A new acetylene black and vegetable oil based polyurethane composite: Preparation, characterization and its potentialities as an electroanalytical sensor

In the search for new electrode materials, a composite based on acetylene black (AB) and a vegetable oil/MDI polyurethane (PU) was prepared, characterized and evaluated regarding its potentialities as a voltammetric electrode. The composites were prepared in different compositions in the 20-60 AB range (AB %, m/m) and characterized regarding morphology with SEM and optical microscopies, composition by thermogravimetry, hydrophobicity by contact angle measurements and conductivity by determining their ohmic resistance. When the composites are submitted to suitable pressure during curing of the agglutinant, these results revealed that it conducted current from 20% AB (m/m), lost mechanical resistance above 60% AB (m/m), and the best conductance were found with 60% AB (m/m). Electrochemical response was evaluated using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), chronocoulometry and flow injection analysis. These results indicated the 60% AB (m/m) as the best composition regarding voltammetric responses to Fe(CN6)3-/ Fe (CN6)4-. The resulting electrode also presented the highest electroactive area and presented a wide useful potential ranges in different electrolytic media. The new composite presents a lower charge transfer resistance when compared with glassy carbon. It also presented a suitable response to organic probes hydroquinone, neurotransmiter dopamine and to the endocrine disruptor bisphenol-A, considered an emerging pollutant. The sensor revealed to be also useful as an amperometric detector in FIA.

Automated summary

A composite material based on acetylene black and a vegetable oil/MDI polyurethane was prepared and evaluated as a voltammetric electrode. The 60% AB composition showed the best performance with good conductivity and voltammetric response.