Synthesis and characterization of Mesoporous silica under different thermal conditions

Reference	Presenter	Authors (Institution)	Abstract
17-016	Carlos Patrick Tomazelli Soares	Soares, C.P.(Universidade Federal de Grande Dourados); Chagas, E.(Instituto Federal de Educação, Ciência e Tecnologia de Mato Grosso do Sul); Andrade, R.C.(Federal University of BAHIA); Falcão, E.A.(Universidade Federal de Grande Dourados); Botero, E.R.(Universidade Federal de Grande Dourados);	Since the 1990s Mesoporous Ordinary Silica (SMO) has been widely studied, as it has good thermal and hydrothermal stability, regular hexagonal arrangement and pore size of approximately 2 to 50 nm. It is prepared by the sol-gel method, adding directors responsible for the inorganic network architecture, thus synthesizing the SBA-15 (neutral structure driver) in four different temperatures (40 ° C, 60 ° C, 80 ° C and 95 ° C) were analyzed by TG / DTG and DSC, FTIR, XRD, SEM, adsorption analysis and desorption of N2. The TG / DTG / DSC results show two large mass losses in these samples associated with the loss of physically adsorbed water and the decomposition of organic compounds, indicating that removal of the surfactant occurs from 180 ° C to ~ 300 ° C, releasing more energy. IR spectra showed the typical absorption bands of mesoporous silica, it is noted that after calcination we do not have the characteristic surfactant peak . X-ray patterns have shown a wide peak between 15 ° and 30 ° for all samples, characteristic of amorphous silica, however, a low angle (<10 °) investigation is required. The SEM showed a morphology with vermicular type particle and strings in the form of strings dependent on the temperature of synthesis, arriving to appear the formation of microspheres. The adsorption / desorption of N2 showed specific characteristics of mesoporous materials, identified by the presence of the isotherm as a narrow hysteresis loop for synthesis at 40 ° C. The increase in temperature in the synthesis did not influence the thermal stability and the phases formed, but considerably modified the textural properties as shown by the SEM and the adsorption and desorption analysis of N2 in which the formation of similar domains to strings and the regularity of the pore diameter is compromised.
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