• Title/Summary/Keyword: Macro-porous silica

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Adsorptive Immobilization of Acetylcholine Esterase on Octadecyl Substituted Porous Silica: Optical Bio-analysis of Carbaryl

  • Norouzy, Amir;Habibi-Rezaei, Mehran;Qujeq, Durdi;Vatani, Maryam;Badiei, Alireza
    • Bulletin of the Korean Chemical Society
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    • v.31 no.1
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    • pp.157-161
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    • 2010
  • A sensory element against carbaryl, as a widely used pesticide was prepared based on adsorbed acetylcholine esterase (AChE) from Torpedo california. Octadecyl was substituted on macro-porous silica, confirmed by infra-red (IR) spectroscopy and quantitatively estimated through thermo-gravimetric analysis (TGA). Immobilization of the enzyme was achieved by adsorption on this support. Activity of the immobilization product was measured as a function of the loaded enzyme concentration, and maximum binding capacity of the support was estimated to be 43.18 nmol.mg-1. The immobilized preparations were stable for more than two months at storage conditions and showed consistency in continuous operations. Possible application of the immobilized AChE for quantitative analysis of carbaryl is proposed in this study.

Fabrication and Characterization of Macro/Mesoporous SiC Ceramics from SiO2 Templates (실리카 주형을 이용한 메크로/메조다공성 탄화규소 세라믹의 제조와 비교특성)

  • ;Hao Wang
    • Journal of the Korean Ceramic Society
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    • v.41 no.7
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    • pp.528-533
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    • 2004
  • Macroporous SiC with pore size 84∼658 nm and mesoporous SiC with pore size 15∼65 nm were respectively prepared by infiltrating low viscosity preceramic polymer solutions into the various sacrificial templates obtained by natural sedimentation or centrifuge of 20∼700 nm silica sol, which were subsequently etched off with HF after pyrolysis at 1000∼140$0^{\circ}C$ in an argon atmosphere. Three-dimensionally long range ordered macroporous SiC ceramics derived from polymethylsilane (PMS) showed surface area 584.64$m^2$g$^{-1}$ when prepared with 112nm silica sol and at 140$0^{\circ}C$, whereas mesoporous SiC from polycarbosilane (PCS) exhibited the highest surface area 619.4 $m^2$g$^{-1}$ with random pore array when prepared with 20-30 nm silica sol and at 100$0^{\circ}C$. Finally, tile pore characteristics of porous SiC on the types of silica sol, polymers and pyrolytic conditions were interpreted with the analytical results of SEM, TEM, and BET instruments.

Fabrication of Silica and Titania Inverse Opals via Supercritical Deposition (초임계 증착법을 통한 실리카와 타이타니아 역 오팔의 제조)

  • Yu, Hye-Min;Lim, Jong-Sung
    • Clean Technology
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    • v.18 no.1
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    • pp.38-42
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    • 2012
  • Photonic crystals (PCs) are highly ordered porous materials which have been much attention because of its potential for controlling the light sauces. There are many methods for synthesizing this kind of materials among them we chose the supercritical deposition. With this method the reactants can easily infiltrate into the complex structure. In this paper, supercritical carbon dioxide ($scCO_2$) was used as a reaction medium, which is known as a sustainable solvent due to its nontoxic and noninflammable characteristics. We coated the colloidal template with metal alkoxide by using $scCO_2$ and then obtained macro-porous inverse opals. The reaction was carried out at $40^{\circ}C$ and 80 bar. We synthesized two different inverse opals which called silica and titania inverse opals by use of tetraethyl orthosilicate (TEOS) and titanium isopropoxide (TTIP) as a precursor, respectively.

Synthesis of Nano Structured Silica and Carbon Materials and Their Application (계면활성제를 이용한 나노 실리카 및 카본 소재의 합성과 응용)

  • Park Seungkyu;Kim Jongyun;Cho Wangoo
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.30 no.3 s.47
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    • pp.321-328
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    • 2004
  • Nano silica ball and nano carbon ball are developed commercially by template synthesis method. Adsorption of unpleasant smelling substances such as ammonia, trimethylamine, acetaldehyde and methyl mercaptane onto nano carbon ball with hollow macroporous core/mesoporous shell structures, nano carbon ball, was investigated and compared with that onto odor adsorbent materials, activated carbon, commercially available. The adsorption and decomposition of malodor at nano carbon ball exhibited superior than those onto activated carbon. The physicochemical properties such as mesopore size distributions, large nitrogen BET specific surface area and large pore volume and decomposition of malodor were studied to interpret the predominant adsorption performance. The nano carbon ball is expected to be useful in many applications such as deodorizers, adsorbent of pollutants.