Nanofibers general properties

Nanofibers generally have a moderately higher tensile strength and modulus than the bulk or film material due to the inner orientation of polymer molecules. Figure 10.28 [111] shows the Tlmoduli of submicron fibers as a hyperbolic function of the fiber radius as a demonstration of the possibilities for the nanofibers. As fiber diameters are decreased below 300 nm, tensile properties also increase notably [110] and the nano-effect takes place. 

In this Chapter, we report on some examples of nanocomposites with CNTs, highlighting a meshwork of interactions between the mechanical, electrical and optical properties of CNTs and the interface with the polymer matrix. CNTs are considered ideal materials for reinforcing fibers due to their exceptional mechanical properties. Functionalization of CNTs seems to be the most effective way to incorporate these nanofibers into the polymer matrix. It is generally accepted that the fabrication of high-performance nanotube-polymer composite depends on the efficient load transfer from the host matrix to the tubes. If the percentage of nano-reinforcements is very low or if it is well-dispersed, there are more strong interfaces that slow down the progress of a crack. ... 

Nanofibers are generally produced from polymers which deviate from the conventional fiber-forming type of materials, and so it may be apprehended that the scope of use of these nanofibers may be far beyond the use of standard fibers, microfibers or fibrous materials. The bottom-up method modifies the fibers at a molecular or supramolecular level of fragmentation and transforms them into a polymer/polymer blend before the formation of fibers, which gives them new, specific properties favorable from a practical point of view. Nanocellulose fibers possess optimized product properties and target-directed development, quantification of eco-efficiency and sustainability factors. 

So far, we have discussed the properties of soft shape-memory materials as a function of their nanoarchitectonics. At the same time, material microarchitectonics, also known as material forms, should be tailored to specific applications as SME in material was generally treated with bulk phenomenon. As such, designing an SMP object at the submicron to microscale is challenging. In particular, the synthesis of well-regulated nanoscale structures built up as meso- or macroscopic materials remains challenging. Recent rapid evolution in SMPs has been developed in efforts to meet various requirements in diverse potential applications. As a result, not only traditional film, tube, and sponge (foam) forms, but also microparticles, surface as well as micro/nanofiber that exhibit SMEs at mesoscopic to microscopic scales, have attracted much attention (Fig. 5.2.4). 

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