Effect of Reaction Time and Hydrothermal Treatment Time on the Textural Properties of SBA-15 Synthesized Using Sodium Silicate as a Silica Source and Its Efficiency for Reducing Tobacco Smoke Toxicity

Abstract

The synthesis of SBA-15 has been optimized using sodium silicate, an inexpensive precursor of SBA-15. In this work, the influence of synthesis times of the precipitation and the hydrothermal treatment steps, on the textural properties developed as well as for reducing the toxic compounds generated in tobacco smoking, has been studied. The hydrothermal treatment has been proved to be necessary to obtain materials with adequate performance in this particular application. Twenty-four hours of hydrothermal treatment provide materials with the best properties. Although the reaction stage usually involves the mixing of reagents during 24 h, 40 min is enough to obtain a material with stick-like morphology and typical textural properties. Moreover, between 1 and 2 h of reaction time, the material proved to have the best performance for the purpose of reducing the toxicity of the products generated during the tobacco smoking process. These results are of great significance for an eventual scaling up to industrial scale of the SBA-15 manufacturing process. Results of a pilot plant experiment in a batch of 4 kg of SBA-15 are reported.

Impregnation of Fe³⁺ into MCM-41 Pores: Effect of Fe³⁺ Concentration on the Weight Percent of Fe-Frameworks and Fe-Non-Frameworks

“…In general, silica precursors such as tetraethyl orthosilicate (TEOS) [5][6][7] and sodium silicate [8][9][10][11] are used in the synthesis of MCM-41, which is relatively expensive. Iron ore tailing [12][13], siliceous sugar industry waste [14], silicon carbide sludge and granite sludge [15], bentonite [16] and rice husk ash [17][18][19] have all been investigated for use as a silica precursor in the manufacture of MCM-41 to minimize production costs.…”

Optimizing Rice Husk Silica Mass and Sonication Time for a More Efficient and Environmentally Friendly Synthesis of SBA-15

“…In general, commercial materials such as tetraethyl orthosilicate (TEOS) [23][24][25] and sodium silicate [26][27] are utilized as silica precursors in the production of SBA-15, which are, of course, relatively expensive. Several natural materials have been used as a source of silica in the synthesis of SBA-15, including sugarcane bagasse [28], brickyard ash [29], coal gangue [30], oil palm ash [31], and rice husk ash [32][33][34], to reduce production costs.…”

“…SBA-15 is typically synthesized using the hydrothermal technique [23][24][25][26][27][28][29][30][31][32][33][34], which involves heating the reactants with air in a closed container (autoclave). The hydrothermal approach is less cost-effective and does not adhere to the green chemistry principle since it takes a long time and a lot of energy to complete the reaction.…”