聚四氟乙烯基磁性液体的制备及在井口密封中的应用

摘要

用电弧放电法,在30% C2H2、70% Ar的混合气氛中制备Fe-Ni合金纳米粒子.利用Fe-Ni合金纳米粒子作为磁性粒子、油酸为表面活性剂、聚四氟乙烯乳液和少量硅油、硅脂的混合液为基液制备高黏度聚四氟乙烯基磁性液体.制备的聚四氟乙烯基磁性液体在25℃时的黏度为6-30 Pa·s,在85℃时的黏度为1-20 Pa·s,室温下饱和磁化强度为18.26-39.66 A·m2 /kg.将制备的聚四氟乙烯基磁性液体应用于油井井口密封,有效密封时间比原密封结构提高50%以上.%Fe-Ni alloy nanoparticles were prepared by arc discharge evaporating Fe-Ni alloy in 30%C2H2 and 70% Ar atmosphere. Magnetic liquid with high viscosity was prepared with Fe-Ni alloy nanoparticles as magnetic particle,oleic acid as surfactant, miscible liquids of polytetrafluoroethene and little silicone oil and silicone grease as base solution. The viscosity of magnetic liquid is 6 ~ 30 Pa ? S at 25 ℃. And 1 ~ 20 Pa ? S at 85 ℃. The saturation magnetization of magnetic liquid is 18. 26 ~39. 66 A -mVkg at room temperature. The magnetic liquid and sealing technology were applied to gap sealing of shaft top. The results show that efficiency of sealing is increased by over 50%.