| Nano and micron silica particles is the sphere structure that obtained by acid leach the Na2O-B2O3-SiO2 glass which has been phase separated on the certain temperature. It has wide use in anti-microbial,chromatographic analysis immobilized enzyme and optical fibre communication for its nature that large specific area,stable chemical property and the tolerance in chemical erosion.Preparation of SiO2 particles through Na2O-B2O3-SiO2 system glasses as raw material by melting method has been introduced in this paper. Meanwhile, glass composition, melting temperature, heat treatment and acid leaching has been discussed to get optimized condition for SiO2 particles preparation. Samples have been characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and field-emission scaning electron microscopy (FE-SEM) to investigate glass structure, particle size and surface morphology. And the results of the tests are the main reason to decide the way how the conditions affect the properties of the nano-micron silica particles.The study indicated that, for 5Na2O-35B2O3-65SiO2 increasing of the heart temperature and time among a certain range is contribute to form the nano-micron silica particles, and 530-610℃,12h is the best condition for heat treatment; the lower concentration and longer time in acid leaching is also helpful to get the nano-micro silica particles. The addition of Ti+ can restrain phase separation, form the respective regions of a silica-rich phase and a borate-rich, which is better for distribution and concentration of partical size. For NO.MNS2 sample, through orthogonal experiment, the best thermal treatment temperature and time is 580℃/6h.And the best acid leaching condition is lmol/L, HCl/24h.The advantages of these SiO2 particles showed uniform morphology, large specific surface area and good dispersivity and so on. |
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