Abstract

Electromagnetic interference (EMI) is an escalating concern in the modern electronic climate. As such it has
become a critical area to consider when designing and packaging electronics. In this context, electroless cobalt-
phosphorous alloy coated nano cenosphere (CPCNC) in polymethyl methacrylate (PMMA) and acrylonitrile
butadiene styrene (ABS) composites have been tried for their EMI shielding effectiveness (SE). The strategy is to
render the polymer conductive by dispersing CPCNC in various proportions in these polymers separately and to
promote wave absorption by making sheet of the polymer-based composite. In our study, energy dispersive X-ray
analysis confirmed the presence of Co-P on the coated nano cenosphere. This was further, confirmed through
phase analysis by X-ray diffractometer pattern. Scanning electron microscope analysis was conducted to see the
size, shape, and adherence of the Co-P alloy on nano cenosphere particles and to observe the distribution of these
particles in polymer matrix in the composite sheet. BET surface area of electroless coated powders was quite
high indicating good surface properties. The processing methods, electrical properties (surface resistivity), and
electromagnetic behavior (EMI SE) were investigated. SE values of approximately 25 dB at a frequency of 1 GHz
was obtained for coatings of electroless CPCNC in ABS polymer which can further be increased by adding other
conductive nano fillers along with coated cenospheres.