Feng Jiachang, Dou Jianpeng, Zhang Youzhen, Wu Zidan, Yin Dongxue, Wu Wenfu
Department of Biological and Agricultural Engineering, Jilin University, Changchun 130000, China.
Polymers (Basel). 2020 Mar 3;12(3):547. doi: 10.3390/polym12030547.
Starch, alginate, and poly(-isopropylacrylamide) (PNIPAAm) were combined to prepare a semi-interpenetrating network (IPN) hydrogel with temperature sensitivity. Calcium chloride was used as cross-linking agent, the non-toxigenic spores were successfully encapsulated as biocontrol agents by the method of ionic gelation. Characterization of the hydrogel was performed by Fourier-transform infrared spectroscopy (FTIR), scanning electron micrograph (SEM), and thermogravimetry analysis (TGA). Formulation characteristics, such as entrapment efficiency, beads size, swelling behavior, and rheological properties were evaluated. The optical and rheological measurements indicated that the lower critical solution temperature (LCST) of the samples was about 29-30 °C. TGA results demonstrated that the addition of kaolin could improve the thermal stability of the semi-IPN hydrogel. Morphological analysis showed a porous honeycomb structure on the surface of the beads. According to the release properties of the beads, the semi-IPN hydrogel beads containing kaolin not only have the effect of slow release before peanut flowering, but they also can rapidly release biocontrol agents after flowering begins. The early flowering stage of the peanut is the critical moment to apply biocontrol agents. Temperature-sensitive hydrogel beads containing kaolin could be considered as carriers of biocontrol agents for the control of aflatoxin in peanuts.
将淀粉、海藻酸盐和聚（N-异丙基丙烯酰胺）（PNIPAAm）结合起来制备具有温度敏感性的半互穿网络（IPN）水凝胶。使用氯化钙作为交联剂，通过离子凝胶法成功将无毒孢子作为生物防治剂进行包封。通过傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）和热重分析（TGA）对水凝胶进行表征。评估了包封效率、珠粒大小、溶胀行为和流变性质等制剂特性。光学和流变测量表明样品的低临界溶液温度（LCST）约为29 - 30℃。TGA结果表明添加高岭土可以提高半IPN水凝胶的热稳定性。形态分析显示珠粒表面具有多孔蜂窝结构。根据珠粒的释放特性，含高岭土的半IPN水凝胶珠粒不仅在花生开花前具有缓释作用，而且在开花开始后还能快速释放生物防治剂。花生的早期开花阶段是施用生物防治剂的关键时刻。含高岭土的温度敏感水凝胶珠粒可被视为用于控制花生中黄曲霉毒素的生物防治剂载体。
