RESUMO
Carbon nanotubes have several applications including the removal of pollutants via adsorption. Many studies were carried out in order to evaluate how the functionalization of these materials improves the efficiency of the process. However, a better understanding of the mechanisms involved in adsorption on nanotubes is still needed. In this work it was evaluated how the oxidation of nanotubes influences the adsorption of a model molecule (methylene blue). For this purpose, a realistic model described on the grand canonical ensemble was used. In this approach, the experimental isotherms were adjusted and provided relevant information about the process, such as the number of layers and the orientation of the adsorbed molecules. In addition, since the treatment is based on statistical mechanics, it was possible to calculate the configurational entropy and Gibbs free energy of the process.
Assuntos
Poluentes Ambientais , Nanotubos de Carbono , Adsorção , Azul de MetilenoRESUMO
Polydiacetylene (PDA) vesicles have been applied as optical sensors in different areas, although there are difficulties in controlling their responses. In this study, we prepared nanoblends of PDA with triblock copolymers (TC) as a better sensor system for detecting temperature change. The influences of diacetylene (DA) monomer, and the TC chemical structure and concentration on the colorimetric response (CR) were examined. The TC/PDA nanoblend was remarkably more sensitive to temperature change, than classical vesicles. A higher L64 concentration of 12.0% (w/w) reduced the chromatic transition temperature (Ttr) to as low as 24°C. When using different TCs, the Ttr values can be ordered as L35Assuntos
Polímeros/química
, Poli-Inos/química
, Colorimetria
, Interações Hidrofóbicas e Hidrofílicas
, Polímero Poliacetilênico