AVALIAÇÃO DO DESEMPENHO DE UMA FASE SENSORA DE POLIURETANO POR MEIO DA ENERGIA DE GIBBS DE SOLVATAÇÃO E ESPECTROSCOPIA DE INFRAVERMELHO PARA DETERMINAÇÃO DE TOLUENO EM ÁGUA

Abstract

A novel sensing phase of polyurethane was predicted by quantum chemical calculations as capable of detecting toluene, with the experimental results revealing a limit of detection of 1.4 mg L-1 in the determination of toluene in water samples. The quantum chemical computational strategy was validated by assessing the impact of the polymer matrix sensing phases polyvinyl chloride (PVC), polydimethylsiloxane (PDMS), and polyisobutylene (PIB), as solvents, on the Gibbs energy of solvation of the organic contaminants toluene, benzene, chlorobenzene and ethylbenzene. Computational results for the set studied indicate that the limit of detection of contaminants for each polymeric matrix correlated well with the Gibbs energy of solvation. As such, the computational methodology was employed to assess the potential applicability of polyurethane matrices on the determination of toluene as a contaminant in water, with positive results. Analyzes were then carried out experimentally by mid-infrared spectroscopy. Finally, experiments revealed good regenerative capacity of polyurethane, further adding to the usefulness of the technique here advanced.

Keywords

• water contaminant
• toluene
• polyurethane
• semiempirical methods
• solvation energies