To cite this article: Ristiawan, M. W. et al. (2018). Synthesis of zinc oxide whiskers with hydrothermal method for composite absorbent material of microwave of ZnOw/MWCNT/ epoxy. J. Phys. Sci., 29(Supp. 2), 257–264, https://doi.org/10.21315/jps2018.29.s2.20
The MWCNT/ZnOw/epoxy composites have great potential as microwave absorbing material. The synthesis of ZnO whiskers (ZnOw) was carried out using precursors ZnSO4 and Na2CO3 via hydrothermal method with temperatures of 120°C, 160°C, 200°C, and 240°C. 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 160°C showed the best crystallinity of ZnO compound, that is at 2θ 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 160°C, 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 160°C and 200°C. 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.