Optical Properties and Aggregation of Graphene Nanoplatelets

Abstract

In the present paper, the optical density of dispersions of randomly oriented multilayer graphene nanoplatelets (GNPs) was estimated. Calculated and experimental data were compared for aqueous GNP dispersions stabilized with various surfactants. It was shown that the sonication of an expanded graphite compound (EGC) in aqueous surfactant solutions leads to the transformation of EGC worm-like particles into weak GNP aggregates which are able to pass into solution upon dilution and agitation of the system. They may be filtered and washed out of surfactants. The concentrated GNP dispersions containing these weak aggregates can be used to synthesize different graphene-based nanostructures and obtain novel composite materials.

The high photocatalytic activity and reduced band gap energy of La and Mn co-doped BiFeO3/graphene nanoplatelet (GNP) nanohybrids

“…Moreover, the tendency of graphene nanosheets to re-agglomerate in dried single layer graphene reduces its commercial applications. 44 Graphene nanoplatelets (GNPs), a low cost commercial product, are comprised of multilayers of graphene 45 (10 to 30 layers or more) in the form of akes, particles or plates. The GNPs have a thickness in the nanometer range, and are less vulnerable to defects.…”

Development of Technical and Technological Solutions in the Field of Multilayer Graphene for Creating Electrode Nanomaterial Energy Storage Devices

“…A prototype of the method of obtaining the GNPs is described in [1][2][3]. According to this method, graphene nanoplatelets were received by exfoliation of expanded graphite materials, which were obtained by intercalation of the crystalline (natural) graphite GSM-1 with peroxo-sulfate compounds.…”

Polycondensation of Hexamethylenetetramine in Anhydrous Acid Media as a New Approach to Carbyne-Like Materials and Its Application as Dispersant of Carbon Materials

“…We compared the effectiveness of one of the traditional surfactants OP-7 (the Russian analogue for Triton X-100) and AC in the process of ultrasonic exfoliation of natural graphite GSM-2. The degree of exfoliation was estimated from the optical density of sample dispersions, which, as it was shown in the literature [25], can be an indicator of the thickness of graphene nanoplatelets for comparative analysis. In this regard, Figure 5 depicts the effective light absorption coefficient versus insonation time for graphite exfoliation in the presence of AC and OP-7 as dispersing agents, respectively, providing the former dispersant with the highest performance for dispersions of graphene nanoplatelets.…”