Intercalation of Dyes in Graphene Oxide Thin Films and Membranes

Abstract

Intercalation of dyes into thin multilayered graphene oxide (GO) films was studied by neutron reflectivity and X-ray diffraction. Methylene blue (MB) penetrates the interlayer space of GO in ethanol solution and remains intercalated after the solvent evaporation, as revealed by the expansion of the interlayer lattice and change in chemical composition. The sorption of MB by thin GO films is found to be significantly stronger compared to the sorption of Crystal violet (CV) and Rose bengal (RB). This effect is attributed to the difference in the geometrical shape of planar MB and essentially nonflat CV and RB molecules. Graphite oxides and restacked GO films are found to exhibit different methylene blue (MB) sorptions. MB sorption by precursor graphite oxide and thin spin-coated films of GO is significantly stronger compared to freestanding micrometer-thick membranes prepared by vacuum filtration. Nevertheless, the sorption capacity of GO membranes is sufficient to remove a significant part of the MB from diluted solutions tested for permeation in several earlier studies. High sorption capacity results in strong modification of the GO structure, which is likely to affect permeation properties of GO membranes. Therefore, MB is not suitable for testing size exclusion effects in the permeation of GO membranes. It is not only hydration or solvation diameter but also the exact geometrical shape of molecules that needs to be taken into account considering size effects for penetration of molecules between GO layers in membrane applications.

Construction of 2D/0D Graphene Oxide/Copper(I) Oxide-Incorporated Titanium Dioxide Mixed-Dimensional Membranes with Ultrafast Water Transport and Enhanced Antifouling Properties

“…The result indicated that the CT60/GO membrane has a stable separation performance. However, the XRD result indicated that the d -spacing of the membrane increased to 12.3 Å (Figure S10), which was potentially due to the invasion of dye molecules into the gap between GO nanosheets. , Figure c compares the CT60/GO membrane with prevailing GO-based membranes in terms of pure water permeance and MB selectivity. ,,,− Moreover, the performance of the CT/GO membrane was also compared against membranes based on other nanomaterials, such as MXene and covalent organic frameworks (COFs), as shown in Table S5. The pure water permeance of the CT60/GO membrane was 171.5 L m –2 h –1 bar –1 and the MB rejection was 96.2%, suggesting the superior water permeance of the CT60/GO membrane and its application feasibility for dye separation.…”

“…However, the XRD result indicated that the dspacing of the membrane increased to 12.3 Å (Figure S10), which was potentially due to the invasion of dye molecules into the gap between GO nanosheets. 42,43 Figure 5c compares the CT60/GO membrane with prevailing GO-based membranes in terms of pure water permeance and MB selectivity. 21,36,40,44−53 Moreover, the performance of the CT/GO membrane was also compared against membranes based on other nanomaterials, such as MXene and covalent organic frameworks (COFs), as shown in Table S5.…”

Amino acid-driven adsorption of emerging contaminants in water by modified graphene oxide nanosheets

“…GO with a prominent number of holes and defects on the surface). 17,26–28 The number of carbonyl and carboxylic groups, mainly located at the defect edges, increased directly with the number of holes. 17…”

“…GO with a prominent number of holes and defects on the surface). 17,[26][27][28] The number of carbonyl and carboxylic groups, mainly located at the defect edges, increased directly with the number of holes. 17 The key role of surface chemistry in the adsorption properties is also proved by the studies of selectivity and efficiencies of functionalized graphene-based sorbents, in comparison with unmodified graphene.…”

Effect of graphene oxide on spectral-luminescenct properties of xanthene dye

“…The study of such processes has been intensively carried out [20,21]. For example, fluorescence quenching of polymers by reduced graphene oxide [22], resonant energy transfer from a dye molecule to graphene [23], and interaction of graphene sheets with a dye using fluorescence quenching microscopy [24] have been reported.…”