the surface of Ni(C) nanocapsules, whereas a thin shell of carbon with 1~2 layers covered on Cu(C) nanocapsules, and the Sn(C) nanocapsules was, in fact, a longger multi-walled carbon nanotubes partially-filled with metal Sn. As one typical magnetic/dielectric nanocomposite particles, Ni(C) nanocapsules and its counterpart of oxide-coated Ni(O) nanocapsules were compared in the electrically conductive behaviors for further applications as the electromagnetic materials.

Preparation and Study of Bioactive Characteristics of Alginate Sponge Containing Quercetin-encapsulated Nanocapsules (쿼세틴 담지 나노캡슐을 함유한 알지네이트 스펀지의 제조 및 생리활성 특성)

  • Kim, Woo Jin;Xu, Shuwen;Noh, Hyun Soo;Lee, Hyun Ju;Jeon, Jae Woo;Ghim, Han Do
    • Textile Coloration and Finishing
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    • v.31 no.4
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    • pp.341-353
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    • 2019
  • Quercetin is one of flavonoids widely distributed in the plants and well known to have antioxidants, antiinflammatory, antimicrobial properties. In this study, alginate sponge containing quercetin-encapsulated nanocapsules was prepared by miniemulsion polymerization, dyring/crosslinking method and their bioactive characteristics were investigated. Alginate sponge containing quercetin-encapsulated nanocapsules were evaluated using a field emission scanning electron microscope(FE-SEM), a high performance liquid chromatography, cell viability, DPPH radical scavenging activity and antibacterial activity. The study indicates that alginate sponge containing quercetin-encapsulated nanocapsules had significant antioxidant, antiinflammatory and antibacterial activities. This study suggested that alginate sponge containing quercetin-encapsulated nanocapsules can be a potential candidate for medical materials.

Characterization of Fe Nanocapsules synthesized by Plasma Arc Discharge Process (플라즈마 아크방전(PAD)법으로 제조된 Fe Nanocapsules의 특성)

  • Park Woo-Young;Youn Cheol-Su;Yu Ji-Hun;Oh Young-Woo;Choi Chul-Jin
    • Journal of Powder Materials
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    • v.11 no.6 s.47
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    • pp.510-514
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    • 2004
  • Iron-carbon nanocapsules were synthesized by plasma arc discharge (PAD) process under various atmosphere of methane, argon and hydrogen gas. Characterization and surface properties were investigated by means of HRTEM, XRD, XPS and Mossbauer spectroscopy. Fe nanocapsules synthesized were composed of three phases $({\alpha}-Fe,\;Y-Fe\;and\;Fe_{3}C)$ with core/shell structures. The surface of nanocapsules was covered by the shell of graphite phase in the thickness of $4{\~}5$nm.

Preparation and Properties of Poly($\varepsilon$-caprolactone) Nanocapsules Containing Phytoncide Oil by Emulsion-diffusion Method(1) (유화확산법을 이용한 피톤치드오일 함유 폴리입실론카프로락톤 나노캡슐의 제조와 성질(1))

  • Jeong, Cheon-Hee;Kim, Hea-In;Park, Soo-Min
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2008.04a
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    • pp.114-116
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    • 2008
  • Poly(${\varepsilon}$-caprolactone) nanocapsules(nanoPCL) containing phytoncide oil were synthesized by emulsion diffusion method using ethyl acetate as organic solvent. The influence of the degree of hydrolyzation of poly(vinyl acohol) used as an emulsion stabilizer, and the different weight ratio of core material to wall material on the particle size, morphology, and emulsion stability was investigated to design nanocapsules. The encapsulated nanoPCL were characterized by FT-IR spetrometry, Scanning electron microscope, Differential scanning calorimetry, and Thermogravimetry analysis, respectively.

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Preparation of Nanocapsules Containing Phase Change Materials by Miniemulsion Polymerization

  • Oh, Keun Jin;Kim, Dae-Su;Lee, Jae Heung;Choi, Kil-Yeong;Lee, Changjin
    • Journal of Adhesion and Interface
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    • v.4 no.1
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    • pp.35-42
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    • 2003
  • Polystyrene nanocapsules containing octadecane as a core material were prepared by miniemulsion polymerization. The morphology and size of the nanocapsules were measured with varying the surfactant concentration, content of initiator, core/shell ratio and content of comonomer. The morphologies of the prepared nanoparticles were examined by a scanning electron microscope, a transmission electron microscope and the core material was confirmed by a differential scanning calorimeter. The particles below 70 nm in diameter were formed at a high surfactant concentration. The size of the nanoparticles was not significantly affected by the initiator content. With increasing the core/shell ratio and polar comonomer content, the particle size and its distribution were increased.

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Preparation of γ-oryzanol-loaded pectin micro and nanocapsules and their characteristics according to particle size (감마오리자놀 함유 칼슘-펙틴 미세 및 나노캡슐의 제조와 입자 크기에 따른 캡슐특성)

  • Lee, Seul;Kim, Eun Suh;Lee, Ji-Soo;Lee, Hyeon Gyu
    • Korean Journal of Food Science and Technology
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    • v.49 no.1
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    • pp.110-116
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    • 2017
  • ${\gamma}-Oryzanol-loaded$ calcium-pectin micro- and nanocapsules were prepared by ionic gelation to improve oxidation stability and the effect of particle size on capsule properties was investigated. The physical properties were influenced by preparation conditions such as concentrations of pectin, $CaCl_2$, ${\gamma}-oryzanol$, and hardening time. Particle sizes of micro- and nanocapsules that showed the maximum encapsulation efficiency and sustained release were $2.27{\pm}0.02mm$ and $347.7{\pm}58.1nm$, respectively. Microcapsules showed higher encapsulation efficiency ($50.73{\pm}1.98%$) than nanocapsules ($17.70{\pm}2.04%$), while nanocapsules showed more sustained release and higher stability than microcapsules. Release of ${\gamma}-oryzanol$ from both microand nanocapsules, which was low in gastric environments and promoted in intestinal environments, showed suitable characteristics for oral administration. Furthermore, antioxidant activity of ${\gamma}-oryzanol$ against autoxidation of linoleic acid was prolonged by both micro- and nanoencapsulation in a ferric thiocyanate test. Therefore, micro- and nanoencapsulation using pectin can be effective for improving biodelivery, stability, and antioxidant activity of ${\gamma}-oryzanol$.

Preparation and Properties of Poly($\varepsilon$-caprolactone) Nanocapsules Containing Tricrecyl phosphate by Emulsion-diffusion Method (유화확산법을 이용한 트리크리실 포스페이트 폴리입실론카프로락톤 나노캡슐의 제조와 성질)

  • Jeong, Cheon-Hui;Park, Yun-Jeong;Kim, Hye-In;Park, Su-Min
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2008.10a
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    • pp.69-70
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    • 2008
  • The study has attempted to prepare nanocapsules containing Tricrecyl phosphate by Emulsion-diffusion method. The study has focused on finding a optimum condition for preparering nano capsules and effect on size distribution and surface morphology.

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Synthesis and Microstructure of Fe(C) Nanocapsules by Chemical Vapor Condensation (화학기상응축공정으로 제조한 Fe(C) 나노캡슐의 합성 및 미세구조)

  • Lee Jung-Han;Kim Sung-Duk;Kim Jin-Chun;Choi Chul-Jin;Lee Chan-Gyu
    • Journal of Powder Materials
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    • v.11 no.6 s.47
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    • pp.515-521
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    • 2004
  • Fe(C) nanocapsules were prepared by the chemical vapor condensation(CVC) process using the pyrolysis of iron pentacarbonyl $(Fe(CO)_5)$. Their characterizations were studied by means of X-ray diffraction, X-ray photoelectron spectrometer and transmission electron microscopy. The long-chained Fe(C) nanocapsules hav-ing the mean size of under 70 nm could be obtained below $1100^{\circ}C$ in different gas flow rates. The particle size of the powders was increased with increasing decomposition temperature, but it was decreased with increasing CO gas flow rate. The Fe powders produced at $500^{\circ}C$ consisted of three layers of ${\alpha}$-Fe/$Fe_3C$/amorphous phases, but it had two phase core-shell structure which consited of $Fe_3C$ phase of core and graphite of shell at $1100^{\circ}C$.

Morphological Properties of Poly(ε-caprolactone) Nano/Microcapsules Prepared by Emulsion-diffusion Method (유화-확산법에 의해 제조된 폴리(ε-카프로락톤) 나노/마이크로캡슐의 형태적 특성)

  • Kim, Hea-In;Jeong, Cheon-Hee;Park, Soo-Min
    • Textile Coloration and Finishing
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    • v.22 no.3
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    • pp.229-238
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    • 2010
  • Poly($\varepsilon$-caprolactone) nano/microcapsules(nmcPCL) containing phytoncide oil were synthesized by emulsion diffusion method using ethyl acetate and poly(vinyl alcohol) (PVA) as an organic solvent and an emulsion stabilizer respectively. The influence of the degree of saponofication of the PVA and the weight ratio of core to wall materials was investigated to design nanocapsules in terms of particle size, morphology, and emulsion stability. The encapsulated nmcPCL were characterized by FT-IR spectrometry, particle size analyzer and scanning electron microscope. Mean size of nanocapsules prepared with PVA with a degree of saponofication of 87% was smaller than those of PVA with a degree of saponofication of 98.5% and the mean particle size of the capsules decreased with increasing core/shell ratio.

Characteristics of Glycyrrhiza uralensis extract-loaded chitosan nanocapsules and their antioxidant activity (감초 추출물 함유 키토산 나노캡슐의 특성 및 항산화 활성)

  • Kim, Min Jung;Lee, Ji-Soo;Lee, Hyeon Gyu
    • Korean Journal of Food Science and Technology
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    • v.53 no.4
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    • pp.479-485
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    • 2021
  • To improve the oxidative stability of Glycyrrhiza uralensis extract (GU), GU extraction conditions were optimized for maximal antioxidant activity, and GU-loaded nanocapsules were prepared by chitosan ionic gelation. The optimized ethanol concentration and extraction time were 83.0% and 32.6 min, respectively, using response surface methodology. The particle size of the GU-loaded nanocapsules ranged from 280 to 370 nm. A GU extract of 0.8 mg/mL and chitosan concentration of 2.0 mg/mL were selected as the optimal conditions for entrapment and loading efficiency. Both free GU and GU-loaded chitosan nanocapsules exhibited concentration-dependent antioxidant activity. However, the antioxidant protection factor of GU was effectively maintained when it was entrapped within the chitosan nanocapsules. In conclusion, chitosan nanoencapsulation is a potentially valuable technique for improving the oxidative stability of GU.