Characterization of Brazilian palygorskite (Guadalupe region) and adsorptive behaviour for solvatochromic dyes
| Autor: | Luiz Antonio d' Avila, Luciana S. Spinelli, Cristiane Gimenes de Souza, Luiz Carlos Bertolino, Rafael Cavalcante dos Santos, Débora França de Andrade, Lívia Melo Bomfim, Tammy Caroline Lima de Jesus |
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| Rok vydání: | 2021 |
| Předmět: |
Thermogravimetric analysis
Infrared spectroscopy Langmuir adsorption model Palygorskite 020101 civil engineering 02 engineering and technology 021001 nanoscience & nanotechnology Nile blue 0201 civil engineering chemistry.chemical_compound symbols.namesake Adsorption chemistry Geochemistry and Petrology Specific surface area symbols medicine Dithizone 0210 nano-technology Nuclear chemistry medicine.drug |
| Zdroj: | Clay Minerals. 56:55-64 |
| ISSN: | 1471-8030 0009-8558 |
| DOI: | 10.1180/clm.2021.16 |
| Popis: | This work presents the results of the physical characterization of palygorskite and its adsorptive behaviour for three solvatochromic dyes (Nile blue chloride (NBC), methylene blue (MTB) and dithizone (DTZ)). Adsorption isotherms were used to determine the maximum adsorption of the solvatochromic dyes on the palygorskite. The characterization of palygorskite was carried out via mineralogical and chemical analysis with X-ray diffraction, X-ray fluorescence, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy, surface-charge measurement (ζ-potential), thermogravimetric analysis, textural analysis and cation-exchange capacity analysis. The material consists of palygorskite and quartz and its chemistry is dominated by SiO2, MgO and Fe2O3. The specific surface area and cation-exchange capacity of the palygorskite are 142 m2 g–1 and 41 cmol(+) kg–1, respectively. The SEM and TEM analyses showed a fibrous structure with fibres 20–100 nm long. The thermogravimetric analysis showed three endothermic events at 57.3°C, 171.8°C and 439.6°C. The adsorption capacities of the palygorskite for NBC (basic pH), MTB (basic pH) and DTZ (neutral pH) were 0.082, 0.013 and 0.102 g g–1, respectively. The adsorptions of NBC and MTB were fitted with the Langmuir isotherm model and the adsorption of DTZ was fitted with the Sips model. |
| Databáze: | OpenAIRE |
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