Controlled synthesis of monodisperse spherical microsilica from rice husk via precipitation process

초록

Spherical microsilica was synthesized from rice husk–derived silica via a precipitation-based process. The effects of key synthesis parameters, including PEG characteristics, nitric acid concentration, aging temperature, and time, were systematically investigated to identify the dominant factor governing particle morphology. Aging time was found to be the most critical parameter, with effective spheronization occurring within a narrow time window around 35.5 h. Under optimized conditions, uniform spherical silica particles with an average diameter of approximately 5.8 μm, narrow size distribution, and high purity (99.7%) were obtained. Structural analyses confirmed that the synthesized silica was amorphous and porous. These results demonstrate that rice husk can be converted into high-quality spherical microsilica through a simple and controllable process without complex pretreatment, indicating its potential applicability in morphology- and purity-sensitive functional material applications.

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