Polyvinylpyrrolidone/CNTs Electrospun Composites for Advanced Applications

Electrospinning has attracted the attention of the scientific community since it is a simple yet effective technique to prepare fibers and their composites for various applications. Moreover, it provides a variety of choices in materials as compared to other methods that are used for fiber fabrication. The composites of interest in this study are CNT-based composites, as they hold a great significance in various applications due to their superior physical properties. There are various studies that confirm the potential of carbon nanotube (CNT)-based composites for advanced applications such as superconductors, microwave absorbers, and biomedical field. In the presented study, polyvinylpyrrolidone (PVP) and CNTs have been utilized to prepare composites using electrospinning technique. The purpose of this study is to prepare wire-like fibers which have good thermal and electrical conductivity and for that, the alignment of CNTs encapsulated in the fibers is one of the main features that was aimed. PVP and CNTs composites are believed to have high thermal and electrical conductivity along with good mechanical strength. Moreover, PVP has proven to be a good source of dispersion for CNTs. Generally, the PAN based CNTs are utilized during electrospinning, however, in the presented study we propose the simplified way to encapsulate CNTs directly in PVP nanofibers by using electrospinning technique. PVP with lower molecular weight (10,000mol/gm) is utilized to attain fine nanofibers by optimizing the molarity, flow rate, voltage and needle to collector distance. The CNTs of length range 5-20µm and diameters 15±5nm, 30±10nm were dispersed ultrasonically in the PVP and ethanol solution. The optimized process parameters were used for electrospinning. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were utilized to study the morphology and structural properties of the prepared composites. The thermal and electrical conductivities of the samples were also analyzed. The CNTs tend to align along the length of the fibers, which led to enhanced thermal and electrical conductivities. Furthermore, considering the good dielectric properties of PVP, increasing the PVP content can lead to high potential of the study in microwave absorption applications.