Novel methodologies for preparing expanded graphite and their application in flexible elastomers

Polymer based materials capable of exhibiting both elasticity and electrical conductivity have been widely used in electronics, electrotechnics, and the automotive sector However, conventional conductive elastomers show limitations for applications which require stretchability, conformability in complex shapes and for dynamic movements. These limitations are caused by the incorporation of rigid, non-elastic electrically conductive fillers. The emergence of expanded graphite provided a promising solution to replace the non-stretched conductive fillers with stretched fillers. Expanded graphite being electrically conductive and mechanical flexibility serves as an excellent filler in the production of highly flexible, stretchable, and electrically conductive elastomers. So, considerable interest of researchers has been enthusiastic to expanded graphite-based elastomers, named as new-generation materials, because of their extraordinary stretchability while maintaining electrical and mechanical properties. The first half of the review focuses on a systematic evolution from carbon-based fillers to graphitic materials, ultimately leading to expanded graphite. It highlights the major intercalation and exfoliation strategies used to convert expandable natural graphite into EG, including modern approaches employing advanced oxidizing systems and blowing agents. Emphasis is placed on recent and innovative methodologies for producing EG with tailored properties suitable for stretchable, electrically conductive elastomeric architectures. The second half of study, creates a bridge between expanded graphite (stretchable electrically conductive materials) and their applications as a filler in flexible matrix (elastomers). As we know that expanded graphite has ability to enhance electrical conductivity, thermal stability, and mechanical resilience in flexible elastomers, which makes it quite a fitting material for different applications such as sensors, energy storage devices, and electromagnetic interference shielding. A comprehensive literature survey compiles the most recent studies exploring the integration of expanded graphite into stretchable elastomer systems.