Development of Supercapacitor Hydrogel from Self-crosslink Polyaniline and Rice Husk (RH-grafted-PANI)

Nowadays, supercapacitor has been widely used in many applications. Therefore,
this research is conducted to synthesize self-crosslink polyaniline (PANI) hydrogel
grafted with rice husk fiber electrode for supercapacitor. Also, this research also
study the effect of rice husk fiber on water absorbency capacity and conductivity of
the hydrogel. Polyaniline (PANI) hydrogel usually synthesized using cross-linkers
which greatly impair the electrochemical properties of hydrogel. Eliminating the
cross-linkers in synthesizing the hydrogel helps increase its electrochemical
properties. Rice husk waste are abundantly dumped and causing environmental and
disposal issues. Hence, it is benificial it in other useful application. Sol-gel method
was chosen to synthesize the hydrogel by using ammonium persulfate (APS) as
initiator, aniline hydrochloric as precursor and gelatin. Five samples of hydrogel
were synthesized with 0wt%, 1.5wt%, 3wt%, 4.5wt% and 6wt% of rice husk fiber
content. The resulted hydrogels were characterized by Fourier Transform Infrared
(FTIR), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis
(TGA). Water absorbency capacity test was conducted by soaking the resulted
hydrogel in water for 24 hours. While conductivity test was determined using DC
conductivity measurement. The highest water absorbency capacity was hydrogel
with 3 wt% rice husk which obtained 96.4% absorbency. The conductivity of
hydrogel decreased when rice husk content increased but within a small range from
3.120× 10−4 to 3.306× 10−4 s.