One step synthesis, characterization of F127-Mn -chlorpyrifos mesoporous silica for sustained release system with pH sensitivity
One step synthesis, characterization of F127-Mn -chlorpyrifos mesoporous silica for sustained release system with pH sensitivity
复制标题
pH敏感性缓释系统F127-Mn-毒死蜱介孔二氧化硅的一步合成及表征
DOI：
10.1080/10601325.2018.1504612
复制
发表时间：
2019
影响因子：
2.5
通讯作者：
Xu Hua
中科院分区：
文献类型：
--
作者：
Chen Huayao;Hu Junlong;Zhou Hongjun;Zhou Xinhua;Xu Hua
以三嵌段共聚物F127(分子式（EO）106（PO)70(EO)106）为模板，TMOS为硅源。在酸性水溶液中引入毒死蜱（CH）和金属离子（Mn+）进行水解，一步构建“F127-Mn+-CH”配位结构。通过改变制备过程中加入的酸性水溶液的组成，制备了不同的缓释体系。表征结果证实了金属离子与介孔二氧化硅、毒死蜱之间存在配位相互作用。还证明了缓释系统中所载毒死蜱以无定形形态存在。通过SEM和TEM观察，材料的孔呈面心笼型立方结构，具有与SBA-16相似的IM-3M对称，符合n2吸附等温线。合成体系在缓释过程中表现出显著的pH敏感性，表明该缓释体系在中性环境中可以很好地储存，在酸性或碱性环境中喷洒到土壤中可以很好地活化。它们的缓释曲线在中性环境下符合Korsmeyer-Peppas方程，在酸性或碱性环境下符合Higuchi方程。
The triblock copolymer F127 (molecular formula (EO)106(PO)70(EO)106) was adopted as template with TMOS as the silica source. They were hydrolyzed by acidic aqueous solution in which chlorpyrifos (CH) and metal ions (Mn+) were introduced to the products to construct "F127-Mn+-CH" coordination structure in one step. Different sustained release systems were prepared through changing the composition of acidic aqueous solution added during the preparation. The characterization results confirmed the coordination interaction existing among metal ions, mesoporous silica and chlorpyrifos. It was also proved that the chlorpyrifos loaded in the sustained release system existed as amorphous state. According to SEM and TEM observation, the pore of the material presented as face-centered cage-type cubic structure with IM-3M symmetry similar to SBA-16 which is in accordance with N2adsorption isotherms. The as-synthesized system showed significant pH sensitivity in the sustained release process indicating that the sustained release system can be well stored in neutral environment and activated while sprayed into earth in acid or basic environment. Their sustained release curves can be described by Korsmeyer-Peppas equation in neutral while accords with Higuchi under acid or basic environment.