Ambient mechanochemical solid-state reactions of carbon nanotubes and their reactions via covalent coordinate bond in solution.

[摘要] In its first part, this thesis deals with ambient mechanochemical solid-statereactions of differently functionalized multiple walled carbon nanotubes(MWCNTs) while in its second part it investigates the cross-linking reactions ofCNTs in solution via covalent coordinate bonds with transitions metals andcarboxylate groups decorating their surfaces. In the first part a series ofmechanochemical reactions involving different reactive functionalities on theCNTs such as COOH/OH, COOH/NH2 and COCl/OH were performed. The solid-state unzipping of CNTs leading to graphene formation was confirmed usingspectroscopic, thermal and electron microscopy techniques. The non-grapheme products were established using in-situ quadruple mass spectroscopy. The experimental results were confirmed by theoretical simulation calculations using the 'hot spots’ protocol. The kinetics of the reaction between MWCNT-COOH and MWCNT-OH was monitored using variable temperature Raman spectroscopy.The low activation energy was discussed in terms of hydrogen bond mediatedproton transfer mechanism. The second part involves the reaction of MWCNTIICOOH with Zn (II) and Cu (II) to form CNT metal-organic frame (MOFs)products that were tested for their effective use as counter-electrodes in dyes sensitized solar cells (DSSC). The thesis concludes by the study of the room temperature reaction between the functionalized graphenes, GOH and G'-COOH followed by the application of compressive loads. The 3D solid graphene pellet product (~0.6gm/cc) is conductive and reflective with a 35MPa ultimate strength as compared to 10MPa strength of graphite electrode (~2.2gm/cc).

[发布机构] Rice University

[效力级别] Carbon