Influence of suspension stability on wet grinding for production of mineral nanoparticles

作     者：S.Sakthivel Venkatesan V.Krishnan B.Pitchumani 

作者机构：Particle Science and Technology LaboratoryDepartment of Chemical EngineeringIndian Institute of TechnologyNew DelhiIndia 

出 版 物：《Particuology》 (颗粒学报（英文版）)

年 卷 期：2008年第6卷第2期

页      面：120-124页

核心收录：

学科分类：07[理学] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

主　　题：Suspension stability ξ-Potential Nanosilica particle Attritor mill 

摘      要：Grinding behavior of nanoparticles in an attritor mill and the minimum achievable particle size are strongly influenced by the suspension stability. In the present work, suspension stability （i.e. ξ-potential） of nanoparticles was studied by measuring pH as a function of grinding time in the wet milling process. It was found that after a certain time in an attritor mill, there is no further size reduction and the average product particle size increases monotonically. One of the reasons is that the production of submicron particles leads to more particle-particle interactions and consequently pH of the suspension decreases with grinding time. Usually pH value is related to suspension stability and it can be enhanced by addition of NaOH solution. The maximum negative ξ-potential of -51.2 mV was obtained at pH of 12 for silica. The higher the ξ-potential with the same polarity, higher will be the electrostatic repulsion between the particles. Hence, the maximum electrostatic repulsion force was maintained by the adjustment ofpH value in wet milling. The experiments were conducted at different pH conditions which were maintained constant throughout the experiments and nanosized particles were obtained consequently.