SUSTAINABLE COMPOSITES: CELLULOSE NANOFIBERS
Iulia Sacui and Jeffrey Gilman
Our main focus is on using cellulose nanofibers (CNF) as nanoparticle reinforcing agents for sustainable composites. CNF are an abundant natural polymer that are easy to surface functionalize, allowing for the attachment of fluorescent dyes. These fluorescence CNF can be used to evaluate the filler-matrix interface in composites using FRET. This technique will help in the development of a fundamental understanding of the controlling features of the interface/interphase in polymer composites and enable tuning of properties to obtain a balance between strength, ductility, and other performance properties. The initial phase has been to thoroughly characterize CNF that are from various sources and hydrolysis techniques. AFM measurements, along with Fiber Tracker software have been used to determine the morphology and length distributions of the nanofibers. IGC and solid state NMR have been use to determine variations in surface energy and crystallinity as a function of source and hydrolysis technique. The CNF were then functionalized with fluorescent dye, allowing for the nanofibers to be imagined in solution and a composite using confocal microscopy. The variety in cellulose sources and hydrolysis techniques offers a wide range of morphology, surface functionalization, surface energy, and aspect ratio, allowing for ease in composite performance properties optimization.