Conductive elastomeric nanocomposites based on oxidation of aniline with silver nitrate via inverse emulsion polymerization

Abstract

The present investigation describes a facile and rapid approach of conductive nanocomposites production and assesses the opportunity of their use as electro-mechanical sensors. Hybrid materials containing silver and polyaniline nanoparticles reinforcing a thermoplastic elastomeric matrix were studied. The approach developed includes ultrasonically assisted in situ inverse emulsion polymerization of aniline oxidized by a weak oxidant and silver nitrate, and supported with a strong oxidant, ammonia peroxydisulfate. Aniline was doped with dodecylbenzene sulfonic acid in the presence of dissolved styrene-isoprene-styrene thermoplastic elastomer. While conventional polymerization of aniline with silver nitrate takes 2 weeks, by utilization of inverse emulsion polymerization, the reaction time reduces to 5 days. The assistance of a strong oxidant dramatically shortens the reaction time to 30 min. The technique developed results in uniform distribution of polyaniline/silver (PANI/Ag) conductive nanoparticles in the elastomeric matrix. The morphological studies of the films reveal spherically shaped 45 nm Ag particles. The presence of PANI/Ag in the styrene-isoprene-styrene elastomeric matrix enhances the electrical, thermal, and mechanical properties of the nanocomposites. The approach described provides an opportunity of the development of tunable structures and a remarkably distinctive architecture. A rapid electrical resistance response to an applied strain makes the nanocomposites developed useful as sensitive strain sensors.

Electro‐mechanical sensors based on conductive hybrid nanocomposites

“…(a)), with a corresponding increase of stress at break (Fig. (b)), in agreement with literature data . The mechanical properties for the SIS‐22% nanocomposites are significantly higher than for the SIS‐14% because of higher polystyrene content.…”

“…This concept is based on positioning conductive features at the interface of the polymer particles instead of random distribution in the polymer matrix . The methodology developed preserves and controls the dispersion morphology of nanoelements in the main matrix . The approach developed consists of two main steps: precipitation and filtration processes (Fig.…”

Polymerization of aniline derivatives by K2 Cr2 O7 and production of Cr2 O3 nanoparticles

“…The peak at 3320 cm ‐1 indicates N‐H stretching, the spectra of homopolymers or copolymer have two major absorption bands at 1583 cm ‐1 and 1511 cm ‐1 . These bands can be attributed to the C = C vibrations of quinoid and benzenoid units respectively …”

“…These bands can be attributed to the C = C vibrations of quinoid and benzenoid units respectively. [20][21][22] The number of quinoid units was almost lower than the number of benzoid units in either homopolymers (PANI and PAA) or copolymer (PANAA) as there was an apparent difference in the relative intensity of quinoid to benzoid band. This reveals to the degree of the oxidation in the polymer chains.…”

EMI shielding and microwave absorption behavior of Au-MWCNT/polyaniline nanocomposites

“…So, the incorporation of metal NPs can effectively enhance the electrical, optical and other properties of polymers and their composites. [13,14] PANi-Ag and PANi-Au composite nanofibers prepared by Pillalamarri et al were reported to have higher electrical conductivity as compared with neat PANi, and this reveals the significance of noble metal NPs in improving the conductivity of PANi. The increase in the electrical conductivity of PANi because of the addition of NPs can enhance the microwave absorption properties via the enhancement in the dielectric losses.…”