Fabrication of conductive elastomer of MXene/natural rubber composite for medical device application

Nowadays, conductive materials have attracted great attention in variety of application such as, electromagnetic interference (EMI) shielding, sensors, energy, and biomedical devices. MXene is a novel family of two-dimensional (2D) transition metal carbides or nitrides as conductive material which has remarkable properties. In this research, MXene was successfully synthesized via chemical etching method. Further, it was also employed to generate single-layer MXene or exfoliated MXene (E-MXene) by immersing in acetone mixture (60%) combined with sonication. The result showed XRD pattern of MXene reveals the characteristic peak at 2θ ≈ 5.4o and E-MXene shift peak of 2θ ≈ 5.8o corresponding to their intelayer spacing. The produced conductive elastomers were based on pre-vulcanized natural rubber (PNR) and two types of conductive fillers were investigated, MXene and E-MXene. Fabrication of composite film was prepared by a facile a latex blending method and use glutaraldehyde (GA) as a crosslink agent. The effect of both MXene and E-MXene concentrations on the film formation and films’ properties, i.e electrical conductivity, mechanical properties with strainability, scanning electron microscope-energy dispersive X-ray (SEM-EDX), thermogravimetric analysis (TGA), and fourier transform infrared spectroscopy (FTIR) was investigated. With proper E-MXene nanosheets concentration (16.67%, namely E-MXene/PNR-3) with GA, the electrical conductivity with strainability and mechanical properties of the composite film were significantly improved. The as-prepared composite film has potential for applying as conductive elastomer in biomedical devices application.

当下，导电材料在电磁干扰（EMI）屏蔽、传感器、能源及生物医学器件等诸多应用领域中受到广泛关注。MXene是一类新型二维（2D）过渡金属碳化物或氮化物基导电材料，具备优异的综合性能。本研究通过化学刻蚀法成功制备了MXene；进一步将其浸入60%丙酮混合液并结合超声处理，得到单层MXene，即剥离型MXene（E-MXene）。研究结果显示，MXene的X射线衍射（XRD）图谱在2θ≈5.4°处存在特征峰，而E-MXene的特征峰偏移至2θ≈5.8°，该变化与其层间距的改变相对应。本研究以预硫化天然橡胶（PNR）为基底制备导电弹性体，并选取MXene与E-MXene两种导电填料开展研究。复合薄膜的制备采用简便的胶乳共混法，以戊二醛（GA）作为交联剂。本研究探究了MXene与E-MXene的添加浓度对复合薄膜成膜性能及各项薄膜特性的影响，包括导电性、兼具应变响应能力的力学性能，并通过扫描电子显微镜-能谱仪（SEM-EDX）、热重分析（TGA）与傅里叶变换红外光谱（FTIR）对样品进行表征。当添加16.67%的E-MXene纳米片（即E-MXene/PNR-3组）并搭配戊二醛时，复合薄膜的导电性、应变响应能力与力学性能均得到显著提升。所制备的复合薄膜具备作为导电弹性体应用于生物医学器件领域的潜力。