2D materials guided interface in polymer based nanocomposites

Abstract

Two dimensional materials based nanocomposite have gained rapid technological and scientific importance in the last few decades. This hybrid material system is a combination of inorganic 2D materials and organic/inorganic polymer materials that finds its application in diverse set of domains such as electronics, aerospace, photovoltaics, ocean technology, healthcare applications etc. The interfaces in these two dimensional materials/polymers nanocomposites plays an important role in determining the overall material properties of these nanocomposites. Thus, the behaviour at interface needs to be understood to evaluate the material property of these nanocomposites as well the interface behaviour can provide insights into the behaviour of material in different loading conditions. The interface informed design of 2D materials based nanocomposites can help is the development of new nanocomposites with enhanced material properties with wide variety of applications. In this study, we are characterizing the effects of crystallization of polyethylene, most abundant polymer used on our planet, on the surface of 2D materials specifically graphene and MoSe2 . The crystal structure of 2D materials is known to guide the crystallization direction of polyethylene which creates anisotropy in the nanocomposite i.e. different material properties in different directions which can be useful in development of flexible electronics, flexible skin for human-robot interaction, flexible semiconductors etc. Therefore, 2D materials can be used a templating agents to create anisotropy in the developed nanocomposite. This study investigates the templating effects of two 2D materials i.e. MoSe2 (2D semiconductor material) and graphene (one of the stiffest and strongest material known) for crystallization of polyethylene. In this study we have studied the fractional crystallization at 2D material-polymer interface with the progression of time. We have also investigated the crystallization orientations and lattice parameters of crystallized polyethylene of these 2D materials. Our results indicates that crystallization of polyethylene starts at the interface and crystallization growth rate is faster for graphene-polyethylene interface compared to MoSe2-polyethylene interface. For graphene-polyethylene nanocomposite the polyethylene chains prefer to align along armchair direction and for MoSe2-polyethylene nanocomposite the polyethylene chains tend to align along selenium valleys.