LIN Yueshun, ZHOU Hongjun, ZHOU Xinhua, et al. Preparation and properties of pH-responsive control release system of PAA/chlorpyrifos/amino functionalized mesoporous silica[J]. CIESC Journal, 2016, 67(10): 4500-4507.
LIN Yueshun, ZHOU Hongjun, ZHOU Xinhua, et al. Preparation and properties of pH-responsive control release system of PAA/chlorpyrifos/amino functionalized mesoporous silica[J]. CIESC Journal, 2016, 67(10): 4500-4507.DOI: 10.11949/j.issn.0438-1157.20160417.
A pH-responsive control release system of PAA/chlorpyrifos/mesoporous silica was prepared by using negative charged polyacrylic acid (PAA) to encapsulate amino functionalized mesoporous silica (NH2-MCM-41) with chlorpyrifos loaded in the pores. The PAA/chlorpyrifos/NH2-MCM-41 system were systematically characterized using X-ray diffraction (XRD)
N2 adsorption-desorption
transmission electron microscopy (TEM)
scanning electron microscopy (SEM)
thermogravimetric analysis (TGA)
Zeta potential and Fourier transform infrared spectroscopy (FTIR). The release behavior of chlorpyrifos was studied at various pH and temperature conditions. The experimental results showed that PAA was coated on the surface of chlorpyrifos/amino functionalized mesoporous silica as a result of electrostatic interaction. The chlorpyrifos release from the PAA/chlorpyrifos/NH2-MCM-41 system was inhibited mainly by PAA blockage with significant pH sensitivity
which increased with pH decrease at pH ≤ 7 and was slightly higher in weak base condition than that in neutral condition. The release also exhibited some temperature dependence and generally followed the Korsmeyer-Peppas kinetic model.