Nesrin Demirsoy

The effect of the dissolution process and the polyaniline content on the properties of polyacrylonitrile–polyaniline composite nanoweb

There are several studies regarding polyacrylonitrile composite nanofibers with polyaniline doped with dodecylbenzene sulfonic acid and solved by N,N′-dimethyl formamide which were mostly performed to analyze the thermal and morphological properties. In this study, camphor sulfonic acid-doped polyaniline and polyacrylonitrile composite nanofibers were electrospun from solutions in dimethylsulfoxide and the effect of polyaniline content and the application of different dissolution methods on the morphology, chemical structure, conductivity, crystallinity, mechanical, and thermal properties of nanowebs were investigated. Morphology, nanofiber diameters, chemical structure, crystallinity, mechanical properties, and thermal properties of the nanofibers were all affected by the polyaniline addition. Compared to the conductivity of neat polyacrylonitrile nanofibers, the conductivity of the composite nanofibers was improved, reaching a value higher than 10−6 S/cm with 3 wt% polyaniline content which was in the range for electrostatic discharge applications (10−9 to 10−6 S/cm). Increase in dissolution time and application of ultrasonic homogenization affected the diameter, mechanical properties, crystallinity, and thermal properties of the nanofibers, while they had negligible effects on conductivity.

The effect of dispersion technique, silver particle loading, and reduction method on the properties of polyacrylonitrile–silver composite nanofiber

The effect of dispersion technique, reduction method, and the amount of silver nanoparticles on the properties of composite polyacrylonitrile nanofiber containing silver nanoparticles is analyzed using differential scanning calorimetry, scanning electron microscopy, electrical conductivity, tensile testing, X-ray diffraction, and antimicrobial efficiency measurements. Composite nanofibers reduced by hydrazine hydroxide result in smaller diameter, higher electrical conductivity, higher breaking strength, higher cyclization enthalpy than the samples reduced by xenon arc method. Reduction process results in smaller diameter and higher breaking strength than those of non-reduced nanofiber web containing AgNO3 nanoparticles. Dispersion by ultrasonic homogenizer/bath provides higher breaking strength, electrical conductivity than the samples dispersed by only magnetic stirrer. An increase of silver nanoparticle generally results in an increase of enthalpy, a decrease of both cyclization temperatures and crystallinity. While 1 wt% AgNO3 loading is suitable for high breaking strength, 3 wt% AgNO3 loading is suitable for both high electrical conductivity and antimicrobial properties. Insulator polyacrylonitrile polymer becomes a semiconducting material.