Effects of oxidant and dopants on the properties of cellulose/PPy conductive composite hydrogels

Abstract

Cellulose/Polypyrrole (PPy) composite hydrogels were prepared by in situ chemically oxidative polymerization of pyrrole in the cellulose matrix. Ferric chloride (FeCl 3 ) was used as an oxidant and four sulfonic compounds were used as dopants in order to investigate the effects on the properties of cellulose/PPy conductive composite hydrogels. The extent of polymerization of PPy was determined by the amount of the oxidant and the composite hydrogels with oxidant at 0.3 M20.5 M exhibited the higher conductivities for the intrachain and interchain conductivities of conductive polymers; the fracture stress of the composite hydrogels could be up to 26.25 MPa with a strain of 86.8% when the oxidant was at 0.5 M. Doping is an efficient way to improve the conductivity of the composite hydrogels and four kinds of dopant were compared in this work. Long alkane chain and side group in dopants can increase the steric hindrance of PPy polymerization which resulted in the lower conductivity of the composite hydrogels compared to dopants with smaller steric hindrance. The conductivity of the composite hydrogel firstly increased and then decreased with the concentration of dopants from 0.1 M to 1.0 M in this work.

Notably enhanced thermoelectric properties of lamellar polypyrrole by doping with β-naphthalene sulfonic acid

“…This phenomenon might be attributed to the following two reasons: one is the large conjugated structure of b-NSA, and the other is the steric hindrance effect of NSA À ion. 55 Firstly, with the increasing of b-NSA content, the enhancement of electrical conductivity is mainly originated from the large conjugated structure of b-NSA. According to the Raman spectra and XRD pattern, the decline of I D /I G indicates that the degree of conjugation and the order of PPy molecular chain are strengthened aer doping with b-NSA.…”

Synthesis and factor affecting on the conductivity of polypyrrole: a short review

“…In recent years, numerous reports have focused on the effect of various oxidants in PPy polymerization 14,44,133 . For instance, Subramanian et al 102 used various oxidants including Fe (III) benzenesulfonate, Fe (III) ethylbenzenesulfonate, Fe (III) dodecyl‐benzenesulfonate, and Fe (III) p‐toluenesulfonate to prepare PPy films.…”

“…The chemical structures of a few CPs are presented in Figure 1. Generally, PPy is one of the most commonly used CPs because of its easy synthesis, unique electrical conductivity, and environmental stability 14‐18 …”

“…PPy is a heterocyclic and positively charged conducting polymer (CP) that contains nitrogen in its oxidized form, and it loses its conductivity and charge when overoxidation occurred 14,19 . Besides, PPy is electroactive in organic electrolyte and aqueous solutions 13 .…”

Self-assembled functional components-doped conductive polypyrrole composite hydrogels with enhanced electrochemical performances

“…Sodium alginate can be combined with divalent or polyvalent cations other than magnesium ions. [5][6][7][8] Considering many advantages of sodium alginate, sodium alginate molecule has a large number of carboxyl and hydroxyl structures. It can be used as an ideal biopolymer for ordered nanostructure template synthesis.…”