%D 2019
%N 66
%R 10.1039/c9ra07811h
%O cited By 25
%J RSC Advances
%L scholars11989
%K Fourier transform infrared spectroscopy; Gravimetric analysis; Particle size; Particle size analysis; Stability; Thermogravimetric analysis; Ultrasonic testing; Viscosity, Conductivity improvement; Covalent functionalizations; Dispersion stability; Functionalized materials; Graphene nanoplatelets; Non-covalent functionalization; Stability of nanofluids; UV-vis spectrophotometry, Thermal conductivity
%X Covalent functionalization (CF-GNPs) and non-covalent functionalization (NCF-GNPs) approaches were applied to prepare graphene nanoplatelets (GNPs). The impact of using four surfactants (SDS, CTAB, Tween-80, and Triton X-100) was studied with four test times (15, 30, 60, and 90 min) and four weight concentrations. The stable thermal conductivity and viscosity were measured as a function of temperature. Fourier transform infrared spectroscopy (FTIR), thermo-gravimetric analysis (TGA), X-ray diffraction (XRD) and Raman spectroscopy verified the fundamental efficient and stable CF. Several techniques, such as dispersion of particle size, FESEM, FETEM, EDX, zeta potential, and UV-vis spectrophotometry, were employed to characterize both the dispersion stability and morphology of functionalized materials. At ultrasonic test time, the highest stability of nanofluids was achieved at 60 min. As a result, the thermal conductivity displayed by CF-GNPs was higher than NCF-GNPs and distilled water. In conclusion, the improvement in thermal conductivity and stability displayed by CF-GNPs was higher than those of NCF-GNPs, while the lowest viscosity was 8 higher than distilled water, and the best thermal conductivity improvement was recorded at 29.2. © 2019 The Royal Society of Chemistry.
%P 38576-38589
%T The influence of covalent and non-covalent functionalization of GNP based nanofluids on its thermophysical, rheological and suspension stability properties
%A O.A. Hussein
%A K. Habib
%A R. Saidur
%A A.S. Muhsan
%A S. Shahabuddin
%A O.A. Alawi
%I Royal Society of Chemistry
%V 9