Untersuchungen am Graphitoxid. VI. Betrachtungen zur Struktur des Graphitoxids

Abstract

Es wird eine Übersicht über die Ergebnisse der Bestimmungen funktioneller Gruppen und der IR‐spektroskopischen Befunde bei auf verschiedene Weise hergestellten Graphitoxid(GO)‐Präparaten gegeben. Auf Grund dieser Befunde wird ein neues Strukturmodell entworfen, das keinen Äthersauerstoff enthält und gewellte Kohlenstoffnetze aufweist, in denen periodisch CC‐Bindungen unterbrochen sind. Das Modell enthält Hydroxylgruppen und Carbonylgruppen in verschiedener Umgebung. Elektronenbeugung und Adsorptionsversuche weisen darauf hin, daß die GO‐Schichten mosaikartig aus derart geordneten Bereichen bei verschiedener Orientierung ihrer a‐Achsen bestehen. Diese Bereiche sind durch weniger geordnete Übergangszonen miteinander verbunden. Dadurch erhält GO Molekularsieb‐Eigenschaften. In den GO‐Teilchen weisen die Schichten keine turbostratische Unordnung auf; sie sind ohne gegenseitige Verdrehung nur in a‐Richtung regellos gegeneinander verschoben.

Intercalation and Stitching of Graphite Oxide with Diaminoalkanes

“…The Scholz-Boehm GO model 5 (recently advocated by Szabo et al 34 ) contains sp 2 ribbons with a rigid quinoidal structure (similar to R1 in Figure 5a). Since these ribbons are the narrowest possible, the double bonds are all isolated.…”

“…2 Both from a practical and a fundamental perspective, it is important to understand the nature of disorder in GO and FGSs. Despite the fact that GO has been known since 1859 and several GO models [3][4][5][6][7] have been suggested, its detailed structure is still under debate, and a definitive atomistic model is not yet available. For a detailed understanding of mechanical and electronic properties of the FGS, we would like to know (i) if the honeycomb carbon network of graphene remains essentially intact or if rings other than sixmembered rings and other topological defects appear in the oxidation process; (ii) if the epoxy and hydroxyl groups are distributed randomly, if they retain some amount of short/ intermediate range order, or if they tend to cluster, creating patches of more strongly oxidized graphene intermixed with patches of near-perfect graphene; and (iii) if a portion of the defect anneals during the thermal treatment process.…”

“…3 Recently much attention has been focused on intercalation of difunctional reagents since they can lead to bridged or pillared nanostructures with potential applications as catalytic supports, selective adsorbents, and molecular vessels. [4][5][6] Depending on the nature of the host and the intercalant, pillaring and stitching can be accomplished by three methods: (i) ion exchange between a difunctional ionic intercalant and the native ions of the host; (ii) exfoliation of the host followed by reaction with the difunctional reagent and reassembly; and (iii) intercalation of a difunctional molecule chemically anchored at one end and capable of undergoing a different reaction on the other end. Noteworthy examples of bridged systems include γ-zirconium phosphate bridged with n-alkanediphosphonic acids or polyethylene oxide, 4,5 montmorillonite (MMT) clay bridged by diaminoalkanes, 6 and graphite oxide (GO) pillared with (3-aminopropyl)trimethoxysilane or iron oxide.…”

Towards the understanding of the graphene oxide structure: How to control the formation of humic- and fulvic-like oxidized debris

“…Therefore, the control in the fabrication of novel hybrid materials and 3-dimensional structures [10] require the development of an adequate and reliable synthesis model which could deep our knowledge in understanding the detailed structure of GO and its reduced forms. Over the past decades, different models for the structure of graphite oxide were proposed, mainly consisting of a homogeneous oxidized structure [19][20][21][22].…”

Experimental and Theoretical Investigations on the Ferroelectricity of Graphene Oxides

“…The charge distribution at the edges of GONRs is ordered and each unit is similar to that of water, indicating hydrogen bonds arranging in line orderly. Besides, based on previous models, [9,30,31] we have analyzed the ordered hydrogen bond structure from two aspects: on the surface and at the edge of GONRs in simulation. In the edge modified case, parallel and anti-parallel alignment of hydrogen-bond chains at two edges of GONRs were considered, and the optimized result shows the energy of former model is lower, indicating parallel alignment of the two polarized structures is more stable (seen in Figure S8).…”