Successful application of a commercial cationic surfactant mixture (benzalkonium chloride) as porosity stabilizer in porous carbons fabrication

LUCIANO TAMBORINI; MIRIAM CASCO; PAULA MILITELLO; JOAQUÍN SILVESTRE-ALBERO; ACEVEDO, DIEGO; CÉSAR BARBERO

Darmstadt

Congreso; Materials Science and Engineering Congress 2016 (MSE); 2016

Darmstadt University of Technology

Porous carbons (BSPCs) were obtained by carbonization of resorcinol-formaldehyde gels prepared in the presence of a mixture of cationic surfactants (benzalkonium chloride) which act as porosity stabilizer. The stabilizing effect of a cationic surfactant on the sol-gel nanostructure allows maintaining the porosity of the gels during conventional air drying. The stabilizing effect simplifies the production of porous carbon by making unnecessary the use complex drying procedures (e.g. supercritical drying), cumbersome solvent exchanges, and long curing times. The application of an inexpensive industrial grade surfactant mixture (benzalkonium chloride) as porosity stabilizer allows obtaining porous carbons with well-developed micro and mesoporosity at low cost. The morphological and textural properties of the BSPCs were studied by scanning electron microscopy and nitrogen physisorption isotherms. The BSPCs present large specific surface areas (up to 645 m2/g) containing mesopores and micropores. The pore distribution and morphology depends on the monomer (resorcinol) to stabilizer (benzalkonium chloride) ratio. The carbonization process of BSPCs was evaluated by TGA analysis. The stabilizer and non-carbon elements (hydrogen and oxygen) are only eliminated during pyrolysis at temperature above 600 °C. Cyclic voltammetry and electrochemical impedance spectroscopy were employed to understand the role of pore size and distribution on the electrochemical performance of BSPCs. The BSPCs exhibit a large specific capacitance (up to 165 F/g) with low charge transfer resistance due to the pores, making it suitable as an active material for fast supercapacitor applications.