Preparation of diester-based ferrofluid and applied research in sealing.

To improve the sealing performance of ferrofluid, a Fe 3 O 4 magnetic nanoparticles with different coating times was synthesized by the chemical co-precipitation method, and the performance of diester-based Fe 3 O 4 ferrofluid was investigated and characterized. A convergent ferrofluid seal (CFFS) device was designed and the prepared ferrofluid was applied to it. The influence of important factors such as seal clearance and pole teeth of CFFS on the pressure capability of the CFFS are investigated using simulations and experiments. The results show that the prepared magnetization intensity of the ferrofluid is 29.5 kA/m. The simulation and experimental results of the CFFS agree well, and its performance is 3.3 times that of the ordinary ferrofluid seal. • The ferrofluid particles prepared by chemical precipitation method have uniform particle size and good anti-precipitation property. • The effect of radial and axial clearance size on the pressure resistance of the convergent ferrofluid seal was investigated. • The effect of the number of radial and axial pole teeth on the pressure resistance of the seal was investigated. • Designed convergent ferrofluid seal provides a theoretical basis for a convergent ferrofluid seal with high sealing performance. [ABSTRACT FROM AUTHOR]