Advanced electron microscopy characterization for pore structure of mesoporous materials; a study of FDU-16 and FDU-18

Klingstedt, Miia; Miyasaka, Keiichi; Kimura, Kosuke; Gu, Dong; Wan, Ying; Zhao, Dongyuan; Terasaki, Osamu

doi:10.1039/c1jm11789k

Cited by 10 publications

(11 citation statements)

References 22 publications

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“…Upon desorption, there is a large hysteresis loop, but the mesopores empty over a broad partial pressure range. This broad desorption (Figure A) correlates well with the poorly ordered morphology for PR-0 (Figures A and A) as the lack of order leads to a distribution of window sizes to enable desorption from the cylindrical mesopores (ink bottle effect). − By addition of DMSO and DOP to the casting solution, the adsorption and desorption isotherms are altered significantly. First, V tol / V film plateaus at high p / p 0 , which suggests that all of the pores are filled.…”

Section: Results and Discussionmentioning

confidence: 64%

Control of Ordering and Structure in Soft Templated Mesoporous Carbon Films by Use of Selective Solvent Additives

et al. 2013

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The structure of ordered mesoporous carbons fabricated using poly(styrene-block-N,N,-dimethyl-n-octadecylamine p-styrenesulfonate) (PS-b-PSS-DMODA) as the template and phenolic resin (resol) as the carbon source can be easily manipulated by inclusion of low concentrations of low volatility selective solvents in the casting solution. Casting from neat methyl ethyl ketone yields a disordered structure even upon thermal annealing. However, addition of both dioctyl phthalate (DOP, PS selective) and dimethyl sulfoxide (DMSO, resol and PSS-DMODA selective) at modest concentrations to this casting solution provides sufficient mobility to produce highly ordered films with cylindrical mesopores. The DOP acts to swell the hydrophobic domain and can more than double the mesopore size, while the DMSO acts to swell the resol phase. Moreover, the surface area of the mesoporous carbons increases significantly as the meosopore size increases. This is a result of the decrease in wall thickness, which can be ascertained by the constant d-spacing of the mesostructure as the pore size increases. This behavior is counter to the typical effect of pore swelling agents that increase the pore size and decrease the surface area. Moreover, with only 4 wt % DOP/DMSO in the solution (20 wt % relative to solids), the scattering profiles exhibit many orders of diffraction, even upon carbonization, which is not typically observed for soft templated films. Variation in the concentration of DOP and DMSO during casting enables facile tuning of the structure of mesoporous carbon films.

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Section: Results and Discussionmentioning

confidence: 64%

Control of Ordering and Structure in Soft Templated Mesoporous Carbon Films by Use of Selective Solvent Additives

et al. 2013

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“…Generally, the connectivity size could be characterized by nitrogen adsorption with the assumption that the connecting pores are cylindrical. However, the connectivity at a size smaller than ∼5 nm cannot be determined due to the delay of capillary evaporation of nitrogen at 77 K to the lower limit of the hysteresis. , There are other methods to solve this problem, including pore surface modification with ligands of different alkyl chain lengths and electron crystallography (EC). ,,,, However, these methods require the use of ideal geometrical models and thus cannot be applied to well-defined OCMSMs with considerable structural disorders and defects. Ersen and coworkers reported the direct observation of pore connections in FDU-12 by ET by assuming the interconnectivity with cylindrical shape .…”

Section: Introductionmentioning

confidence: 99%

“…6,8 There are other methods to solve this problem, including pore surface modification with ligands of different alkyl chain lengths 4 and electron crystallography (EC). 2,9,10,27,28 However, these methods require the use of ideal geometrical models and thus cannot be applied to well-defined OCMSMs with considerable structural disorders and defects. Ersen and coworkers reported the direct observation of pore connections in FDU-12 by ET by assuming the interconnectivity with cylindrical shape.…”

Section: ■ Introductionmentioning

confidence: 99%

New Insight into Ordered Cage-Type Mesostructures and Their Pore Size Determination by Electron Tomography

Yuan

Yang²,

Zhang³

et al. 2015

Langmuir

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In this work, a new approach based on electron tomography (ET) has been developed to measure the pore size, through which new insight into cage-type ordered mesostructures and their pore size determination has been obtained. It is demonstrated that the accurate pore diameter, especially for cage-type cubic mesoporous materials, can be determined only through our ET approach by considering that the pore geometry is a real 3D space. We use the established ET method to revisit the applicability of different models for the pore size calculation in nitrogen adsorption analysis. Different from the overwhelming understanding that the nonlocal density functional theory (NLDFT) and Derjaguin-Broekhoff-de Boer (BdB) model are recommended to calculate the pore size of cage-type cubic mesoporous materials while the Barret-Joyner-Halenda (BJH) model should not be used, a new understanding is gained through this study. The choice of a suitable model for pore size determination depends on the precise pore structure. For a cage-type cubic mesoporous material with fcc symmetry and a large entrance connecting the cages, the BJH model is more accurate while the other two methods overestimate the pore size (by up to 40%). The DFT model is more appropriate when the pore shape is a perfect sphere than the BJH model, which underestimates the pore size, and the BdB model, which overestimates the pore size. It is our opinion that the unique ET approach should be used to revisit a vast number of large-pore cubic mesoporous materials to provide genuine structural information.

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“…In recent years, porous nanomaterials emerged and quickly became one of the hotspots of contemporary scientic research. For example, Zhao et al were famous for their representative porous silica materials, such as SBA series and FDU series [95][96][97][98][99] . Most biological applications of these materials are in the eld of proteomics research.…”

Section: Nanoporous Materials Based Enzymatic Nanoractorsmentioning

confidence: 99%

High-efficiency nano/micro-reactors for protein analysis

Liang

Liu

et al. 2015

RSC Adv.

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Advanced electron microscopy characterization for pore structure of mesoporous materials; a study of FDU-16 and FDU-18

Cited by 10 publications

References 22 publications

Control of Ordering and Structure in Soft Templated Mesoporous Carbon Films by Use of Selective Solvent Additives

Control of Ordering and Structure in Soft Templated Mesoporous Carbon Films by Use of Selective Solvent Additives

New Insight into Ordered Cage-Type Mesostructures and Their Pore Size Determination by Electron Tomography

High-efficiency nano/micro-reactors for protein analysis

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