Synthesis and characterization of catalytic metal semiconductor-doped siliceous materials with ordered structure for chemical sensoring

Pt-doped semiconductive oxides loaded on mesoporous SBA-15 for gas sensing

“…The number of available holes depends on the solid structure. In the case of a film deposited by the casting technique, as in our previous paper [44], the packing of the doped SBA-15 rods is very soft and the inner volume of the mesopores is easily accessible for the diffusion of the propene molecule. In the case of compressed pastilles conditioning used in this work, the packing of the solid particles is a lot more compact, so the diffusion of propene to the mesopores is partly hindered and the signal will be weakened.…”

“…In the case of compressed pastilles conditioning used in this work, the packing of the solid particles is a lot more compact, so the diffusion of propene to the mesopores is partly hindered and the signal will be weakened. The close packing of the solid pressed in pastilles is also proved by the values of the intrinsic electrical resistance of the pressed tablets, which are of the order of the MV, higher by three of fours orders of magnitude than that of a film deposited by nanocasting [44]. The modifications due to propene oxidation cannot reach a high level in this range of solid electrical resistances.…”

“…It has a hexagonal array of uniform tubular channels with free pore diameters in the range of 5-30 nm, much larger than those of MCM-41, allowing much lower internal diffusion resistance and thicker walls, making it more stable during thermal and hydrothermal operations. These structural properties makes SBA-15 a suitable candidate for the confined immobilization and growth of semiconductive oxide nanostructures [8,9]. For the development of semiconducting metal oxide gas sensors [10], efforts are focused on the research of mesoporous silica materials to improve the properties of metal oxide gas sensors.…”

O papel da sílica mesoporosa nanoestruturada SBA-15 na ativação do inflamassoma NLRP3.

“…Adaptado de Garcia, 2015. Figura 3 -Sílica mesoporosa ordenada SBA-15 contendo poros interligados Microscopia eletrônica de varredura da SBA-15 e um modelo esquemático da sua estrutura hexagonal contendo poros interligados. Adaptado de Seftel et al, 2013. Descoberta na Faculdade da Califórnia em Santa Barbara, de onde origina seu nome, O próximo passo é a adição da fonte de silício, quando as moléculas de TEOS são incorporadas na porção hidrofóbica das micelas, onde são hidrolisadas, gerando SiO2 e etanol. O SiO2 se assenta na porção hidrofílica das micelas, dando origem às paredes da SBA-15.…”