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CH5190: Inroduction to Macromolecules
General survey of important response functions measured
Polarization of composite structure made of Ppy and PDMS.
Visco-elasticity of structure.
Young modulus.(Mechanical response)
CH5190: Inroduction to Macromolecules
General survey of important response functions measured (contd.)
Tunable electrical and mechanical responses of PDMS and polypyrrole nanowire composites-Ping Du, Xi Lin and Xin Zhang-Journal of Physics D: Applied Physics,2013
Function Why is this function important?Dielectric Response high dielectric constant may play an important
role in various applications such as dielectric resonators, patch antennas, dielectric lensesand dielectric elastomer actuators
Viscoelastic response various micro-structures (posts, grooves,channels, etc) can be potentially applied to study the cellular behaviour and its interaction with extra cellular environment in morphological, mechanical and electrical approaches
Young modulus Of particular interest because theirelectromechanical transduction is similar to the natural muscle-great potential in the biomimetic robots
CH5190: Inroduction to Macromolecules
Example 1: Dielectric response function
• Dielectric constants of have similar frequency-dependent relaxation behavior, decreasing monotonically as the frequency f increases.
• High dielectric constant of the PPy at lower frequency is mainly due to the interfacial polarization.
CH5190: Inroduction to Macromolecules
Example 2: Viscoelastic response function
solvated counter ions, increased the effective free volumes in the conducting polymer phase, and therefore further enhanced the viscous behaviour of the PDMS–PPy composites.
creep depth increased with the support electrolyte conc entration, which suggested that the dopant ions were dominant in the viscoelastic response of conducting polymers.
CH5190: Inroduction to Macromolecules
Example 3:Young’s Modulus
Elastic moduli of the composites increase monotonically with the nanowire concentration.
Moderate enhancement in the elastic moduli-beneficial for the elastomer applications which require compliant structures.
CH5190: Inroduction to Macromolecules
Summary
• Dielectric constant of 10 vol% PDMS composite achieved an 85-fold augment as compared with the pristine PDMS.
• Tunable multifunctionality of PPy composites that possess enhanced electrical and viscoelastic properties within mechanically compliant structures enables the design of more advanced sensing and actuating applications.
Tunable electrical and mechanical responses of PDMS and polypyrrole nanowire composites-Ping Du, Xi Lin and Xin Zhang-Journal of Physics D: Applied Physics,2013
CH5190: Inroduction to Macromolecules
A research statement about the polymeric system of case study
Feasibility of Using Polypyrrole As A RAM(Radar
Absorbent Material) For Aircrafts
CH5190: Inroduction to Macromolecules
Research Motivation
• Polypyrrole–coated materials and other related mixtures have been used for RAM.
• More study on conductivity and thermal stability for this application is needed.
• Feasibility to produce low cost products.
CH5190: Inroduction to Macromolecules
Work plan
• To check shielding effect of conducting fabric against electromagnetic radiation
• Finding the cause behind conducting nature of Polypyrrole.
• Thermal stability of Polypyrrole in airborne situation.
• Feasibility for ground level structures made with such RAM.
CH5190: Inroduction to Macromolecules
Expected outcome
• Low budget radar absorbent material preparation for aircrafts and static radar structures.