TAILORING THE INTERPHASE IN A HIERARCHICAL COMPOSITE BASED ON CARBON NANOTUBE FIBERS

Xiao-Meng Sui ¹ Israel Greenfeld ¹ Mayank Tiwari ² Lin Yang ³ Hagai Cohen ⁴ XiaoHua Zhang ⁵ QinWen Li ⁵ H. Daniel Wagner ¹

¹Materials and Interfaces, Weizmann Institute of Science, Rehovot, Israel
²Department of Mechanical Engineering, Indian Institute of Technology Ropar, Punjab, India
³Mechanical and Mechatronic Engineering, University of Sydney, Sydney, Australia
⁴Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
⁵Division of Nano-devices & Materials, Suzhou Institute of Nano-Tech and Nano-Bionics, Suzhou, China

As a arising reinforcing material, carbon nanotube fibers (CNTFs) have drawn a great deal of attention due to the mechanical and electrical properties, as well as the flexibility. [1, 2] The CNTF is composed of thousands of millions of carbon nanotubes, with abundant interface between the CNTs and between the CNTs and the matrix. Unlike the traditional reinforcing fibers, matrix has the possibility to penetrate the voids between the CNTs in a CNTF to form an interphase. In our previous work, the amount of interphase is controlled by applying different level of densification treatments to the CNTFs prior to their embedding in an epoxy matrix.[3] A continuously monitored fragmentation test shows that the apparent interfacial shear strength can be doubled by the treatment.

Due to the formation of the interphase, one would expect the changes in the mechanical properties of the CNTF after the infiltration of polymer matrices. In this work, we will focus on the mechanical behaviour of CNTFs with different arrangement (aligned or entangled), before and after the surface treated with various polymer (thermoplastic or thermoset). Then a hierarchical composite based on the treated CNTFs was prepared, and the mechanical properties were evaluated by tensile tests. It is shown that the CNTF has a great potential to become the next generation reinforcing material, and the mechanical properties of the CNTF as well as the composites based on CNTF can be tailored.

References

[1] Li YL, et.al. Science 2004, 304(5668): 276-278.

[2] Jiang KL, et.al. Nature 2002, 419(6909): 801-801.

[3] Sui XM, et.al. Compos Sci Technol, 137, 2016, p. 35-43.