2.3.2. Acid treatment
Themechanical-condensed CNT filmswere immersed into HNO3 for
30 min at room temperature. Subsequently, the samples were washed
by de-ionized water and dried in a fume hood at room temperature.
In this article,we define the CNT filmswithout post treatments,with
mechanical condensation and with mechanical condensation followed
by acid treatment as: as-prepared, mechanical-condensed and acidtreated
CNT film respectively.