​Research on the Preparation Process of Ultrafine Zinc Oxide Particles

Nanomaterials refer to materials with structural unit sizes ranging from 1nm to 100nm. They exhibit three significant effects and are widely applied in industries such as the chemical, electronic, and engineering sectors. Ultrafine zinc oxide, a commonly used nanomaterial, was subjected to dry grinding using a horizontal vibration mill in this study. Different shapes and sizes of grinding media, specifically zirconia ceramics, were experimented with to analyze the particle size data post-grinding, aiming to determine the influence of the grinding media's size and shape on particle size.

The experiment revealed that when the filling rate is constant, the grinding effect of zinc oxide is associated with the specific gravity of the grinding media. A higher specific gravity of the grinding media resulted in a greater impact force and better grinding effects.

Ultrafine zinc oxide, sized approximately between 1nm to 100nm, embodies unique surface effects, volume effects, and quantum tunneling effects typical of nanomaterials. It possesses favorable thermal and chemical stability, displaying various effects beneficial in biotechnology, optics, electronics, and chemical industries, leading to its widespread application and research.

The preparation methods for ultrafine zinc oxide include physical and chemical methods. While chemical preparation methods are costly and limited in application scope, mechanical grinding methods allow large-scale production, offering high yields, cost-effectiveness, simple processes, and broader applicability. During mechanical grinding, particles and grinding media collectively interact, resulting in particle reduction. However, the particle size distribution tends to be relatively wide. In vibration milling, factors like the diameter and shape of the grinding media significantly affect the grinding efficiency and final product fineness, impacting subsequent industrial applications.

Table: Experimental Set-Up

Materials and Equipment

The study focused on dry grinding, particle size measurement, and analysis of the influence of different grinding media configurations on particle size. The effects of grinding time, materials, and the filling rate of the grinding media were kept constant. Various shapes and sizes of grinding media were mixed in pairs to examine their combined grinding effects on zinc oxide. Particle size distribution after grinding was analyzed using a laser particle size analyzer to assess the grinding efficiency.

Experimental Results Analysis

The experiment involved comparing different combinations of grinding media and their effects on particle sizes. For instance, combining Ф20mm zirconia beads with Ф10mm spherical grinding media indicated a gradual decrease in particle size until approximately 60 minutes of grinding, followed by a sudden drop. A similar trend was observed when mixing Ф20mm zirconia beads with 7×Ф7mm cylindrical grinding media, showcasing a steady reduction in particle size.

Conclusion

The study demonstrated that the particle size reduction of ultrafine zinc oxide is influenced by the specific gravity of the grinding media when the filling rate is constant. The combination of Ф10mm spherical grinding media with 7×Ф7mm cylindrical grinding media produced favorable grinding effects, achieving smaller particle sizes in a shorter duration.