Rodriguez-Diaz J.M.,Federal University of Pernambuco |
Garcia J.O.P.,Amazonic State University |
Sanchez L.R.B.,Amazonic State University |
da Silva M.G.C.,University of Campinas |
And 2 more authors.
Bioenergy Research | Year: 2015
This study provides a full characterization of ashes generated from the combustion of bagasse at two different sugarcane ethanol plants, one in the state of Pernambuco, Brazil (SBA1), and the other in Villa Clara, Cuba (SBA2), with a view to examining their usage as adsorbing agents for the removal of heavy metals and various organic impurities. The ash samples were analyzed for both chemical composition and for structural features that would aid their use. Chemical characterization was done spectrally, through the examination of X-ray fluorescence and diffraction, Fourier transform infrared spectroscopy, and thermally, through thermogravimetric and differential thermal analysis. Structural and surface characterization was carried out by examining N2-physisorption, helium pycnometry, and scanning electron microscopy. The results of each analysis were compared to those of recognized or potential adsorbent materials. Both ashes have structural similarities, heterogeneous morphologies, irregular surfaces, and a prevalence of superficial polar groups (carbonyl, carboxyl, and hydroxyl). Based on their physical and chemical characteristics, ashes could be used as adsorbent for both, organic (e.g., dyes, phenols, etc.) and inorganic (e.g., heavy metals) compounds. © 2015 Springer Science+Business Media New York
Gonzalez Hurtado M.,Engineering and Chemical Research Center |
Gonzalez Hurtado M.,University of Habana |
PimentaCheble Caplan S.,Federal University of Rio de Janeiro |
Guenther Soares B.,Federal University of Rio de Janeiro |
And 4 more authors.
Journal of Materials and Environmental Science | Year: 2015
Threehydroxylatedtitanium matrixloadedwith ibuprofen (TiO2OH-IBU) were obtained by the sol-gel method using different molar ratio of alkoxide / water. These nanostructured materials (NM) were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning microscopy (SEM), Thermogravimetric analysis (TGA) and N2 adsorption isotherm. As water/alkoxide ratio increases, the specific surface areas for the composites (TiO2OH-IBU) and also for references (TiO2OH-Ref),(without ibuprofen) decreased, being more pronounced in the latter case. By contrast, the average pore diameter increases following the same trend being more remarkable for references. Finally, the analysis showed mesopores and micropores. FTIR indicates the presence of hydroxyls and also water physically adsorbed, but hydroxyls free were not observed. Also, higher water/alkoxide ratios enable the production of materials with negligible non-hydrolyzed alkoxide as TGA and FTIR results indicate. It was observed that ibuprofen incorporated to the composites corresponds to 7%w. by TGA. Analysis of X-ray diffraction showed that for reference (TiO2OH-Ref) withamolarratioalkoxide/water (1:24) the presence of anatase phase even at room temperature and that ibuprofen prevents crystallinity.Therelease of the drug for these systems was analyzed in vitro, showing typical controlled release profiles for all materials studied.This behavior could be evaluated for its use in implants near the affected area or in topical forms.