Porous Texture and Surface Character of Dehydroxylated and Rehydroxylated MCM-41 Mesoporous Silicas—Analysis of Adsorption Isotherms of Nitrogen Gas and Water Vapor

Naono, Hiromitu; Hakuman, Masako; Tanaka, Takashi; Tamura, Nobuki; Nakai, Kenta

doi:10.1006/jcis.2000.6777

Cited by 29 publications

(36 citation statements)

References 23 publications

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“…The precursors of PS-C10 were prepared as follows: The precursors of PS-C10 and PS-C18n were calcined at 823 K under a nitrogen flow for 6 h and then under an air flow for 2 h. In this process, the surfactant was removed from the precursor, giving the mesoporous silica. Preparation of the other mesoporous silicas (PS-C12, PS-C14, PS-C16, and PS-C18) were reported in previous papers (14).…”

Section: Preparation Of Mcm-41mentioning

confidence: 98%

“…In the previous work, the d (100) values for PS-C12, PS-C14, PS-C16, and PS-C18 were determined to be 3.32, 3.55, 3.89, and 4.24 nm, respectively (14). With these d (100) values together with the V p(N 2 ) values listed in Table 3, r p (=w/2) was calculated by Eq.…”

Section: Figmentioning

confidence: 99%

“…previous work (14), was taken into consideration. The corrected values of r p are shown in linear line B of Fig.…”

Section: Figmentioning

confidence: 99%

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A New Method of Calculating Pore Size Distribution: Analysis of Adsorption Isotherms of N2 and CCl4 for a Series of MCM-41 Mesoporous Silicas

Hakuman

Naono

2001

Journal of Colloid and Interface Science

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Section: Preparation Of Mcm-41mentioning

confidence: 98%

Section: Figmentioning

confidence: 99%

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A New Method of Calculating Pore Size Distribution: Analysis of Adsorption Isotherms of N2 and CCl4 for a Series of MCM-41 Mesoporous Silicas

Hakuman

Naono

2001

Journal of Colloid and Interface Science

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“…(3)]. [47][48][49][50] However, even with this special surface-dehydroxylated SiO 2 sample (see Figure 2 for its relative silanol population), no stabilisation of Meisenheimer complex was observed, while chemical analysis indicated that the adsorption of Meisenheimer complex is somewhat enhanced (5 wt %) with respect to uncalcined SiO 2 samples. This result seems to indicate attack of atmospheric agents as the main process responsible for the disappearance of Meisenheimer complex on the surface of nonmicroporous SiO 2 or SiO 2 -Al 2 O 3 rather than the presence of silanol groups in the solids.…”

Section: Resultsmentioning

confidence: 73%

Anionic Organic Guests Incorporated in Zeolites: Adsorption and Reactivity of a Meisenheimer Complex in Faujasites

Herance

Concepción

Doménech

et al. 2005

Chemistry A European J

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Zeolites are suitable microporous hosts for positively charged organic species, but it is believed that they cannot adsorb organic anions. Pure Meisenheimer complex, derived from reduction of 2,4-dinitroaniline with NaBH4, was adsorbed inside faujasite cavities. Evidence for the internal incorporation of this negatively charged reaction intermediate comes from 1) XPS elemental analysis as a function of the depth of penetration into the particle, 2) the remarkable blue shift in lambda(max) of the Meisenheimer complex adsorbed on zeolite (ca. 470 nm) as compared to that in acetonitrile (580 nm) and 3) from the lack of reactivity with size-excluded hydride-acceptor reagents. Evidence is provided in support of an adsorption mechanism in which a neutral ion pair (alkali metal ion + Meisenheimer anion) is the actual species being adsorbed. In fact it appears that there is remarkable increase in the association constant for the ion-pair complex within the zeolite cavities as compared to DMF solution. Although this mechanism of adsorption as an ion-pair complex has precedents in the adsorption of some inorganic salts, what is novel is the notable increase in the stability and persistence of the Meisenheimer anion (a anionic reaction intermediate) as a result of zeolite inclusion. Adsorbed Meisenheimer complex exhibits much lower reactivity towards electron acceptors, oxygen, and water. Cyclic voltammetry of zeolite-modified electrodes reveals for the Meisenheimer complex adsorbed on LiY a reversible redox peak that is not observed in solution and has been interpreted as arising from site isolation and stabilisation of the electrochemically generated species.

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“…3(b), the N 2 adsorption-desorption isotherms of the samples present typical type-IV adsorption. 17 which show an apparent capillary condensation step at relative pressure (P/P 0 ) of 0.3. The pore size was calculated as 2.4 nm by the Barrett-Joyner-Halenda (BJH) method.…”

Section: Resultsmentioning

confidence: 99%

Magnetic properties and microstructures of iron oxide@mesoporous silica core-shell composite for applications in magnetic dye separation

Hao

Yang

et al. 2012

Journal of Applied Physics

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, X. L. (2012). Magnetic properties and microstructures of iron oxide@mesoporous silica core-shell composite for applications in magnetic dye separation. Journal of Applied Physics, 111 (7), 07B301-1-07B301-2.Magnetic properties and microstructures of iron oxide@mesoporous silica core-shell composite for applications in magnetic dye separation Abstract "In this report, hollow mesoporous silica (HMS) and iron oxide-hollow mesoporous silica (FexOy@HMS) core-shell composite were prepared by a one-step facile fabrication method. Transmission electron microscopy, X-ray diffraction, N-2 adsorption-desorption isotherms, and vibrating sample magnetometer were used to characterize the morphology, microstructure, and magnetic properties of the HMS and coreshell composite. The magnetic separability of FexOy@HMS core-shell composite was tested in Rhodamine B In this report, hollow mesoporous silica (HMS) and iron oxide-hollow mesoporous silica (Fe x O y @HMS) core-shell composite were prepared by a one-step facile fabrication method. Transmission electron microscopy, X-ray diffraction, N 2 adsorption-desorption isotherms, and vibrating sample magnetometer were used to characterize the morphology, microstructure, and magnetic properties of the HMS and core-shell composite. The magnetic separability of Fe x O y @HMS core-shell composite was tested in Rhodamine B (Rh.B) dye solution. The results indicate that the core-shell composite can absorb Rh.B dyes molecules effectively up to 90.1%.

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Porous Texture and Surface Character of Dehydroxylated and Rehydroxylated MCM-41 Mesoporous Silicas—Analysis of Adsorption Isotherms of Nitrogen Gas and Water Vapor

Cited by 29 publications

References 23 publications

A New Method of Calculating Pore Size Distribution: Analysis of Adsorption Isotherms of N2 and CCl4 for a Series of MCM-41 Mesoporous Silicas

A New Method of Calculating Pore Size Distribution: Analysis of Adsorption Isotherms of N2 and CCl4 for a Series of MCM-41 Mesoporous Silicas

Anionic Organic Guests Incorporated in Zeolites: Adsorption and Reactivity of a Meisenheimer Complex in Faujasites

Magnetic properties and microstructures of iron oxide@mesoporous silica core-shell composite for applications in magnetic dye separation

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