PDMS-Ni coated flyash cenosphere composite for broadband microwave absorption

In search of novel light weight broadband microwave absorber for defense and civilian applications, industrial waste hollow microsphere (fly ash cenosphere or FAC) filler based polymer composite system was studied in the present work owing to its attractive microwave absorbing characteristics. PDMS is chosen as the matrix. FAC, being dielectric, is coated with Ni using standard electroless coating method to synthesize core-shell filler (magneto-dielectric). The dielectrics and microwave absorption study was carried out for the frequency range 8.2-18 GHz (X-band and Ku-Band). The minimum reflection loss (RL) was obtained to be -43 dB with an excellent bandwidth. Hence, an ultra-thin Ni coated FAC loaded PDMS can be considered as a smart candidate for broad band microwave absorption.