Synthesis of conducting Polymer/Ceramics Nanocomposites for radiation shielding and their characterization

In recent years, an explosive growth in use of electrical and electronic devices in industrial, commercial, R & D and home applications has resulted in many-fold increase of electromagnetic interference (EMI) to other devices. High conductivity (σ) and high dielectric constant (ε') of materials contribute to high EMI shielding efficiency (SE). While typical metals, the 1st generation materials for shielding EMI, have good mechanical strength, they have disadvantages such as heavy weight, easy corrosion, and poor processibility. Doped polyaniline, for example, is conducting. So, its composite [15-16] with a suitable conducting powder or electro-active ceramic will be promising to supplement the disadvantages of typical metal sheets for EMI shielding. Such ceramics in proper nano-structure or nano-composites of these solids with suitable polymers can be more effective, and due attention will be paid to this nano-phase aspect [4,8,15,24]. Specific objectives are given below.

(1) Radiation damage due to energetic ion beam (VECC / IUAC) as well as due to γ-radiation will be studied after optimized materials are developed. Use of the EMI shielding materials / radar absorbing materials / specialized piezo-electric sensor & actuator materials in such radiation environment is more likely, making damage studies in these materials commercially and scientifically important. It is a satisfying expectation that high energy ion beams from superconducting cyclotron will be readily available in VECC if the materials are developed in-house.

(2) EMI affects adversely measurements of small signals, sensitive & other electronic instrumentations including some medical units. Main objective is to develop 2nd generation EMI shielding materials for above areas based on materials mentioned in the project title.

(3) Microwave / radar absorption material (RAM), is closely related to EMI shielding materials. Such RAMs form the core of stealthy defense system for all the military platforms, in air, sea and land in India and abroad. Here, we can cite one 2005 Canadian R & D to develop composites of carbon-nanotube and a conducting polymer (PANI) as RAM – comparable to what we do and plan. Such developments, welcome also by national defence laboratories, can be a by-product of our R & D on EMI shielding.

(4) Piezo-electric ceramics are best known electro-active ceramics. We have worked on these as well as on piezo-electric polymers. Newer materials for ultrasonic sensors or transducers, suitable for high temperature corrosive environment in advanced reactors of interest to the Department will be developed, based on our above-mentioned experience of piezo-electric materials and presently proposed synthesis and characterization facilities. A major target will be raising the Curie temperature of the piezo-electric sensor / actuator materials to withstand match the high operating temperature in these advanced power reactors.

In brief, the project objective is generation of new knowledge potentially useful for (a) EMI shielding materials, and (b) materials for ultrasonic transducer and sensor technology particularly with respect to advanced reactors, and also training of young minds to generate and apply that knowledge for DAE purposes and in the technology enhancement in general.

Project Co-ordinator : Dr. U. De

Email : ude@veccal.ernet.in