Liquids adsorption behavior and surface properties of polyanilines doped by lignosulfonate-modified carbon nanotubes

The liquid adsorption behavior and surface properties of polyaniline, PANI, doped by lignosulfonate, LGS, modified carbon nanotubes, CNTs, were studied and compared with a normal PANI. According to capillary rise method recorded adsorption amount, both these two PANIs can adsorb liquids, while the visible differences are that the normal PANI can adsorb the non-polar liquid greatly while the doped PANI can adsorb the polar liquid greatly to indicate the doping-induced the change of the surface properties of PANI. The doping was found to enhance the surface free energy of PANI and this was mainly in the enhancement of the Lifshitz-van der Waals interactions component. The doping-induced changes in the acid–base properties of PANI are also found because the acid/base ratio of doped PANI increased while its polarity was reduced as compared with the normal PANI.

Adsorption of two polar and two non-polar probe liquids in a novel polyanilines which was doped by lignosulfonate-modified carbon nanotubes was studied and compared with the normal PANI by capillary rise method. According to liquid adsorption curves, the surface properties of these two PANIs were deduced and furthermore studied.Figure optionsDownload as PowerPoint slideHighlights
► The normal PANI can adsorb non-polar liquid greatly.
► The doping of LGS-modified CNT in PANI caused PANI adsorbed polar liquid greatly.
► The reason is the doping of PANI induced its Lifshitz–van der Waals interactions and total surface free energy enhanced, while the Lewis acid–base interactions reduced.