Mesoporous Hybrid Materials Research Articles

Synthesis of Highly Ordered Hybrid Mesoporous Material Containing Etenylene (–CH=CH–) within the Silicate Framework

Abstract A hybrid mesoporous material containing etenylene in a two-dimensional, hexagonally arranged mesoporous silicate framework with long-range symmetry is successfully synthesized. Quantitative analysis of the reactive etenylene groups within the silicate framework indicates that approximately 30% of the etenylene is exposed at the surface and is available for further modification.

Synthesis and spectroscopic study of mesoporous aluminum methylphosphonate foam templated by dibutyl methylphosphonate

New types of templates and novel interactive mechanisms between template and framework are very important for creating porous materials. In this work, by using neutral dibutyl methylphosphonate as a template, an inorganic–organic hybrid mesoporous material, aluminum methylphosphonate, was prepared. The as-synthesized material was studied by 31P magnetic angle spinning nuclear magnetic resonance (MAS NMR), 27Al MAS NMR, 13C CP/MAS, FT-IR spectroscopy, thermogravimetry (TG), differential thermal analysis (DTA), and transmission electron microscopy. After thermal treatment at 673 K and 10 mmHg for 2 h, hybrid mesoporous foam was obtained. The transformation process was investigated by FT-IR. TG–DTA results indicate that the methyl group bonded to the framework keeps intact up to 792 K under air and 823 K under nitrogen. The characterization results from nitrogen gas adsorption–desorption measurements show that the BET surface area and the Barrett–Joyner–Halenda desorption cumulative pore volume of the foam are 90 m 2 g −1 and 0.32 cm 3 g −1 respectively.

Preparation and properties of lipase immobilized on MCM-36 support

Based on pure MCM-22 precursor, MCM-36 was produced by swelling and pillaring with SiO 2 pillars. These materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), MAS NMR, and N 2 adsorption isotherms. Compared with the MCM-22 sample, the resulting MCM-36 material contains a mesoporous region between the microporous layers, with a mesopore volume of 0.472 cm 3/g, and the surface area increased up to 671 m 2/g. Lipase from Candida antarctica B (CALB) was immobilized on both supports by physical adsorption at equilibrium. Twenty milligrams of CALB/g of MCM-22 was adsorbed on the external surface of crystals, while only 4 mg CALB/g support was adsorbed onto the mesoporous hybrid material MCM-36. The mechanism of adsorption was also discussed. The acylation of alcohols (1-butanol and 1-octanol) by vinyl esters (vinyl acetate and vinyl stearate) was used as a test reaction in order to evaluate the catalytic activity of MCM-36-immobilized lipase. The test reaction indicated MCM-36-immobilized enzyme as an active catalyst for the acylation and its activity was approximately two times higher than that of the free lipase (for the vinyl acetate/1-butanol system).

Mesoporous hybrid materials containing two transition metal ions, one in the framework, the other in the channel pores

Download options Please wait... Supplementary files SAXS pattern of XCu PDF (64K) Article information DOI https://doi.org/10.1039/B303492P Article type Communication Submitted 27 Mar 2003 Accepted 14 May 2003 First published 03 Jun 2003 Download Citation Chem. Commun., 2003, 1564-1565 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Mesoporous hybrid materials containing two transition metal ions, one in the framework, the other in the channel pores R. J. P. Corriu, A. Mehdi, C. Reyé and C. Thieuleux, Chem. Commun., 2003, 1564 DOI: 10.1039/B303492P To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Social activity Tweet Share Search articles by author Robert J. P. Corriu Ahmad Mehdi Catherine Reyé Chloé Thieuleux

Control of coordination chemistry in both the framework and the pore channels of mesoporous hybrid materials

Mesoporous materials containing bridged cyclam moieties inside the framework were prepared by using a neutral templating route. Quantitative formation of bridged CuII-cyclam complexes was obtained by the direct incorporation of CuCl2 inside the hybrid material, showing thus the complete accessibility of cyclam moieties located inside the framework. Grafting of a metal-N-triethoxysilylpropylcyclam complex inside the channel pores followed by the incorporation of another metal salt into the framework gave rise to an hybrid material containing two strongly chelated metal salts, one located inside the framework, the other in the channel pores.

Synthesis of Smart Mesoporous Materials

AbstractThis study details development of hybrid mesoporous materials in which molecular transport through mesopores can be precisely controlled and reversibly modulated. Mesoporous silica materials formed by surfactant templating were modified by surface initiated atom transfer radical polymerization of poly(N-isopropyl acrylamide) (PNIPAAm) a stimuli responsive polymer (SRP) within the porous network. Thermo gravimetric analysis and FTIR spectroscopy were used to confirm the presence of PNIPAAm on the silica surface. Nitrogen porosimetry, transmission electron microscopy and X-ray diffraction analyses confirmed that polymerization occurred uniformly within the porous network. Uptake and release of fluorescent dyes from the particles was monitored by spectrofluorimetry and scanning laser confocal microscopy. Results suggest that the presence of PNIPAAm, a SRP, in the porous network can be used to modulate the transport of aqueous solutes. At low temperature, (e.g., room temperature) the PNIPAAm is hydrated and extended and inhibits transport of analytes; at higher temperatures (e.g., 50°C) it is hydrophobic and is collapsed within the pore network, thus allowing solute diffusion into or out of the mesoporous silica. The transition form hydrophilic to hydrophobic state on polymer grafted mesoporous membranes was determined by contact angle measurements. This work has implications for the development of materials for the selective control of transport of molecular solutes in a variety of applications.

Synthesis, Characterization, and Applications of Organic-Inorganic Hybrid Mesoporous Silica Prepared by Microwave Heating

AbstractOrganic-inorganic hybrid mesoporous materials containing homogeneously distributed ethane group in silica framework were prepared using 1,2 bis(trimethoxysilyl) ethane (BTME) as a precursor and alkyltrimethylammonium chloride/bromide surfactant as a template. Characterization of the materials was performed using XRD, TEM/SEM, 29Si– / 13C– NMR, and N2-adsorption. Hydrothermal synthesis assisted by microwave heating produced a 1-3 micronsized hybrid material with spherical morphology in substantially reduced time. Bifunctional materials containing BTME and either aminopropyl- or mercaptopropy- group within the same silica framework were also prepared with or without the presence of a swelling agent, mesitylene. Mn-salen complex tethering on the hybrid material produced a catalyst with a somewhat enhanced performance in cyclohexene etherification using TBHP as an oxidant. Testing of the hybrid material as a reverse phase HPLC column material after C18 surface-functionalization demonstrated a promising result, which warrants further optimization of synthesis parameters.

Mesoporous hybrid materials containing functional organic groups inside both the framework and the channel poresElectronic supplementary information (ESI) available: 29Si CP MAS NMR spectrum of a representative hybrid material. See http://www.rsc.org/suppdata/cc/b2/b202179j/

Mesoporous hybrid materials containing cyclam moieties inside the framework have been obtained by using a neutral templating route; these materials with large pores and narrow pore size distribution are shown to be particularly suitable for grafting functional organic groups inside the channel pores giving rise to bifunctional hybrid materials.

Ordered mesoporous hybrid materials containing cobalt(ii) Schiff base complex

Immobilisation of Co-salen and Co-fluomine onto ordered mesoporous silica has been achieved through coordination of the cobalt to pyridine or imidazole groups covalently attached to the silica matrix. Two routes have been investigated to obtain mesoporous hybrid materials containing coordinating ligands: post synthesis grafting of 4-[2-(trimethoxysilyl)ethyl]pyridine 1 and N-trimethoxysilylpropylimidazole 2 on hexagonally ordered mesoporous silica via SiOH groups or direct synthesis method i.e. co-hydrolysis and polycondensation of the same functionalised organotrimethoxysilane with a number of equivalents of TEOS in the presence of n-hexadecylamine as structure directing agent. The first method gave rise to hexagonally ordered mesoporous hybrid materials. The second afforded mesoporous hybrid materials with a typically disordered wormhole-like framework structure in which the organic groups are probably regularly distributed. The O2-binding capacity of Co-fluomine immobilized on these materials via the imidazole group was investigated.

A New Mesoporous Hybrid Material: Porphyrin-Doped Aerogel as a Catalyst for the Epoxidation of Olefins

A new hybrid organic–inorganic material has been obtained by the incorporation of a manganese(III) porphyrin into a mesoporous aerogel matrix. The new heterogeneous catalyst was active in the epoxidation of a variety of olefins and polycyclic aromatic hydrocarbons, using iodosylbenzene as oxidizing agent. The catalyst was stable, readily recovered, and re-used without loss of activity. The hybrid aerogel catalyst was more active than the corresponding metalloporphyrin in homogeneous solution.

Titanium containing inorganic–organic hybrid mesoporous materials with exceptional activity in epoxidation of alkenes using hydrogen peroxide

Titanium containing ethane bridged hybrid mesoporous materials with uniform hexagonal arrangement are prepared by two different routes and characterized using several analytical techniques. The effect of substitution of bridged silsesquioxane precursors for siloxane precursors on the properties of resultant mesoporous bulk materials are also evaluated and discussed in term of mesoscopic order and oxidation catalysis. The materials are highly hydrophobic and selectively epoxidize the α-pinene to α-pinene oxide (with >99% selectivity) and display high hydrogen peroxide efficiencies.

Design of Transition Metal Oxide and Hybrid Mesoporous Materials

AbstractMesostructured transition metal (Ti, Zr, V, Al and Ce-Zr) oxide-based hybrid thin films, templated by poly(ethylene oxide)-based surfactants or block copolymers, have been prepared reproducibly, displaying 2D-hexagonal (p6m) or 2D-centred rectangular (c2m) structure. By carefully adjusting the variables involved it is possible to combine both high organisation and excellent optical quality. TiO2 and ZrO2-based materials show thermal stability up to 400-550°C. The elimination of the template can be conducted efficiently and gives rise to high surface area mesoporous films. For the other metal oxide hybrids the inorganic framework is much more fragile, and requires a precise sequence of post-treatments to be stabilised. In addition, original and homogeneous macrotextures shaped with coral-like, helical or macroporous sieves morphologies have been obtained following a nanotectonic approach based on the template-directed assembly by poly-γ-benzyl-L-glutamate (PBLG) of organically functionalised CeO2 crystalline nanoparticles.

Organic-Containing Mesoporous Silicas with a Variety of Mesophases and a Periodic Pore Wall Structure

AbstractIn this report we introduce new types of organic-inorganic hybrid mesoporous materials, in which organic and inorganic moieties are distributed homogeneously at the molecular level in the framework, forming a covalently bonded network. Possessing unique surfaces on which both organic and inorganic components are exposed, these materials are expected to have applications in various areas as catalysts, adsorbents and separators, and as hosts for nano-cluster synthesis. The hybrid mesoporous materials showed not only unique surface properties but also unique structural features in micron- or angstrom-scales. Mesoporous materials containing ethylene groups in the main framework formed a variety of particle morphologies of hexagonal rod, spherical, and decaoctahedral shapes in the sizes of 1-10 μm. Mesoporous material containing phenylene groups showed novel crystal-like 7.6 Å periodicity in the pore walls. The mesoporous material has periodically arranged hydrophobic-hydrophilic surfaces, which is a great advantage for use as catalyst and host material for inclusion chemistry.

Hybrid ethane–siloxane mesoporous materials with cubic symmetry

The structure of and synthesis conditions for an organic–inorganic hybrid mesoporous material, HMM-3, containing ethane fragments (–CH2CH2–) within the pore walls were studied. High resolution transmission electron microscope images and electron diffraction patterns obtained for different crystal axes of HMM-3 indicated that it was of the cubic Pm-3n space group, similar to mesoporous silica SBA-1. Scanning electron micrographs of HMM-3 in different directions confirmed that all of the produced HMM-3 particles had the crystal-like external morphology of a decaoctahedron (18-hedron) with six square {100} and 12 hexagon {110} planes with a cubic symmetry. The synthesis conditions for HMM-3 were optimized in a synthesis system comprising 1,2-bis(trimethoxysilyl)ethane (BTME), hexadecyltrimethylammonium chloride (C16TMA), sodium hydroxide (NaOH), and water (H2O). The highly ordered HMM-3 material was obtained at 95°C with the mixture ratio of BTME:C16TMA:NaOH:H2O=5.27:4.79:12:1773. The C16TMA/BTME ratio and C16TMA concentration affected the structural order of the produced mesophase. Only the cubic Pm-3n phase was formed even though the C16TMA/BTME ratio and the C16TMA concentration were varied with in wide ranges at 95°C.

Polymethacrylate–Silica Hybrid Nanoporous Materials: A Bridge Between Inorganic and Polymeric Molecular Sieves

Mesoporosity combined with organic polymer functionality and hydrophobicity could give rise to promising new materials with applications in host–guest chemistry and biosensor devices. The synthesis of polymer–silica hybrid mesoporous materials with pore sizes of 3–6 nm is described, in which materials with large specific surface areas (∼800 m2 g–1) and pore volumes (∼0.7 cm3 g–1) as well as relatively narrow pore size distributions are produced by a sol-gel reaction in the presence of a non-surfactant template or pore-forming agent, which is subsequently removed by solvent extraction.

A new class of hybrid mesoporous materials with functionalized organic monolayers for selective adsorption of heavy metal ions

Thiol- and amino-functionalized SBA-15 silicas with uniform mesoporosities were prepared and employed for removing heavy metal ions from waste water; the thiolated SBA-15 adsorbent exhibited a higher complexation affinity for Hg2+, while the other metal ions (Cu2+, Zn2+, Cr3+ and Ni2+) showed exceptional binding ability with its aminated analogue.

Periodic mesoporous organosilicas with organic groups inside the channel walls

Surfactant-mediated synthesis methods have attracted much interest for the production of inorganic mesoporous materials, which can, on removal of the surfactant template, incorporate polymeric, organic, inorganic and organometallic guests' in their pores 1,2 . These materials-initially made of silica 3-5 , but now also available in the form of other oxides 6-9 , sulphides 10,11 , phosphates 12 and metals 13 -could find application in fields ranging from catalysis, adsorption and sensing technology to nanoelectronics. The extension of surfactant-mediated synthesis to produce inorganic-organic hybrid material (that is, materials that contain organic groups as an integral part of their framework structure) promises access to an even wider range of application possibilities. Such hybrid materials have been produced in the form of amorphous silicates (xerogels) that indeed display unique properties different to those of the individual components 14-20 , but their random networks with broad pore-size distributions severely limit the shape and size selectivity of these materials. Mesoporous hybrid materials with periodic frameworks have been synthesized, but the organic groups are all terminally bonded to the pore surface, rather than incorporated into the pore walls 21-26 . Here we describe a periodic mesoporous organosilica containing bridge-bonded ethene groups directly integrated into the silica framework. We are able to solvent-extract and ion-exchange the surfactant templates to create a stable and periodic mesoporous ethenesilica with high surface area and ethene groups that are readily accessible for chemical reaction. Recent syntheses of similar periodic mesoporous organosilicas 27,28 and the ability to incorporate a variety of bridging organic and organometallic species raise the prospect of being able to fuse organic synthesis and inorganic materials chemistry to generate new materials with interesting chemical, mechanical electronic, optical and magnetic properties.

Novel Mesoporous Materials with a Uniform Distribution of Organic Groups and Inorganic Oxide in Their Frameworks

Novel organic−inorganic hybrid mesoporous materials have been synthesized, in which organic and inorganic oxide moieties are distributed homogeneously at the molecular level in the framework, forming a covalently bonded network. They are highly ordered at the mesoscale, with two- and three-dimensional hexagonal symmetries and well-defined external morphologies. Nitrogen adsorption measurements show a uniform pore-size distribution with pore diameters of 31 and 27 A, and high surface areas of 750 and 1170 m2/g. The synthetic procedure to polymerize the organosilane monomer containing two trialkoxysilyl groups in the presence of surfactant can be applied to the synthesis of a variety of highly ordered organic−inorganic hybrid mesoporous materials.

Synthesis of Ordered Mesoporous Methacrylate Hybrid Systems: Hosts for Molecular Polymer Composites

A functionalized, highly ordered mesoporous hybrid material based on the MCM-41 structure is synthesized through room temperature cocondensation of 3-(trimethoxysilyl)propyl methacrylate (TMSiPMA) and tetramethyl orthosilicate (TMOS) in molar ratios of up to 1:3 in the presence of cetyltrimethylammonium chloride. Successful template removal through solvent extraction results in highly ordered mesoporous materials, as confirmed by X-ray diffraction and transmission electron microscopy. Characterization with nitrogen sorption and IR spectroscopy shows that methacrylate groups are incorporated into the host channel system. The functional groups are stable to at least 200 °C under vacuum. The CC double bonds of the methacrylate groups are readily and completely accessible to bromination. Inorganic/organic composites coupled on the molecular level are prepared by efficient polymerization of adsorbed methyl methacrylate monomer (MMA) with the intrapore grafted methacrylate groups.

Synthesis by neutral surfactant assembly of ordered mesoporous organic-inorganic hybrid materials incorporating phosphorus centres

The co-condensation of tetraethoxysilane (TEOS) and organotrialkoxysilane R'Si(OEt)3 (R' group containing a phosphorus atom) in the presence of a neutral surfactant (n-C16H33NH2) template provides ordered mesoporous hybrid materials. We show that further chemical reactions (sulfuration and quaternization) at phosphorus centres do not disrupt the ordered structure and the textural characteristics of the materials.