^{Zhang Zishuo， Sun Yuli， Zhao Chuang， Yang Yixin， Yan Zhe， Zhao Xu’ang， Lu Wenzhuang， Zuo Dunwen}

College of Mechanical and Electrical Engineering， Nanjing University of Aeronautics and Astronautics， Nanjing 210016， China

Abstract

Objective To address the problems of particle agglomeration and sedimentation of Al₂O₃-SiO₂ hybrid nanoparticles in aqueous media， this study investigates the effects of the mechanical action of high-pressure homogenization and the interfacial regulation of dispersants on the dispersion stability of Al₂O₃-SiO₂ hybrid nanofluids， and determines the optimal preparation process parameters for obtaining stable Al₂O₃-SiO₂ hybrid nanofluids.

Methods Al₂O₃-SiO₂ hybrid nanofluids were prepared by combining high-pressure homogenization with dispersant addition， with an Al₂O₃-to-SiO₂ mass ratio of1∶1 and a total mass fraction of Al₂O₃ and SiO₂ nanoparticles set at 0.1%. The magnitude of the zeta potential was used as the evaluation indicator. The homogenization pressures were set at 30， 60，90，120，and 150 MPa. The numbers of homogenization passes were set at 1， 3， 5， 7， and 9， and the mass fractions of sodium dodecylbenzenesulfonate （SDBS） were set at 0.1%，0.3%，0.5%，0.7%，and 0.9%. Single-factor experiments were conducted to investigate the effects of homogenization pressure， number of homogenization passes， and SDBS mass fraction on dispersion stability， and an L₉（3³） orthogonal test was employed to optimize the process parameters. Finally， a zeta potential analyzer， laser particle size analyzer， and scanning electron microscope were used to characterize and verify the Al₂O₃-SiO₂ hybrid nanofluid prepared under the optimized process parameters.

Results and Discussion With increasing homogenization pressure， the magnitude of the zeta potential of the Al₂O₃-SiO₂ hybrid nanofluid gradually increased,whereas with increasing number of homogenization passes and SDBS mass fraction， the magnitude of the zeta potential first increased and then decreased. The effects of the three factors on the magnitude of the zeta potential decreased in the following order： SDBS mass fraction， homogenization pressure， and number of homogenization passes. The optimal combination of process parameters was an SDBS mass fraction of 0.3%，a homogenization pressure of 120 MPa， and 5 homogenization passes. Under the optimal process conditions， the maximum magnitude of the zeta potential of prepared Al₂O₃-SiO₂ hybrid nanofluid reached 66.1 mV. The agglomeration and accumulation of nanoparticles in the sample were reduced， and the nanoparticles exhibited good dispersion uniformity. After standing for 24 h， the mean particle size increased from 441 nm to 463 nm， corresponding to an increase of only 5%， indicating good dispersion stability.

Conclusion Under the optimal process conditions， the mechanical deagglomeration effect of high-pressure homogenization and the interfacial regulation effect of SDBS synergistically improve the dispersion stability of Al₂O₃-SiO₂ hybrid nanofluids.

Keywords： alumina；silica；hybrid nanofluid；high-pressure homogenization；sodium dodecylbenzenesulfonate；dispersion stability；process parameter optimization

Get Citation:Zhang Zishuo， Sun Yuli， Zhao Chuang， et al. Dispersion stability and process parameter optimization of Al₂O₃-SiO₂ hybrid nanofluids［J］. China Powder Science and Technology， 2027， 33（3）： 1-10.

Received:2026-07-20， Revised： 2026-09-20， online： 2026-11-03。

Funding： The research was supported by the National Natural Science Foundation of China (Grant No. 52575506) and the Postgraduate Research & Practice Innovation Program of Nanjing University of Aeronautics and Astronautics [Grant No. xcxjh20250505].

DOI：10.13732/j.issn.1008-5548.2027.03.001

CLC No.:TB383；TB44

Type Code:A

Serial No.:1008-5548（2027）03-0001-10