航空用金属/还原氧化石墨烯负载织物超临界流体制备及其电磁屏蔽性能研究

Metal coated fabric is a kind of promising electromagnetic shielding materials in aviation field because it possesses the characteristics such as flexibility, folding, light weight and air permeability. However, there are a few conductive circuits in the metal coated fabric. In addition, conductive circuits in the metal coated fabric are easily broken when it is used. In addition, there is weak adhesion between metal coating and fabric. In this project, metals (silver, copper or nickel)/reduced graphene oxide nanocomposites will be deposited on glass fiber fabric through chemical reduction method in supercritical carbon dioxide fluid. The fabric will be modified with two-dimensional graphene nanosheets before metal coating in order to increase electron transfer paths, therefore improve electromagnetic shielding effectiveness of the fabric. The effects of process parameters of plasma pretreatment and supercritical fluid treatment on the interfacial bonding properties between the coating and the fabric will be investigated. Interface formation mechanism between the coating and the fabric will be discussed. Correlation mechanism of condition of deposition, microstructure and properties will be clarified. Growth mechanism metals/reduce graphene oxide nanocomposite coatings will be explored. Microstructures and properties will be controlled. This project will provide a new idea for the design of electromagnetic shielding fabric, and lay a theoretical foundation for the development and application of light, thin and flexible aviation electromagnetic shielding materials with high shielding effectiveness in wide frequency.

金属涂覆织物具有柔韧、可折叠、质轻、透气等特性，成为极有前途的航空电磁屏蔽材料。针对其在使用过程中存在导电通道少且易断开，涂层与织物的界面结合弱的问题，本项目拟开展采用化学还原法在超临界流体中制备金属（银、铜或镍）/还原氧化石墨烯（M/rGO）负载玻璃纤维织物的研究，利用石墨烯独特的片状结构增加导电通道，提高电磁屏蔽效能。考察低温等离子体改性处理和超临界流体工艺参数对涂层与织物界面结合性能的影响规律，探讨界面结合形成机理。探索M/rGO复合涂层沉积条件-微观结构-电磁屏蔽性能的内在联系，揭示M/rGO复合涂层的生长机理，调控微观结构及电磁屏蔽性能。本项目为电磁屏蔽织物提供新的设计思路，同时也为航空电磁屏蔽材料向“轻、薄、柔、宽、强”发展奠定理论基础。

项目针对航空用电磁屏蔽材料在使用过程中存在导电通道少且易断开，涂层与织物的界面结合弱的问题，项目采用聚多巴胺(PDA)前处理玻璃纤维织物，还原氧化石墨烯(RGO)修饰后化学还原法镀覆镍，获得的Ni/RGO-PDA涂覆织物电加热温度达到168℃。此外，Ni/RGO-PDA涂覆织物的电磁屏蔽效能（EMI SE）在2-18GHz范围内达到88dB，甚至在腐蚀后仍能保持。RGO的引入对导电网络的建立起到了积极的作用，使金属导电纤维中纤维与纤维交界处将“点连接”转化为金属/RGO的“面连接”，增加导电通道，且避免使用时纤维滑移导致导电通道断开，提高导电性和电磁屏蔽性能。获得的织物具有优异导电性、电加热、电磁屏蔽性能的Ni/RGO涂覆织物。.成功地将牛血清白蛋白(BSA)前处理玻璃纤维织物，涂覆Ni/RGO在织物上，BSA和RGO表现出良好的协同作用，促进了Ni的生长和导电网络的形成。所制备的BSA/RGO-Ni涂覆织物EMI SE 达到72dB。涂覆织物还具有优良的牢度、导电性、柔韧性、电加热、光热和抗菌性能。对织物BSA前处理改性提高了金属镍/RGO与织物之间结合力。.将壳聚糖(CTS)前处理后,涂覆Cu/RGO到玻璃纤维织物上，Cu/RGO-CTS涂覆织物表现出 12.6mΩ sq-1 的低方块电阻，电导率高达8589.3S/cm。在 2 GHz-18 GHz 的频率范围内具有高电磁屏蔽性能（93.6dB），并且在500次弯折试验和超声洗涤处理后仍具有极低的方块电阻和高电磁屏蔽性能。Cu/RGO-CTS涂覆织物的导热性得到提高，接触角为127.9°，对金黄色葡萄球菌和大肠杆菌具有优异的抗菌性能。.通过在超临界CO2流体中处理三氨丙基三甲氧基硅烷对玻璃纤维进行前处理再化学镀镍。玻璃纤维表面镀层颗粒致密均匀，超临界CO2辅助处理后镀镍所得镀层电磁屏蔽效能提高，提高了金属镀层的均匀性，及镀层与织物之间结合力。.本项目的实施，获得的金属/RGO涂覆玻璃纤维织物，具有优异的导电性、电磁屏蔽、电加热、导热、拒水、抗菌等多功能性，将有望在航空电磁屏蔽材料及抗菌材料、探冰和除冰中具有良好的应用前景。