Indian Institute of Technology (BHU), India
Dr. Srivastava did his master and Ph.D. degree in Mechanical Engineering from IIT(BHU), Varanasi, India. Also, did post Doc from University of Bath, UK (under European Fellowship); QMW, London (under Commonwealth Fellowship); and MPA, University of Stuttgart, Germany (under BMBF Fellowship). He has involved for the development of ceramic composites, polymer composites and Nano composites. He has published more than 155 papers in peer reviewed international journals. He has collaborated various international projects with UK, USA, Germany, Australia, Japan, South Korea, Italy, Czech Republic, Poland and France. He is FOUNDER PRESIDENT of “ICRACM SERIES” international conference. He is Adjunct Professor, Faculty of Industrial Science & Engineering, Swinburne University of Technology, Victoria, Australia.
A Carbon Nano material such as multi-walled carbon nanotubes (MWCNTs) and Graphene Nano platelets (GnPs) has attracted considerable interest over recent years due to its intrinsic mechanical, thermal and electrical properties. Incorporation of small quantity of Nano fillers into polymer can create novel Nano composites with improved structural and functional properties. The properties of polymers, as reflected by their response to externally applied stresses, are dependent on both time and temperature. The dynamic mechanical analysis (DMA) of polymer-based MWCNT/epoxy resin and GnP/epoxy resin Nano composites provides important insight into the intimate conformation of the polymer chains in the sample, as well as the interactions of these chains with MWCNT and GnP components in the composite system.Therefore, dynamic mechanical and Nano hardness measurements of MWCNT/epoxy resin and GnP/epoxy resin Nano composite were used to evaluate the effect of temperature on dynamic elastic modulus. These provide direct information on various other characteristic structural parameters, such as dynamic viscoelastic behaviour, glass transition temperature (Tg), storage and loss moduli, and tan δ. The results of these measurements for all samples were compared, and allowed the evaluation of the effect of a magnetic field on the MWCNT/epoxy resin and GnP/epoxy resin Nano composites. It can be seen that the storage modulus decreased with the increase of temperature, whereas loss modulus increased with increase of temperature. At low temperatures all the samples show a very high value of the storage elastic modulus, followed by gradual drops due to second order transactions between 400C to 1100C. The principal drop, due to the glass transaction, is evident for all samples in the range 1300C to 1400C. But, tanδ curves show a peak value 1500C to1600C of temperature range indication glass transaction temperature. This indicates that the addition of Nano filler improves the elastic properties of the epoxy system at elevated temperatures in the rubbery region. The loss modulus indicates that the energy has been converted into heat and can thus be used as a measurement of viscous component or unrecoverable oscillation energy dissipated per cycle. It may be further concluded that the Nano hardness increases with increase of elastic modulus.