Electrically responsive ultrafiltration polyaniline membrane to solve fouling under applied potential

Membrane fouling is indispensable in all membrane systems and remains one major problem to large scale application. In view of this, an in-situ method of fouling control is desperately needed to sustain membrane technologies. The objective of this study is to develop electrically conductive PANI membranes with stimuli-response properties and to solve fouling under applied potential. Electrically conductive polyaniline membranes were prepared by non-solvent induced phase separation method. Exfoliated graphite and DBSA were incorporated into membrane to form PANI membranes with different electrical conductivities. The results showed that the conductivity of Memb-PAMPSA was improved by two orders of magnitude by the incorporation of EG, and further enhanced by twenty times using a long chain acid DBSA as a secondary dopant. Compared to Memb-PAMPSA whose effective contact angle did not change between 0 and 30 V measurements, the significant dynamic contact angle change of Memb-PAMPSA-EG and Memb-PAMPSA-EG/DBSA gave a quantitative indication of the electrical tuneability of these membranes. All the membranes showed fouling removal ability under applied electrical potential and the fouling removal behaviour was closely related to the membrane conductivity. The results of this study open the pathway for the development of electrically responsive membranes for in situ control of fouling in membrane filtration systems.