Title
Viscose-barium titanate composites for electromagnetic shielding
Authors
RAZVAN ROTARU CRISTIAN PEPTU and VALERIA HARABAGIU

Published Volume 50 Issue 5-6 May-June
Keywords viscose, barium titanate, composites, ultrasonication and microwave assisted process

Abstract
The paper proposed an ultrasound assisted method for the preparation of a material appropriate for uses in the manufacturing of electromagnetic shields. Thus, viscose fiber-barium titanate polymeric composites of different compositions were obtained by heating the precursors and homogenizing the mixture via ultrasonication. As proved by FTIR and scanning electronic microscopy, the composites consist of perovskite-type barium titanate particles of 400 600 µm, uniformly disposed around the viscose fibers. The composites possess high dielectric constants, the values being dependent on the content of barium titanate and on the preparation procedure. The materials were found to be useful as electromagnetic shields in the range of industrial frequency (50-55 Hz). The best results were obtained for a sample prepared under high electric field, which was characterized by a penetration depth of 240 µm and a total shielding effectiveness of -9 dB.