Preparation of Functionalized Yarns Via Ionic Liquid Based Natural Fiber Welding

Natural fiber welding (NFW) is a process that uses controlled amounts of ionic liquid and molecular co-solvent(s) to swell and mobilize portions of a natural polymer substrate. By carefully selecting factors controlling NFW such as time, temperature and solvent system composition, partial dissolution occurs, mobilizing and redistributing only a small portion of the natural polymer and leaving much of the underlying substrate intact. The NFW process results in fibers with a shell of dissolved/mobilized polymer, permanently adhered to both the outer diameter of the fiber and (depending on the extent of welding) to the surface of adjacent fibers. When polymeric and/or particulate materials are added during the NFW process, these substances can be integrated into the natural polymer matrix and modify its properties to include novel functionalities. In the present work we have applied the NFW process to the modification of natural polymer yarns. We have studied the processing conditions that impact the NFW of natural polymer yarns and the accompanied incorporation of functional materials (e.g., magnetic, conductive, and capacitive). We will discuss the preparation these functionalized yarns, and we will show data for their analysis using tensile testing, infrared spectroscopy, and scanning electron and con-focal fluorescence microscopies.