Moumita Khutia

Preparation of modified polymer blend and electrical performance

In this study, a modified binary polymer blend made up of polycarbonate and polystyrene blend has been prepared by loading of aluminum oxide (Al2O3) as a dopant. The role of alumina with polymer blend system was addressed in view of interfacing criteria. The filler concentration of modified blend was taken as 5, 10, and 15%. The morphological, thermal, and electrical properties were characterized by various techniques. Optical microscopy confirms the homogenous dispersion of Al2O3 in blend. The presence of alumina was detected by subatomic level using atomic force microscope (both two and three dimensional approach). The differential scanning calorimetric thermographs demonstrate decreasing softing point as function of alumina loading. The dielectric properties such as dielectric constant, loss, and electrical modulus were studied under DC bias. The effect of DC bias exhibits significant changes at low amount of Al2O3. The dielectric polarization supports Maxwell Wagner (MW) theory due to low frequency response. 15% Al2O3 gives the highest dielectric constant (ε′) value (3.5 × 105) at 10 Hz. The polymer modified blend with Al2O3 may be used as a one of the best dielectric medium.

Optimization of Dielectric Constant of Polycarbonate/Polystyrene Modified Blend by Ceramic Metal Oxide

We modified a polycarbonate (PC)/polystyrene (PS) blend by loading alumina (Al2O3) into the blend. X-ray diffraction (XRD) shows a decrease in crystallinity. The optical microscopy and atomic force microscopy (AFM) confirms the homogeneous dispersion of alumina. The differential scanning calorimetry (DSC) data shows improved results in glass transition (Tg) and melting temperature (Tm) of blend systems. The electrical properties of polymer blends modified by Al2O3 were studied as a function of frequency (50 Hz–35 MHz) at 323 K. The alumina showed a significant effect in resulting in a high dielectric constant with low dielectric loss and dissipation factor. GRAPHICAL ABSTRACT

Development of Thermal Sensor by Reinforced Graphene Nano Platelets Thermoplastic Blends

ABSTRACT Polymer composites made of carbon allotropes were highly crucial for various engineering applications. We demonstrated the successful modification of polyacrilonitrile/polyvinylfloride blends by reinforced graphene nanoplatelets. The atomic force microscopy confirms the partial immiscible traces of polymer systems with asperities on the surface of the modified blends due to loading of graphene. The phase angle (Ɵ) measurement across the temperature (40–150°C) with the broadband frequency (50–35 MHz) is performed using the impedance analyzer. The results demonstrated the decrease in phase angle as a function of temperature. This investigation is highly suitable for the development of thermal sensor for engineering and health applications. GRAPHICAL ABSTRACT

PVA/K2Ti6O13 synthetic composite for dielectric applications

We demonstrated the preparation of polyvinyl alcohol (PVA) /Potassium titanate (K2Ti6O13) synthetic composite by solution blending. The loading of K2Ti6O13 well dispersed in PVA and improved electrical performance. The dielectric constant and loss as a function of temperature were recorded under frequency (200Hz-1 kHz). The real dielectric constant value obtained is (e=1000) feasible for various electronic and non-conventional energy applications.

Optimized surface topography of thermoplastics blends modified by graphene

Polyacrilonitrile (PAN)/ Polyvinylfloride (PVDF) blends were modified by loading the graphene (0.5 to 1.5 wt %). The presence of graphene reveals the interesting surface properties. The decrease in surface roughness as function of graphene loading was confirmed by the topographic method of recording (two and three dimensional images) with atomic force microscope (AFM). The blends become smoother in nature due to occupied smaller surface area of graphene. This property may be useful for several applications in the marine, naval, nuclear domain and engineering applications as barrier medium.