Surfactant recovery from mesoporous metal-modified materials (Sn–, Y–, Ce–, Si–MCM-41), by ultrasound assisted ion-exchange extraction and its re-use for a microwave in situ cheap and eco-friendly MCM-41 synthesis
| Autor: | Emiliano Fratini, Celia Duce, Emilia Bramanti, I. R. Galindo-Esquivel, J. Tovar-Rodríguez, Carlo Ferrari, Iginio Longo, José González-Rivera |
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| Rok vydání: | 2014 |
| Předmět: |
Materials science
Ion exchange Renewable Energy Sustainability and the Environment Extraction (chemistry) Analytical chemistry General Chemistry law.invention Physisorption Pulmonary surfactant MCM-41 template removal law molecular-sieves solid-state NMR Hydrothermal synthesis General Materials Science Calcination silica-nanoparticles Mesoporous material enzyme immobilization |
| Zdroj: | Journal of Materials Chemistry A 2 (2014): 7020–7033. doi:10.1039/c3ta15078j info:cnr-pdr/source/autori:Gonzalez-Rivera, J.; Tovar-Rodriguez, J.; Bramanti, E.; Duce, C.; Longo, I.; Fratini, E.; Galindo-Esquivel, I. R.; Ferrari, C./titolo:Surfactant recovery from mesoporous metal-modified materials (Sn-, Y-, Ce-, Si-MCM-41), by ultrasound assisted ion-exchange extraction and its re-use for a microwave in situ cheap and eco-friendly MCM-41 synthesis/doi:10.1039%2Fc3ta15078j/rivista:Journal of Materials Chemistry A/anno:2014/pagina_da:7020/pagina_a:7033/intervallo_pagine:7020–7033/volume:2 |
| ISSN: | 2050-7496 2050-7488 |
| DOI: | 10.1039/c3ta15078j |
| Popis: | Different metal substituted (Y, Sn and Ce) MCM-41 materials were synthesized and detemplated by a low temperature surfactant removal methodology. All metal substituted materials showed an increase in the d(100) lattice parameter compared to the parent MCM-41 matrices. The increase depends on both the metal type and amount that is successfully incorporated by direct conventional hydrothermal synthesis. The metal modified MCM-41 materials were detemplated by an ultrasound assisted (US) ion-exchange process using methanol as the solvent (NH4NO3/US/MeOH). The effect of the ultrasound amplitude, extraction time and salt concentration were explored, and optimal values were determined for Y-MCM-41 detemplation (40 mM of NH4NO3, 60% of US amplitude and 15 min of adiabatic treatment). The removal percentage achieved with these values was in the following order: Y (97.7%) > Ce (94.4%) > Sn ;(92.1%) > Si (90.3%). Several techniques (SAXS, FTIR, TGA, H-1 MAS, Si-29 HPDEC MAS NMR and N-2 physisorption) demonstrated that the mesoporous materials keep their hexagonal structure and high surface area after the NH4NO3/US/MeOH surfactant extraction. Moreover, the thermal shrinkage of the structure was reduced in the following order: Si (0.6%) < Sn (4%) < Ce (5%) < Y (9%) < calcined samples (from 9 to 15%). The surfactant recovered was successfully recycled in a consecutive microwave assisted hydrothermal synthesis cycle (MW-HT). The synergy of different strategies (MW-HT synthesis, NH4NO3/US/MeOH surfactant removal and surfactant recovery) produces considerable time, energy and cost abatement, environmental impact reduction and promising scale up projections in the eco-friendly synthesis of MCM-41 materials. |
| Databáze: | OpenAIRE |
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