The impact of surfactants on the stability and thermal conductivity of graphene oxide de-ionized water nanofluids


KEKLİKCİOĞLU ÇAKMAK N.

JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY, vol.139, no.3, pp.1895-1902, 2020 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 139 Issue: 3
  • Publication Date: 2020
  • Doi Number: 10.1007/s10973-019-09096-6
  • Title of Journal : JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
  • Page Numbers: pp.1895-1902
  • Keywords: Thermal conductivity, Graphene oxide, Surfactants, Nanofluid, Thermal properties, Stability, CARBON NANOTUBES, ENHANCEMENT, SUSPENSIONS, ADSORPTION, DISPERSION, VISCOSITY, SODIUM

Abstract

The effects of three different surfactants were analyzed on the stability and thermal conductivity of GO/de-ionized water nanofluids. One surfactant was cationic, cetyltrimethyl ammonium bromide (CTAB), one was anionic, sodium dodecyl sulfate (SDS), and one was nonionic, TritonX-100 (TX-100). These were added to synthesized graphene oxide (GO) prepared in de-ionized water at different concentrations (0.01, 0.05, 0.1, 0.15, 0.2, and 0.25 mass%). The transient hot-wire technique was employed to measure the thermal conductivity of all nanofluids at 20-40 degrees C. The stability of the GO/de-ionized water nanofluids without a surfactant was better than that of nanofluids with a surfactant. The stability and dispersion of the nanofluid with SDS were considerably better than nanofluids with the other two surfactants. All nanofluids without a surfactant had higher thermal conductivity than de-ionized water at all temperatures. An increase in the GO concentration from 0.01 to 0.2 mass% improved thermal conductivity by 3.05 and 22.03% at 20 degrees C, respectively. A further increase to 0.25 mass% caused a 23.73% increase in thermal conductivity.