Enthalpies of Immersion in Caffeine and Glyphosate Aqueous Solutions of SBA-15 and Amino-Functionalized SBA-15

Abstract

Mesostructured silica SBA-15 and amino-functionalized silica SBA-15-NH 2 were synthesized, and then, characterization, adsorption capacity, and immersion enthalpies in caffeine and glyphosate on SBA-15 and SBA-15-NH 2 were evaluated. The enthalpy parameter was determined using a local construction Tian-type heat conduction calorimeter. Calorimetric studies in caffeine solutions exhibit negative enthalpy values; exothermic process characteristics for SBA-15 were between −13.90 and −194.06 J g –1 and those for SBA-15-NH 2 were between −7.22 and −60.34 J g –1 , and the adsorption capacity of caffeine was better in SBA-15 than that in SBA-15-NH 2 . In contrast, the enthalpies of immersion in glyphosate solutions were −5.06 to −56.2 J g –1 and the immersion of SBA-15-NH 2 in each solution generated enthalpy values of −9.06 to −41.2 J g –1 , but the adsorption capacity of glyphosate was better in the amino-functionalized SBA-15. The results show that functionalization of SBA-15 produced differences in physicochemical characteristics of solids, since energy and affinity for the calorimetric liquids are related to the surface properties of solids as well as the chemical nature of the target molecule, immersion enthalpy, was different.

Confined Mesospace Synthesis of Sulfur‐Doped Graphene Quantum Dots for Direct H2O2 Detection

“…C/S/SBA‐15 is composed of short rods with a size of approximately 1 μm, as shown in Figure 1B. The observed morphology is similar to that previously observed for silica SBA‐15, [26] suggesting that the sulfur‐doped carbon does not aggregate on the outer surface of silica SBA‐15 and that carbon loading occurs on the inner walls of silica. In addition, energy dispersive spectroscopy (EDS) mapping of C, O, S, and Si in the sample demonstrated that these elements were homogeneously dispersed in C/S/SBA‐15.…”

Metal ion-supported mesoporous silica materials for the removal of sulfamethizole from water

“…Mesoporous silicon materials possess an ordered pore structure, high specific surface area, and abundant modifiable sites of silicon hydroxyl. 26,27 In recent years, metal-doped SBA-15 porous materials have been widely applied as ideal adsorbents in the removal of different pollutants, such as metal ions in wastewater, sulfur and nitrogen compounds in oil, small organic molecules and CO 2 . [28][29][30][31] It has advantages such as stability, good dispersibility in water, and good recovery performance.…”

Surface Properties and Microstructures of Al-SBA-15 under Different Temperature Calcinations in Relation to Adsorption Performance

“…SBA-15 has unique excellent properties, such as large pore size, large specific surface area, high orderliness, and high hydrothermal stability. , Moreover, the surface of the SBA-15 material is rich in Si–OH groups, which can load a large number of organic and inorganic functional groups by condensation or grafting, leading it to be one of the promising adsorbent or catalytic materials. , Sousa et al used a post-synthesis method to load ZnO onto SBA-15 for the adsorption of ciprofloxacin, and the adsorption capacity of the ZnO-SBA-15 was proportional to the incorporated amount of ZnO while maintaining the mesoporous structure of SBA-15. Rodríguez-Estupiñan et al synthesized amino-functionalized SBA-15 by a post-grafting method and compared it with SBA-15 for the adsorption of caffeine and glyphosate in aqueous solution. The results showed that the amino-functionalized SBA-15 material produced a difference in the physical and chemical properties of the solids.…”

“…10−12 SBA-15 has unique excellent properties, such as large pore size, large specific surface area, high orderliness, and high hydrothermal stability. 13,14 Moreover, the surface of the SBA-15 material is rich in Si−OH groups, 15 which can load a large number of organic and inorganic functional groups by condensation or grafting, leading it to be one of the promising adsorbent or catalytic materials. 16,17 Sousa et al 18 of ciprofloxacin, and the adsorption capacity of the ZnO-SBA-15 was proportional to the incorporated amount of ZnO while maintaining the mesoporous structure of SBA-15.…”

“…16,17 Sousa et al 18 of ciprofloxacin, and the adsorption capacity of the ZnO-SBA-15 was proportional to the incorporated amount of ZnO while maintaining the mesoporous structure of SBA-15. Rodri ́guez-Estupinãn et al 15 synthesized amino-functionalized SBA-15 by a post-grafting method and compared it with SBA-15 for the adsorption of caffeine and glyphosate in aqueous solution. The results showed that the amino-functionalized SBA-15 material produced a difference in the physical and chemical properties of the solids.…”