The awareness of developing eco-friendly polymer composites via green chemistry attract much attention in the recent years. In the current work, we explore preparing functional epoxy/ graphene nanocomposites using mechanochemical approach. Graphene platelets (GnPs) were modified with long-chain surfactant via high-energy ball milling. Modified-GnPs (m-GnPs) promote the dispersion quality and interface strength with epoxy matrix leading to higher mechanical properties, and better electrical and thermal conductivity compared to unmodified GnPs system. At 2.0 vol% m-GnPs, elastic modulus, tensile strength, and thermal conductivity of epoxy were improved by 889%, 163%, and 105%, respectively. In addition, percolation threshold of electrical conductivity was observed at 0.71 vol% m-GnPs. Halpin-Tsai micromechanical model was able to predict the elastic modulus of the epoxy/GnP nanocomposites. The model results were compared experimental measurements. Furthermore, the measurements showed epoxy/m-GnP film possess high sensitivity to mechanical strains and impact loads. The current work gives a step forward to use mechanochemistry approach in the production of functional epoxy/graphene composites.

In recent years, the use of nano-fillers in flexible polymer matrix to prepare highly flexible, stretchable, and multifunctional product has been widely studied. However, the uneven dispersion of nano-fillers in polymer matrix is an important factor hindering their performance. In this study, a method to prepare graphene nanosheets by ball milling and modification with the silane coupling agent APTES is reported, and this method can reduce the thickness of the nanosheets, improving the dispersion effect and compatibility of the nanosheets in the PDMS matrix. The mechanical and conductive properties of the prepared composite films were further analyzed. The morphology showed that our modified graphene (MGE and BMGE) are more evenly dispersed in the PDMS matrix compared to the unmodified graphene (GNP). The MGE/PDMS composite film has significantly improved electrical conductivity. It has a wide sensing range (up to 48%), high sensitivity (GF of 152 in the 20%-40% strain range) and reliable cycle repeatability (>10,000 cycles) with a response time of 0.12 s. The results show that the modified graphene/PDMS conductive elastic nanocomposite film is an ideal material for making flexible electronic products.

A high-performance porous flexible composite film sensor for tension monitoring. The sensor can monitor the strain of the whole field and then use contour maps to locate damage.

There has been an increase in interest in developing functional polymer composites based on green chemistry principles. The purpose of this study was to investigate the preparation of functional epoxy/carbon nanotube nanocomposites using ball milling methods. In contrast to mechanical mixing, ball milling promoted good dispersion of CNTs within the epoxy matrix, thereby improving their mechanical properties and electrical conductivity. In epoxy nanocomposites with ball milling, Young’s modulus and tensile strength were increased by 653% and 150%, respectively, when CNT loading was 1.0 vol%. Additionally, the ball milling of CNTs improves their dispersion, resulting in a low percolation threshold at 0.67 vol%. The epoxy/CNT film sensor that was produced using the ball milling approach not only exhibited high reliability and sensitivity to mechanical strains and impact loads, but also possessed the ability to self-detect damage, such as cracks, and accurately locate them. This study marks a notable milestone in the advancement of functional epoxy/CNT composites through the ball milling approach.