• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2650-2656
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• 2013

Mesoporous alumina was synthesized using bayberry tannin (BT) as template. This novel synthesis strategy was based on a precipitation method associated with aluminum nitrate as the source of aluminum in an aqueous system. $N_2$ adsorption/desorption, XRD, SEM and TEM were used to characterize the as-prepared mesoporous alumina. The results showed that the mesoporous alumina possessed crystalline pore wall, high specific surface area, narrow pore distribution and excellent thermal stability. Moreover, the surface area and pore size of the mesoporous alumina can be tuned by changing the experimental parameters. Further, the mesoporous alumina was investigated as the support of palladium catalyst ($Pd-Al_2O_3{^*}$) for the hydrogenation of propenyl, styrene and linoleic acid. For comparison, the reference catalyst ($Pd-Al_2O_3$) prepared without barberry tannin was also employed for the catalytic hydrogenation. The experimental results showed that $Pd-Al_2O_3{^*}$ exhibited the superior catalytic performance than $Pd-Al_2O_3$ for all the investigated substrates, especially for the hydrogenation of linoleic acid with larger molecular.

• 접착 및 계면
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• 제21권3호
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• pp.113-122
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• 2020

중간 세공체(mesoporous) 물질은 높은 표면적과 조절 가능한 기공 크기를 가진 규칙적인 다공성 구조로 최근 다양한 응용분야를 가진 매력적인 재료로 알려져 있다. 중간 세공체 물질 중 특히 유/무기 하이브리드형 실리카 나노세공체(Periodic Mesoporous Organosilica; PMO)는 세공의 크기가 확대되고 골격에 유기물을 도입함으로써 더욱 다양한 응용분야를 확보할 수 있는 새로운 재료로 큰 주목을 받고 있다. 골격 구조에 유기 그룹을 도입하게 되면 표면 물성과 재료 전체 물성의 제어가 가능하게 된다. 본 총설은 PMO의 합성, 기능성, 모폴로지는 물론이고 촉매나 환경분야 응용 등을 포함한 내용을 개괄적으로 고찰하였으므로, PMO의 주요 기능과 응용성에 대한 이해를 높이는데 기여할 것이다.

• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.193-196
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• 2009

Mesoporous $TiO_2$ material was synthesized from diblock copolymers with ethylene oxide chains via a sol-gel process in aqueous solution. The properties of these materials were characterized with several analytical techniques including field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), wide angle X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, and Barrett-Joyner-Halenda (BJH) analysis. The mesoporous $TiO_2$ materials calcined at 400${^{\circ}C}$ were found to have specific surface areas 212 $m^2g^-1$, average pore sizes 6.2 nm, and their average crystal sizes were found to be 8.2 nm. The photocatalytic activity of mesoporous $TiO_2$ was characterized with UV-Vis spectroscopy, and it was found to be 5.8 times higher than that of Degussa P25 $TiO_2$ (P25). For deactivation of Escherichia coli, mesoporous $TiO_2$ also has high photocatalytic inactivity than that of P25. Such a high photocatalytic activity is explained with large surface area and small crystal size with wormhole-like mesoporous structure.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.277-277
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• 2006

Conducting polymers (e.g. poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylen vinylene] (MEH-PPV)) confined in one-dimensional nanoscale channels of mesoporous materials, are expected to lead the novel applications for electroconductive and optoelectronic devices. We investigated the adsorption behavior of MEH-PPV on organically surface-modified mesoporous silica (FSM-16) and mesoporous organosilica. The amount of the confined MEH-PPV was found to strongly depend on the surface modifications of the mesoporous materials. The optical absorption edge of the confined MHE-PPV was clearly blue-shifted when compared to that of a free MHE-PPV.

• 한국환경과학회지
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• 제16권6호
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• pp.689-698
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• 2007

Mesoporous silicas for heavy metals adsorption were prepared by co-condensation of surfactant as a template and Ludox HS-40 as a silica precursor. Various mesoporous silicas with the introduction of chelating ligands (mercaptopropyl and aminopropyl groups) were synthesized to remove heavy metal ions from aqueous solutions. The surface modification was conducted with a co-condensation process using the sequential or simultaneous addition of mesoporous silica and high concentration of the organosilane(3-mercaptopropyltrimethoxysilane and 3-aminopropyltriethoxysilane). These materials have been characterized by elemental analysis, XRD, SEM and TEM analysis. Adsorbents synthesized with 3-mercaptopropyltrimethoxysilane and 3-aminopropyltriethoxysilane shows a high loading capacity for Hg(II), Pb(II), Cd(II) and anion Cr(VI). Especially the one synthesized with a mercaptopropyl function has the highest adsorption capacity for Hg(II) and Cd(II).

• 대한환경공학회지
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• 제30권6호
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• pp.673-679
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• 2008

본 연구에서는 실리카 원으로 tetraethylorthosilcate(TEOS)를 이용하고, template로 cetyltrimethylammonium bromide(CTMABr)을 사용하여 메조포러스 실리카(mesoporous silica)를 수열합성 하였다. 최적의 합성 조건을 알기 위해 template와 실리카의 몰비를 조절하였다. 메조포러스 실리카의 표면 성질과 구조는 XRD, SEM 그리고 BET를 이용하여 살펴보았다. 비표면적($S_{BET}$), 전체 기공부피(V$_T$), 그리고 평균 기공지름(D$_{BJH}$)을 포함하는 N$_2$ 등온 흡착 특성은 BET식을 이용하여 확인하였다. 또한, 메조포러스 실리카의 Pb(II)와 Cd(II)의 흡착 특성은 Zeta potential과 ICP를 이용하여 측정하였다. 그 결과, N$_2$ 등온 흡착으로부터 S$_{BET}$는 100$\sim$1,500 m$^2$/g이었으며, 평균 기공 크기는 2$\sim$4 nm이었다. 메조포러스 실리카의 Pb이온과 Cd이온의 흡착 특성은 용액의 pH변화에 의존하였고, 기존의 흡착제인 실리카겔보다 더 좋은 흡착 거동을 보였다.

• 전기화학회지
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• 제11권3호
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• pp.147-153
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• 2008

Improvement of the selectivity of nonenzymatic glucose based on mesoporous platinum ($H_1$-ePt) by using A.C. impedance is reported. The idea of the present work is based on the novel effect of the mesoporous electrode that the apparent exchange current due to glucose oxidation remarkably grows although the reaction kinetics on the surface is still sluggish. It is expected that the enlarged apparent exchange current on the mesoporous electrode can raise the sensitivity of admittance in A.C. impedance to glucose concentration. At a low frequency, A.C. impedance could become more powerful. The admittance at 0.01 Hz is even more sensitive to glucose than to ascorbic acid while amperometry exhibits the inverse order of sensitivity. This is the unique behavior that is neither observed by A.C. impedance on flat platinum electrode nor obtained by amperometry. The study shows how the combination of A.C. impedance and nano-structured surface can be applied to the detection of sluggish reaction such as electrochemical oxidation of glucose.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.132.2-132.2
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• 2010

Mesoporous tinoxide ($SnO_2$) as anode materials for Li-ion battery were prepared by hydrothermal method and templating method using SBA-15 as template. And electrochemical properties of $SnO_2$ electrode were investigated with cyclic voltammogram (CV). The morphology and structures of $SnO_2$ were characterized by transmission electron microscopy (TEM) and X-ray diffractometer (XRD), respectively. The specific surface area was defined by $N_2$ adsorption with BET(Brunauer-Emmett-Teller) method. As a result, the surface area of mesoporous $SnO_2$ which was made from templating method is higher than the case of using hydrothermal method. In addition, in anodic performance, mesoporous $SnO_2$ which is prepared by templating method showed higher charge-discharge capasity compared to hydrothermal method and exhibited excellent stability over the entire cycle number. It was indicated that electrochemical performances of mesoporous $SnO_2$mainly affected to the structural features, such as specific surface area and porosity.

• KEPCO Journal on Electric Power and Energy
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• 제7권1호
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• pp.167-169
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• 2021

In this study, monodispersive silica nanoparticles with double mesoporous shells were synthesized, and the pore size of synthetic mesoporous silica nanoparticles was controlled. Cetyltrimethylammonium chloride (CTAC), N, N-dimethylbenzene, and decane were used as soft template and induced to form outer mesoporous shell. The resultant double mesoporous silica nanoparticles were consisted of two layers of shells having different pore sizes, and it has been confirmed that outer shells with larger pores (Mean pore size > 2.5 nm) are formed directly on the surface of the smaller pore sized shell (Mean pore size < 2.5 nm). It was confirmed that the regulation of the molar ratio of pore expansion agents plays a key role in determining the pore size of double mesoporous shells.

• 한국분말재료학회지
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• 제17권3호
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• pp.209-215
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• 2010

Mesoporous alumina particles were prepared by spray pyrolysis using cetyltrimethyl-ammonium bromide (CTAB) as a structure directing agent and the effect of Al precursor types on the texture properties was studied using $N_2$ adsorption isotherms, small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The surface area and the microstructure of alumina particles were significantly influenced by the Al precursor type. The largest BET surface area was obtained when Al chloride was used, whereas alumina particles prepared from Al acetate had the largest pore volume. According to small-angle X-ray scattering (SAXS) analysis, the alumina powders prepared using nitrate and acetate precursors had a clear single SAXS peak around $2{\theta}=1.0{\sim}1.5^{\circ}$, indicating that regular mesopores with sponge-like structure were produced. On the basis of TEM, SAXS, and $N_2$ isotherm results, the chloride precursor was most profitable to obtain the largest surface area ($265\;m^2/g$), whereas, the nitrate precursor is useful for the preparation of non-hollow mesoporous alumina with regular pore size, maintaining high surface area (${\sim}233\;m^2/g$).