Synthesis of Zinc Oxide Whiskers with Hydrothermal Method for Composite Absorbent Material of Microwave of ZnOw/MWCNT/Epoxy

The MWCNT/ZnOw/epoxy composites have great potential as microwave absorbing material. The synthesis of ZnO whiskers (ZnOw) was carried out using precursors ZnSO 4 and Na 2 CO 3 via hydrothermal method with temperatures of 120C, 160C, 200C, and 240C. X-ray diffraction (XRD) and scanning electron microscope (SEM) were applied to find out the morphology and structure of ZnOw powder. The best results of the XRD and SEM-EDX at hydrothermal temperature of 160C showed the best crystallinity of ZnO compound, that is at 2 values of 31. 7, 32.2, 34.3, 36.1, 37.9, 56.5, 62.8, 67.8, 76.8 and 89.5 with a Miller index of 111, 100, 002, 101, 102, 110, 103, 112, 202 and 203, respectively. At 160C, ZnO whiskers had a size of 97.7 nm, with a purity level of 72.6%. By adding 4% MWCNT, the result of synthesis via spray pyrolysis method (purity 90%) and 4% of epoxy, the ZnOw synthesised by hydrothermal method formed MWCNT/ ZnOw/epoxy composites. To determine the composite's microwave absorption capability, a vector network analyser was administered at hydrothermal temperatures of 160C and 200C. The MWCNT/ZnOw/epoxy composites had a reflection loss of -11.9 dB. This value exceeds the standard for microwave absorbing material which is -11.9 dB. Therefore, the composite has great potential as a microwave absorbing material.