There are many studies which use different types of reduction methods that affect the final properties of composite material containing silver nitrate (AgNO 3 ). The use of poly(N-vinylpyrrolidone) (PVP) in the composite also affects the final properties of composite material. However, as seen from the literature, it is difficult to find any studies focusing on polymer composite nanofibers reduced using different reduction methods and studies with different PVP loadings which are compared to each other, although it is very important to determine the most suitable reduction method and PVP loading for final composite properties. Thus, in this work, the effect of different reduction methods on polyacrylonitrile (PAN) composite nanofibers incorporating AgNO 3 and the comparison of different amounts of stabilizer (PVP) are studied in detail to determine the most suitable reduction method and the effect of PVP loading on the structure and the properties of the final product. PAN composite nanofibers having different amounts of PVP are reduced by four different methods namely arc-sol method, hydrazine method, arcweb method, and reflux method and characterized by electrical conductivity, mechanical testing, and thermal and SEM analyses. It has been observed that the hydrazine method provides higher breaking strength, electrical conductivity, enthalpy, smallest diameter, and lower cyclization temperature (T c ) than other reduction methods. Presence of PVP results in an increase of breaking strength and cyclization temperature, a decrease of enthalpy and the electrical conductivity. While highest breaking strength was obtained by hydrazine reduction with highest PVP loading, highest electrical conductivity was obtained by hydrazine reduction without PVP. As a direct result of the incorporation of AgNO 3 with or without PVP, insulator pure PAN (10 -12 S/cm) becomes semi-conductive material (10 -7 S/cm), which can be used as an antistatic material.

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 AgNO 3 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% AgNO 3 loading is suitable for high breaking strength, 3 wt% AgNO 3 loading is suitable for both high electrical conductivity and antimicrobial properties. Insulator polyacrylonitrile polymer becomes a semiconducting material.

There are several studies regarding polyacrylonitrile composite nanofibers with polyaniline doped with dodecylbenzene sulfonic acid and solved by N,N 0 -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 À6 S/cm with 3 wt% polyaniline content which was in the range for electrostatic discharge applications (10 À9 to 10 À6 S/cm). Increase in dissolution time and application of ultrasonic homogenization affected the diameter, mechanical properties,

In this study, DMSO was used as the solvent and composite nanofibers of PAN with 1 and 3w% AgNO3 content were electrospun. Then silver nanoparticles were in situ synthesized by chemical reduction. The effect of silver nitrate amount on the morphology, conductivity and mechanical properties of PAN/AgNPs composite nanofibers were investigated. Beadless and uniform composite nanofibers, the diameters of which were in the 499-515 nm range, were successfully electrospun. The breaking stress and breaking elongation of PAN/Ag composite nanofibers were higher than the neat PAN nanofibers. The conductivity was improved to around 10-8S/cm with the incorporation silver nanoparticles.

ABSTRACT:In this study, the effects of different dopants such as camphorsulfonic acid (CSA), dodecylbenzene sulfonic acid sodium salt (DBSANa + ), different solvents such as N,N'-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO) and different mixing processes such as magnetic mixing and mechanical mixing on the morphology, conductivity and mechanical properties of PAN/PANi composite nanofibers are investigated. It has been seen that composite nanofibers had the smallest fiber diameter, lowest conductivity and lowest mechanical properties when CSA (dopant) and DMF (solvent) are used. However, the composite nanofibers in which the polyaniline is doped with CSA in DMSO (solvent) had better conductivity and mechanical properties, besides having thicker diameters. When the mixing effects compared, mechanical mixing process resulted in higher mechanical properties of nanofibers compared to magnetic mixing process, while there was not much difference between fiber diameter and conductivity values.