Advanced Characterisation Techniques of Carbon nanotube Polymer Composites for Recent Applications

Abstract

Carbon Nanotube (CNT) based polymer composites are the next generation materials paving their pathway for various scientific and technological applications. Owing to CNT’s extraordinary mechanical strength, high electrical and thermal parameters, large surface area, and unique optical properties, CNT polymer nanocomposites (PNCs) are being employed recently in automotive, aerospace, energy sector, sporting goods and biomedical usages. The employment of novel PNC material begins with fabrication and characterization, demanding expertise for the effective execution of the investigation. The present report focuses the depiction of microscopic as well as macroscopic investigation of CNT & polymer matrix utilising advanced characterisation technique. Complete understanding of the superior behaviour of CNT reinforced nanocomposites needs information of the interactions at the interface between the carbon nanotubes and the matrix. Spectroscopic techniques like Raman, NMR, FTIR etc. have facilitated validation regarding biocompatibility, chemical reactivity and reinforcing ability of CNT in various matrices. Viscoelastic, thermal & mechanical parameters relevant to their strength, modulus, flexibility and conductivity are tested using Dynamic Mechanical Analyser, Universal Testing Machine, and Differential Scanning Calorimetry. Sophisticated instruments like Scanning Electron Microscope, Transmission Electron Microscope are significant to confirm the bonding & structural reinforcement within nanocomposites. Confocal laser Scanning Microscope in reflection mode is used to obtain quantitative spatial dispersion levels and calculate ‘relative dispersion index’ representing the uniformity of the dispersion of CNTs in the matrix. Realizing the potential for EMI shielding applications, scientists are now making efforts to fabricate novel composites with CNT fillers for high-end industrial applications. EMI shielding effectiveness and dielectric properties of these composites are measured by vector network analyser. Furthermore, the magnetic behaviour was examined by using a Vibrating Sample Magnetometer and the estimation of magnetic domains in the materials was conducted through Magnetic Force Microscopy. Regardless of the extensive advantages of CNTs, challenges still exist like production of economical defect-free nanotubes in a bigger scale. Moreover, inadequate performance by PNCs arises due to non-uniform dispersion of CNTs in polymer matrices and weaker bonding at nanotubes/matrix interface. Future research efforts should therefore emphasis on exploring compounds more compatible with CNT that have better control over their properties to facilitate more effective use of nanotubes.