0.1 wt.% of as-received nanodiamonds to polydimethylsiloxane. According to the viscosity measurements of the melts, nanodiamonds alter the conformation of polydimethylsiloxane macromolecules, resulting in better mechanical performance of the composite173 . This is an example of interphase-mediated property change. In another study, increased Young’s modulus and glass transition temperature (Tg) were aquired due to the addition of 0.25 wt.% of as-received ND to polyurethane-2-hydroxyethylmethacrylate (PU-PHEMA). These development, in this case is explained by a reaction between nanodiamonds – COOH groups and the isocyanate groups formed during the polymerization of PU-PHEMA, give an example of interface-mediated property change. In most situations, nevertheless, refinement of nanodiamonds is required to achieve the enhanced performance in composites174. To increase the affinity of nanodiamonds to polyethylene (a polymer consisting of a –CH2– backbone with no side chains) alkyl groups of inconsistant length were grafted to nanodiamonds. DSC measurements carry out on these polyethylene– nanodiamonds composites indicate the increased crystallinity, as well as higher crystallization and melting temperatures of the nanocomposites with increasing nanodiamonds content and alkyl chain length. In parallel, 2.5 times higher Young’s modulus and 4.5 times higher hardness were also evaluate for these composites by AFM, with a larger increase correlate with longer grafted alkyl chains. These enhancement were elucidate by a significant increase in crystallinity of the polymer — an instance of how a proper nanodiamonds surface functionalization can be used to design an interphase175. Electrospun PAN and PA11 nanofibers with high contents of nanodiamonds show dramatically modified mechanical properties. In this study, nanodiamonds was purified by air oxidation, followed by HCl treatment to minimize the content of metals and to hydrolyze the anhydrides and lactones formed on nanodiamonds surface during oxidation in air and in order to maximize the number of carboxylic groups on the surface, which was confirmed by FTIR134.
The electrospun fiber mats were then melted, yielding uniform nanodiamonds –polymer films on the substrate. A 400% increase in Young’s modulus and a 200% increase in hardness were