Electromagnetic wave absorbing cement-based composite using Nano-Fe3O4 magnetic fluid as absorber

The idea of preparing electromagnetic wave absorption cement-based composite using nano-Fe3O4 magnetic fluid as electromagnetic wave absorber is proposed. Nano-Fe3O4 magnetic fluid with obvious superparamagnetism is synthesized based on the co-precipitation method. When 5% nano-Fe3O4 magnetic fluid is added into cement, the composite prepared shows excellent electromagnetic wave absorption properties, e.g. the absorption bandwidth with reflection loss lower than −10 dB and lower than −15 dB is about 9.5 GHz and 6.3 GHz respectively, much better than that of the composite prepared with nano-Fe3O4 powder and bulk Fe3O4 powder. As well, nano-Fe3O4 magnetic fluid accelerates the early hydration of cement and improves its early age compressive strength obviously. Due to the advantages of easy processing, cheap cost, non-toxic and high electromagnetic wave absorption, cement-based composite prepared with nano-Fe3O4 magnetic fluid shows the huge potential application in construction of electromagnetic wave interference shielding buildings.