Faculty Publications
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Item Analysis of coefficient of thermal expansion in carbon black filled PDMS composite(Trans Tech Publications Ltd ttp@transtec.ch, 2020) Hiremath, H.; Sangamesh, R.; Kulkarni, S.M.Polymer composites are gaining attention due to their superior thermal properties. Especially carbon black /carbon nanotubes/ graphene filled polymer composites are used in energy harvesting, thermal actuators and MEMS. The coefficient of thermal expansion (CTE) is one of the most important properties in the polymer composite. In the present study, thermal expansion of polydimethylsiloxane (PDMS) matrix is filled with carbon black particle of varied volume fraction is modeled. Two-dimensional finite element (FE) model is computed in order to explain the thermal expansion behavior of the polymer composite and same is carried out for ambient to 70 K temperature. A 2D regular arrangement of circular particle packing model is set up and simulated. The FE model predicts that filler geometry has a little effect on the thermal expansion than the percentage of filler in the composite. Thermal expansion of composite is compared with the theoretical model. It shows that the CTE of composite reduces as the filler percentage increase, also gives good agreement in the both models. Hence, it is found that the addition of carbon black to the polymer composite could make it perform significantly better in thermal expansion. © 2020 Trans Tech Publications Ltd, Switzerland.Item Modeling and optimization of thermally excited carbon black and polymer composite actuator(Elsevier Ltd, 2020) Hiremath, H.; Kulkarni, S.M.As of late, actuators in view carbon black, carbon nanotube and graphene were shown in the extraordinary potential application in the field of drug delivery system, relay switches, robotics, energy harvesting and so on. Now a day electro-thermal and photo-thermal driven actuator based on polymer composite show larger actuation compare to the traditional thermal actuator. Though, the impact of structural dimensions and material parameters on the actuator execution ought to be investigated further. Since it is a critical point in the design and fabrications of the high-performance actuator In the present work, finite element (FE) analysis is adopted to simulate the thermally driven bilayer actuator and investigated the performance based on carbon black and polymer composite. Thus, the computational method is carried out to design and optimize the geometry and material parameters such as thickness, the coefficient of thermal expansion and so on. FE simulation results demonstrate that each layer thickness of the actuator has an important role in curvature deformation. A maximum curvature is obtained of 8.9 m-1 by simulation, which is a decent expected value in light of the geometry and material. Furthermore, a larger change in temperature and CTE between two layers additionally predicts the more prominent bending curvature. Consequently, this investigation is relied upon to give a theoretical baseline to plan and fabrication of CB based thermal actuator for a greater actuation performance. © 2018 Elsevier Ltd.Item Study on low-frequency dielectric behavior of the carbon black/polymer nanocomposite(Springer, 2021) Hiremath, H.; Mathias, K.A.; Sondar, P.R.; Shrishail, M.H.; Kulkarni, S.M.Recently, polymer-based dielectric materials have become one of the key materials to play an essential role in clean energy production, energy transformation, and energy storage applications. The end usage is the energy storage capability because it is a trade-off between dielectric permittivity, dielectric loss, and dissipation factor. Hence, it is of prime importance to study the dielectric properties of polymer materials by adding filler material at a low-frequency range. In the present study, polydimethylsiloxane/carbon black nanocomposites are prepared using the solution cast method. The dielectric properties, such as dielectric constant, dielectric loss, and dissipation factors due to the concentration of filler particles and low-frequency effect on the nanocomposites, are examined. Also, different empirical models are used to estimate the dielectric permittivity of polymer nanocomposites. The low-frequency range of 100 Hz to 1 MHz and the effect of varying volume fractions of carbon black show a significant change in the dielectric properties. It is found that the nanocomposites have a higher dielectric permittivity than the base polymer material. It is also observed that an increase in filler concentration increases the dielectric permittivity, which is confirmed with an empirical model. © 2021, The Author(s).Item Physico-mechanical behavior of carbon black-infused polymer composite(Springer, 2022) Hiremath, H.; Rajole, S.; Sondar, P.R.; Mathias, K.A.; Kulkarni, S.M.This article deals with the development of polymer composites by incorporating carbon blacks (CBs) into polydimethylsiloxane (PDMS) matrix material for improving the mechanical and physical properties of the polymer composites. CBs of nano-size were used as filler material in varying volume percentages (5–25%), and the polymer composite was processed by solution casting method. Density, elastic modulus and hardness were measured in order to study the effect of the CB-reinforced PDMS matrix. Experimentally obtained mechanical properties were then compared with the standard empirical model. Density of the polymer composite was increased by five times as compared to the pure polymer material. With the increase in volume percentage of CB, both hardness and elastic modulus of the polymer composites were enhanced. Scanning electron microscope images of the composite material showed uniform distribution of CBs, implying strong binding with the matrix material, which attributed to improved mechanical properties. © 2021, Indian Academy of Sciences.