When submitted to square-wave potentials of 2V, single-walled carbon nanotube films with an ionic liquid, taking part of an actuator, show high-frequency electromechanical responses (up to 100 Hz), with anodic current evolutions showing two maxima. Similar anodic chronoamperometric responses have been obtained from films of conducting polymers exchanging balancing anions with the electrolyte during reaction, being described by two stretched exponential functions deduced on physico-chemical bases: oxidation under nucleation-relaxation structural control and oxidation/swelling completion under diffusion control. Now by adding a third stretched function, describing a greater contribution now of the charge of the electrical double layer, a good mathematical fit of the chronoamperometric response of the carbon nanotube films was carried out. By recovering the original physico-chemical meaning of the electrochemical stretched functions, capacitive and structural faradic components of the chronoamperometric charge were quantified as a function of the applied frequency (1-10 Hz). The capacitive component of the charge ranges with frequency between 8.6% and 12.2% of the involved charge. The faradic (reactive) component ranges between 91.4% and 87.8%, being the main contributor to the volume variations in the actuating films. The order of magnitude of the diffusion coefficients was 10(-6) cm(2) s(-1), in good agreement with the fast response of the reactive actuators constructed with those materials. A good separation of capacitive and faradic components will allow a better design of electrochemical applications of single-walled carbon nanotube films. (C) 2011 Elsevier Ltd. All rights reserved.