Lee Seongeun, Yang Eunyeong, Lee Juyun, Ko Tae Yun, Kim Seon Joon
Extreme Materials Research Center, Korea Institute of Science and Technology, Seoul, 02792, South Korea.
Department of Materials Science and Engineering, Korea University, Seoul, 02841, South Korea.
Adv Mater. 2025 Jun 23:e2502440. doi: 10.1002/adma.202502440.
MXenes have garnered significant interest for use in conductive inks, processed either in aqueous solutions or organic solvents following surface modification. However, maintaining their electrical conductivity during dispersion across a broad range of solvents, particularly non-polar ones, has proven challenging, limiting their potential applications as conductive dispersions. Here, a straightforward method is presented for synthesizing electrically conductive and amphiphilic MXenes via surface modification. Alkoxide groups, such as ethoxide and phenoxide, are covalently attached to TiCT MXene surfaces using a nucleophilic substitution mechanism, enabling stable dispersion in both polar and non-polar solvents. These alkoxide-functionalized MXenes exhibited an electrical conductivity of up to 2,700 S cm and dispersibility in non-polar solvents like toluene, surpassing previous modification approaches. Additionally, they demonstrate enhanced oxidative stability and excellent coating performance on substrates with varied surface energies. The electromagnetic interference (EMI) shielding films fabricated with these MXenes exhibited some of the highest performance among surface-modified MXenes and their composites, achieving shielding efficiency comparable to that of pristine TiCT MXene films, while offering significantly improved durability. These findings may contribute to the development of improved processing approaches for MXenes, paving the way for advancements in printable and wearable electronics while addressing key challenges in MXene processing and modification.
MXenes因可用于导电油墨而备受关注，在经过表面改性后可在水溶液或有机溶剂中进行加工。然而，事实证明，在广泛的溶剂（尤其是非极性溶剂）中分散时保持其导电性具有挑战性，这限制了它们作为导电分散体的潜在应用。在此，我们提出了一种通过表面改性合成导电且两亲性MXenes的简单方法。使用亲核取代机制将醇盐基团（如乙氧基和苯氧基）共价连接到TiCT MXene表面，使其能够在极性和非极性溶剂中稳定分散。这些醇盐功能化的MXenes表现出高达2700 S/cm的电导率，并能在甲苯等非极性溶剂中分散，超过了以往的改性方法。此外，它们还表现出增强的氧化稳定性以及在具有不同表面能的基材上优异的涂层性能。用这些MXenes制备的电磁干扰（EMI）屏蔽膜在表面改性的MXenes及其复合材料中表现出一些最高的性能，屏蔽效率与原始TiCT MXene膜相当，同时耐久性显著提高。这些发现可能有助于开发改进的MXenes加工方法，为可印刷和可穿戴电子产品的发展铺平道路，同时解决MXenes加工和改性中的关键挑战。
