Contribution to the study of the formation mechanism of mesoporous SBA-15 and SBA-16 type silica particles in aqueous acid solutions

Mesa, Mónica; Sierra, Ligia; Guth, J.L.

doi:10.1016/j.micromeso.2007.10.008

Cited by 73 publications

(71 citation statements)

References 35 publications

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“…The morphologies of mesoporous materials are developed after step (3) and depend on the competition between the free energy of the mesostructure self-assembly (ΔG) and the colloidal surface free energy (F). Similarly, M. Mesa et al [12] followed the formation mechanism of SBA-16 from the earliest stage of the reaction until the formation of the particles by a dynamic light scattering technique, and suggested three steps for that: (1) silica coating of the surfactant micelles and decrease of the zeta potential, (2) formation of micron-sized "liquid particles" by aggregation and fusion of the composite colloids (silica coated micelles), and (3) solidification of the "liquid particles" and transformation into the final particles of mesoporous silica.…”

Section: Sba-16 Is a Mesoporous Materials With 3d Cubic Pore Arrangemementioning

confidence: 90%

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Influence of synthesis temperature on morphology of SBA-16 mesoporous materials with a three-dimensional pore system

Ballem

Córdoba

Odén

2010

Microporous and Mesoporous Materials

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Spherical particles of mesoporous silica SBA-16 with cubic Im3m structure were synthesized at low pH using Pluronic F127 as template and TEOS as silica source. The diameter of the spherical particles can be controlled in the range of 0.5 -8 µm by varying synthesis temperature between 1 °C up to 40 °C. A sharp transition from large particle sizes at approximately 20 °C to smaller ones is observed when the temperature is increased. It is suggested that this morphology transition is due to a change in hydrolysis and condensation rate of the silica source and as a result the assembly of F127 micelles will differ. The SBA-16 samples were characterized using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Nitrogen adsorption techniques.

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Section: Sba-16 Is a Mesoporous Materials With 3d Cubic Pore Arrangemementioning

confidence: 90%

“…6 step 3), which will transform into the final particles ( Fig. 6 step 4), the details of this step have been discussed extensively by M. Mesa et al [12] using the DLVO (Derjaguin, Landau, Verwey and Overbeek) theory.…”

Section: Figure 6 Schematic Drawing Of the Formation Steps Of Sba-16 mentioning

confidence: 99%

Influence of synthesis temperature on morphology of SBA-16 mesoporous materials with a three-dimensional pore system

Ballem

Córdoba

Odén

2010

Microporous and Mesoporous Materials

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“…5 The SBA-16 silica is a mesoporous material with 3D cubic pore arrangement corresponding to Im3m space group. 6,7 In this bodycentered-cubic structure, each mesopore is connected with its eight nearest neighbors to form a mesoporous network, which is also connected with micropores. The combination of high surface area and thermal stability with 3D structure of the SBA-16 silica allows its use as a host for the synthesis of composite materials.…”

Section: Introductionmentioning

confidence: 99%

Polymerization of Aniline in Different Sba-16 Silica Hosts

Giraldo¹,

Vélez²,

Mesa³

2016

Química Nova

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publicado na web em 06/06/2016Polyaniline-silica composites made with mesoporous silica have been reported to improve the mechanical properties of the free polymer. However, there are not many studies about the effect of the chemical and physical properties of the inorganic material used as hosts over the final properties of polyaniline and the composites. Here, polyaniline-silica composites, exhibiting electrical conductivity, were synthesized using different types of SBA-16 mesoporous silica as hosts. The effects of the characteristics of the hosts in the polymerization kinetic, molecular weight and electrical conductivity of the final polymer were studied. The composites showed higher electrical conductivity in comparison with polyaniline synthesized under similar conditions of this work but in the absence of silica. The use of silica allowed to obtain composites with defined morphology, which did not occur in the absence of these hosts. From the results of this work, it can be concluded that SBA-16 mesoporous silica hosts have a bifunctional role in the formation of polyaniline-silica composites: the hosts behaved like nucleation sites, which favors polymerization of high molecular weight polyaniline and they catalyzed the polymerization reaction, especially when aluminum is present in the structure of the host.

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“…Estas sustancias poseen la facultad de formar micelas que durante la reacción de condensación son atrapadas por la creciente red inorgánica de siloxanos. Como resultado, se obtiene un material híbrido cuyo esqueleto orgánico, formado por las micelas de tensoactivo, puede ser removido por extracción con solventes o calcinación para dar origen a una estructura sólida basada en un arreglo regular o irregular de canales definidos por paredes de sílice (Sierra et al, 2000;Aramendia et al, 2004;Prouzet y Boissière, 2005;Liu et al, 2007;Mesa et al, 2007;Mesa et al, 2008;Wang y Shantz, 2008).…”

Section: Introductionunclassified

“…Estudios recientes muestran las ventajas de usar tensoactivos no iónicos (neutros), con relación a tensoactivos que involucran interacciones electrostáticas, tales como su fácil remoción mediante extracción con solventes no corrosivos o calcinación, y la tendencia de los tensoactivos neutros a producir estructuras con paredes más gruesas y sólidos de menor tamaño de partícula, lo cual mejora la estabilidad y la textura porosa (Leonard et al, 2003;Aramendia et al, 2004;Prouzet and Boissière, 2005;Biswas et al, 2008). Para la síntesis de sílices porosas se han utilizado tradicionalmente tensoactivos no iónicos tales como Triton X100, Pluronic F127, Twin 20, 40, 60 entre otros (Sierra et al, 2000;Aramendia et al, 2004;Guth et al, 2007;Mesa et al, 2007;Venkatathri, 2007;Mesa et al, 2008;Sierra et al, 2008), con los cuales se han obtenido sílices de altas áreas superficiales BET, estrechas distribuciones de tamaños de poros, morfologías y tamaños de partícula regulares. A pesar de esto, dichos tensoactivos presentan desventajas que restringen su aplicación a nivel industrial, como son, sus altos costos, debido a que se derivan de materias primas no renovables, y la necesidad de importación ya que ninguno es producido localmente.…”

Section: Introductionunclassified

Producción de Sílice Mesoporosa Empleando Monoestearato de Glicerol como Porógeno Oleoquímico

et al. 2009

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ResumenEl presente trabajo describe el desarrollo de una novedosa síntesis de sílices mesoporosas basada en un mecanismo en dos etapas en medio ácido (pH = 2), empleando materias primas renovables. La primera etapa consistió en la formación de micelas híbridas estables, producto de la interacción entre silicatos y el agente porógeno, y la segunda en la policondensación de silicatos para formar sílice. Se evaluaron dos fuentes de silicio: tetraetilortosilicato (TEOS) y metasilicato de sodio (MSiNa). Como porógeno oleoquímico se usó monoestearato de glicerol y como iniciador de la reacción de policondensación se usó fluoruro de sodio (NaF). Las sílices obtenidas con las mejores propiedades texturales, poseen características superficiales interesantes para un potencial aplicación en catálisis heterogénea, con área superficial BET de 727. Production of Mesoporous Silica using Glycerol Monostearate as Oleochemical Porogen AbstractThis paper describes the development of a novel synthesis of mesoporous silica based on a twostep process, in acidic media (pH = 2), using renewable raw materials. The first stage was the formation of stable hybrid micelles, product of the interaction between the porogen and silicates, and the second was the polycondensation of silicates to produce silica. Two sources of silicon were used: tetraethylortosilicate (TEOS) and sodium metasilicate (MSiNa). Glycerol monostearate was used as oleochemical porogen and sodium fluoride was used as initiator for the reaction of condensation of silica. The silica obtained with the best textural properties have interesting surface characteristics for potential applications in heterogeneous catalysis, with BET surface area of 727.4 m 2 / g, total volume of pores of 0.50 cm 3 /g and pore size distribution of about 46.2 Å.

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Contribution to the study of the formation mechanism of mesoporous SBA-15 and SBA-16 type silica particles in aqueous acid solutions

Cited by 73 publications

References 35 publications

Influence of synthesis temperature on morphology of SBA-16 mesoporous materials with a three-dimensional pore system

Influence of synthesis temperature on morphology of SBA-16 mesoporous materials with a three-dimensional pore system

Polymerization of Aniline in Different Sba-16 Silica Hosts

Producción de Sílice Mesoporosa Empleando Monoestearato de Glicerol como Porógeno Oleoquímico

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