Effect of various surfactants on stability and thermophysical properties of nanofluids

Jin Wang,Min Zeng,Bengt Sundén,Tan Li,Guolong Li

doi:10.1007/s10973-020-09381-9

Jin Wang, Min Zeng + Show 3 more

Open Access

https://doi.org/10.1007/s10973-020-09381-9

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Abstract

The effect of Fe3O4 nanoparticles and carbon nanotubes (CNTs) on the viscosity of a nanofluid is experimentally investigated from 278 to 313 K by changing the nanoparticle volume fraction. These nanoparticles were put into distilled water with various surfactants, i.e., Colace (docusate sodium), trisodium citrate dihydrate (TSC), polyvinyl pyrrolidone, cetyl trimethylammonium bromide, tetramethylammonium hydroxide (TMAH), acacia senegal (GA), sodium dodecyl benzene sulfonate, sodium dodecyl sulfate (SDS), and sodium laurylsulfonate (SLS). Based on the present measurements, new empirical formulas are proposed for Fe3O4–water, CNT–water and Fe3O4–CNT–water nanofluids to provide accurate predictions for the nanofluid viscosity. Based on the viscosity testing, stabilities and thermal conductivities of Fe3O4–TMAH, Fe3O4–Colace, Fe3O4–TSC, CNT–SDS, CNT–GA, Fe3O4–CNT–SLS, and Fe3O4–CNT–TSC nanofluids with a volume concentration of 0.5% are investigated in the present research. Results indicate that better stability, smaller viscosity, and higher thermal conductivity are obtained, when the surfactants TMAH, SDS, and SLS are added into the Fe3O4–water, CNT–water, and the Fe3O4–CNT–water nanofluid, respectively. The CNT–water and Fe3O4–CNT–water nanofluids exhibit a shear-thinning behavior, whereas a linear rheological behavior can be observed by water-based Colace–Fe3O4, TMAH–Fe3O4, and TSC–Fe3O4 nanofluids.

Highlights

Nanofluids as a stable colloidal suspension are prepared by dispersing nanoparticles in base fluids, such as water, ethylene glycol, and oil
After the sodium dodecyl benzene sulfonate (SDBS) is mixed into carbon nanotubes (CNTs)–water nanofluids with nanoparticles 0.5% and 1%, the viscosities of the CNT–water nanofluids increase by 167.5% and 290.8%, respectively
(b) 1% volume fraction show that the surfactants sodium laurylsulfonate (SLS) and trisodium citrate dihydrate (TSC) result in about 39% increase in the average viscosity for 1% F e3O4–CNT–water nanofluids, whereas about 35% increase occurs for 0.5% nanofluids

Summary

Introduction

Nanofluids as a stable colloidal suspension are prepared by dispersing nanoparticles in base fluids, such as water, ethylene glycol, and oil. Ranjbarzadeh et al [9] experimentally studied the thermal conductivity of water-based silica nanofluid with different solid volume fractions and temperatures. The main purpose of this systematic study is to systematically investigate the effect of using various surfactants on the stability and thermophysical properties (viscosity and thermal conductivity) of F e3O4–water, CNT–water, and Fe3O4–CNT–water nanofluids. For the CNT–water nanofluid, acacia senegal (GA), CTAB, sodium dodecyl benzene sulfonate (SDBS), and sodium dodecyl sulfate (SDS) were used as the surfactants When both the nanoparticles F e3O4 and CNTs were used to synthesize the hybrid nanofluid, the effect of the surfactants on viscosity of the nanofluid was investigated by using GA, TMAH, sodium laurylsulfonate (SLS), and TSC.

Results and discussion

Base fluid

Base fluid: water

CNTs-water nanofluid

Findings

Conclusions