Study of ionic solvent-free carbon nanotube nanofluids and its composites with epoxy matrix

A facile way to synthesis ionic solvent-free multi-walled carbon nanotubes (CNTs) (MWNTs) nanofluids has been introduced. Fourier transform infrared spectra and transmission electron microscope (TEM) were employed to study the surface structure of MWNTs in the nanofluids. The thermal property of the nanofluids was characterized by thermogravimetric analysis and differential scanning calorimetry. The stability of the nanofluids in the deionized water was obtained through UV–Vis absorption spectrum. Rotary rheometer was used to test the flow feature of the nanofluids. The results of conductivity indicate that the seepage threshold value of solvent-free nanofluids in water is about 0.408 vol.% (volume fraction). Meanwhile, it is found that the ionic nanofluids dispersed well in epoxy matrix. The mechanical properties, such as bend modulus, strength and impact toughness have been improved at the same time. TEM images can tell the great dispersion of solvent-free CNTs nanofluids in the epoxy matrix. It means that this kind of nanofluids will be excellent nanofiller in the nanocomposites.