Study On Surface Modification Of K₂Ti₄O₉ Whisker And Rheological Properties Of Its Slurries

In this text,K₂Ti₄O₉ whiskers,as the main material,were pretreated by ball milling and water washing,and then modified by stearic acid,coupling agent,coupling agent/acrylamide.We analyzed the influences of different modifying agents to the surface of K₂Ti₄O₉ whisker and rheology and stability of K₂Ti₄O₉slurry.What's more,we acquired the optimum process conditions of modifying agents used on the surface of K₂Ti₄O₉ whiskers.More importantly,the structure composition and surface structure of K₂Ti₄O₉ whisker were tested by means of TG-DSC,SEM,FT-IR and other characterization methods.The experimental results show that the solid content of slurry was increased from 30wt%to 55wt%by milling 6h and washing.The K₂Ti₄O₉ whisker surface modified with 3%stearic acid at 80?for 15 min,the solid content of slurry was increased from 55 wt%to 68 wt%.When KH-792 are used to modified the surface of K₂Ti₄O₉ whisker,the solid content of slurry reaches 72wt%,with the amount of0.8%KH-792 at 60?for 3 h.The optimum conditions for modified with Double coated:1.5%acrylamide monomer dosage and 2%initiator dosage at 70?for 2h.To reduce the viscosity of slurry,K₂Ti₄O₉ whisker is modified by import the hydroxyl groups of stearic acid.After modification,the modified powder has obvious C-H and C=O stretching vibration peaks,the grafting rate of steric acid is5.5%,and the rheological performance of the slurry are influenced by the proportion of the hydrophilia and oleophylic groups in the K₂Ti₄O₉ whisker.The modification of KH-792 is in detail,as follow,the alkoxy group of KH-792reacted with the hydroxyl groups of K₂Ti₄O₉ whisker,which reduced the ability of surface groups to form hydrogen bonds with water molecules,and improved the maximum solid content of the slurry,surface grafting rate of KH-792 is 5.26%.Double coated polyacrylamide is an anionic polyelectrolyte,the surface of modified K₂Ti₄O₉ whisker has obvious C-N and C-H vibration peaks of,surface grafting rate of KH-792 is 5.57%,and the common role of electrostatic and steric interaction of modified powder make K₂Ti₄O₉ whisker dispersive.Modified K₂Ti₄O₉ whisker was prepared into the proper concentration of slurry,and the K₂Ti₄O₉ foam ceramics were produced by polymeric sponge impregnation process.The methylene blue degradation rate increased from63.85%to 93.9%by comparing with the original K₂Ti₄O₉ whisker.