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Rauscher MV, Seyffertitz M, Kohns R, Stock S, Amenitsch H, Huesing N, Paris O. Optimizing surfactant removal from a soft-templated ordered mesoporous carbon precursor: an in situ SAXS study. J Appl Crystallogr 2023; 56:801-809. [PMID: 37284273 PMCID: PMC10241053 DOI: 10.1107/s1600576723003886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 05/02/2023] [Indexed: 06/08/2023] Open
Abstract
In situ small-angle X-ray scattering (SAXS) was employed to identify critical parameters during thermal treatment for template removal of an ordered mesoporous carbon precursor synthesized via a direct soft-templating route. The structural parameters obtained from the SAXS data as a function of time were the lattice parameter of the 2D hexagonal structure, the diameter of the cylindrical mesostructures and a power-law exponent characterizing the interface roughness. Moreover, detailed information on contrast changes and pore lattice order was obtained from analysis of the integrated SAXS intensity of the Bragg and diffuse scattering separately. Five characteristic regions during heat treatment were identified and discussed regarding the underlying dominant processes. The influence of temperature and O2/N2 ratio on the final structure was analyzed, and parameter ranges were identified for an optimized template removal without strongly affecting the matrix. The results indicate that the final structure and controllability of the process are optimum for temperatures between 260 and 300°C with a gas flow containing 2 mol% of O2.
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Affiliation(s)
- Max Valentin Rauscher
- Chair of Physics, Department Physics, Mechanics and Electrical Engineering, Montanuniversität Leoben, Leoben, Austria
| | - Malina Seyffertitz
- Chair of Physics, Department Physics, Mechanics and Electrical Engineering, Montanuniversität Leoben, Leoben, Austria
| | - Richard Kohns
- Department of Chemistry and Physics of Materials, Paris Lodron University Salzburg, Salzburg, Austria
| | - Sebastian Stock
- Chair of Physics, Department Physics, Mechanics and Electrical Engineering, Montanuniversität Leoben, Leoben, Austria
| | - Heinz Amenitsch
- Institute of Inorganic Chemistry, Graz University of Technology, Graz, Austria
| | - Nicola Huesing
- Department of Chemistry and Physics of Materials, Paris Lodron University Salzburg, Salzburg, Austria
| | - Oskar Paris
- Chair of Physics, Department Physics, Mechanics and Electrical Engineering, Montanuniversität Leoben, Leoben, Austria
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2
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Enhanced Phenol Tert-Butylation Reaction Activity over Hierarchical Porous Silica-Alumina Materials. Catalysts 2020. [DOI: 10.3390/catal10091098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Hierarchical aluminum-silicon materials have been successfully prepared by mixing pre-crystallization of silica-alumina sol and citric acid under hydrothermal conditions. The influence of pre-crystallization time on the micro-mesoporous structure is studied using Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), N2 physical adsorption, and high-resolution transmission electron microscopy (HRTEM). The catalytic performance of hierarchical silica-alumina material is evaluated by alkylation of phenol with tert-butanol. The results show that the silica-alumina materials with a pre-crystallization time of 16 h show micro-mesoporous structure and excellent catalytic activity.
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3
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Shakeri M, Zarnagh AS. New Insights into the Deactivation and Stabilization Causes of Plugged AlSBA‐15 in Liquid‐phase Friedel‐Crafts Organic Reactions. ChemCatChem 2020. [DOI: 10.1002/cctc.202000873] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Mozaffar Shakeri
- Laboratory of Heterogeneous Catalysis Department of Chemical and Petroleum Engineering Chemistry and Chemical Engineering Research Center of Iran P.O. Box 14977 16363 Tehran Iran
| | - Ali Shirzadeh Zarnagh
- Laboratory of Heterogeneous Catalysis Department of Chemical and Petroleum Engineering Chemistry and Chemical Engineering Research Center of Iran P.O. Box 14977 16363 Tehran Iran
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4
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Improved facile synthesis of mesoporous SBA-15-CTA using citric acid under mild conditions. J SOLID STATE CHEM 2020. [DOI: 10.1016/j.jssc.2019.121079] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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5
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Hiraide S, Yamada M, Kataoka S, Inagi Y, Endo A. Time evolution of the framework structure of SBA-15 during the aging process. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.123807] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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6
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A Small-Angle Neutron Scattering Environment for In-Situ Observation of Chemical Processes. Sci Rep 2018; 8:7299. [PMID: 29740024 PMCID: PMC5940810 DOI: 10.1038/s41598-018-24718-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/03/2018] [Indexed: 12/18/2022] Open
Abstract
A new sample environment for the observation of ongoing chemical reactions is introduced for small-angle neutron scattering (SANS) experiments which enables structural changes to be followed continuously across a wide Q-range in response to changes in the chemical environment. The approach is demonstrated and validated by performing single and multiple potentiometric titrations on an aqueous anionic surfactant solution (oligo-oxyethylene alkylether carboxylic acid in D2O) with addition times varying from 1 s to 2 h. It is shown that the continuous flow set-up offers considerable advantages over classical ‘static’ measurements with regards to sample throughput, compositional precision and the ability to observe fast structural transitions. Finally, the capabilities and ongoing optimisation of the sample environment are discussed with reference to potential applications in the fields of biology, colloidal systems and complex soft matter.
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Wang B, Zhou Y, Li L, Xu H, Sun Y, Wang Y. Novel synthesis of cyano-functionalized mesoporous silica nanospheres (MSN) from coal fly ash for removal of toxic metals from wastewater. JOURNAL OF HAZARDOUS MATERIALS 2018; 345:76-86. [PMID: 29128728 DOI: 10.1016/j.jhazmat.2017.10.063] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 10/30/2017] [Accepted: 10/31/2017] [Indexed: 06/07/2023]
Abstract
Trace amounts of toxic metals are usually difficult to be purified by conventional chemical precipitation or physical adsorption in wastewater. In this study, in order to realize high-value utilization of coal fly ash for wastewater purification, a novel method was applied to prepare high-performance mesoporous silica materials from coal fly ash. In comparison with a commonly used method, characterizations revealed that the new method obtained mesoporous silica nanospheres with uniformly distributed cyano groups (denoted by MSN), while the common method only obtained irregular sponge-like microstructure (denoted by ISM). Besides, MSN showed better hydrothermal stability, higher specific surface area (693m2/g) and more ordered mesopores from the comparison. Moreover, the sorption experiments of simulated wastewater suggested that MSN was better in removing toxic metals (Ni2+ and Cd2+) than ISM. For the practical wastewater from a battery plant, 2g/L dosage of MSN showed excellent performance for purification of trace amounts of various toxic metals (Ni, Cd, Mn, Zn, Hg and Pb), the concentration of which reduced to ppb level after MSN treated. The results suggested that MSN can be an effective and low-cost sorbent for removing various toxic metals from wastewater.
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Affiliation(s)
- Bangda Wang
- School of Environment, Tsinghua University, Beijing 100084, China; Key Laboratory for Solid Waste Management and Environment Safety (Tsinghua University), Ministry of Education of China, Tsinghua University, Beijing 100084, China
| | - Yuexi Zhou
- Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Lei Li
- School of Environment, Tsinghua University, Beijing 100084, China; Key Laboratory for Solid Waste Management and Environment Safety (Tsinghua University), Ministry of Education of China, Tsinghua University, Beijing 100084, China
| | - Hui Xu
- School of Environment, Tsinghua University, Beijing 100084, China; Key Laboratory for Solid Waste Management and Environment Safety (Tsinghua University), Ministry of Education of China, Tsinghua University, Beijing 100084, China
| | - Yinglong Sun
- School of Environment, Tsinghua University, Beijing 100084, China; Key Laboratory for Solid Waste Management and Environment Safety (Tsinghua University), Ministry of Education of China, Tsinghua University, Beijing 100084, China
| | - Yi Wang
- School of Environment, Tsinghua University, Beijing 100084, China; Key Laboratory for Solid Waste Management and Environment Safety (Tsinghua University), Ministry of Education of China, Tsinghua University, Beijing 100084, China.
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8
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Blin J, Michaux F, Stébé M. Nanostuctured mesoporous materials from different silica sources using fluorinated surfactants as templates. Colloids Surf A Physicochem Eng Asp 2016. [DOI: 10.1016/j.colsurfa.2016.04.067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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9
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Wang H, Wang T, Yu M, Huang X, Zhong J, Huang W, Chen R. Elaborate control over the morphology and pore structure of porous silicas for VOCs removal with high efficiency and stability. ADSORPTION 2016. [DOI: 10.1007/s10450-016-9815-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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10
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Abstract
X-ray scattering is a structural characterization tool that has impacted diverse fields of study. It is unique in its ability to examine materials in real time and under realistic sample environments, enabling researchers to understand morphology at nanometer and angstrom length scales using complementary small and wide angle X-ray scattering (SAXS, WAXS), respectively. Herein, we focus on the use of SAXS to examine nanoscale particulate systems. We provide a theoretical foundation for X-ray scattering, considering both form factor and structure factor, as well as the use of correlation functions, which may be used to determine a particle's size, size distribution, shape, and organization into hierarchical structures. The theory is expanded upon with contemporary use cases. Both transmission and reflection (grazing incidence) geometries are addressed, as well as the combination of SAXS with other X-ray and non-X-ray characterization tools. We conclude with an examination of several key areas of research where X-ray scattering has played a pivotal role, including in situ nanoparticle synthesis, nanoparticle assembly, and operando studies of catalysts and energy storage materials. Throughout this review we highlight the unique capabilities of X-ray scattering for structural characterization of materials in their native environment.
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Affiliation(s)
- Tao Li
- X-ray Science Division, Argonne National Laboratory , 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Andrew J Senesi
- X-ray Science Division, Argonne National Laboratory , 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Byeongdu Lee
- X-ray Science Division, Argonne National Laboratory , 9700 South Cass Avenue, Lemont, Illinois 60439, United States
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11
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Zanatta LD, Barbosa IA, Zanardi FB, de Sousa Filho PC, Bolzon LB, Ramos AP, Serra OA, Iamamoto Y. Hydrocarbon oxidation by iron-porphyrin immobilized on SBA-15 as biomimetic catalyst: role of silica surface. RSC Adv 2016. [DOI: 10.1039/c6ra18395f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We describe a heterogeneous catalyst containing iron-porphyrins in SBA-15 structures for biomimetic catalysis, correlating surface adsorption/wetting characteristics to oxidation mechanisms.
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Affiliation(s)
- L. D. Zanatta
- Department of Chemistry
- Faculdade de Filosofia
- Ciências e Letras de Ribeirão Preto
- University of São Paulo
- Ribeirão Preto
| | - I. A. Barbosa
- Department of Chemistry
- Faculdade de Filosofia
- Ciências e Letras de Ribeirão Preto
- University of São Paulo
- Ribeirão Preto
| | - F. B. Zanardi
- Department of Chemistry
- Faculdade de Filosofia
- Ciências e Letras de Ribeirão Preto
- University of São Paulo
- Ribeirão Preto
| | - P. C. de Sousa Filho
- Department of Chemistry
- Faculdade de Filosofia
- Ciências e Letras de Ribeirão Preto
- University of São Paulo
- Ribeirão Preto
| | - L. B. Bolzon
- Department of General and Inorganic Chemistry
- Institute of Chemistry
- Federal University of Bahia
- Salvador
- Brazil
| | - A. P. Ramos
- Department of Chemistry
- Faculdade de Filosofia
- Ciências e Letras de Ribeirão Preto
- University of São Paulo
- Ribeirão Preto
| | - O. A. Serra
- Department of Chemistry
- Faculdade de Filosofia
- Ciências e Letras de Ribeirão Preto
- University of São Paulo
- Ribeirão Preto
| | - Y. Iamamoto
- Department of Chemistry
- Faculdade de Filosofia
- Ciências e Letras de Ribeirão Preto
- University of São Paulo
- Ribeirão Preto
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12
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Alfredsson V, Wennerström H. The dynamic association processes leading from a silica precursor to a mesoporous SBA-15 material. Acc Chem Res 2015; 48:1891-900. [PMID: 26107533 DOI: 10.1021/acs.accounts.5b00165] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
During the last two decades, the synthesis of silica with an ordered mesoporous structure has been thoroughly explored. The basis of the synthesis is to let silica monomers polymerize in the presence of an amphiphilic template component. In the first studies, cationic surfactants were used as structure inducer. Later it was shown that pluronic copolymers also could have the role. One advantage with the pluronics copolymers is that they allow for a wider variation in the radius of pores in the resulting silica material. Another advantage lies in the higher stability resulting from the thicker walls between the pores. Mesoporous silica has a very high area to volume ratio, and the ordered structure ensures surface homogeneity. There are a number of applications of this type of material. It can be used as support for catalysts, as templates to produces other mesoporous inorganic materials, or in controlled release applications. The synthesis of mesoporous silica is, from a practical point of view, simple, but there are significant possibilities to vary synthesis conditions with a concomitant effect on the properties of the resulting material. It is clear that the structural properties on the nanometer scale are determined by the self-assembly properties of the amphiphile, and this knowledge has been used to optimize pore geometry and pore size. To have a practical functional material it is desirable to also control the structure on a micrometer scale and larger. In practice, one has largely taken an empirical approach in optimizing reaction conditions, paying less attention to underlying chemical and physicochemical mechanisms that lead from starting conditions to the final product. In this Account, we present our systematic studies of the processes involved not only in the formation of the mesoporous structure as such, but also of the formation of structures on the micrometer scale. The main point is to show how the ongoing silica polymerization triggers a sequence of structural changes through the action of colloidal interactions. Our approach is to use a multitude of experimental methods to characterize the time evolution of the same highly reproducible synthesis process. It is the silica polymerization reactions that set the time scale, and the block copolymer self-assembly responds to the progress of the polymerization through a basically hydrophobic interaction between silica and ethylene oxide units. The progression of the silica polymerization leads to an increased hydrophobicity triggering an aggregation process resulting in the formation of silica-copolymer composite particles of increasing size. The particle growth occurs in a stepwise way caused by intricate shifts between colloidal stability and instability. By tuning reaction conditions one can have an end product of hexagonal prism composite particles with single crystal 2D hexagonal order.
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Affiliation(s)
- Viveka Alfredsson
- Division of Physical Chemistry,
Department of Chemistry, Lund University P.O.Box 124, SE 22100 Lund, Sweden
| | - Håkan Wennerström
- Division of Physical Chemistry,
Department of Chemistry, Lund University P.O.Box 124, SE 22100 Lund, Sweden
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13
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Rebbin V, Rothkirch A, Ohta N, Hikima T, Funari SS. Size limit on the formation of periodic mesoporous organosilicas (PMOs). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:1900-1905. [PMID: 24494621 DOI: 10.1021/la404060a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The decrease of the lattice size of periodic mesoporous organosilicas (PMOs) is one important goal in obtaining a microporous material for storage or adsorption of small molecules. To determine the influence of different synthesis parameters in the lattice size, here we performed in situ small-angle X-ray diffraction studies and show that a variation of the surfactant's headgroup size is not directly followed by the lattice parameter of the resulting structure. We show that in the surfactant series of penta-, hexa-, hepta-, octa-, nona-, and decaethylene glycol monododecyl ether (C12(EO)n, n = 5, 6, 7, 8, 9, 10) the lattice size decreases between n = 5 and n = 8 and then increases, while the ordering of the materials is always cubic (space group Fd3m). This size effect is due to the ethylene oxide (EO) chain conformation that changes as the number of EO groups increases. Short ethylene oxide chains tend to have a so-called "zigzag" conformation while an increase of the chain length leads to a "Mäander" (coiling) conformation. Although this phenomenon is most commonly observed for chains consisting of more than 10 ethylene oxide units, we found a minimum PMO lattice size for 8 EO units and intermediate values for 6 and 7 EO units. The increase of the lattice parameter for more than 9 EO units is attributed to the increasing number of "Mäander" configurated EO units.
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Affiliation(s)
- Vivian Rebbin
- HASYLAB/DESY, Notkestrasse 85, 22607 Hamburg, Germany
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14
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Björk EM, Söderlind F, Odén M. Tuning the shape of mesoporous silica particles by alterations in parameter space: from rods to platelets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:13551-13561. [PMID: 24102575 DOI: 10.1021/la403201v] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The knowledge of how to control the pore size and morphology of separated mesoporous silica particles is crucial for optimizing their performance in applications, such as molecular sieves and drug delivery systems. In this work, we have systematically studied the effects of various synthesis parameters to gain a deeper understanding of how particle morphologies can be altered. It was found that the morphology for isolated particles of SBA-15 type, with unusually short and wide pores, could be altered from rods to platelets by variations in the NH4F concentration. The pore length is nearly constant (~300 nm) for the different morphologies, but the particle width is increasing from 200 nm to >3 μm when decreasing the amount of NH4F, and the pore size can be tuned between 10 and 13 nm. Furthermore, other synthesis parameters such as heptane concentration, pH, silica precursor, and additions of ions have also been studied. The trend regarding particle width is independent of heptane concentration, at the same time as heptane increases the particle length up to a plateau value of ~500 nm. In all, parameters controlling particle width, length, and pore size have been separated in order to evaluate their function in the particle formation. Additionally, it was found that the formation time of the particles is strongly affected by the fluoride ion concentration, and a mechanism for particle formation for this system, where micelles transform from a foam, to multilamellar vesicles, and finally to cylindrical micelles, is suggested.
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Affiliation(s)
- Emma M Björk
- Nanostructured Materials, Department of Physics, Chemistry and Biology, Linköping University , Linköping SE-58183, Sweden
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15
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Schmitt J, Impéror-Clerc M, Michaux F, Blin JL, Stébé MJ, Pedersen JS, Meneau F. Formation of nanostructured silica materials templated with nonionic fluorinated surfactant followed by in situ SAXS. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:2007-2023. [PMID: 23305390 DOI: 10.1021/la304648j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The formation of two-dimensional (2D)-hexagonal (p6m) silica-based hybrid materials from concentrated micellar solutions (10 wt %) of two nonionic fluorinated surfactants, R(7)(F)(EO)(8) and R(8)(F)(EO)(9), is investigated in situ using synchrotron time-resolved small angle X-ray scattering (SAXS). The two surfactants form direct micelles with different structures prior to the silica precursor addition as demonstrated by SAXS and SANS. R(8)(F)(EO)(9) gives spherical micelles and R(7)(F)(EO)(8) more complex ones, modeled here as short wormlike micelles. The in situ SAXS experiments reveal that both surfactants form well-ordered 2D-hexagonal hybrid materials after the addition of the silica precursor, in coexistence with an excess of surfactant micelles. The structures of both 2D-hexagonal phases are compared just after precipitation, and it is found that more robust and larger silica walls are formed for R(8)(F)(EO)(9) than for R(7)(F)(EO)(8). This could explain why only the material obtained with R(8)(F)(EO)(9) is stable upon washing, as observed previously. Moreover, it is proposed that in both cases, only a part of the micelles interact with the silica oligomers and undergo structural modifications before forming the 2D-hexagonal mesophase. The obtained results are finally discussed in the more general framework of the templating mechanism for nonionic surfactants.
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Affiliation(s)
- Julien Schmitt
- Laboratoire de Physique de Solides, UMR 8502, Bât. 510, Université Paris-Sud, F-91405 Orsay, France
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16
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Blin JL, Impéror-Clerc M. Mechanism of self-assembly in the synthesis of silica mesoporous materials: in situ studies by X-ray and neutron scattering. Chem Soc Rev 2013; 42:4071-82. [DOI: 10.1039/c2cs35362h] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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17
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Kjellman T, Alfredsson V. The use of in situ and ex situ techniques for the study of the formation mechanism of mesoporous silica formed with non-ionic triblock copolymers. Chem Soc Rev 2013; 42:3777-91. [DOI: 10.1039/c2cs35298b] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Michaux F, Baccile N, Impéror-Clerc M, Malfatti L, Folliet N, Gervais C, Manet S, Meneau F, Pedersen JS, Babonneau F. In situ time-resolved SAXS study of the formation of mesostructured organically modified silica through modeling of micelles evolution during surfactant-templated self-assembly. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:17477-17493. [PMID: 23214421 DOI: 10.1021/la3038318] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The mechanisms of formation of organically modified (phenyl, vinyl, and methyl) silica materials with cubic Pm3n and hexagonal p6m periodic mesostructures obtained in one step in the presence of the cetyltrimethylammonium bromide (CTA(+)B) surfactant are reported in this study. Understanding the way these complex materials form is difficult but undoubtedly necessary for controlling the material structure and its properties because of the combined presence of surface organic groups and large surface areas. Here, the mechanism of formation is clarified on the basis of the modeling of time-resolved in situ small angle X-ray scattering (SAXS) experiments, with a specific focus on the micelle evolution during material formation. Their fast self-assembly is followed for the first time with a quick temporal resolution of a few seconds using a third-generation synchrotron radiation source. To better understand the behavior of the complex organic-containing mesostructure, we perform a comparative study with the corresponding organo-free, isostructural materials obtained from three different surfactants (CTA(+), CTEA(+), and CTPA(+)) having a constant chain length (C(16)) and an increasing polar head volume (met-, et-, and prop-). Numerical modeling of SAXS data was crucial to highlighting a systematic sphere-to-rod micellar transition, otherwise undetected, before the formation of the 2D hexagonal phase in both organo-free and organo-containing systems. Then, two different pathways were found in the formation of the cubic Pm3n mesostructure: either an ordering transition from concentrated flocs of spherical micelles (from CTEA(+) or CTPA(+)) for pure TEOS systems or a structural transformation from an intermediate 2D hexagonal mesophase in organosilane systems (from CTA(+)). Combining the comparison between organo-free and organo-containing systems with numerical modeling, we find that the hexagonal-to-cubic phase transition in the organically modified materials seems to be strongly influenced not only by the obvious presence of the organic group but also by the quicker and more massive condensation kinetics of silicate oligomers on the CTA(+) micellar surface. Finally, quite unexpectedly, we find a wormlike-to-sphere micellar transition in the CTPA(+) system.
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Affiliation(s)
- Florentin Michaux
- UPMC Univ. Paris 06, UMR 7574, Chimie de la Matière Condensée de Paris, F-75005, Paris, France
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19
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Chen H, Wu Y, Tan Y, Li X, Qian Y, Xi H. Mesoscopic simulation of surfactant/silicate self-assembly in the mesophase formation of SBA-15 under charge matching interactions. Eur Polym J 2012. [DOI: 10.1016/j.eurpolymj.2012.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Impéror-Clerc M. Three-dimensional periodic complex structures in soft matter: investigation using scattering methods. Interface Focus 2012; 2:589-601. [PMID: 24098843 PMCID: PMC3438567 DOI: 10.1098/rsfs.2011.0081] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 01/05/2012] [Indexed: 11/12/2022] Open
Abstract
Three-dimensional periodic complex structures are encountered in various soft matter systems such as liquid crystals, block-copolymer phases and the related nano-structured materials. Here, we review several well-defined topologies: two-dimensional hexagonal phase, three-dimensional packing of spheres, tetrahedral close packing (tcp) bi-continuous and tri-continuous cubic phases. We illustrate how small-angle X-ray scattering experiments help us to investigate these different structures and introduce the main available structural models based on both direct and inverse methods.
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21
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Ruan J, Kjellman T, Sakamoto Y, Alfredsson V. Transient colloidal stability controls the particle formation of SBA-15. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:11567-11574. [PMID: 22758927 PMCID: PMC3836357 DOI: 10.1021/la3013969] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 07/03/2012] [Indexed: 06/01/2023]
Abstract
A hypothesis about (transient) colloidal stability as a controlling mechanism for particle formation in SBA-15 is presented. The hypothesis is based on results from both in situ and ex situ investigations, including cryogenic transmission electron microscopy (cryo-TEM), UV-vis spectroscopy, and dynamic light scattering (DLS). Cryo-TEM images show that particles grow via the formation of silica-Pluronic-water "flocs", which coalesce in a seemingly arbitrary manner. Despite this, the final material consists of well-defined particles with a small size distribution. We argue that the interface between the flocs and surrounding media is covered by Pluronic molecules, which provide steric stabilization. As the flocs grow, the coverage of polymers at the interface is increased until a stable size is reached, and that regulates the particle size. By targeting the characteristics of the Pluronic molecules, during the on-going synthesis, the hypothesis is tested. The results are consistent with the concept of (transient) colloidal stability.
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Michaux F, Blin JL, Teixeira J, Stébé MJ. Structural Investigation of Nonionic Fluorinated Micelles by SANS in Relation to Mesoporous Silica Materials. J Phys Chem B 2011; 116:261-8. [DOI: 10.1021/jp209853r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Florentin Michaux
- Equipe Physico-chimie des Colloïdes, UMR SRSMC N° 7565, Université Nancy-1/CNRS Faculté des Sciences, BP 70239, F-54506 Vandoeuvre-les-Nancy cedex, France
| | - Jean-Luc Blin
- Equipe Physico-chimie des Colloïdes, UMR SRSMC N° 7565, Université Nancy-1/CNRS Faculté des Sciences, BP 70239, F-54506 Vandoeuvre-les-Nancy cedex, France
| | - José Teixeira
- Laboratoire Léon Brillouin (CEA/CNRS), CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Marie José Stébé
- Equipe Physico-chimie des Colloïdes, UMR SRSMC N° 7565, Université Nancy-1/CNRS Faculté des Sciences, BP 70239, F-54506 Vandoeuvre-les-Nancy cedex, France
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23
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Manet S, Schmitt J, Impéror-Clerc M, Zholobenko V, Durand D, Oliveira CLP, Pedersen JS, Gervais C, Baccile N, Babonneau F, Grillo I, Meneau F, Rochas C. Kinetics of the Formation of 2D-Hexagonal Silica Nanostructured Materials by Nonionic Block Copolymer Templating in Solution. J Phys Chem B 2011; 115:11330-44. [DOI: 10.1021/jp200213k] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sabine Manet
- Laboratoire de Physique de Solides, UMR 8502, Bât. 510, Université Paris-Sud, F-91405 Orsay, France
| | - Julien Schmitt
- Laboratoire de Physique de Solides, UMR 8502, Bât. 510, Université Paris-Sud, F-91405 Orsay, France
| | - Marianne Impéror-Clerc
- Laboratoire de Physique de Solides, UMR 8502, Bât. 510, Université Paris-Sud, F-91405 Orsay, France
| | - Vladimir Zholobenko
- Chemistry Department, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Dominique Durand
- Institut de Biochimie et de Biophysique Moléculaire et Cellulaire, Bât. 430, Université Paris-Sud, F-91405 Orsay, France
| | - Cristiano L. P. Oliveira
- Department of Chemistry and iNANO Interdisciplinary Nanoscience Center, Århus University, DK-8000 Århus, Denmark
| | - Jan Skov Pedersen
- Department of Chemistry and iNANO Interdisciplinary Nanoscience Center, Århus University, DK-8000 Århus, Denmark
| | - Christel Gervais
- Laboratoire de Chimie de la Matière Condensée, Collège de France, F-75231 Paris Cedex 05, France
| | - Niki Baccile
- Laboratoire de Chimie de la Matière Condensée, Collège de France, F-75231 Paris Cedex 05, France
| | - Florence Babonneau
- Laboratoire de Chimie de la Matière Condensée, Collège de France, F-75231 Paris Cedex 05, France
| | | | - Florian Meneau
- SWING, Synchrotron Soleil, BP 48, F-91192 Gif-sur-Yvette, France
| | - Cyrille Rochas
- D2AM, ESRF, 6 rue Jules Horowitz, F-38000 Grenoble, France
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24
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Manet S, Lecchi A, Impéror-Clerc M, Zholobenko V, Durand D, Oliveira CLP, Pedersen JS, Grillo I, Meneau F, Rochas C. Structure of Micelles of a Nonionic Block Copolymer Determined by SANS and SAXS. J Phys Chem B 2011; 115:11318-29. [DOI: 10.1021/jp200212g] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sabine Manet
- Laboratoire de Physique de Solides, UMR 8502, Bât. 510, Université Paris-Sud, F-91405 Orsay, France
| | - Amélie Lecchi
- Laboratoire de Physique de Solides, UMR 8502, Bât. 510, Université Paris-Sud, F-91405 Orsay, France
| | - Marianne Impéror-Clerc
- Laboratoire de Physique de Solides, UMR 8502, Bât. 510, Université Paris-Sud, F-91405 Orsay, France
| | - Vladimir Zholobenko
- Chemistry Department, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Dominique Durand
- Institut de Biochimie et de Biophysique Moléculaire et Cellulaire, Bât. 430, Université Paris-Sud, F-91405 Orsay, France
| | - Cristiano L. P. Oliveira
- Department of Chemistry and iNANO Interdisciplinary Nanoscience Center, Århus University, DK-8000 Århus, Denmark
| | - Jan Skov Pedersen
- Department of Chemistry and iNANO Interdisciplinary Nanoscience Center, Århus University, DK-8000 Århus, Denmark
| | | | - Florian Meneau
- SWING, Synchrotron Soleil, BP 48, F-91192 Gif-sur-Yvette, France
| | - Cyrille Rochas
- D2AM, ESRF, 6 rue Jules Horowitz, F-38000 Grenoble, France
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25
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Jammaer J, van Erp TS, Aerts A, Kirschhock CEA, Martens JA. Continuous Synthesis Process of Hexagonal Nanoplates of P6m Ordered Mesoporous Silica. J Am Chem Soc 2011; 133:13737-45. [DOI: 10.1021/ja205627t] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jasper Jammaer
- Center for Surface Chemistry and Catalysis, Catholic University of Leuven, Kasteelpark Arenberg 23, B-3001 Leuven, Belgium
| | - Titus S. van Erp
- Center for Surface Chemistry and Catalysis, Catholic University of Leuven, Kasteelpark Arenberg 23, B-3001 Leuven, Belgium
| | - Alexander Aerts
- Center for Surface Chemistry and Catalysis, Catholic University of Leuven, Kasteelpark Arenberg 23, B-3001 Leuven, Belgium
| | - Christine E. A. Kirschhock
- Center for Surface Chemistry and Catalysis, Catholic University of Leuven, Kasteelpark Arenberg 23, B-3001 Leuven, Belgium
| | - Johan A. Martens
- Center for Surface Chemistry and Catalysis, Catholic University of Leuven, Kasteelpark Arenberg 23, B-3001 Leuven, Belgium
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26
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Oppel C, Prévost S, Noirez L, Gradzielski M. The use of highly ordered vesicle gels as template for the formation of silica gels. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:8885-8897. [PMID: 21692463 DOI: 10.1021/la104972r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A spontaneously forming gel of unilamellar vesicles based on sodium oleate (Na oleate) and 1-octanol as amphiphiles has been employed as a template in the formation of a silica gel formed by the hydrolysis of the inorganic precursor tetraethyl orthosilicate (TEOS). Up to about 10 wt % TEOS can be incorporated into this vesicle gel without phase separation and in a fully homogeneous formation process by simple mixing of the components. The process itself relies solely upon the self-organizing properties of this amphiphilic template system. The formation process was followed by means of time-resolved turbidity, rheology, and small-angle neutron scattering (SANS) experiments. It can be concluded that the presence of the precursor TEOS affects the kinetics of the process but the original vesicle gel structure is retained even up to highest TEOS content. The kinetic studies confirm that under the chosen conditions the vesicle formation proceeds much faster than the hydrolysis of TEOS and the subsequent formation of the silica gel. SANS displays in the low q-range an additional scattering due to the silica gel network, i.e., a hybrid material of an amphiphilic vesicle gel and an inorganic oxide gel is formed. Thus, this method is a very facile novel route of forming a highly ordered silica/vesicle gel by employing a self-organizing amphiphilic system as template and the formation of the silica network proceeds in a fully homogeneous fashion under kinetic control.
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Affiliation(s)
- Claudia Oppel
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Berlin, Germany.
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27
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Teixeira CV, Amenitsch H, Linton P, Lindén M, Alfredsson V. The role played by salts in the formation of SBA-15, an in situ small-angle X-ray scattering/diffraction study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:7121-7131. [PMID: 21548622 DOI: 10.1021/la1043798] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The influence of salts (NaCl, NaBr, and NaI) on the formation of mesoporous silica SBA-15 was studied in situ by small-angle X-ray scattering and diffraction. Pluronic P104 was used as structure director. The micellar properties and the dynamics of formation were clearly dependent on the presence of salt. It was also shown that the kinetics of mesophase formation, the initial value of the cell parameters, and the extent of long-range order were all influenced by salt additions. The observations are explained to primarily originate from the influence of the anions on the ethylene oxide part of the polymer, i.e., the corona region of the Pluronic micelles. Two effects are identified: a general ion effect causing dehydration of the ethylene oxide part and consequently inducing micellar growth, and a specific ion effect that counterbalances this. The study provides the basis for understanding the means by which addition of simple Na-salts influence the formation of mesoscopically ordered silicas synthesized using nonionic surfactants as structure directors, hence advancing the knowledge base toward a more rational design of mesoporous materials.
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Affiliation(s)
- C V Teixeira
- Universitad Autonoma de Barcelona, Facultad de Medicina, Unidad de Biofisica-Cerdanyola del Valles, 08193, Spain
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28
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Johansson EM, Ballem MA, Córdoba JM, Odén M. Rapid synthesis of SBA-15 rods with variable lengths, widths, and tunable large pores. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:4994-9. [PMID: 21413751 DOI: 10.1021/la104864d] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Dispersed SBA-15 rods have been synthesized with varying lengths, widths, and pore sizes in a low-temperature synthesis in the presence of heptane and NH(4)F. The pore size of the material can systematically be varied between 11 and 17 nm using different hydrothermal treatment times and/or temperatures. The particle length (400-600 nm) and width (100-400 nm) were tuned by varying the HCl concentration. All the synthesized materials possess a large surface area of 400-600 m(2)/g and a pore volume of 1.05-1.30 cm(3). A mechanism for the effect of the HCl concentration on the particle morphology is suggested. Furthermore, it is shown that the reaction time can be decreased to 1 h, with well-retained pore size and morphology. This work has resulted in SBA-15 rods with the largest pore size reported for this morphology.
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Affiliation(s)
- Emma M Johansson
- Nanostructured Materials, Department of Physics, Chemistry and Biology, Linköping University, Linköping SE-58183, Sweden.
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29
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30
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Pienack N, Bensch W. In-Situ Monitoring of the Formation of Crystalline Solids. Angew Chem Int Ed Engl 2011; 50:2014-34. [DOI: 10.1002/anie.201001180] [Citation(s) in RCA: 203] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Indexed: 11/10/2022]
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31
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Grosso D, Ribot F, Boissiere C, Sanchez C. Molecular and supramolecular dynamics of hybrid organic–inorganic interfaces for the rational construction of advanced hybrid nanomaterials. Chem Soc Rev 2011; 40:829-48. [DOI: 10.1039/c0cs00039f] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Wang W, Shan W, Ru H. Facile preparation and new formation mechanism of plugged SBA-15 silicas based on cheap sodium silicate. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm13669k] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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33
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Abstract
In the recent years the driving force for technological change in many respects has shifted towards the design and process of materials that offer a set of responses to external stimuli or environmental conditions. These materials are called “smart materials”. Such responses are designed to fulfil the range of scenarios to which a material or structure may be exposed providing them with a particular functionality. These materials are not only useful because of their structural, chemical, physical or mechanical properties; they can also perform an action within a process. It has been described that smart structures exhibit one or more of the following features; they can act as sensors or actuators within a structural material or bonded in the surface; or they have controllable capabilities that permit to respond to the stimuli according to a prescribed function. These materials become intelligent when they have the ability to respond intelligently and autonomously to changing conditions. There are lots of possibilities within the term functional “smart materials” but in all of them, the term is used to describe systems which respond to a stimulus in a useful and predictable manner. Nowadays it is widely known the useful capability of, piezoelectric, electro-optic, magnetic, electro-mechanic materials, etc…that respond to stimuli such as, electric or magnetic fields, stress, temperature, moisture or pH. These multifunctional character and capability of biomaterials makes them suitable for a big number of applications in every order of human activity, from photochromic lenses for sunglasses to military and aerospace uses. They are already a big part of the market in the engineering industry.
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34
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Rebbin V, Rothkirch A, Ohta N, Funari SS. Formation mechanism studies of phenylene-bridged periodic mesoporous organosilicas (PMOs). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:9017-9022. [PMID: 20397657 DOI: 10.1021/la904837v] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The formation of phenylene-bridged periodic mesoporous organosilicas (PMOs) in the presence of three diblock copolymers differing in hydrophobic hydrocarbon chain lengths was investigated. Hexaethylene glycol octadecylether (C(18)(EO)(6)), hexaethylene glycol hexadecylether (C(16)(EO)(6)), and hexaethylene glycol dodecylether (C(12)(EO)(6)) were chosen in order to obtain insight on the influence of the hydrocarbon chain length on the mesostructure. 1,4-Bis(triethoxysilyl)benzene (BTEB) was used as organosilica precursor under mild acidic conditions. The reactions were followed by in situ small-angle X-ray diffraction (SAXD) on-time in a capillary flow setup. It was found that during the reaction the formation of different structures was observed, which is ascribed to the hydrolysis and condensation of the organosilica precursor. In all cases, different structures evolve with time and phase transitions are observed during the measurements independent of the hydrocarbon chain length.
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Affiliation(s)
- V Rebbin
- HASYLAB@DESY, Notkestr. 85, 22607 Hamburg, Germany.
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35
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Sundblom A, Palmqvist AEC, Holmberg K. Study of the pluronic-silica interaction in synthesis of mesoporous silica under mild acidic conditions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:1983-1990. [PMID: 20041679 DOI: 10.1021/la902144h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The interaction between silica and poly(ethylene oxide) (PEO) in water may appear trivial and it is generally stated that hydrogen bonding is responsible for the attraction. However, a literature search shows that there is not a consensus with respect to the mechanism behind the attractive interaction. Several papers claim that only hydrogen bonding is not sufficient to explain the binding. The silica-PEO interaction is interesting from an academic perspective and it is also exploited in the preparation of mesoporous silica, a material of considerable current interest. This study concerns the very early stage of synthesis of mesoporous silica under mild acidic conditions, pH 2-5, and the aim is to shed light on the interaction between silica and the PEO-containing structure directing agent. The synthesis comprises two steps. An organic silica source, tetraethylorthosilicate (TEOS), is first hydrolyzed and Pluronic P123, a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymer, is subsequently added at different time periods following the hydrolysis of TEOS. It is shown that the interaction between the silica and the Pluronic is dependent both on the temperature and on the time between onset of TEOS hydrolysis and addition of the copolymer. The results show that the interaction is mainly driven by entropy. The effect of the synthesis temperature and of the time between hydrolysis and addition of the copolymer on the final material is also studied. The material with the highest degree of mesoorder was obtained when the reaction was performed at 20 degrees C and the copolymer was added 40 h after the start of TEOS hydrolysis. It is claimed that the reason for the good ordering of the silica is that whereas particle formation under these conditions is fast, the rate of silica condensation is relatively low.
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Affiliation(s)
- Andreas Sundblom
- Applied Surface Chemistry, Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Goteborg, Sweden
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36
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Linton P, Wennerström H, Alfredsson V. Controlling particle morphology and size in the synthesis of mesoporous SBA-15 materials. Phys Chem Chem Phys 2010; 12:3852-8. [DOI: 10.1039/b923364d] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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37
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Yu C, Chu H, Wan Y, Zhao D. Synthesis of easily shaped ordered mesoporous titanium-containing silica. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/b925864g] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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38
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Li J, Hu Q, Tian H, Ma C, Li L, Cheng J, Hao Z, Qiao S. Expanding mesoporosity of triblock-copolymer-templated silica under weak synthesis acidity. J Colloid Interface Sci 2009; 339:160-7. [DOI: 10.1016/j.jcis.2009.07.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 07/15/2009] [Accepted: 07/20/2009] [Indexed: 10/20/2022]
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39
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Linton P, Rennie AR, Zackrisson M, Alfredsson V. In situ observation of the genesis of mesoporous silica SBA-15: dynamics on length scales from 1 nm to 1 microm. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:4685-4691. [PMID: 19260727 DOI: 10.1021/la803543z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report on the mechanism of growth of mesoporous silica (SBA-15, plane group p6m). In situ studies of the formation using ultrasmall angle X-ray scattering (USAXS) and small-angle X-ray scattering (SAXS) covering length scales from 5 to 10,000 A, complemented with UV-vis and transmission electron microscopy (TEM), provide unique data on particle growth coupled with information regarding the progression of the mesostructure formation and the micellar evolution.
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Affiliation(s)
- Peter Linton
- Physical Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
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40
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Angelov B, Angelova A, Vainio U, Garamus VM, Lesieur S, Willumeit R, Couvreur P. Long-living intermediates during a lamellar to a diamond-cubic lipid phase transition: a small-angle X-ray scattering investigation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:3734-3742. [PMID: 19708151 DOI: 10.1021/la804225j] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
To generate nanostructured vehicles with tunable internal organization, the structural phase behavior of a self-assembled amphiphilic mixture involving poly(ethylene glycol) monooleate (MO-PEG) and glycerol monooleate (MO) is studied in excess aqueous medium by time-resolved small-angle X-ray scattering (SAXS) in the temperature range from 1 to 68 degrees C. The SAXS data indicate miscibility of the two components in lamellar and nonlamellar soft-matter nanostructures. The functionalization of the MO assemblies by a MO-PEG amphiphile, which has a flexible large hydrophilic moiety, appears to hinder the epitaxial growth of a double diamond (D) cubic lattice from the lamellar (L) bilayer structure during the thermal phase transition. The incorporated MO-PEG additive is found to facilitate the formation of structural intermediates. They exhibit greater characteristic spacings and large diffusive scattering in broad temperature and time intervals. Their features are compared with those of swollen long-living intermediates in MO/octylglucoside assemblies. A conclusion can be drawn that long-living intermediate states can be equilibrium stabilized in two- or multicomponent amphiphilic systems. Their role as cubic phase precursors is to smooth the structural distortions arising from curvature mismatch between flat and curved regions. The considered MO-PEG functionalized assemblies may be useful for preparation of sterically stabilized liquid-crystalline nanovehicles for confinement of therapeutic biomolecules.
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Affiliation(s)
- Borislav Angelov
- Institute of Biophysics, Bulgarian Academy of Sciences, BG-1113 Sofia, Bulgaria
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41
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Hong J, Chernavskii PA, Khodakov AY, Chu W. Effect of promotion with ruthenium on the structure and catalytic performance of mesoporous silica (smaller and larger pore) supported cobalt Fischer–Tropsch catalysts. Catal Today 2009. [DOI: 10.1016/j.cattod.2008.10.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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42
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Linton P, Hernandez-Garrido JC, Midgley PA, Wennerström H, Alfredsson V. Morphology of SBA-15-directed by association processes and surface energies. Phys Chem Chem Phys 2009; 11:10973-82. [DOI: 10.1039/b913755f] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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43
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Zholobenko VL, Khodakov AY, Impéror-Clerc M, Durand D, Grillo I. Initial stages of SBA-15 synthesis: an overview. Adv Colloid Interface Sci 2008; 142:67-74. [PMID: 18599009 DOI: 10.1016/j.cis.2008.05.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Revised: 05/26/2008] [Accepted: 05/28/2008] [Indexed: 11/17/2022]
Abstract
This work presents an overview of the data obtained for SBA-15 synthesis under the reaction conditions using synchrotron based small angle X-ray scattering and small angle neutron scattering. Three major stages in the synthesis of SBA-15 materials proceeding according to the cooperative self-assembly mechanism have been identified, and the structures of the intermediates species have been established. Our in situ time-resolved neutron scattering experiments demonstrate that only spherical micelles of the templating agent are present in the synthesis mixture during the first stage of the reaction. According to the neutron scattering and X-ray scattering data, in the second stage of the reaction the formation of hybrid organic-inorganic micelles is accompanied with the transformation from spherical to cylindrical micelles, which takes place before the precipitation of the ordered SBA-15 phase. During the third stage, these micelles aggregate into a two-dimensional hexagonal structure, confirming that the precipitation takes place as the result of self-assembly of the hybrid cylindrical micelles. As the synthesis proceeds, the voids between the cylinders are filled with the silicate species which undergo condensation reactions resulting in cross-linking and covalent bonding, leading to the formation of highly ordered SBA-15 mesostructure. This work demonstrates that valuable structural information can be obtained from X-ray and neutron scattering characterisation of complex systems containing periodic phases with d-spacing values up to 30 nm, and that both techniques are powerful means for in situ monitoring of the formation of nanostructured materials.
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44
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Gianotti E, Berlier G, Costabello K, Coluccia S, Meneau F. In situ synchrotron small-angle X-ray scattering study of MCM-41 crystallisation using Gemini surfactants. Catal Today 2007. [DOI: 10.1016/j.cattod.2006.08.064] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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45
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Affiliation(s)
- Ying Wan
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Key Laboratory of Molecular Engineering of Polymers, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, P. R. China
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46
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Wan Y, Shi Y, Zhao D. Designed synthesis of mesoporous solids via nonionic-surfactant-templating approach. Chem Commun (Camb) 2007:897-926. [PMID: 17311122 DOI: 10.1039/b610570j] [Citation(s) in RCA: 156] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The continual needs for improved performances in applications derived by diversified compositions and mesostructures have pushed forward the development of mesoporous solids. The nonionic-surfactant-templating approach has been a critical route in this advancement. A large number of nonionic surfactants widely used in industries and featured with low cost, low toxicity, bio-degradation and ordered microdomains can be utilized as effective templates to the design and synthesis of abundant mesoporous solids. This feature article provides recent reports on the use of nonionic surfactant self-assembly as examples to fabricate high-quality ordered mesoporous solids which illustrates advances in synthesis and understanding of formation mechanisms. It includes the selection of surfactants, a summary of the effects of synthetic parameters, the current understanding of the synthetic pathways and related mechanisms with some emphasis on evaporation induced self-assembly (EISA), as well as the design and synthesis on the microscale (atomic and molecular compositions) and mesoscale (mesostructures). Preliminary applications of mesoporous solids particularly in optical devices, electrodes and biomaterials are also presented.
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Affiliation(s)
- Ying Wan
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, P. R. China
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47
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Impéror-Clerc M, Grillo I, Khodakov AY, Durand D, Zholobenko VL. New insights into the initial steps of the formation of SBA-15 materials: an in situ small angle neutron scattering investigation. Chem Commun (Camb) 2007:834-6. [PMID: 17308647 DOI: 10.1039/b611208k] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Time-resolved in situ SANS investigations have provided direct experimental evidence for the three initial steps in the formation of the SBA-15 mesoporous material: an induction period is followed by a shape transformation of the micelles from spherical to cylindrical ones followed by the precipitation of a two-dimensional hexagonal phase.
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Affiliation(s)
- Marianne Impéror-Clerc
- Laboratoire de Physique de Solides, UMR 8502, Bât. 510, Université Paris-Sud, 91405 Orsay Cedex, France.
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Beurroies I, Agren P, Büchel G, Rosenholm JB, Amenitsch H, Denoyel R, Linden M. Detailed in Situ XRD and Calorimetric Study of the Formation of Silicate/Mixed Surfactant Mesophases under Alkaline Conditions. Influence of Surfactant Chain Length and Synthesis Temperature. J Phys Chem B 2006; 110:16254-60. [PMID: 16913751 DOI: 10.1021/jp053746y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The formation of mesoscopically ordered silica/surfactant composites under alkaline synthesis conditions has been studied by time-resolved in situ small-angle X-ray diffraction with synchrotron radiation. Alkyltrimethylammoniumbromide surfactants, C(n)()TAB, of different chain lengths (n = 14, 16, and 18) as well as mixtures thereof were used as structure directing agents and the measurements were carried out at two different temperatures. A linear relationship between the mean surfactant chain length and the d spacing of the hexagonal phase was observed, suggesting an ideal mixing of the surfactants in the supramolecular surfactant aggregates. It is shown that the formation of the hexagonal phase is kinetically controlled mainly by the rate of silicate condensation, while the effect of changes in the surfactant chain length on the kinetics is small under the studied conditions. Two concominant, albeit partly interlinked, processes, suggested being intra- and intermicellar condensation, followed by aggregate-aggregate condensation, govern the nucleation and growth of the hexagonal phase. The two-step mechanism is confirmed by a microcalorimetric study where the heat evolved during the hydrolysis-condensation reactions is followed as a function of time.
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Affiliation(s)
- Isabelle Beurroies
- MADIREL (CNRS-Universite de Provence), Centre de St Jérôme, 13397 Marseille Cedex 20, France
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Wasielewski MR. Energy, Charge, and Spin Transport in Molecules and Self-Assembled Nanostructures Inspired by Photosynthesis. J Org Chem 2006; 71:5051-66. [PMID: 16808492 DOI: 10.1021/jo060225d] [Citation(s) in RCA: 480] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Electron transfer in biological molecules provides both insight and inspiration for developing chemical systems having similar functionality. Photosynthesis is an example of an integrated system in which light harvesting, photoinduced charge separation, and catalysis combine to carry out two thermodynamically demanding processes, the oxidation of water and the reduction of carbon dioxide. The development of artificial photosynthetic systems for solar energy conversion requires a fundamental understanding of electron-transfer reactions between organic molecules. Since these reactions most often involve single-electron transfers, the spin dynamics of photogenerated radical ion pairs provide important information on how the rates and efficiencies of these reactions depend on molecular structure. Given this knowledge, the design and synthesis of large integrated structures to carry out artificial photosynthesis is moving forward. An important approach to achieving this goal is the development of small, functional building blocks, having a minimum number of covalent bonds, which also have the appropriate molecular recognition sites to facilitate self-assembly into a complete, functional artificial photosynthetic system.
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Affiliation(s)
- Michael R Wasielewski
- Department of Chemistry and International Institute for Nanotechnology, Northwestern University, Evanston, IL 60208-3113, USA.
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Ruthstein S, Schmidt J, Kesselman E, Talmon Y, Goldfarb D. Resolving Intermediate Solution Structures during the Formation of Mesoporous SBA-15. J Am Chem Soc 2006; 128:3366-74. [PMID: 16522118 DOI: 10.1021/ja0559911] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The evolution of the solution microstructures during the formation of the hexagonal mesoporous material SBA-15 was studied by direct imaging and freeze-fracture replication cryo-TEM. A reaction mixture was sampled at different times after the addition of tetramethoxyorthosilane (TMOS) to an acidic solution of Pluronic P123 held at 50 degrees C. Solution microstructures were detected by direct imaging cryo-TEM in the time window of 6.5-40 min after the addition of the TMOS (t = 0). The micrographs revealed that the initial spheroidal micelles evolve into threadlike micelles, which become longer and straighter with time. Then bundles with the dimensions similar to those found in the final material appeared, although there was no sign of a hexagonal arrangement up to 40 min. Due to the appearance of a precipitate at 40 min the sample became too viscous, preventing clear observation of its content. To observe the structures present after 40 min, freeze-fracture replication was carried out as well. Such samples were collected also at 22 min and showed the presence of threadlike micelles in agreement with the direct imaging cryo-TEM micrographs. The 2 h samples showed some areas of hexagonal ordered structures, which become very clear at 2 h 50 min. The cryo-TEM measurements were carried out under the same reaction conditions used in earlier in situ EPR experiments, thus allowing us to correlate molecular level events with the microstructure shape evolutions. This showed that the elongation of the micelles is a consequence of a reduction of the polarity and the water content within the micelles due to silicate adsorption and polymerization. Similar experiments were carried out also on SBA-15 prepared with HCl and TMOS at 35 degrees C. The appearance of threadlike micelles, followed by clustering of the TLMs, was observed under these conditions as well, but the reaction rate was faster. This suggests that the observed mechanism for the formation of SBA-15 is general.
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Affiliation(s)
- Sharon Ruthstein
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
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