Temperature Variation of β-Type Interlamellar Sorption Complexes of Graphitic Acid with Alcohols

García, Araceli Ramírez; Cano-Ruiz, J.; MacEwan, Douglas M. C.

doi:10.1038/2031063c0

Cited by 24 publications

(37 citation statements)

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“…In this case the size of hydrated ions or molecules was speculated to be the only parameter which determines permeability of a GO membrane. [29][30][31][32] An extreme example of concentration dependence is GO swelling in basic solutions. It is very likely that several factors other than size of hydration shell can affect permeation of ions/molecules through GO membranes, first of all their chemical reactivity towards GO functional groups, ability of solutes to intercalate and expand GO structure, dependence of GO swelling on pH and concentration of dissolved molecules.…”

Section: Introductionmentioning

confidence: 99%

Structure of graphene oxide membranes in solvents and solutions

et al. 2015

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The change of distance between individual graphene oxide sheets due to swelling is the key parameter to explain and predict permeation of multilayered graphene oxide (GO) membranes by various solvents and solutions. In situ synchrotron X-ray diffraction study shows that swelling properties of GO membranes are distinctly different compared to precursor graphite oxide powder samples. Intercalation of liquid dioxolane, acetonitrile, acetone, and chloroform into the GO membrane structure occurs with maximum one monolayer insertion (Type I), in contrast with insertion of 2-3 layers of these solvents into the graphite oxide structure. However, the structure of GO membranes expands in liquid DMSO and DMF solvents similarly to precursor graphite oxide (Type II). It can be expected that Type II solvents will permeate GO membranes significantly faster compared to Type I solvents. The membranes are found to be stable in aqueous solutions of acidic and neutral salts, but dissolve slowly in some basic solutions of certain concentrations, e.g. in NaOH, NaHCO3 and LiF. Some larger organic molecules, alkylamines and alkylammonium cations are found to intercalate and expand the lattice of GO membranes significantly, e.g. up to ∼35 Å in octadecylamine/methanol solution. Intercalation of solutes into the GO structure is one of the limiting factors for nano-filtration of certain molecules but it also allows modification of the inter-layer distance of GO membranes and tuning of their permeation properties. For example, GO membranes functionalized with alkylammonium cations are hydrophobized and they swell in non-polar solvents.

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Section: Introductionmentioning

confidence: 99%

Structure of graphene oxide membranes in solvents and solutions

et al. 2015

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“…Later studies by the same group also demonstrated that a GO structure intercalated with some alcohol molecules may exhibit an "alpha phase" at ambient temperature while at low temperature (223 K), a "beta phase" with an expanded interlayer distance is found. 23 In principle, multilayered graphene oxide materials intercalated with a standing up orientation of long chain hydrocarbons are known, as reported e.g. for ionically bonded alkylammonium molecules.…”

Section: Introductionmentioning

confidence: 99%

“…The hydrophilic nature of GO has already been reported in very early studies, 22 while by the 1960s it was already well known that GO swells in polar solvents with expansion of the interlayer distance from 6-7 Å to 40-50 Å depending on the molecular size and the amount of intercalated solvent. 23,24 Perhaps the most studied GO solvates by now are those with alcohols. Previous studies revealed that B-GO is intercalated with one layer of methanol, ethanol, and propanol under ambient conditions (in excess of solvent), while an increase in pressure or a decrease in temperature leads to reversible phase transition into a two-layered solvate phase.…”

Section: Introductionmentioning

confidence: 99%

“…The expansion is even larger for alcohols with longer carbon chains. 23 D. MacEwan and J. Cano-Ruiz 23 explained this change, speculating that alcohol molecules with less than four carbon atoms are intercalated parallel to the graphene oxide sheets (alpha-phase). For molecules with a higher number of carbon atoms, the orientation of inserted molecules was suggested to change from "lying down" to "standing up" (betaphase).…”

Section: Introductionmentioning

confidence: 99%

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Multilayered intercalation of 1-octanol into Brodie graphite oxide

et al. 2017

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Multilayered intercalation of 1-octanol into the structure of Brodie graphite oxide (B-GO) was studied as a function of temperature and pressure. Reversible phase transition with the addition/removal of one layer of 1-octanol was found at 265 K by means of X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC). The same transition was observed at ambient temperature upon a pressure increase above 0.6 GPa. This transition was interpreted as an incongruent melting of the low temperature/high pressure B-GO intercalated structure with five layers of 1-octanol parallel to GO sheets (L-solvate), resulting in the formation of a four-layered structure that is stable under ambient conditions (A-solvate). Vacuum heating allows the removal of 1-octanol from the A-solvate layer by layer, while distinct sets of (00l) reflections are observed for three-, two-, and one-layered solvate phases. Step by step removal of the 1-octanol layers results in changes of distance between graphene oxide planes by ∼4.5 Å. This experiment proved that both L- and A-solvates are structures with layers of 1-octanol parallel to GO planes. Unusual intercalation with up to five distinct layers of 1-octanol is remarkably different from the behaviour of small alcohol molecules (methanol and ethanol), which intercalate B-GO structure with only one layer under ambient conditions and a maximum of two layers at lower temperatures or higher pressures. The data presented in this study make it possible to rule out a change in the orientation of alcohol molecules from parallel to perpendicular to the GO planes, as suggested in the 1960s to explain larger expansion of the GO lattice due to swelling with larger alcohols.

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“…short and long chain alcohols, [50][51] glycols, [52] various kind of amines, [53][54] amides, [54] ketones. [52,54] The common feature of all these solvents is that they are liquid at ambient conditions.…”

Section: Introductionmentioning

confidence: 99%