tailieunhanh - Báo cáo hóa học: " Initial susceptibility and viscosity properties of low concentration e-Fe3 N based magnetic fluid"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Initial susceptibility and viscosity properties of low concentration e-Fe3 N based magnetic fluid | Nanoscale Res Lett 2007 2 155-160 DOI s11671-007-9047-7 NANO EXPRESS Initial susceptibility and viscosity properties of low concentration -Fe3 N based magnetic fluid Wei Huang Jianmin Wu Wei Guo Rong Li Liya Cui Received 10 December 2006 Accepted 8 February 2007 Published online 13 March 2007 To the authors 2007 Abstract In this paper the initial susceptibility of e-Fe3N magnetic fluid at volume concentrations in the range F are measured. Compared with the experimental initial susceptibility the Langevin Weiss and Onsager susceptibility were calculated using the data obtained from the low concentration E-Fe3N magnetic fluid samples. The viscosity of the e-Fe3N magnetic fluid at the same concentrations is measured. The result shows that the initial susceptibility of the low concentration e-Fe3N magnetic fluid is proportional to the concentration. A linear relationship between relative viscosity and the volume fraction is observed when the concentration F . Keywords Magnetic fluid Nano-material Initial susceptibility Viscosity Introduction Magnetic fluid MF is stable colloidal suspensions composed of single-domain magnetic nanoparticles dispersed in appropriate solvents. In order to prevent agglomeration due to attractive Van der Waals or magnetic dipole-dipole interactions the nanoparticle surface is covered with chemically adsorbed surfactant molecules steric stabilization or is electrically charged electrostatic stabilization 1 . Owing to W. Huang H J. Wu W. Guo R. Li L. Cui Department of Functional Material Research Central Iron Steel Research Institute Beijing 100081 P. R. China e-mail 5543837@ their unique physical and chemical properties these ferromagnetic liquids have attracted wide interest since their inception in the late 1960s. In a sufficiently diluted ferrofluid the magnetic particles can be thought of as noninteracting and the magnetic properties of such a ferrofluid are similar to those of an ideal paramagnetic gas. The