In SituReduction of Graphene Oxide in Polymers

Abstract

In situ reduction of graphene oxide (GO) at moderate temperatures within a polymer was observed using differential scanning calorimetry (DSC). Comparison of heats of reduction from DSC data in poly(vinylpyrrolidone), poly(vinyl acetate), and poly(vinylpyrrolidone/vinyl acetate) nanocomposites demonstrates that the polymer chemistry strongly influences the extent of reduction. These results are compared to the time–temperature relationship for GO reduction in air and in dimethylformamide at the same temperatures, determined through changes in the atomic carbon-to-oxygen ratio. GO reduction was independently confirmed by electrical conductivity and optical absorption measurements, as well as Raman spectroscopy. These results show that GO sheets are reduced depending on the time–temperature history and polymer chemistry at the particles’ location. For nanocomposites this can lead to improvement or reduction of desired properties and is thus pertinent to thermal processing of polymer nanocomposites based on functionalized graphene.

The preparation of the poly(vinyl alcohol)/graphene nanocomposites with low percolation threshold and high electrical conductivity by using the large-area reduced graphene oxide sheets

“…So the LrGO sheets have following two advantages which are more suitable for improving the electrical conductivity of nanocomposites than the small one: 1) there are less intersheet junctions leading to the high intrinsic electrical conductivity, and 2) the large area is prone to form a continuous electrical conductive network. GO sheets could be reduced in different media such as water [10], ethanol, butanol, and ethylene glycol [11] at a special temperature, and the GO sheets also could be reduced in polymer matrix such as poly (vinylpyrrolidone), poly(vinyl acetate) [12] or polyvinylidene fluoride [13]. Glover et al [12] reported that the GO sheets could be reduced in PVA matrix at the temperature range from 150 to 250°C, and the result of Raman peak shift shown that the C:O ratio is less than 10 after reduction.…”

“…GO sheets could be reduced in different media such as water [10], ethanol, butanol, and ethylene glycol [11] at a special temperature, and the GO sheets also could be reduced in polymer matrix such as poly (vinylpyrrolidone), poly(vinyl acetate) [12] or polyvinylidene fluoride [13]. Glover et al [12] reported that the GO sheets could be reduced in PVA matrix at the temperature range from 150 to 250°C, and the result of Raman peak shift shown that the C:O ratio is less than 10 after reduction. However, this method can maintain the good dispersion of rGO sheets and get rid of introducing the surfactant agents into polymer matrix [14,15], meanwhile avoids using reducing agents, especially hazardous ones.…”

“…However, this method can maintain the good dispersion of rGO sheets and get rid of introducing the surfactant agents into polymer matrix [14,15], meanwhile avoids using reducing agents, especially hazardous ones. In this work, we use poly(vinyl alcohol) (PVA) as polymer matrix, and disperse the GO sheets in PVA matrix homogeneously through the interaction between the hydroxyl groups on the PVA chains and oxygen-functional groups located on the surface of GO sheets, and then to reduce the GO sheets through the in-situ thermal reduction at a special temperature which depends on the decomposition temperature of PVA [12,13,16]. In our method, there are two purposesintended, 1) usage of the LGO sheets to construct a continuous filler network, and 2) avoiding the introduction of reducing and surfactant agents during the reduction processing.…”

The Influence of Epitaxial Crystallization on the Mechanical Properties of Polyamide 66/Reduced Graphene Oxide Nanocomposite Injection Bar

“…Graphene is one of the strongest materials found to date [23] and has great potential for improving the mechanical properties of polymers [24][25][26][27][28][29]. Reduced graphene oxides (RGO) are typical graphene materials with slight topological defects in their periodic structures [22].…”

Graphene derivatives in responsive hydrogels: Effect of concentration and surface chemistry

“…If the synthesis procedure of the gel is not too sensitive for the environment, in situ reduction methods (i.e. reduction agent added to the initial precursor mixture) may be used [28,29]. An effective way to make RGO containing gel composites is to reduce the already incorporated GO inside the gel matrix [30,31], however the circumstances of the reduction (e.g.…”