Thermal degradation of CTAB in as-synthesized MCM-41

Goworek, J.; Kierys, Agnieszka; Gac, Wojciech; Borόwka, A.; Kusak, R.

doi:10.1007/s10973-008-9055-6

Cited by 84 publications

(39 citation statements)

References 37 publications

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“…Trimethylamine is a product of the template degradation at lower temperatures. In the case of siliceous MCM-41 an intensive release of trimethylamine was observed within the temperature range 200-300 °C [31]. At a relatively low temperature 250-300 °C fragmentation of the alkyl chain takes also place producing shorter hydrocarbons [35,36].…”

Section: Thermal Analysismentioning

confidence: 98%

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Pore ordering in mesoporous matrices induced by different directing agents

et al. 2014

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Mesoporous silica particles of MCM-41 type were synthesized by sol-gel method from tetraethyl orthosilicate (TEOS) in 2-methoxyethanol and deionized water mixture in base conditions at room temperature. Ammonia or sodium hydroxides were used as catalysts and cetyl-trimethylammonium bromide (CTAB) and n-dodecyl-trimethylammonium bromide (DTAB) as structure directing agents. The porosities and the ordered structure have been analyzed using transmission and scanning electron microscopy, small angle neutron and Xray diffraction, nitrogen adsorption, thermal analysis and FTIR spectroscopy. The samples consist of spherical particles of sub-micrometer size, with radially arranged pores. The comparison of the effect of the different surfactants and catalysts shows that by varying the surfactant type and their proportion, the pore sizes can be controlled. As compared to the commonly used ammonia catalyst, the use of NaOH as catalyst results in a much smaller porosity of the as-prepared materials. These materials are not resisting to the heat treatment at 700 ºC used for the template removal, and the ordered porous structure is completely lost.

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Section: Thermal Analysismentioning

confidence: 98%

“…The first weight loss is accompanied by an endothermic effect on the DTA curves ( Fig. 2), due to desorption of the physisorbed and chemisorbed water [31][32][33]. CTAB starts to decompose above 200 °C [34].…”

Section: Thermal Analysismentioning

confidence: 99%

Pore ordering in mesoporous matrices induced by different directing agents

et al. 2014

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“…According to [13], if the surfactant removal peak occurs at higher temperatures, then this indicates that the surfactant is more difficult to decompose, and this in turn means that it interacts stronger with the silanol groups. Moreover, it is also known [12] that the template removal efficiency is higher for pure siliceous MCM-41 as compared with the aluminium containing MCM-41, and the F-MCM-41(3) sample had the highest Al content (Table 5) of all the samples examined. The investigation has shown, therefore, that the degree of surfactant removal depends on the properties of the F-MCM-41 material from which the surfactant is removed, and especially on its composition and structure.…”

Section: Thermal Analysismentioning

confidence: 97%

“…As indicated by the conducted research [12][13][14][15][16][17], thermogravimetric analysis (TGA) provides a lot of valuable information both on the thermal behaviour of samples of mesoporous materials and on the course of their synthesis process itself. Thermal analysis is used [12][13][14][15][16][17] for the TG monitoring of the synthesis of MCM-41 mesoporous materials being obtained from silicon sources, such as regular silica-gel or colloidal fumed silica, which allows the evaluation of the effect of adjusting pH during the hydrothermal synthesis on the quality of the obtained material.…”

Section: Introductionmentioning

confidence: 99%

“…Thermal analysis is used [12][13][14][15][16][17] for the TG monitoring of the synthesis of MCM-41 mesoporous materials being obtained from silicon sources, such as regular silica-gel or colloidal fumed silica, which allows the evaluation of the effect of adjusting pH during the hydrothermal synthesis on the quality of the obtained material. The monitoring encompasses also the process of removing the surfactant from the MCM-41 materials, serving for the determination of the appropriate time and temperature of calcination to obtain a good-quality mesoporous material.…”

Section: Introductionmentioning

confidence: 99%

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Thermogravimetry applied to characterization of fly ash-based MCM-41 mesoporous materials

Majchrzak‐Kucęba

2011

J Therm Anal Calorim

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The thermogravimetry (TG) was used for characterization of the fly ash (FA)-based MCM-41 mesoporous materials. MCM-41 mesoporous materials were synthesized using silica extracts from different FA. The synthesis of MCM-41 from FA was carried out by the hydrothermal method using the supernatants of coal FA (in the form of sodium silicate) and cationic cetyltrimethylammonium bromide (CTAB) surfactants as the structuredirecting agents. On the basis of the data obtained from the TG analysis, thermal behaviour of FA-based MCM-41 mesoporous materials was assessed. This study has established the range of temperatures corresponding to the desorption of water, decomposition of the surfactant and condensation of silanol, thereby making the overall quality assessment of FA-based MCM-41 mesoporous materials.

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