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要提高磁带、磁盘等磁记录材料的记录密度,“分散”问题是关键之一,而分散过程中的润湿、磁粉团的解体和粒子的凝聚都直接与磁粉的表面特性有关。本文通过各种极性或非极性液体对密堆积磁粉的渗透速度以及磁粉在这些液体中沉降体积测定,研究了液体对磁粉的润湿特性,估测了它们的接触角;文内还尝试按Fowkes理论假定进行了计算,求得γ-Fe_2O_3磁粉表面张力为:γ_s~d=24dyn/cm,γ_s~p=17dyn/cm,γ_s=γ_s~d+γ_s~p=41dyn/cm。
To improve the recording density of magnetic recording materials such as tapes and disks, the problem of “dispersion” is one of the key issues. However, the wetting in the dispersion process, the disintegration of the magnetic powder clusters and the agglomeration of the particles are all directly related to the surface properties of the magnetic powders. In this paper, through various polar or nonpolar liquid penetration velocity of close-packed magnetic powder and the sedimentation volume of magnetic powder in these liquids, the wetting properties of liquid to magnetic powder were studied and their contact angles were estimated. According to the Fowkes theory, the surface tension of γ-Fe 2 O 3 magnetic powder is calculated as follows: γ_s ~ d = 24dyn / cm, γ_s ~ p = 17dyn / cm and γ_s = γ_s ~ d + γ_s ~ p = 41dyn / cm.