【摘要】 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-Fe₂O₃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。更多还原

【Abstract】 Dispersion of γ-Fe₂O₃ powder in polymer solution plays an important role in gover-ning the recording density of magnetic recording materials. The wetting of the powders,disintegration of agglomerates and agglutination of particles are closely related to the surfacecharacteristics of γ-Fe₂O₃ powder. In this paper, the wetting characteristics and the appa-rent contact angles of γ-Fe₂O₃ powder in polar and non-polar liquids were estimated bydetermining the penetration rates of these liquids through powders, as well as the sedimen-tative volume of powders in liquids. Based on Fowkes’ theoretical assumption,the valuesof the surface tension of γ-Fe₂O₃ powder were calculated: γ_s^d= 24 dyn/cm,γ_s^p=17dyn/cmand γ_s=41dyn/cm.更多还原