This study investigates the nucleate boiling heat transfer properties of a nanofluid composed of DI water and multi-walled carbon nanotube-manganese ferrite (MWCNT/MnFe2O4) nanocomposites, with a focus on enhancing stability and heat transfer performance using surfactants dioctyl sodium sulfosuccinate (AOT), Tween-80, and an ionic liquid 1-octadecyl-3-methylimidazolium chloride (Cl [C18 mim]). In this study, the heat transfer coefficients of MWCNT and MWCNT/MnFe2O4 nanocomposites were compared at concentrations of 0.001 mass% and 0.003 mass%, highlighting the impact of surfactants and ionic liquids on deposit formation, thermal resistance, and wall temperature reduction. The surfactants of AOT and Tween-80 and the ionic liquid of Cl [C18 mim] were used in order to increase the stability of synthesized nanofluids. The functionalizing MWCNT with manganese ferrite has enhanced its stability (for 1 month). In the comparison between MWCNT and MWCNT/MnFe2O4 at two concentrations of 0.001 mass% and 0.003 mass%, it was found that at a concentration of 0.001 mass%, MWCNT/MnFe2O4 has a higher HTC and reduced wall temperature more effectively than MWCNT. And at a concentration of 0.003 mass%, MWCNT has a higher HTC than MWCNT/MnFe2O4. In the section on combining MWCNT with surfactants and ionic liquids, AOT exhibited the best performance at concentrations of 0.001% and 0.003 mass%. For the combination of MWCNT@MnFe2O4 with surfactants and ionic liquids, Tween-80 demonstrated the best performance at the same concentrations. The effects of heat flux, concentration, and surface wettability on the boiling performance have been analyzed, as these factors influence the efficiency and dynamics of the heat transfer during the process. The surface roughness resulting from boiling in fluids containing MWCNT is different from MWCNT/MnFe2O4. When MWCNT nanofluid used in boiling process, cluster deposits have formed on the heater surface. These deposits have created additional nucleation sites on the heated surface. While such deposits can enhance boiling heat transfer in the short term, surfactants and functionalization are essential to maintain dispersion stability and ensure consistent long-term performance. In the combination of MWCNT/MnFe2O4 with surfactants and ionic liquids, this nanocomposite forms soft sedimentary deposits on the heater surface during the boiling process. Therefore, the nanocomposite deposits exhibit less thermal resistance. Based on experimental results, for the concentration of 0.001 mass% and the heat flux of 20 W cm−2, the enhancement ratio of HTC for MWCNT/MnFe2O4, MWCNT + AOT, and MWCNT/MnFe2O4 + Tween-80 is 36.4%, 35.8%, and 22%, respectively. Also, for the concentration of 0.003 mass%, the enhancement ratio of HTC for MWCNT, MWCNT + AOT, and MWCNT/MnFe2O4 + Tween-80 is 36.8%, 38.5%, and 38.5%, respectively. Graphical abstract

Enhancing pool boiling heat transfer using MWCNT-based nanocomposites, ionic liquid, and surfactants

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发表日期：

2025年11月7日

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Pouya Fazlallahzadeh,
Seyed Reza Shabanian,
Mostafa lashkarbolooki

摘要

This study investigates the nucleate boiling heat transfer properties of a nanofluid composed of DI water and multi-walled carbon nanotube-manganese ferrite (MWCNT/MnFe₂O₄) nanocomposites, with a focus on enhancing stability and heat transfer performance using surfactants dioctyl sodium sulfosuccinate (AOT), Tween-80, and an ionic liquid 1-octadecyl-3-methylimidazolium chloride (Cl [C₁₈ mim]). In this study, the heat transfer coefficients of MWCNT and MWCNT/MnFe₂O₄ nanocomposites were compared at concentrations of 0.001 mass% and 0.003 mass%, highlighting the impact of surfactants and ionic liquids on deposit formation, thermal resistance, and wall temperature reduction. The surfactants of AOT and Tween-80 and the ionic liquid of Cl [C₁₈ mim] were used in order to increase the stability of synthesized nanofluids. The functionalizing MWCNT with manganese ferrite has enhanced its stability (for 1 month). In the comparison between MWCNT and MWCNT/MnFe₂O₄ at two concentrations of 0.001 mass% and 0.003 mass%, it was found that at a concentration of 0.001 mass%, MWCNT/MnFe₂O₄ has a higher HTC and reduced wall temperature more effectively than MWCNT. And at a concentration of 0.003 mass%, MWCNT has a higher HTC than MWCNT/MnFe₂O₄. In the section on combining MWCNT with surfactants and ionic liquids, AOT exhibited the best performance at concentrations of 0.001% and 0.003 mass%. For the combination of MWCNT@MnFe₂O₄ with surfactants and ionic liquids, Tween-80 demonstrated the best performance at the same concentrations. The effects of heat flux, concentration, and surface wettability on the boiling performance have been analyzed, as these factors influence the efficiency and dynamics of the heat transfer during the process. The surface roughness resulting from boiling in fluids containing MWCNT is different from MWCNT/MnFe₂O₄. When MWCNT nanofluid used in boiling process, cluster deposits have formed on the heater surface. These deposits have created additional nucleation sites on the heated surface. While such deposits can enhance boiling heat transfer in the short term, surfactants and functionalization are essential to maintain dispersion stability and ensure consistent long-term performance. In the combination of MWCNT/MnFe₂O₄ with surfactants and ionic liquids, this nanocomposite forms soft sedimentary deposits on the heater surface during the boiling process. Therefore, the nanocomposite deposits exhibit less thermal resistance. Based on experimental results, for the concentration of 0.001 mass% and the heat flux of 20 W cm⁻², the enhancement ratio of HTC for MWCNT/MnFe₂O₄, MWCNT + AOT, and MWCNT/MnFe₂O₄ + Tween-80 is 36.4%, 35.8%, and 22%, respectively. Also, for the concentration of 0.003 mass%, the enhancement ratio of HTC for MWCNT, MWCNT + AOT, and MWCNT/MnFe2O4 + Tween-80 is 36.8%, 38.5%, and 38.5%, respectively.

Graphical abstract