Controlling the Morphology of Mesostructured Silicas by Pseudomorphic Transformation: a Route Towards Applications

Galarneau, Anne; Iapichella, Julien; Bonhomme, K.; Renzo, Francesco Di; Kooyman, Patricia J.; Terasaki, Osamu; Fajula, François

doi:10.1002/adfm.200500825

Cited by 158 publications

(126 citation statements)

References 45 publications

Supporting

Mentioning

124

Contrasting

Order By: Relevance

“…On the other hand, 7.5%-PMS had channel length around 300-400 nm. This feature would be important because the mesoscopic structure, mesopore channel orientation, and macroscopic morphology of mesoporous silica may affect the overall diffusion and mass transfer of substrates in catalysis [37][38][39].…”

Section: Resultsmentioning

confidence: 99%

Asymmetric Catalysis in Confined Space Provided by l-Proline Functionalized Mesoporous Silica with Plugs in the Pore

2009

View full text Add to dashboard Cite

Mesoporous silica having L-proline functionality and plugged pore structure was synthesized by direct microwave synthesis under acidic condition using Pluronic P123 as template and sodium metasilicate nonahydrate as silica source. The direct synthesis resulted in the prismatic or disk types with short channels and plugs in the pore structure. Due to the presence of plugs, dual mesoporosities with 7 and 3 nm pore diameter were generated leading to an existence of cavitation. Tri-functionality of this materials i.e. chiral organofunctional group, plugs, and short channel, would be useful for the asymmetric diethyl malonate addition reaction and asymmetric epoxidation reaction of a,b-unsaturated aldehydes. We proved that the formation of plugs in the mesoporous silica governs the formation of dual mesoporosities providing an enhancement of enantiomeric excess in the asymmetric catalysis.This finding might open an important application of the amino-acid organo multifunctionalized mesoporous silica for asymmetric reactions.

show abstract

Section: Resultsmentioning

confidence: 99%

Asymmetric Catalysis in Confined Space Provided by l-Proline Functionalized Mesoporous Silica with Plugs in the Pore

2009

View full text Add to dashboard Cite

show abstract

“…The PSD confirms that there is no aggregation. XRD patterns and TEM [36] reveal the change in pore structure from amorphous to ordered mesoporous materials with hexagonal (MCM-41, MTS-TMB, MTS-TMB/decane) or cubic (MCM-48) symmetries. The pore connectivity, which should influence the mass transfer kinetics in chromatography, can be therefore controlled, from long unidimensional pores for the hexagonal symmetry to uniform tridirectional interconnected pores for the cubic symmetry.…”

Section: Pseudomorphic Mts Particlesmentioning

confidence: 98%

Spherical ordered mesoporous silicas and silica monoliths as stationary phases for liquid chromatography

Galarneau¹,

Iapichella

Brunel

et al. 2006

J of Separation Science

View full text Add to dashboard Cite

Ordered mesoporous silicas such as micelle-templated silicas (MTS) feature unique textural properties in addition to their high surface area (approximately 1000 m2/g): narrow mesopore size distributions and controlled pore connectivity. These characteristics are highly relevant to chromatographic applications for resistance to mass transfer, which has never been studied in chromatography because of the absence of model materials such as MTS. Their synthesis is based on unique self-assembly processes between surfactants and silica. In order to take advantage of the perfectly adjustable texture of MTS in chromatographic applications, their particle morphology has to be tailored at the micrometer scale. We developed a synthesis strategy to control the particle morphology of MTS using the concept of pseudomorphic transformation. Pseudomorphism was recognized in the mineral world to gain a mineral that presents a morphology not related to its crystallographic symmetry group. Pseudomorphic transformations have been applied to amorphous spherical silica particles usually used in chromatography as stationary phases to produce MTS with the same morphology, using alkaline solution to dissolve progressively and locally silica and reprecipitate it around surfactant micelles into ordered MTS structures. Spherical beads of MTS with hexagonal and cubic symmetries have been synthesized and successfully used in HPLC in fast separation processes. MTS with a highly connected structure (cubic symmetry), uniform pores with a diameter larger than 6 nm in the form of particles of 5 microm could compete with monolithic silica columns. Monolithic columns are receiving strong interest and represent a milestone in the area of fast separation. Their synthesis is a sol-gel process based on phase separation between silica and water, which is assisted by the presence of polymers. The control of the synthesis of monolithic silica has been systematically explored. Because of unresolved yet cladding problems to evaluate the resulting macromonoliths in HPLC, micromonoliths were synthesized into fused-silica capillaries and evaluated by nano-LC and CEC. Only CEC allows to gain high column efficiencies in fast separation processes. Capillary silica monolithic columns represent attractive alternatives for miniaturization processes (lab-on-a chip) using CEC.

show abstract

“…[40][41][42][43] Herein, monodisperse MSNs with tunable particle diameter and pore size were synthesized by using modified sol-gel method and adjusting a single variable, such as the amount of N-cetyltrimethylammonium bromide (CTAB) or tetraethyl orthosilicate (TEOS), the ethanol/water volume ratio, or the pore-enlarging agent. The particles and pore size of MSNs were confirmed by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N 2 sorption isotherms.…”

Section: Analysis Of Size-controllable Msnsmentioning

confidence: 99%

Dual‐Cargo Selectively Controlled Release Based on a pH‐Responsive Mesoporous Silica System

et al. 2014

View full text Add to dashboard Cite

A pH-controlled delivery system based on mesoporous silica nanoparticles (MSNs) was constructed for dual-cargo selective release. To achieve a better controlled-release effect, a modified sol-gel method was employed to obtain MSNs with tunable particle and pore sizes. The systems selectively released different kinds of cargo when stimulated by different pH values. At the lower pH value (pH 2.0) only one kind of cargo was released from the MSNs, whereas at a higher pH value (pH 7.0) only the other kind of cargo was released from the MSNs. The multi-cargo delivery system has brought the concept of selective release to new advances in the field of functional nanodevices and allows more accurate and controllable delivery of specific cargoes, which is expected to have promising applications in nanomedicine.

show abstract

Controlling the Morphology of Mesostructured Silicas by Pseudomorphic Transformation: a Route Towards Applications

Cited by 158 publications

References 45 publications

Asymmetric Catalysis in Confined Space Provided by l-Proline Functionalized Mesoporous Silica with Plugs in the Pore

Asymmetric Catalysis in Confined Space Provided by l-Proline Functionalized Mesoporous Silica with Plugs in the Pore

Spherical ordered mesoporous silicas and silica monoliths as stationary phases for liquid chromatography

Dual‐Cargo Selectively Controlled Release Based on a pH‐Responsive Mesoporous Silica System

Contact Info

Product

Resources

About