Materials Research Institute and Department of Materials Science & Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
Department of Materials Science and Engineering and A.J. Drexel Nanomaterials Institute, Drexel University, Philadelphia, PA, 19104, USA.
Adv Mater. 2018 Aug;30(32):e1801846. doi: 10.1002/adma.201801846. Epub 2018 Jun 26.
Nanocomposites containing 2D materials have attracted much attention due to their potential for enhancing electrical, magnetic, optical, mechanical, and thermal properties. However, it has been a challenge to integrate 2D materials into ceramic matrices due to interdiffusion and chemical reactions at high temperatures. A recently reported sintering technique, the cold sintering process (CSP), which densifies ceramics with the assistance of transient aqueous solutions, provides a means to circumvent the aforementioned problems. The efficacious co-sintering of Ti C T (MXene), a 2D transition carbide, with ZnO, an oxide matrix, is reported. Using CSP, the ZnO-Ti C T nanocomposites can be sintered to 92-98% of the theoretical density at 300 °C, while avoiding oxidation or interdiffusion and showing homogeneous distribution of the 2D materials along the ZnO grain boundaries. The electrical conductivity is improved by 1-2 orders of magnitude due to the addition of up to 5 wt% MXene. The hardness and elastic modulus show an increase of 40-50% with 0.5 wt% MXene, and over 150% with 5 wt% of MXene. The successful densification of ZnO-MXene nanocomposite demonstrates that the cold sintering of ceramics with 2D materials is a promising processing route for designing new nanocomposites with a diverse range of applications.
由于二维（2D）材料具有增强电、磁、光、机械和热性能的潜力，因此含有 2D 材料的纳米复合材料引起了广泛关注。然而，由于高温下的互扩散和化学反应，将 2D 材料集成到陶瓷基体中一直是一个挑战。最近报道的一种烧结技术——冷烧结工艺（CSP），在瞬时水溶液的辅助下使陶瓷致密化，为解决上述问题提供了一种途径。本研究报道了一种 2D 过渡碳化物 TiCT（MXene）与 ZnO 氧化物基体的有效共烧结。使用 CSP，在 300°C 下可以将 ZnO-TiCT纳米复合材料烧结至理论密度的 92-98%，同时避免了氧化或互扩散，并显示出 2D 材料沿 ZnO 晶界的均匀分布。由于添加了高达 5wt%的 MXene，电导率提高了 1-2 个数量级。随着 0.5wt%MXene 的添加，硬度和弹性模量分别增加了 40-50%，而添加 5wt%的 MXene，硬度和弹性模量增加了 150%以上。成功致密化 ZnO-MXene 纳米复合材料证明了使用 2D 材料冷烧结陶瓷是设计具有广泛应用的新型纳米复合材料的一种很有前途的加工方法。
