Facile synthesis of highly ordered mesoporous ZnTiO3 with crystalline walls by self-adjusting method

Highly ordered mesoporous ZnTiO(3) with crystalline walls was directly prepared by a sol-gel process combined with evaporation induced self-assembly in ethanol, using amphiphilic triblock copolymers as structure directing agents. The whole process is self-adjusting to organize the network-forming metal oxide species without additional acid or base. The mesoporous material is pure cubic-phase ZnTiO(3) and has large surface area (up to 134 m(2)/g), large pore volume (0.17 cm(3)/g), and narrow pore size distribution (3-4.5 nm). The optic behavior was systematically studied, which is very helpful to understand the mesoporous ZnTiO(3) material either in fundamental study or for potential applications in optics and catalysis. This work provides a "self-adjusting" approach to fabricate the mesoporous functional materials with diverse compositions: the diverse hydrolysis-condensation kinetics of various metal oxides is homogenized to yield stable multicomponent precursors. The development of such a simple, versatile, and reproducible method is important for applications in practice.     

Importance of solution equilibria in the directed assembly of metal chalcogenide mesostructures

We describe the new nanostructured Pt/Ge/Se materials prepared from the molecular units [Ge2Se6](4-) and [GeSe4](4-) and linking Pt(2+) ions in the presence of surfactant micelles. X-ray diffraction coupled with transmission electron microscopy images reveals hexagonal pore symmetry. The solvent dependence and solution speciation of these building blocks were investigated by means of multinuclear NMR spectroscopy and by fast atom bombardment (FAB) mass spectroscopy and it is shown that rapid exchange equilibrium is reached between species like [Ge4Se10](4-), [Ge2Se6](4-), and [GeSe4](4-) in both water and formamide. This results in multiple Ge/Se anions being incorporated in the mesostructured materials which is supported by Raman and IR spectroscopic data. It is likely that the presence of multiple building units both in water and formamide solutions favors the assembly of mesostructured metal chalcogenides with good pore order. Systematic variation of both surfactant headgroup and chain length modulates the optoelectronic properties of the mesostructures. The Pt/Ge/Se materials show sharp band gap transitions in the range of 1.24-1.97 eV. Finally, the materials exhibit reversible ion-exchange properties and a marked inorganic framework flexibility that enables a contraction-expansion process in response to the exchange. The Pt/Ge/Se framework possesses a very high surface area as estimated by small-angle X-ray scattering techniques.     

Hemicyanine dye as a surfactant for the synthesis of bicontinuous cubic mesostructured silica

In this paper, we developed a facile way to synthesize highly ordered optically active MCM-48 at room temperature, by using mixtures of hemicyanine dye N-alkyl-2-[p-(N,N-diethylamino)-o-(alkyloxy)]pyridinium bromide (denoted as o-CnPOCm, Scheme 1) and cetyltrimethylammonium bromide (CTAB) as the structure-directing agents. The mesoporous materials were systematically characterized by powder X-ray diffraction, transmission electron microscopy, nitrogen sorption, and thermogravimetry. The resultant MCM-48 exhibits unusually high thermal stability. For example, in the case of o-C(2)POC(14), it can retain its cubic structure even under calcinations at 900 degrees C for 5 h, although the pore size is shifted to the micropore region because of shrinkage of the framework. The typical surface area and pore volume are 980 m(2)/g and 0.44 cm(3)/g, respectively, for the powder calcined under such a high temperature. This is the first report of room-temperature synthesis of MCM-48 with such good thermal stability using cationic-cationic mixed surfactant as the structure-directing agent. The fluorescence lifetimes of the as-synthesized mesostructured MCM-48 were also measured, and the result showed that the incorporated dye molecules have a 1 order of magnitude longer lifetime than that of free species in solution, showing that the hemicyanine dye molecules are well dispersed within the CTAB surfactant matrix. Furthermore, we compared eight other dye congeners (Scheme 1) to fully investigate the mesophase resulting from the dye-CTAB system. The results show that, upon addition of the dye surfactant to the starting mixtures, the mesostructured silica undergoes an intrinsic phase-transition process; however, specific dye geometry is required to obtain MCM-48 at room temperature. Those functionalities as well as the designed synthesis of this novel mesostructured MCM-48 material promise a bright future in multifunctional optical and electric nano- and microdevices (e.g., waveguides, laser, light-emitting diodes, etc.) and also shed light on the self-assembly behavior in complex colloidal system.     

Mesoporous silica nanoparticle based controlled release, drug delivery, and biosensor systems

Recent advancements in controlling the surface properties and particle morphology of the structurally defined mesoporous silica materials with high surface area (>700 m(2) g(-1)) and pore volume (>1 cm(3) g(-1)) have significantly enhanced their biocompatibility. Various methods have been developed for the functionalization of both the internal pore and exterior particle surfaces of these silicates with a tunable pore diameter ranging from 2 to 30 nm and a narrow pore size distribution. Herein, we review the recent research progress on the design of functional mesoporous silica materials for stimuli-responsive controlled release delivery of pharmaceutical drugs, genes, and other chemicals. Furthermore, the recent breakthroughs in utilizing these nanoscale porous materials as sensors for selective detections of various neurotransmitters and biological molecules are summarized.     

Novel mesoporous mixed Nb-M (M = V, Mo, and Sb) oxides for oxidative dehydrogenation of propane

Novel thermally stable mesoporous mixed metal Nb-M (M = V, Mo and Sb) oxides were synthesized in the presence of a nonionic Pluronic P123 surfactant. These oxides displayed promising pore structures and chemical compositions for selective oxidative functionalization of propane: high surface areas (up to 200 m2/g), large pore sizes (5-14 nm), and high pore volumes (up to 0.46 cm3/g). The oxidative dehydrogenation of propane to propylene over mesoporous mixed metal Nb-M oxides employed as a probe reaction suggested that the M component was dispersed as the molecular surface species and also formed a solid solution with NbOx in the inorganic walls of these mesoporous mixed metal oxides.     

Synthesis and characterization of pore size-tunable magnetic mesoporous silica nanoparticles

Magnetic mesoporous silica nanoparticles (M-MSNs) are emerging as one of the most appealing candidates for theranostic carriers. Herein, a simple synthesis method of M-MSNs with a single Fe(3)O(4) nanocrystal core and a mesoporous shell with radially aligned pores was elaborated using tetraethyl orthosilicate (TEOS) as silica source, cationic surfactant CTAB as template, and 1,3,5-triisopropylbenzene (TMB)/decane as pore swelling agents. Due to the special localization of TMB during the synthesis process, the pore size was increased with added TMB amount within a limited range, while further employment of TMB lead to severe particle coalescence and not well-developed pore structure. On the other hand, when a proper amount of decane was jointly incorporated with limited amounts of TMB, effective pore expansion of M-MSNs similar to that of analogous mesoporous silica nanoparticles was realized. The resultant M-MSN materials possessed smaller particle size (about 40-70 nm in diameter), tunable pore sizes (3.8-6.1 nm), high surface areas (700-1100 m(2)/g), and large pore volumes (0.44-1.54 cm(3)/g). We also demonstrate their high potential in conventional DNA loading. Maximum loading capacity of salmon sperm DNA (375 mg/g) was obtained by the use of the M-MSN sample with the largest pore size of 6.1 nm.     

Solid-state 23Na and 7Li NMR investigations of sodium- and lithium-reduced mesoporous titanium oxides

Mesoporous titanium oxide synthesized using a dodecylamine template was treated with 0.2, 0.6, and 1.0 equiv of Li- or Na-naphthalene. The composite materials were characterized by nitrogen adsorption, powder X-ray diffraction, X-ray photoelectron spectroscopy, elemental analysis, thermogravimetric analysis, and solid-state 23Na and 7Li NMR spectroscopy. In all cases the wormhole mesoporosity was retained as evidenced by BET surface areas from 400 to 700 m(2)/g, Horvath-Kawazoe pore sizes in the 20 Angstroms range, and a lack of hysteresis in the nitrogen adsorption isotherms. Variable-temperature conductivity studies show that the Li-reduced materials are semiconductors, with conductivity values 3 orders of magnitude higher than those of the Na-reduced materials. Electrochemical measurements demonstrate reversible intercalation/deintercalation of Li+ ions into pristine mesoporous Ti oxides with good cycling capacity. Solid-state 23Na NMR reveals two distinct Na environments: one corresponding to sodium ions in the mesoporous channels and the other corresponding to sodium ions intercalated into the metal framework. 23Na NMR spectra also indicate that the relative population of the framework site increases with increased reduction levels. Solid-state 7Li NMR spectra display a single broad resonance, which increases in breadth with increased reduction levels, though individual resonances inferring the presence of channel and framework Li species are not resolved. Comparisons of the lithium chemical shifts with published values suggests an "anatase-like structure" with no long-range order in the least-reduced samples but a "lithium titanate-like structure" with no long-range order in the higher reduced materials.     

Adsorption of NO and CO over transition-metal-incorporated mesoporous catalytic materials

Novel high-surface-area mesoporous catalysts of type Al-MCM-41 containing transition metals such as iron, nickel, cobalt, zinc, copper, and cobalt were prepared and characterized using techniques such as BET, FTIR, ICP-MS, XPS, and XRD. The XPS measurements indicated that the transition-metal particles are located in the bulk or pore channels of the Al-MCM-41 materials. A detailed in situ FTIR investigation undertaken on the adsorption and disproportionation of NO and CO over the transition-metal-Al-MCM-41 mesoporous catalysts indicated the formation of various NO/CO species or complexes with active metal sites. The structure and dynamics of the metal activated complex and reactive species formed during the CO/NO reaction together with advantages of these catalysts and the influence of reaction temperature and pressure have been studied. NO adsorption at room temperature leads to the formation of adsorbed N(2)O, NO(2), MNO(2), MNO, and [M(NO)(2)] complexes. CO adsorption at room temperature leads to the formation of physisorbed carbon dioxide and cationic Lewis acid carbonyl moieties as well as transition-metal carbonyl complexes. The copper mesoporous catalysts prepared by different procedures (ion exchanged and as-synthesized) were compared for their interactions with CO and NO probe molecules.     

Adsorption characteristics of organosilica based mesoporous materials

Hybrid organosilica mesoporous materials with pores of ordered three-dimensional hexagonal structure were prepared by the hydrolysis and co-condensation of 1,2-bis(triethoxysilyl)ethane with various concentrations of a surfactant as structure directing agents. The materials had high pore volume of 1-1.5 mL/g and high surface area from 1057 to 1445 m(2)/g. Adsorption measurement and adsorption calorimetry revealed that the prepared materials exhibited high hydrophobicity and high affinity toward nonpolar organic vapor such as n-hexane. The dynamic adsorption properties of the materials for n-hexane in the presence of water vapor showed that these hybrid organosilica materials preferentially adsorbed n-hexane vapor and were stable in the presence of water compared to the siliceous MCM48.     

Organic-inorganic hybrid mesoporous silicas: functionalization, pore size, and morphology control

Topological design of mesoporous silica materials, pore architecture, pore size, and morphology are currently major issues in areas such as catalytic conversion of bulky molecules, adsorption, host-guest chemistry, etc. In this sense, we discuss the pore size-controlled mesostructure, framework functionalization, and morphology control of organic-inorganic hybrid mesoporous silicas by which we can improve the applicability of mesoporous materials. First, we explain that the sizes of hexagonal- and cubic-type pores in organic-inorganic hybrid mesoporous silicas are well controlled from 24.3 to 98.0 A by the direct micelle-control method using an organosilica precursor and surfactants with different alkyl chain lengths or triblock copolymers as templates and swelling agents incorporated in the formed micelles. Second, we describe that organic-inorganic hybrid mesoporous materials with various functional groups form various external morphologies such as rod, cauliflower, film, rope, spheroid, monolith, and fiber shapes. Third, we discuss that transition metals (Ti and Ru) and rare-earth ions (Eu(3+) and Tb(3+)) are used to modify organic-inorganic hybrid mesoporous silica materials. Such hybrid mesoporous silica materials are expected to be applied as excellent catalysts for organic reactions, photocatalysis, optical devices, etc.     

Synthesis of a three-dimensional cubic mesoporous silica monolith employing an organic additive through an evaporation-induced self-assembly process

We demonstrate a robust approach to the synthesis of a 3D cubic Im3m mesoporous silica monolith from SiO2/cetyltrimethylammoniumbromide (CTAB)/1,3,5-triisopropylbenzene (TIPB) sols having molar compositions of 1SiO2/0.0017HCl/5.2H2O/10EtOH/0.10CTAB/0.1-0.5TIPB by the evaporation-induced self-assembly (EISA) process. The addition of TIPB is aimed at altering the micelle geometry to spheroid from rodlike in the gel state; the change in micelle geometry leads to the formation of a 3D cage-type cubic mesostructure in the monolith. The synthesized materials exhibit BET surface areas of 800-1000 m(2)/g, a BJH pore diameter of 2.9-4.3 nm, and a pore volume of 0.7-1.0 cm(3)/g, demonstrating ultrahigh porosity of the 3D cubic mesostructure.     

Solvent evaporation induced aggregating assembly approach to three-dimensional ordered mesoporous silica with ultralarge accessible mesopores

A solvent evaporation induced aggregating assembly (EIAA) method has been demonstrated for synthesis of highly ordered mesoporous silicas (OMS) in the acidic tetrahydrofuran (THF)/H(2)O mixture by using poly(ethylene oxide)-b-poly(methyl methacrylate) (PEO-b-PMMA) as the template and tetraethylorthosilicate (TEOS) as the silica precursor. During the continuous evaporation of THF (a good solvent for PEO-b-PMMA) from the reaction solution, the template molecules, together with silicate oligomers, were driven to form composite micelles in the homogeneous solution and further assemble into large particles with ordered mesostructure. The obtained ordered mesoporous silicas possess a unique crystal-like morphology with a face centered cubic (fcc) mesostructure, large pore size up to 37.0 nm, large window size (8.7 nm), high BET surface area (508 m(2)/g), and large pore volume (1.46 cm(3)/g). Because of the large accessible mesopores, uniform gold nanoparticles (ca. 4.0 nm) can be introduced into mesopores of the OMS materials using the in situ reduction method. The obtained Au/OMS materials were successfully applied to fast catalytic reduction of 4-nitrophenol in the presence of NaHB(4) as the reductant. The supported catalysts can be reused for catalytic reactions without significant decrease in catalysis performance even after 10 cycles.     

Self-assembling and size-selective synthesis of Ni and NiO nanoparticles embedded in ordered mesoporous carbon and polymer frameworks

We demonstrate the self-assembling and size-selective synthesis of uniform and highly dispersed Ni or NiO nanoparticles with diameters below 12 nm embedded in ordered mesoporous carbon or polymer frameworks. Self-assembly is induced by evaporation of the solvent from a mixture of metal-containing liquid crystalline (LC) mesophases of triblock copolymer and transition metal nitrate hydrate, and the carbon source is low-polymerized phenolic resol. Characterization by XRD, N(2) sorption isotherms, TEM, HRSEM, ICP-AES, TG, and XPS techniques has indicated an ordered 2D hexagonal mesostructure, high surface areas between 524 and 721 m(2) g(-1), uniform pore sizes of about 4.0 nm, large pore volumes ranging from 0.34 to 0.58 cm(3) g(-1), and metal contents ranging from 0.6 to 10.0 wt%. There is a high degree of dispersion, and a small size of nanoparticles throughout the whole framework, without aggregation outside of the pores due to the confinement effect of the mesoporous ordered matrix. The mesoporous solids show excellent adsorption properties for dyes and permit an easy magnetic separation procedure. This method is expected to be applicable to other mesoporous transition metal(oxide)-containing carbon catalysts.     

Mesostructured gamma-Al(2)O(3) with a lathlike framework morphology

A novel three-step assembly pathway is reported for the formation of a mesostructured alumina with framework pore walls made of crystalline, lathlike gamma-Al(2)O(3) nanoparticles. In the initial supramolecular assembly step of the pathway a mesostructured alumina with a wormhole framework morphology and amorphous pore walls is assembled through the hydrolysis of Al(13) oligocations and hydrated aluminum cations in the presence of a nonionic diblock or triblock poly(ethylene oxide) surfactant as the structure-directing porogen. The walls of the initial mesostructure are then transformed in a second hydrolysis step at a higher temperature to a surfactant-boehmite mesophase, denoted MSU-S/B, with a lathlike framework made of boehmite nanoparticles. A final thermal reaction step topochemically converts the intermediate boehmitic mesophase to a mesostructure with crystalline gamma-Al(2)O(3) pore walls, denoted MSU-gamma, with retention of the lathlike framework morphology. The boehmitic MSU-S/B intermediates formed from the chloride salts of aluminum incorporate chloride anions into the mesostructure. Chloride ion incorporation tends to disorder the nanoparticle assembly process, leading to a broadening of the slit-shaped framework pores in the final MSU-gamma phases and to the introduction of intra- and interparticle textural mesopores. However, the well-ordered MSU-gamma phases made from aluminum nitrate as the preferred aluminum reagent exhibit narrow framework pore size distributions and average pore sizes that are independent of the surfactant size and packing parameter, in accord with a lathlike framework assembled from nanoparticles of regular size and connectivity. The high surface areas ( approximately 300-350 m(2)/g) and pore volumes ( approximately 0.45-0.75 cm(3)/g) provided by these mesostructured forms of gamma-Al(2)O(3) should be useful in materials and catalytic applications where the availability of surface Lewis acid sites and the dispersion of supported metal centers govern reactivity.     

Self-assembly of novel dye molecules and [Cd8(SPh)12]4+ cubic clusters into three-dimensional photoluminescent superlattice

The use of organic multidentate ligands to organize inorganic species is an effective method to prepare porous solids with tunable pore sizes. However, thus far, inorganic building units are generally limited to individual metal ions (e.g., Zn2+) or their oxide clusters (e.g., Zn4O6+). To expand applications of porous materials to electronic, electrooptic, or optical areas, the organization of semiconducting chalcogenide nanoclusters is desirable. Here we report the organization of cubic [Cd8(SPh)12]4+ clusters by in-situ-generated tetradentate 1,2,4,5-tetra(4-pyridyl)benzene molecules. The structure consists of three-dimensional inorganic-organic open framework with large unidimensional channels. The combination of dye molecules and inorganic cluster units in the same material creates a synergetic effect that enhances the emission of the inorganic cluster at 580 nm. Such an emission can be excited by a broad spectral range down to the UV, which is believed to result from the absorption of dye molecules and the subsequent energy transfer. The inorganic double four-ring cluster, [Cd8(SPh)12]4+, is formed from conversion of supertetrahedral clusters, while the novel tetradentate dye molecule is formed by oxidative coupling of two diamines.     

Three-dimensional low symmetry mesoporous silica structures templated from tetra-headgroup rigid bolaform quaternary ammonium surfactant

Two kinds of highly ordered mesoporous silica materials (FDU-11, FDU-13) with novel three-dimensional (3-D) tetragonal and orthorhombic structures were synthesized by using tetra-headgroup rigid bolaform quaternary ammonium surfactant [(CH(3))(3)NCH(2)CH(2)CH(2)N(CH(3))(2)CH(2)(CH(2))(11)OC(6)H(4)C(6)H(4)O(CH(2))(11)CH(2)N(CH(3))(2)CH(2)CH(2)CH(2)N(CH(3))(3).4Br] (C(3-12-12)(-)(3)) as a template under alkaline conditions. High-resolution transmission electron microscopy (HRTEM), small-angle X-ray scattering (SAXS), and X-ray diffraction (XRD) show that mesoporous silica FDU-11 has primitive tetragonal P4/mmm structure with cell parameters a = b = 8.46 nm, c = 5.22 nm, and c/a ratio = 0.617. N(2) sorption isotherms show that calcined FDU-11 has a high BET surface area of approximately 1490 m(2)/g, a uniform pore size of approximately 2.72 nm, and a pore volume of approximately 1.88 cm(3)/g. Mesoporous silica FDU-13 has primitive orthorhombic Pmmm structure. The cell parameters are a = 9.81, b = 5.67, and c = 3.66 nm. N(2) sorption isotherms show that calcined FDU-13 has a high BET surface area of 1210 m(2)/g, a uniform mesopore size of approximately 1.76 nm, and a large pore volume of approximately 1.83 cm(3)/g. Such low symmetries for 3-D mesostructures (tetragonal and orthorhombic system) have not been observed before even in amphiphilic liquid crystals, which maybe resulted from an oblate aggregation of the bolaform surfactant and its strong electrostatic interaction with inorganic precursor. A probable mechanism has been proposed for the formation of such a 3-D low symmetrical mesostructure. These results will further extend the synthesis of mesoporous materials and may open up new opportunities for their new applications in catalysis, separation, and nanoscience.     

Triconstituent co-assembly to ordered mesostructured polymer-silica and carbon-silica nanocomposites and large-pore mesoporous carbons with high surface areas

Highly ordered mesoporous polymer-silica and carbon-silica nanocomposites with interpenetrating networks have been successfully synthesized by the evaporation-induced triconstituent co-assembly method, wherein soluble resol polymer is used as an organic precursor, prehydrolyzed TEOS is used as an inorganic precursor, and triblock copolymer F127 is used as a template. It is proposed for the first time that ordered mesoporous nanocomposites have "reinforced concrete"-structured frameworks. By adjusting the initial mass ratios of TEOS to resol, we determined the obtained nanocomposites possess continuous composition with the ratios ranging from zero to infinity for the two constituents that are "homogeneously" dispersed inside the pore walls. The presence of silicates in nanocomposites dramatically inhibits framework shrinkage during the calcination, resulting in highly ordered large-pore mesoporous carbon-silica nanocomposites. Combustion in air or etching in HF solution can remove carbon or silica from the carbon-silica nanocomposites and yield ordered mesoporous pure silica or carbon frameworks. The process generates plenty of small pores in carbon or/and silica pore walls. Ordered mesoporous carbons can then be obtained with large pore sizes of approximately 6.7 nm, pore volumes of approximately 2.0 cm(3)/g, and high surface areas of approximately 2470 m(2)/g. The pore structures and textures can be controlled by varying the sizes and polymerization degrees of two constituent precursors. Accordingly, by simply tuning the aging time of TEOS, ordered mesoporous carbons with evident bimodal pores at 2.6 and 5.8 nm can be synthesized.     

Recent advances in synthesis and applications of transition metal containing mesoporous molecular sieves

Work in mesoporous silica-based materials began in the early 1990s with work by Mobil. These materials had pore sizes from 20-500 A and surface areas of up to 1500 m(2) g(-1) and were synthesized by a novel liquid crystal templating approach. Researchers subsequently extended this strategy to the synthesis of mesoporous transition metal oxides, a class of materials useful in catalysis, electronic, and magnetic applications because of variable oxidation states, and populated d-bands-features not found in silicates. These materials are already showing promise in electronic and optical applications hinging on the semiconducting properties of transition metal oxides and their potential to act as electron acceptors, an important feature in the design of cathodic materials. This is the first general review of non-silicate mesoporous materials and will focus on recent advances in this area, emphasizing materials possessing unique electronic, magnetic, or optical properties. Also covered are advances in the synthesis and applications of mesostructured sulfides as well as a new class of template-synthesized platinum-based materials that show promise in heterogeneous catalysis.     

Preparation of ordered mesoporous SiC from preceramic polymer templated by nanoporous silica

Highly ordered mesoporous SiC materials were prepared by infiltrating viscous liquid preceramic polymer, allylhydridopolycarbosilane, into two types of surface modified nanoporous silica templates: mesoporous silica SBA-15 and mesocellular siliceous foam. The silica templates were subsequently etched off after pyrolysis at 1000 degrees C under nitrogen atmosphere with the resultant formation of ordered mesoporous structures. The mesoporous SiC materials, synthesized from both types of templates possessed high Brunauer-Emmett-Teller (BET) surface areas in the range of 250-260 m(2)/g with pore sizes of 3.4-3.6 nm. The ordered structures of mesoporous SiC were exact inverse replicas of their respective silica templates, as characterized by small angle X-ray diffraction (XRD), transmission electron microscope (TEM) images, and the adsorption-desorption isotherm of nitrogen.     

Bifunctional hybrid mesoporous organoaluminosilicates with molecularly ordered ethylene groups

We report the synthesis and characterization of crystal-like structurally well-ordered ethylene-containing hybrid mesoporous organoaluminosilicate materials, which exhibit molecular-level periodicity in the pore walls and enhanced hydrothermal stability. Distilled 1,2-bis(triethoxysilyl)ethylene (BTEE) was used as the organosilica precursor, aluminum isopropoxide as aluminum source, and cetyltrimethylammonium bromide as template. The materials are structurally well-ordered and exhibit high surface area (>1300 m(2)/g) and pore volume (>1.10 cm(3)/g). The presence of molecularly ordered ethylene groups was confirmed by powder X-ray diffraction, (29)Si and (13)C MAS NMR, and Raman spectroscopy. The ethylene groups are thermally stable up to a temperature of 300 degrees C. The presence of ethylene groups enhances the hydrothermal stability in boiling water of both organosilica and organoaluminosilicate materials. The organoaluminosilicate materials possess a bifunctional character arising from the presence of both tetrahedrally coordinated Al and molecularly ordered ethylene groups in their frameworks.