磁流变“石墨烯墨水”的可控制备及其磁场辅助熔融挤出3D打印

3D printed graphene aerogel have attracted lots of interests due to be controlled structure,low density and ultrafine, high conductivity and good mechanical properties for wild application in energy storage, sensors, catalyzer and so on. However, Three-dimensional structure of graphene aerogel showed still the low resolution. The problem must be addressed before its wild applications in engineering. Therefore, a new 3D inks------magnetorheological graphene inks and 3D printed technology based on magnetic assistance was developed for design and preparing three-dimensional graphene aerogel with high resolution in this project. The main contents novels of this project are shown in following. Firstly, a model of “graphene ink” based on Artificial Neural Network will be proposed for design of ink’ components, and the relationship between components and rheological properties are presented in detail. Secondly, the novel magnetorheological “graphene ink” is prepared by the ions liquid exfoliation-swelling method, in which it has high shear thinning and magnetorheological effect. Finally, the 3D printed process and optimization of 3D printed parameters under magnetic field is investigated by the 3D printed equipment with magnetic field. And the relationship between structure, 3D printed parameters and resolution are investigated in detail. These studies were very important for preparing three-dimensional graphene based electrode with high resolution.

3D打印石墨烯气凝胶因为结构可控、密度低、高压缩性和高电导率等特性，在能量存储、传感器和催化剂等领域具有广泛应用前景。然而当前3D打印石墨烯气凝胶还存在结构分辨率偏低的问题，严重限制了其工程化应用。为此，本项目提出一种新型3D打印“墨水”------磁流变“石墨烯墨水”及其磁场辅助熔融挤出3D打印技术。具体研究内容和创新点包括：首先，基于人工神经网络和MATLAB有限元构建可计算分析“墨水”的配方-外场条件-性能之间关系的模型和数学函数；其次采用离子液体直接分散-溶胀法可控制备由高导电率单层石墨烯、纳米磁性粒子和离子液体组成的磁流变“石墨烯墨水”；最后利用自主改装的3D打印设备，结合多场耦合磁流变仪，分析“墨水”的配方对其结构和性能的影响规律，为“石墨烯墨水”配方设计和性能优化，并最终实现高分辨率3D打印提供理论依据和指导。

针对目前3D打印石墨烯材料存在3D打印性能差，及3D打印结构稳定性偏低问题，本项目提出一种新型3D打印“墨水”及其磁场辅助熔融挤出3D打印技术。具体研究内容包括：(1)“石墨烯墨水”的配方设计， 基于人工神经网络构建应非线性回归问题的反向传播网络模型，并利用所建网络模型，结合MATLAB有限元分析磁流变“石墨烯墨水”的配方-外场条件-动态模量之间关系，并根据下述一系列的实验结果，对建立的网络模型进行验证和修正。(2) “石墨烯墨水”的可控制备， 采用气泡辅助-液相机械剥离法制备“石墨烯墨水”，研究“墨水”的配方和制备工艺条件对“石墨烯墨水”的微观结构和性能。(3) 3D打印电极材料参数优化及电化学性能，自主搭建3D打印平台，探索石墨烯墨水组成结构和打印结构对其电化学性能的影响规律。.根据本项目研究计划，设计研制一种机械挤出式凝胶型3D打印设备，可打印高固含量和模量的凝胶材料，确保了3D打印结构的稳定性和精度；同时，开发了一种高品质石墨烯凝胶的新型制备方法------气泡辅助－液相机械剥离法，该方法相对传统化学还原法，不仅获得获得石墨烯缺陷少，且制备工艺更简单，相对传统液相机械剥离法，石墨烯剥离效率高，该高品质石墨烯凝胶制得电极具有优异的电化学储能性能，面积电容达到35~57 mF/cm2，是通过喷墨或丝网印刷制造微型超级电容器中最高的。另外，开发出一种新型石墨烯凝胶体系，不仅适合3D打印，可以打印高固含量（80%）凝胶，同时打印分辨率达到0.1mm，且可方便掺杂其它活性物质，进一步提高石墨烯电极材料的性能。这些研究结果，为加速石墨烯及相关产品的产业化提供理论依据和方法。