Influence of porous substrate on mesopore structure and water permeability of surfactant templated mesoporous silica membranes

Chowdhury, Sankhanilay Roy; Peters, A.M.; Blank, Dave H.A.; Elshof, Johan E. ten

doi:10.1016/j.memsci.2005.12.015

Cited by 23 publications

(23 citation statements)

References 32 publications

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“…On the other hand, the secondary pore volume of intermediate layer seems to affect the permeability and the porous structure of supported silica membranes. The specific permeability ( k Si L ) of silica layer in A000/Si is close to the value reported by Chowdhury et al 13 . possibly because the preparation method of the silica sol is similar.…”

Section: Resultssupporting

confidence: 88%

“…shows the TEM micrograph of surfactant templated silica (Si) after calcined at 450°C for 1.5 h. A superstructure is clearly visible in Si and it is found oriented in a certain direction. Chowdhury et al 13 . reported that the average pore radius of the similar surfactant templated silica is approximately 0.9 nm.…”

Section: Resultsmentioning

confidence: 99%

“…23 Figure 1(d) shows the TEM micrograph of surfactant templated silica (Si) after calcined at 4501C for 1.5 h. A superstructure is clearly visible in Si and it is found oriented in a certain direction. Chowdhury et al 13 reported that the average pore radius of the similar surfactant templated silica is approximately 0.9 nm. However, the average pore size of Si measured using polyethyleneglychol (PEG) retention in previous work 23 is only in the range of 0.5-0.6 nm.…”

Section: Resultsmentioning

confidence: 99%

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Preparation of Silica/γ‐Alumina Membrane with Bimodal Porous Layer for Improved Permeation in Ions Separation

Ahmad¹,

Leo²,

Shukor³

2008

Journal of the American Ceramic Society

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Creating secondary pores in the intermediate layer of hierarchical ceramic membranes successfully increases the permeability of bi‐layered membranes by reducing the density of the separating layer. With the optimum secondary pore volume, the permeability of the silica/γ‐alumina membrane with low secondary volume is enhanced with a satisfactory retention of organic ions and inorganic ions. However, the silica layer is not well formed when excessive secondary pores were generated in the intermediate layer. This is likely because the bimodal porous structure of γ‐alumina with high secondary pore volume is inadequate to prevent the penetration of silica sol into the α‐alumina support during dip coating. Thus, the bi‐layered membrane with high secondary pore volume shows insufficient retention of Reactive Orange 16 dye and NaCl at low pH.

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Section: Resultssupporting

confidence: 88%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Preparation of Silica/γ‐Alumina Membrane with Bimodal Porous Layer for Improved Permeation in Ions Separation

Ahmad¹,

Leo²,

Shukor³

2008

Journal of the American Ceramic Society

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“…Tortuosity values slightly above 20 have been reported for mesoporous structures of galumina and silica. 27 Further, the constrictivity accounts for the slowing down of diffusion caused by small pores and narrow pore throats in a porous medium and it is, thus, a characteristic of the socalled bottleneck effect. 28 Four empirical equations relating the constrictivity to the ratio of the diameter of the diffusing molecule to the pore diameter have been developed; these vary with the nature of the diffusing molecule and the porous medium in which diffusion occurs.…”

Section: Dissolution Profilementioning

confidence: 99%

“…This, in turn, gave a tortuosity value for the pore system in Upsalite ® of about 15, significantly higher than tortuosity values reported for macro-porous media but somewhat lower than, although in the same order of magnitude as, the values for the g-alumina and silica mesoporous materials mentioned above. 27…”

Section: Dissolution Profilementioning

confidence: 99%

Diffusion-Controlled Drug Release From the Mesoporous Magnesium Carbonate Upsalite ®

Zhang

Torre

Forsgren

et al. 2016

Journal of Pharmaceutical Sciences

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In vitro drug release from well-defined particle-size fractions of the mesoporous magnesium carbonate material Upsalite(®) was investigated in detail using ibuprofen, a biopharmaceutics classification system class II drug, as the model compound. The weight of loaded drug corresponded to 30% of the weight of the carrier and the pores were filled to approximately 80%. The incorporated ibuprofen was found to be in an amorphous state and was physisorbed, rather than chemisorbed, to the surfaces of the pore walls. In contrast to ibuprofen in mesoporous silica, there was no detectable drug on the outer surface of the carrier particles. Two ibuprofen doses were loaded into Upsalite(®) particles with size fractions ranging from 25 μm to more than 200 μm. The initial release rate was controlled by the particle size; the dissolution rate of the loaded ibuprofen during this period was more than four times faster than that of the crystalline drug. An extended-release period of about 24 h followed the initial rapid-release period. The features of this extended-release period were dependent on the total drug concentration in the release medium. Detailed analysis of the diffusion of ibuprofen in Upsalite(®) provided the ibuprofen diffusion coefficient (9.8 × 10(-8) cm(2)/s), the constrictivity of the diffusion process (0.47) and the tortuosity of the carrier (15). This relatively high tortuosity value indicates that Upsalite(®) can be used not only to enhance the dissolution rate of poorly soluble drugs but also as a carrier in sustained-release applications by using larger particle sizes or even pellets of the material.

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The Use of Different Templates for the Synthesis of Reproducible Mesoporous Titania Thin Films and Small Pore Ultrafiltration Membranes

et al. 2019

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State-of-the-art commercial membranes are made with the sol-gel method. But the pore size is somewhat restricted to control in a reproducible way. Furthermore, the synthesis of uniform pores via the sol-gel method is challenging, and therefore the resulting membranes often exhibit a limited selectivity. In contrast, the template-assisted method (evaporation-induced self-assembly) described herein is able to form defect-free membranes and thin films with more narrow pore size distributions and thus sharper cutoff curves in a more reproducible way. Moreover, the effect of different templates (Brij 58, Brij 56, Brij 78, Brij 76) and concentrations on the porosity of the titania top layer and separation performance is thoroughly investigated. The pore formation mechanism of the template-assisted method is discussed. Under the synthesis conditions described herein, the Brij templates act as a separator, whereby the final pore size can be easily controlled by adjusting the amount of template used. Furthermore, the pores obtained with this template-assisted method are more uniform. Such defect-free, reproducible small pore ultrafiltration membranes with controllable pore size and narrow pore size distribution can open the path to further process intensification and more sustainable production by separating molecules with a small difference in molecular weight.

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Influence of porous substrate on mesopore structure and water permeability of surfactant templated mesoporous silica membranes

Cited by 23 publications

References 32 publications

Preparation of Silica/γ‐Alumina Membrane with Bimodal Porous Layer for Improved Permeation in Ions Separation

Preparation of Silica/γ‐Alumina Membrane with Bimodal Porous Layer for Improved Permeation in Ions Separation

Diffusion-Controlled Drug Release From the Mesoporous Magnesium Carbonate Upsalite ®

The Use of Different Templates for the Synthesis of Reproducible Mesoporous Titania Thin Films and Small Pore Ultrafiltration Membranes

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