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Our understanding of the catalyst-free growth of single-walled carbon nanotubes by chemical vapor deposition is limited. Toward improving our knowledge base, we conducted systematic investigations into the initial preparation of C(60) fullerenes as nucleation precursors for single-wall and even double-wall carbon nanotube fabrication. The role of the dispersing media is shown to be crucial and is related to the initial fullerene cluster size. Oxygen-based groups, in particular, epoxy groups, are shown to be vital prior to actual growth. Moreover, the presence of oxygen groups during the growth phase is necessary for tube development. We also demonstrate the possibility of fabricating the tubes in crossbar configurations with bespoke crossing angles in a single synthesis step, unlike other routes which require at least two synthesis steps. The systematic studies significantly advance our understanding of the growth mechanisms involved in all-carbon catalyst-free growth of single- and double-walled carbon nanotubes.

Nanographene oxides (NGO) with well-defined sizes were produced from graphite via chemical exfoliation and separated into three different size distributions (300 nm, 200 nm, and 100 nm) using intense sonication and sucrose density gradient centrifugation. Prior to carboplatin (CP) loading, the NGO was functionalized with zero generation polyamidoamide (PAMAM) which renders improved dispersibility and stability of the nanocarrier platform in physiological media. Cell viability tests were conducted on pristine NGO samples with average widths of 200 nm and 300 nm that showed a cytotoxic effect on HeLa cancer cells and mesenchymal stem cells at low (50 mg ml À1 ) and high (100 mg ml À1 ) concentrations, while the pristine NGO sample with an average width of 100 nm revealed no significant cytotoxicity at 50 mg ml À1 , and only recorded a 10% level at 100 mg ml À1 . After functionalization with PAMAM, the carrier was found to be able to deliver carboplatin to the cancer cells, by enhancing the drug anticancer efficiency. Moreover, the carboplatin loaded NGO carrier shows no significant effect on the viability of mesenchymal stem cells (hMSCs) even at high concentration (100 mg ml À1 ).

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