Electric Conductivity Study of Porous Polyvinyl Alcohol/Graphene/Clay Aerogels: Effect of Compression

Abstract

In this work, poly­(vinyl alcohol) (PVOH)/graphene (GN) oxide/clay aerogels were prepared using montmorillonite (MMT) and kaolinite (KLT) as fillers. This work paves the way for the development of aerogels filled with MMT or KLT with high conductivity. The mechanical properties of the polymer/clay aerogels are enhanced by incorporating GN into these systems. These composite materials have an enhanced thermal stability, and the combination of PVOH and GN leads to interconnected channels which favored the conductivity when a clay (MMT or KLT) is added to the mixed PVOH/GN matrix. However, after compressing the samples, the conductivities drastically decreased. These results show that the design of solid MMT/GN and KLT/GN composites as aerogels allows maximizing the space utilization of the electrode volume to achieve unhindered ion transport, which seems contrary to the general design principle of electrode materials where a suitable porous structure is desired, such as in our uncompressed samples. These findings also demonstrate the potential of these materials in electrodes, sensors, batteries, pressure-sensing applications, and supercapacitors.

Synthesis and Electrical Percolation of Highly Amorphous Polyvinyl Alcohol/Reduced Graphene Oxide Nanocomposite

“…It is based on polyvinyl alcohol modified with diol monomers and has excellent extrusion processability, water solubility, and oxygen barrier properties; furthermore, it can be easily used for coating, and it is biodegradable [22][23][24]. In the literature, there are some works about composite based on PVOH and GO in the form of light aerogel, with interesting functional properties such as fire resistance and EMI shielding [25] and potential applications in electrodes, sensors, batteries, pressure-sensing applications, and supercapacitors [26]. In particular, the possibility that in the conduction mechanisms also, protons can assume a relevant role together with the electronic charge carriers is explored, opening new routes for the study of conductivity behavior in nanocomposites [26].…”

“…In the literature, there are some works about composite based on PVOH and GO in the form of light aerogel, with interesting functional properties such as fire resistance and EMI shielding [25] and potential applications in electrodes, sensors, batteries, pressure-sensing applications, and supercapacitors [26]. In particular, the possibility that in the conduction mechanisms also, protons can assume a relevant role together with the electronic charge carriers is explored, opening new routes for the study of conductivity behavior in nanocomposites [26]. However, there are few works about composites based on PVOH and rGO, and the most significant report PVOH-based composites with rGO inclusions, with a very good percolation threshold (~1 wt%) but low conductivity (~10 −3 S/m), due to the weak interaction between PVOH moieties and reduced graphene oxide functional groups [27,28].…”