Shajari Shaghayegh, Rajabian Mahmoud, Kamkar Milad, Sudak Les Jozef, Sundararaj Uttandaraman
Center for Applied Polymer and Nanotechnology (CAPNA), Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada.
Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada.
Soft Matter. 2022 Oct 12;18(39):7537-7549. doi: 10.1039/d2sm00838f.
The use of fluoroelastomer nanocomposites for flexible electronics is increasing due to their high deformability and recoverability. Often, a high amount of conductive nanofillers and crosslinking agents is required to improve their mechanical performance, which unfavorably affects the electrical percolation threshold and conductivity due to dispersion issues. Herein, we developed a unique solution mixing (SM) technique by a fine-tuned formulation to obtain well-dispersed carbon nanotubes (CNTs) in fluoroelastomer FKM for both low and high CNT concentrations (0.2 phr and 3 phr). Effective nano-network formation was confirmed by transmission electron microscopy (TEM) and oscillatory shear rheological tests. Compared to the melt mixing (MM) process, the stretchability of neat FKM improves to 503% in the SM process 430% in the MM process. The electrical conductivity of the SM samples percolates at significantly lower filler concentrations (, 0.35 phr in SM 0.45 phr in MM) with a maximum value of 7 × 10 S cm for 3 phr. Overall, the 2 phr CNT/FKM nanocomposite fabricated by SM exceeds those of carbon-based FKM conductors reported in the literature. The enhanced electrical and mechanical properties include an electrical conductivity of 3 × 10 S cm, a strain-to-failure of 300%, and a tensile strength at break of 12 MPa. This process is a promising approach for fabricating fluoroelastomer nanocomposites of a mechanically robust and stable stretchable conductor for various wearable electronic devices.
由于其高可变形性和可恢复性，含氟弹性体纳米复合材料在柔性电子领域的应用正在增加。通常，需要大量的导电纳米填料和交联剂来改善其机械性能，但由于分散问题，这会对电渗流阈值和导电性产生不利影响。在此，我们通过微调配方开发了一种独特的溶液混合（SM）技术，以在含氟弹性体FKM中获得低浓度和高浓度（0.2 phr和3 phr）的碳纳米管（CNT）均匀分散体。通过透射电子显微镜（TEM）和振荡剪切流变测试证实了有效的纳米网络形成。与熔融混合（MM）工艺相比，纯FKM在SM工艺中的拉伸性提高到503%，在MM工艺中为430%。SM样品的电导率在显著更低的填料浓度下（SM中为0.35 phr，MM中为0.45 phr）达到渗流，3 phr时的最大值为7×10 S/cm。总体而言，通过SM制备的2 phr CNT/FKM纳米复合材料超过了文献中报道的碳基FKM导体。增强的电学和力学性能包括电导率为3×10 S/cm、断裂应变率为300%以及断裂拉伸强度为12 MPa。该工艺是制备用于各种可穿戴电子设备的机械坚固且稳定的可拉伸导体的含氟弹性体纳米复合材料的一种有前景的方法。
