Journal of Inorganic Materials ›› 2019, Vol. 34 ›› Issue (6): 653-659.DOI: 10.15541/jim20180359

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B2O3-SiO2-Na2O Controlled-release Material: Synthetic Parameters Optimization and Release Mechanisms Exploration

Chang-Xing HUANG,Jun CUI,Yuan-Sheng PEI()   

  1. Key Laboratory of Water and Sediment Sciences, School of Environment, Beijing Normal University, Beijing 100875, China
  • Received:2018-08-02 Revised:2018-10-10 Published:2019-06-20 Online:2019-05-23
  • Supported by:
    National Natural Science Foundation of China(51579009);Beijing Municipal Science and Technology Plan Projects(Z181100005518005)

Abstract:

Aiming at optimization of synthetic process, reduction of raw materials loss and control of production cost, the single factor method was used to study the effects of different heating rate, holding time, melting temperature, and initial temperature on the B2O3 volatilization and bubble formation during the preparation of borate controlled- release material (BCRM). The physicochemical properties of BCRM before and after controlled-release were characterized by X-ray diffraction analysis, infrared spectroscopy and X-ray photoelectron spectroscopy, and the release mechanism of BCRM was analyzed by Korsmeyer-Peppas model. The results show that the amount of B2O3 volatilization can be reduced to 1.08%, no bubble forms in the transparent BCRM, and controlled-release performance is acceptable under optimum conditions of initial temperature 1050 ℃, holding time 2 h and melting temperature 1050 ℃. Controlled-release mechanism of BCRM, affected by temperature, is Super Case II transport at 30 and 35 ℃ while it is non-Fickian diffusion at 40 ℃. However, the cumulative release rate of boron is greater than 95% at different temperatures.

Key words: borate, process parameter optimization, volatilization volume, release mechanism

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