Experimental investigation of the rheological behavior and viscosity of decorated multi-walled carbon nanotubes with TiO sub(2) nanoparticles/water nanofluids

• Published in: Journal of thermal analysis and calorimetry Vol. 123; no. 1; pp. 81 - 89
• Main Authors: Abbasi, Sedigheh, Zebarjad, Seyed Mojtaba, Baghban, Seyed Hossein Noie, Youssefi, Abbas, Ekrami-Kakhki, Mehri-Saddat
• Format: Journal Article
• Language: English
• Published: 01.01.2016
• Subjects: Decoration; Nanofluids; Nanoparticles; Nitric acid; Pseudoplasticity; Rheological properties; Titanium dioxide; Viscosity
• DOI: 10.1007/s10973-015-4878-4
• ISSN: 1388-6150

The effects of temperature and concentration on the flow behavior and viscosity of nanofluids containing TiO sub(2) nanoparticles, pristine MWCNTs, oxidized MWCNTs and decorated MWCNTs with TiO sub(2) nanoparticles are experimentally investigated. The results of rheological characteristics of nanofluids revealed that nanofluid of TiO sub(2) nanoparticle and MWCNT-TiO sub(2) exhibits shear thickening or dilatant behavior. In contrast, nanofluids containing pristine and oxidized MWCNTs depict the shear thinning or pseudoplastic behavior. Also results demonstrated that the rheological characteristics of nanofluids are functions of temperature and concentration, whereas the viscosity of all prepared nanofluids decreases with increasing the temperature and decreasing the concentration. In addition, the results show that the oxidation of MWCNTs in nitric acid leads to the reduction in viscosity. The rheological behavior of decorated MWCNTs illustrates that viscosity decreases by increasing the attached TiO sub(2) nanoparticles. TEM results show that TiO sub(2) nanoparticles successfully attached to the outer surface of oxidized MWCNTs.