(Invited) Towards Advanced Functional Natural Polymer Materials through Ionic Liquid Based Methods

Abstract

Throughout history humankind has exploited the remarkable properties of natural polymers such as silk and cellulose. In modern times, these natural materials still possess properties that rival the most advanced synthetic polymers. Recent work has shown ionic liquids (IL) to be effective solvents for the dissolution of a wide variety of natural polymers, and new materials can be created from these natural feedstocks by processes that involve their full dissolution and subsequent reconstitution. However, many reports show that the dissolution and reconstitution processes eliminate the native polymer structure, often with negative consequences to the physical properties of the resulting materials. Alternatively, if only the surface layers of these natural materials are mobilized through an ionic liquid facilitated process called Natural Fiber Welding (NFW), the underlying material retains its native character and mechanical properties while still allowing for significant material modification. Furthermore, the addition of functional materials (e.g. magnetic, conductive, antimicrobial) into the IL welding solution, allows for these substances to be entrained in and on the surface of the substrate imparting unique properties to the natural materials. Our group has endeavored to utilize NFW to modify natural materials to introduce novel functionalities. This work has encompassed the incorporation of a wide variety of polymeric, organic and inorganic materials into natural fiber matrices. Through the introduction of the appropriate materials we have been able to impart capacitive, conductive, catalytic, magnetic, optical, antimicrobial, and/or fire retardant functionalites into natural polymeric materials. In this presentation we will show our most recent efforts utilizing NFW to prepare novel functional natural materials.