Synthesis and mechanical analysis of electroconductive high density polyethylene polyanilinedodecylbenzenesulfonic acid/alumina composite

• Main Author: Mustaffa, Nurul Akmil
• Format: Thesis
• Language: English; English
• Published: 2018
• Subjects: Q Science (General); QD Chemistry
• Online Access: http://eprints.utem.edu.my/id/eprint/23385/; https://plh.utem.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=112874

Polyaniline (PANI) based composites have become of great interest in supercapacitor electrode application due to its high conductivity (13.37 Scm-1) and capacitance (501.31 Fg-1).Some researchers have established excellent capacitance of PANI based electrodes.Yet pseudo-capacitive nature of the PANI electrodes causes swelling, shrinking and cracking during doping/dedoping of charged ions that have resulted in poor cycle stability thus limits its application.This study aims to enhance the PANI properties to be used as a supercapacitor electrode. PANI doped with dodecylbenzene sulfonic acid (PANI-DBSA) was synthesized through oxidative polymerization by varying concentrations of dopant (DBSA) and concurrently nano alumina (Al2O3) was synthesized and functionalized with silane.Later,high density polyethylene/PANI-DBSA/ Al2O3 (HDPE/PANI-DBSA/Al2O3) composite was fabricated via a statistical approach to optimize the level of DBSA, PANI-DBSA and nano alumina in HDPE in order to incorporate comparable mechanical strength and conductivity.The application of conductive composite of HDPE/PANI-DBSA/Al2O3 towards supercapacitor electrode performance has been verified.As the result,the DBSA doping of PANI produces the protonation of amine nitrogen atoms of PANI.This redox reaction creates charge carrier in form of bipolarons and polaron species in PANI structure thus has enhanced the conductivity of PANI. However,over-doping leads to a decrease of polaron population, due to its conversion to bi-polarons which decrease the conductivity of PANI.Afterwards,through RSM study,the recommended optimum formulation of HDPE/PANIDBSA/Al2O3 composite is made by controlling the concentration of DBSA at 2.00 mmol,composition of PANI-DBSA at 20 wt%,and composition of nano alumina at 5wt %. This recommended formulation yielded a desirability of confident level at 86.65% which is well above the accepted of 80 %.It demonstrates the improved compatibility between PANIDBSA,nano alumina and HDPE through intermolecular forces from the interactions between two organic molecules.The hydrophobic effect of the organic substitution in DBSA and silane could be linked with the free energy transfer of hydrocarbon molecules from an aqueous phase (hydrophilic substitution in PANI molecule and nano alumina surface) to a homogeneous hydrocarbon phase.As a final point,the results demonstrate the fabrication of a promising electrode material derived from HDPE filled PANI-DBSA and nano alumina particles have improved the electrochemical performance of HDPE/PANI/Al2O3║MWCNT asymmetric supercapacitors in Na2SO4,KOH,and H2SO4 aqueous electrolytes.Among the electrolytes,KOH exhibited better specific gravimetric capacitance (145.58 Fg-1) and good capacitance retention (101%) after 10,000 charge-discharge cycles.In brief,HDPE/PANI/Al2O3║MWCNT asymmetric supercapacitor has maximum energy density of 0.55 Whkg-1 with a power density of 0.33 kWkg-1.Thus,the asymmetric supercapacitor is well-suited for power storage since it has a high power density,then it can output large amounts of energy based on its volume.