• Title/Summary/Keyword: Agglomeration blocking

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Diameter Control of Carbon Nanotubes Using Surface Modified Fe Nano-Particle Catalysts with APS (APS로 표면 처리한 Fe 나노 입자 촉매를 이용한 CNT의 직경제어)

  • Lee, Sunwoo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.6
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    • pp.478-481
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    • 2013
  • Diameter controlled carbon nanotubes (CNTs) were grown using surface modified iron nano-particle catalysts with aminpropyltriethoxysilane (APS). Iron nano-particles were synthesized by thermal decomposition of iron pentacarbonyl-oleic acid complex. Subsequently, APS modification was done using the iron nano-particles synthesized. Agglomeration of the iron nano-particles during the CNT growth process was effectively prevented by the surface modification of nano-particles with the APS. APS plays as a linker material between Fe nano-particles and $SiO_2$ substrate resulting in blocking the migration of nano-particles. APS also formed siliceous material covering the iron nano-particles that prevented the agglomeration of iron nano-particles at the early stages of the CNT growth. Therefore we could obtain the diameter controlled CNTs by blocking agglomeration of the iron nano-particles.

Formulation Studies for Surface Modification and Application to Cosmetics of Jadeite Powder (경옥 가루 표면 개질과 화장품에의 응용을 위한 제형 연구)

  • Kim, Yong Woo;Park, Soo Nam
    • Applied Chemistry for Engineering
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    • v.30 no.2
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    • pp.167-177
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    • 2019
  • The jadeite powder has a disadvantage affecting the stability of the formulation due to the agglomeration of the powder when applied to cosmetic formulations. To overcome this problem, a new composite powder was prepared by modifying the surface of jadeite powder and applied to foundation pact and sun stick. In this study, a triethoxycaprylylsilane among various surface modifiers was selected as an optimum component, and applied to each formulation by making the jadeite powder composite. As a result, the foundation pact maintained the clarity of the product color, and the sun stick gave about 30% higher UV blocking effect in the UVB area compared with that of the blank. In the user sensory evaluation, the formulation containing the jadeite powder composite showed a high score for the overall indicator. The stability evaluation of the formulation was also confirmed that it was stable against discoloration, detachment and hardness. In conclusion, the jadeite powder composite is stable as an inorganic pigment which is applicable to cosmetics as a multifunctional material while maintaining the color clarity of the product and acting as a booster for sunscreen agents.