Novel Hybrid Composites Based on Polymers of Diphenyl-Amine-2-Carboxylic Acid and Highly Porous Activated IR-Pyrolyzed Polyacrylonitrile

Abstract

Hybrid composites based on electroactive polymers of diphenylamine-2-carboxylic acid (PDPAC) and highly porous carbon with a hierarchical pore structure were prepared for the first time. Activated IR-pyrolyzed polyacrylonitrile (IR-PAN-a), characterized by a highly developed surface, was chosen as a highly porous N-doped carbon component of the hybrid materials. IR-PAN-a was prepared using pyrolysis of polyacrylonitrile (PAN) in the presence of potassium hydroxide under IR radiation. Composite materials were obtained using oxidative polymerization of diphenylamine-2-carboxylic acid (DPAC) in the presence of IR-PAN-a both in an acidic and an alkaline medium. The composite materials were IR-heated to reduce the oxygen content and enhance their physical and chemical properties. The chemical structure, morphology, and electrical and thermal properties of the developed IR-PAN-a/PDPAC composites were investigated. The IR-PAN-a/PDPAC composites are thermally stable and electrically conductive. During the synthesis of the composites in an acidic medium, doping of the polymer component occurs, which makes the main contribution to the composite conductivity (1.3 × 10–5 S/cm). A sharp drop in the electrical conductivity of the IR-PAN-a/PDPACac-IR composites to 3.4 × 10–10 S/cm is associated with the removal of the dopant during IR heating. The IR-PAN-a/PDPACalk composites prepared before and after IR heating show a gradual increase in electrical conductivity by five orders of magnitude to 1.6 × 10–5 S/cm at 25–106 Hz. IR heating of the obtained materials leads to a significant increase in their thermal properties. The IR-heated composites lose half of their initial weight in an inert atmosphere at temperatures above 1000 °C, whereas for IR-PAN-a/PDPAC, the temperature range is 840–849 °C.

Novel Hybrid Electrode Coatings Based on Conjugated Polyacid Ternary Nanocomposites for Supercapacitor Applications

“…Figure 3 shows the ATR FTIR spectra of the ternary nanocomposites obtained in an acidic medium (IR-PAN-a/SWCNT/PDPAC ac ) and in an alkaline medium (IR-PAN-a/SWCNT/PDPAC alk ). The main bands of IR-PAN-a/SWCNT/PDPAC and IR-PAN-a/PDPAC are the same [ 59 , 60 ]. The chemical structure of the polymer component mainly depends on the pH of the reaction medium for the nanocomposite synthesis ( Figure 1 ).…”

“…The G band is a distinctive feature of graphite structures, whereas the D band is associated with disordered and defective structures [ 43 ]. The intensity ratio of these bands in the Raman spectrum of neat IR-PAN-a is I D /I G = 0.91 [ 59 ]. The splitting of the G and D bands in the Raman spectra of the binary and ternary composites is associated with the presence of a polymer component.…”

“…SWCNTs from Carbon Chg, Ltd. (Moscow, Russia) with values of d = 1.4–1.6 nm, l = 0.5–1.5 µm were produced by electric arc discharge technique with Ni/Y catalyst. To prepare IR-PAN-a, the suspension of IR-heated polyacrylonitrile in the KOH aqueous solution was dried at 80 °C in a vacuum, and the powder was IR heated at 800 °C for 2 min in a nitrogen atmosphere [ 59 ]. The GC-2000 glassy carbon plates (NIIgrafit, Moscow, Russia) sized 0.5 × 3 cm was polished with a diamond paste of the ASM-3/2 type.…”

Advanced Electrode Coatings Based on Poly-N-Phenylanthranilic Acid Composites with Reduced Graphene Oxide for Supercapacitors

“…Hybrid materials were synthesized for the first time via in situ oxidative polymerization of N-PAA in the presence of GO in the heterophase system in an alkaline medium (RGO/P-N-PAA-1), as well as from a solution of P-N-PAA in DMF containing GO (RGO/P-N-PAA-2). P-N-PAA polyacid, synthesized by the authors for the first time, is well adsorbed on graphene nanosheets due to π-stacking and hydrogen bonding of carboxylic groups [55,56] to oxygen-containing groups on the graphene oxide. With the further recovery of GO and removal of oxygen, the polymer layers prevent aggregation of graphene nanosheets.…”

“…groups [55,56] to oxygen-containing groups on the graphene oxide. With the further re covery of GO and removal of oxygen, the polymer layers prevent aggregation of graphene nanosheets.…”