双功能高极性蚕沙基复合多孔炭及新烟碱类农药可控缓释研究

In view of the problem of low drug loading and uncontrollable release rate, a novel bifunctional and polar hierarchical porous carbon (SHPC) is proposed to be used for a controlled release carrier of the neonicotinoids in this proposal. We will use silkworm feces as the main carbon precursor to prepare the SHPC pesticide carrier due to it being due to it being nontoxic, widespread, and sustainable from a kind of waste in cocoon industrial process. We will use polymers with high polar groups to modify pore and surface property of the SHPC material, and thus improve the adsorption capacity and release rate for the neonicotinoids. It is the new and the most characteristic of this proposal.This proposal puts the emphasis on the following three parts: (1) the effects of the pore structure, surface chemical properties and spatial distribution of adsorption sites of the SHPC on the adsorption phase equilibrium and dynamics of the neonicotinoids release will be investigated at the theoretical layer, (2) the preparation methods of the high polar SHPC material with high adsorption capacity and proper pesticide release rate for the neonicotinoids will be investigated at the technical layer, (3) the process of drug adsorption and release rate control of the neonicotinoids using the SHPC bifunctional carrier under natural surroundings will be investigated at the application layer. The research achievements can provide a new way for cocoon diversified utilization and some useful information for the preparation of high polar porous biocarbon with high performance for the neonicotinoids adsorption and release, which has important academic value and practical significance.

针对新烟碱类农药的载药量低和缓释速度快的问题，本项目提出利用广西蚕茧产业主要废弃物蚕沙作为吸附载药体，通过使用高含N(O)多聚物对蚕沙孔道进行修饰，研制对新烟碱类农药具有高吸附量且释放速度可控的双功能高极性复合多孔炭(SHPC)。这是本项目立项的新意和特色之处。涉及从理论层面，研究双功能SHPC复合材料孔隙结构、表面性质以及空间吸附位点对新烟碱类农药分子的吸附相平衡和吸/脱附动力学扩散性能的影响规律；从材料制备技术层面，研究和掌握SHPC复合材料的孔结构、表面性质以及空间吸附位点的调控技术，制备出对新烟碱类农药吸附容量高和释放速度可控的高极性SHPC载药材料；从应用层面，以SHPC控释材料为核心，研究自然种植环境下新烟碱类农药的控释给药过程。项目成果将为广西蚕沙资源多元化利用开辟一条新途径，同时又可为生物炭农药控释剂的工业化应用提供理论和技术支持，项目研究具有重要的科学价值和实际意义。

本项目针对新烟碱类农药载药量低、缓控释速率慢和难以被快速降解等问题，提出利用广西蚕茧产业主要废弃物蚕沙以及MOFs材料作为主要吸附载药体和催化剂，开展一系列工作。.1、以蚕沙为碳源，通过碳化活化的方式获得一系列高比表面生物炭材料，采用表面负载金属离子、阴离子和氧化改性以调控材料孔径和表面积对新烟碱类噻虫嗪分子的吸附作用力，以实现蚕沙多孔炭对农药噻虫嗪的缓控释。结果表明：蚕沙基多孔炭对噻虫嗪的吸附容量560 mg·g-1，释放动力学可分为快速持续释放过程和慢速释放过程两个过程。按照一般农作物的需药量，该吸附剂只要按照0.5 g·day-1·m2的投入量便能很好地对农作物进行长效的虫害防治（>40天）。.2、以蚕沙为碳源制备出类珊瑚状Fe基蚕沙气凝胶，并通过原位合成的方式与MIL-100(Fe)复合合成出一系列MIL(Fe)/FCA复合材料，用于对新烟碱类农药噻虫嗪的高效降解。结果表明：Fe基蚕沙气凝胶与MIL-100(Fe)复合后所形成的新的界面能对噻虫嗪降解过程中的难降解产物产生化学吸附，从而加快了噻虫嗪分子的快速矿化。.3、基于分子印迹、原位Cu桥和高稳定Fe基炭片桥连策略制备了一系列MOFs改性及复合材料Pca-MIL88(Fe)、Cu2O/MIL(Fe/Cu)和Fe-GDY@MIL(Fe)，用于对新烟碱类农药啶虫脒、噻虫啉和呋虫胺的高效降解。结果表明：分别通过印迹配体缺陷吸附强化降解、原位铜桥掺入光敏半导体Cu2O制备紧密异质结界面和高稳定Fe基石墨炔以及高导电界面C=C-Fe|O cluster的构筑，能使最终合成的催化剂具有更高的催化稳定性，对新烟碱类农药农药的降解速率提升6-10倍，且在60 min内实现完全降解，在120 min内被完全矿化。