Poly(vinyl alcohol) nanocomposites based on graphene and graphite oxide: a comparative investigation of property and mechanism

Abstract

Polymer/graphene nanocomposites have generated intensive interest due to their unique properties. Dispersion and interface interactions between graphene and the polymer matrix are two key factors to obtain property enhancements. According to the open literature, in poly(vinyl alcohol) (PVA) nanocomposites, graphene usually obtains more significant property enhancements than graphite oxide (GO), although GO can much more easily form a good dispersion and strong interaction in the PVA matrix because of its oxygenated functionalities, and the reason has not been well documented yet. In this work, graphene and GO were successfully incorporated into PVA; the properties and the mechanism for the property enhancements were investigated. GO formed better dispersion and exfoliation while graphene caused more property enhancements including mechanical properties, electrical conductivity and thermal stability. The mechanical strength of the graphene/GO nano-layers is attributed to be the fundamental cause for the enhancements in crystallinity and mechanical properties; the hydrogen bond among the PVA molecules is the key factor to influence the glass transition temperatures; the hydrogen bond between the graphene/GO nano-layers and PVA matrix is the decisive factor for the exfoliation and dispersion of graphene/GO; the conducting network is the explanation for the increased electrical conductivity; the physical barrier effect of graphene nano-sheets is the main cause for improved thermal stability. This work investigates the mechanisms for property enhancements, clarifies the roles of the hydrogen bond and the mechanical strength of the graphene/GO nano-layers, and explains why graphene usually achieves more property enhancements than GO.

Preparation of Poly(Vinyl) Alcohol/Chitosan Hybrid Membranes Doped with Graphene Nanosheets

“…Moreover, doping or hybridizing the polymeric matrix via sol-gel methods with inorganic [6] and organic [6,7] salts may also enhance membrane performance [8][9][10]. Particularly, carbonaceous materials are known as additives capable of improving the ionic conductivity, reducing the permeability and increasing the robustness [11][12][13][14]. Polymer industry is generally devoted to the synthesis and manufacture of ion exchange membranes dominated by the use of synthetic polymers obtained from non-renewable resources or complex, toxic …”

High Performance of Alkaline Anion-Exchange Membranes Based on Chitosan/Poly (vinyl) Alcohol Doped with Graphene Oxide for the Electrooxidation of Primary Alcohols

“…In this regard, Bao et al [58] performed a comparative study between the influence of using pristine G and GO within a PVA polymeric matrix demonstrating that the hydrogen bonds between PVA polymer and the oxygenated functionalized groups present in the G nanosheets were not only responsible for the adequate dispersion and exfoliation of this carbon nanofiller in the polymer matrix, but they also play a role as far the thermal stability is concerned. Thus, GO act as a physical barrier increasing the transition temperature, and consequently improving the thermal stability of the composite membrane [59]. Water uptake (WU) of the anion-exchange membranes are correlated with the crystallinity or the crosslinking degree of the membrane matrix, as well as the nature and concentration of the fixed ion exchange groups, the counter ions and membrane homogeneity and the composition of the solution [57].…”

Graphene Oxide/Polymer‐Based Biomaterials

“…Xu et al [128] prepared micron-thick films by 3 wt% GO in PVA by vacuum filtration, which led to the alignment of GO sheets in the PVA matrix. Bao et al [28] prepared nacre-like GO/PVA films by vacuum-assisted self-assembly. In their nanocomposites, approximately 55 wt% GO was the inorganic building block and PVA was used as a soft organic binder.…”

“…[28,126,127,151] Vacuum filtration [27,128] and layer by layer self-assembly [129] was also used to prepare GO/PVA films. Xu et al [128] prepared micron-thick films by 3 wt% GO in PVA by vacuum filtration, which led to the alignment of GO sheets in the PVA matrix.…”

“…The hydrogels were mainly produced for soft tissue engineering applications including cartilage, muscle, and peripheral nerve tissue regeneration applications. [6][7][8][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] Table 1 shows the production route for different GO/polymer scaffolds and the findings of the studies are presented.…”