Microwave-Assisted Synthesis of Functionalized Polyaniline Nanostructures with Advanced Antioxidant Properties

Abstract

Facile and fast microwave- (MW) assisted synthesis of copolymers of aniline and 2-aminobenzoic acid (2ABA) or 2-aminosulfonic acid (2SULFO) was performed by chemical polymerization of several mole ratios of aniline to functionalized aniline (FA). The physicochemical properties of the copolymers thus prepared were compared with the poly(aniline-co-2-aminobenzoic acid) (2ABAPANI) and poly(aniline-co-2-sulfonic acid) (2SULFOPANI) copolymers synthesized by conventional synthesis (CS) at the same temperature. FTIR and UV−vis spectra show the 2ABAPANI or 2SULFOPANI structure in all samples synthesized either conventionally or in the microwave reactor, however the yield was 2.5−3 times higher for nanostructured functionalized copolymers (fPANI) synthesized by MW. The effect of microwave irradiation on the antioxidant properties of the nanostructured 2ABAPANI and 2SULFOPANI copolymers was investigated. These samples showed 2.1−2.4 times better radical scavenger efficacy than their conventionally synthesized counterparts. A formation mechanism of polyaniline nanofibers under MW conditions is tentatively proposed based on thermal and nonpurely thermal effects on the nucleation modes.

Synergistic effects of conductivity and cell-imprinted topography of chitosan-polyaniline based scaffolds for neural differentiation of adipose-derived stem cells

“…The transmission peaks corresponding to the C=N stretching vibration of the quinonoid ring and the C=C stretching vibration of the benzenoid ring can be seen at 1554/1519 cm −1 , respectively. 34,35 The presence of these peaks confirms that the synthesized composite samples contained PANI. the substrates was increased from 7.5×10 -8 to 10 -4 S/cm by enhancing the amount of PANI from 0 to 2.5 wt.…”

One‐Dimensional Nanostructured Polyaniline: Syntheses, Morphology Controlling, Formation Mechanisms, New Features, and Applications

“…With microwave irradiation of an aqueous solution of aniline and 2‐aminobenzoic acid or 2‐aminosulfonic acid, nanofibers of the copolymers were successfully prepared by chemical polymerization with potassium iodate as the oxidant 188,189. In a comparison with the copolymers prepared by the conventional polymerization, where no other external irradiation such as microwave, ultrasonic, or UV light was applied, the copolymers achieved using microwave‐assisted polymerization showed not only nanofibrous morphologies but also significantly increased yields.…”

Soluble polyaniline nanofibers prepared via surfactant-free emulsion polymerization

“…Although the template method is considered as an effective way to preparing PANI nanofibers, the complicated post-processing [15] to remove template may destroy the PANI. Many template-free means adopted include nanofiber seeding polymerization [16], oligomer-assisted polymerization [17], dilute solution polymerization [18], interfacial polymerization [19], rapid mixing polymerization [20], radiolytic synthesis [21], snochemical synthesis [22], photolithographic synthesis [23] and UV-irradiation of an aqueous precursor solution [24] together with the microwave-assisted synthesis [25]. All the above mentioned methods require a specific condition, except the rapid mixing polymerization, in which a relatively low aniline concentration is employed and may be an obstacle to prepare PANI nanofibers on a large scale.…”