Nanofiber stability

A different method for evaluating the stabilization extent is to study thermal behavior of untreated and stabilized PAN nanofibers using DSC analysis [19] in certain heating rate (in this study 10°C/min). As mentioned, the DSC curve of PAN nanofibers has two exothermic peaks, the first one is related to the cyclization reactions and the latter confirms oxidation processes. Thermally stabilized nanofiber shows wider exothermic peaks with lower heights. Figure 3 shows DSC curves of nanofibers stabilized in different conditions. The conditions (times and temperatures) are selected according to higher calculated EOR. 

The potential of carbon nanomaterials for the Fischer-Tropsch synthesis was investigated by employing three different nanomaterials as catalyst supports. Herringbone (HB) and platelet (PL) type nanofibers as well as multiwalled (MW) nanotubes were examined in terms of stability, activity, and selectivity for Fischer-Tropsch synthesis (FTS). 

It has been observed that cobalt may undergo large-scale reconstruction under a synthesis gas environment.27 Reconstruction is a thermodynamically driven process that results in the stabilization of less reactive surfaces. Recent molecular modeling calculations have shown that atomic carbon can induce the clock reconstruction of an fee cobalt (100) surface.28 It has also been postulated and shown with in situ x-ray adsorption spectroscopy (XAS) on cobalt supported on carbon nanofibers that small particles (<6 nm) undergo a reconstruction during FTS that can result in decreased activity.29... 

The wall of the BASYC tubes consists of BC loaded with water in the nanofiber network up to 99%. The hollow space of the material transports water, monovalent ions and small molecules, but not biopolymers or corpuscular blood constituents. The stored water not only stabilizes the cellulose network, but also contributes to the tissue- and hemocompatibility of the nanocellulose device. 

R. Wood, and R. Wetherbee. 2008. Divalent cations stabilize the aggregation of sulfated glycoproteins in the adhesive nanofibers of the biofouling diatom Toxarium undulatum, Soft Matter, doi 10.1039/b715455k. 

Reference experiments show that non-coated [Pt(NH3)4](HC03)2 nanofibers are not stable over long periods. They tend to agglomerate to non-regular structures. Only the rigid Si02 layers, forming the silica walls, stabilize the needle-like structure. 

Among conductive plastics, polyaniline has attracted much interest because of its environmental stability and its tunable electrical properties. Composite materials consisting of polyaniline nanofibers... 

Fig. 1 Nanofiber modification strategies. In step 1, many polymer and solution properties will affect the size, stability, and reactivity of nanofihers in the final mat, including multipolymer blending strategies, incorporation of soluble factors/drugs/spheres, and/or loading concentrations. In step 2, during spinning, the ambient conditions and voltage applied must be tailored for each polymer source and can be dictated by the nature of the collector or the number of jets employed simultaneously. In step 5, the as-spun mat can be modified by various crosslinking techniques to stabilize the polymers or, in the case of soluble or carrier polymers, these can be leached out by subsequent liquid washes...

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