@inbook{25997, abstract = {{Recent Advances in the Synthesis of Mesostructured Aluminium Phosphates...}}, author = {{Tiemann, Michael and Fröba, Michael}}, booktitle = {{Host‐Guest‐Systems Based on Nanoporous Crystals}}, title = {{{Recent Advances in the Synthesis of Mesostructured Aluminum Phosphates}}}, doi = {{10.1002/3527602674.ch10}}, year = {{2003}}, } @article{41307, abstract = {{We have applied nuclear inelastic absorption (NIA) to the molecular glass former dibutylphthalate/ferrocene, both in bulk and in nanoporous matrices having pore sizes of 50 and 25 A, respectively. The quantity g(E)/E2, where g(E) is the vibrational phonon density of states (VDOS) of the resonant nuclei, exhibits a pronounced maximum at low energies. Confinement in pores leads to a suppression of the VDOS below 1.5 meV, independent of the pore size. Also in the scaled heat capacity C(T)/T3, we observe a decrease of the peak maximum for low temperatures. Our observations are discussed in the light of experimental and theoretical results on nanocrystals and a recent theoretical model for the boson peak.}}, author = {{Asthalter, T. and Bauer, Matthias and van Buerck, U. and Sergueev, I. and Franz, H. and Chumakov, A. I.}}, journal = {{Hyperfine Interactions}}, number = {{12}}, pages = {{77--83}}, title = {{{Phonons in Confinement and the Boson Peak Using Nuclear Inelastic Absorption}}}, doi = {{10.1023/A:1025434512268}}, volume = {{43}}, year = {{2002}}, } @article{25998, abstract = {{The formation of mesoscopically ordered silica/surfactant composites under acidic synthesis conditions is studied by time-resolved in-situ small-angle X-ray scattering (SAXS) using synchrotron radiation. Benzene is used a an additive which acts as a weak swelling agent although most of the benzene molecules are found to reside near the surfactant/silicate interface region rather than in the micelle cores. With increasing relative amounts of benzene, the curvature of the micellar aggregates decreases, which finally leads to a transition from (hexagonally) rodlike to lamellar; a mechanism for this change in curvature is suggested.}}, author = {{Tiemann, Michael and Goletto, Valérie and Blum, Raphaël and Babonneau, Florence and Amenitsch, Heinz and Lindén, Mika}}, issn = {{0743-7463}}, journal = {{Langmuir}}, pages = {{10053--10057}}, title = {{{In-Situ SAXS Studies on the Formation of Silicate/Surfactant Mesophases with Solubilized Benzene under Acidic Conditions}}}, doi = {{10.1021/la026473w}}, year = {{2002}}, } @article{26001, abstract = {{Mesoporous aluminophosphates with a strict ratio of Al∶P = 1∶1 have been synthesised from a single-source molecular precursor.}}, author = {{Tiemann, Michael and Fröba, Michael}}, issn = {{1359-7345}}, journal = {{Chemical Communications}}, pages = {{406--407}}, title = {{{Mesoporous aluminophosphates from a single-source precursor}}}, doi = {{10.1039/b110662g}}, year = {{2002}}, } @article{26000, abstract = {{Phase Behaviour of the System Triethanolamine-Decanoic Acid-Water...}}, author = {{Backlund, Sune and Friman, Rauno and Karlsson, Stefan and Tiemann, Michael}}, journal = {{Tenside Surfactants Detergents}}, number = {{5}}, pages = {{136--140}}, title = {{{Phase Behaviour of the System Triethanolamine-Decanoic Acid-Water}}}, volume = {{39}}, year = {{2002}}, } @article{26003, abstract = {{Long-chain n-alkylamine surfactants have been used as structure-directing agents in the synthesis of mesoporous aluminophosphates by a highly cooperative formation mechanism in an alcoholic system. Small amounts of water in the synthesis mixture play a significant role in the hydrolysis of the aluminum precursor (Al[OiPr]3) and are important for the quality of the mesostructured products. The materials exhibit disordered mesostructures, the stability and structural order of which can be improved by a postsynthetic thermal treatment. The products are then stable enough for the removal of the surfactant molecules by acidic solvent extraction, yielding surface areas up to 690 m2/g.}}, author = {{Tiemann, Michael and Schulz, Marcus and Jäger, Christian and Fröba, Michael}}, issn = {{0897-4756}}, journal = {{Chemistry of Materials}}, pages = {{2885--2891}}, title = {{{Mesoporous Aluminophosphate Molecular Sieves Synthesized under Nonaqueous Conditions}}}, doi = {{10.1021/cm011044p}}, year = {{2001}}, } @article{26002, abstract = {{Over the past few years a growing number of scientists have dedicated their attention to the synthesis of mesostructured aluminophosphates following the concept of supramolecular structure direction. Their research has produced a large variety of synthetic approaches and yielded materials with various structural properties. Today a substantial number of publications have accumulated; this short review provides a general summary of the literature with the aim to display the opportunities for future work.}}, author = {{Tiemann, Michael and Fröba, Michael}}, issn = {{0897-4756}}, journal = {{Chemistry of Materials}}, pages = {{3211--3217}}, title = {{{Mesostructured Aluminophosphates Synthesized with Supramolecular Structure Directors}}}, doi = {{10.1021/cm0110371}}, year = {{2001}}, } @article{26005, abstract = {{Mesostructured aluminophosphate/dodecyl phosphate composite materials were synthesized under aqueous and alcoholic conditions. The syntheses were monitored by temperature- and time-resolved in-situ small-angle X-ray scattering (SAXS). In the aqueous synthesis, a lamellar mesostructure is formed within the first few minutes of the reaction; this structure maintains a constant d spacing independent of the reaction time and temperature. The alcoholic synthesis at low temperature yields a mixture of a lamellar and a supposedly inverted hexagonal mesostructure. SAXS investigations show that these two phases evolve competitively. The lamellar structure is favored by higher temperatures and/or longer synthesis times; above ∼70 °C it is formed exclusively. Mixtures of both phases can be isolated as solid materials, but thermal analysis shows that the inverted hexagonal product transforms into the lamellar phase at ∼35−43 °C. The alcoholic synthesis is a highly cooperative reaction; the pure surfactant/alcohol systems are not lyotropic as long as the inorganic reactants are absent. In comparison, the surfactant/water system with the same surfactant concentrations as employed for the aqueous syntheses is lyotropic with a lamellar structure.}}, author = {{Tiemann, Michael and Fröba, M. and Rapp, G. and Funari, S. S.}}, issn = {{0897-4756}}, journal = {{Chemistry of Materials}}, pages = {{1342--1348}}, title = {{{Nonaqueous Synthesis of Mesostructured Aluminophosphate/Surfactant Composites:  Synthesis, Characterization, and In-Situ SAXS Studies}}}, doi = {{10.1021/cm991165d}}, year = {{2000}}, } @article{26004, abstract = {{The atomic structure of ordered mesostructured aluminophosphates with dodecyl phosphate as the structure-directing template was investigated by multinuclear solid-state NMR. Two different types of materials were studied:  one with the template headgroup as the only phosphate source and one where additionally phosphoric acid was used in the synthesis. All 31P and 27Al NMR resonances can be subdivided into three groups depending on the sample composition. Furthermore, 2D heteronuclear correlation NMR measurements allow a conclusive and unambiguous identification of the phosphate headgroup resonances of the template molecules and the determination of water and/or hydroxyl units. Most notably, there is an obvious correlation between the d001 values of the samples as measured by powder X-ray diffraction and the appearance of the various groups of 27Al and 31P resonances.}}, author = {{Schulz, M. and Tiemann, Michael and Fröba, M. and Jäger, C.}}, issn = {{1520-6106}}, journal = {{The Journal of Physical Chemistry B}}, pages = {{10473--10481}}, title = {{{NMR Characterization of Mesostructured Aluminophosphates}}}, doi = {{10.1021/jp000337n}}, year = {{2000}}, } @inbook{26006, abstract = {{Mesostructured aluminophosphate / surfactant composite materials were prepared from aqueous and alcoholic systems. Syntheses in ethanol or methanol, respectively, lead to mixtures of two nanostructured phases. One of these consists of hexagonally arranged rod-like assemblies of the surfactant molecules with the head groups located in the centres, encapsulating the inorganic aluminophosphate; the other is lamellar. The syntheses were monitored by in-situ temperature- and time-resolved small angle X-ray scattering (SAXS).}}, author = {{Tiemann, Michael and Fröba, M. and Rapp, G. and Funari, S.S.}}, booktitle = {{Nanoporous Materials II, Proceedings of the 2nd Conference on Access in Nanoporous Materials}}, issn = {{0167-2991}}, title = {{{In-situ small angle x-ray scattering (SAXS) studies on the formation of mesostructured aluminophosphate / surfactant composite materials}}}, doi = {{10.1016/s0167-2991(00)80258-x}}, year = {{2000}}, } @article{26008, abstract = {{Multiple K-edge XAS for the structural analysis of thiophenolate bridged heterotrinuclear complexes}}, author = {{Meyer-Klaucke, W. and Glaser, T. and Fröba, M. and Tiemann, Michael and Wong, J. and Trautwein, A. X.}}, issn = {{0909-0495}}, journal = {{Journal of Synchrotron Radiation}}, pages = {{397--399}}, title = {{{Multiple K-edge XAS for the structural analysis of thiophenolate bridged heterotrinuclear complexes}}}, doi = {{10.1107/s0909049598017804}}, year = {{1999}}, } @article{26007, abstract = {{We report on the synthesis of lamellar mesostructured aluminophosphate composites which contain variable relative amounts of aluminium oxide species in the core regions of the lamellae; this is investigated quantitatively by Al K-edge XANES spectroscopy. Templating is achieved by the utilisation of monododecyl phosphate surfactant. If no phosphorous source (such as H3PO4) is used for the synthesis, the phosphate head groups of the surfactant become incorporated into the inorganic network to form similar lamellar aluminophosphate structures. Thus, the surfactant serves as both template and reactant.}}, author = {{Tiemann, Michael and Fröba, M. and Wong, J.}}, issn = {{0272-9172}}, journal = {{MRS Proceedings}}, title = {{{Synthesis and Al K-Edge Xanes Investigation of Mesostructured Aluminophosphates}}}, doi = {{10.1557/proc-547-87}}, year = {{1999}}, } @article{26009, abstract = {{Lamellar mesostructured aluminophosphates were synthesized from aluminum triisopropoxide and phosphoric acid; monododecyl phosphate surfactant was used as structure-directing template. Depending on the relative Al/P ratio in the samples, variable relative amounts of tetrahedrally and octahedrally coordinated Al are found, indicating that both aluminophosphate and aluminum oxide species (as thermodynamically favored) are being formed in the syntheses. This is investigated quantitatively by Al K-edge XANES spectroscopy. The same syntheses were carried out without phosphoric acid, resulting in similar lamellar structures. The inorganic lamellae of these products consist to a significant extent of aluminophosphate rather than exclusively of aluminum oxide, which means that the phosphate headgroups of the surfactant molecules become incorporated into the inorganic network. Thus, for the first time, the surfactant serves as both template and reactant.}}, author = {{Fröba, Michael and Tiemann, Michael}}, issn = {{0897-4756}}, journal = {{Chemistry of Materials}}, pages = {{3475--3483}}, title = {{{A New Role of the Surfactant in the Synthesis of Mesostructured Phases:  Dodecyl Phosphate as Template and Reactant for Aluminophosphates}}}, doi = {{10.1021/cm980712c}}, year = {{1998}}, }