M.S. (Master of Science)
Department of Mechanical Engineering
Cellulose nanocrystals (CNCs) are a distinctive nanomaterial derived from cellulose, the most abundant natural polymer on Earth, and the primary reinforcing structural component of cellulose fibrils found within the plant cell wall. These nanocrystals exhibit mechanical properties comparable to synthetic aramid fibers but are advantageous as they are biodegradable, renewable, and can be produced sustainably as they are predominantly extracted from naturally occurring cellulosic materials. These qualities make it a sustainable, highly renewable and environmentally friendly material to be used in place of synthetic materials in a variety of applications. With their high surface area to volume ratio, low level of defect, impressive mechanical stiffness and potentiality for engineered surface chemistries, CNCs have been exploited to develop cheaper, renewable nanocomposite materials with unique capabilities. In these nanocomposites, CNCs serve as the reinforcing filler phase within a synthetic polymer matrix such as acrylic glasses or polystyrene foams. While nanocomposites have been fabricated with CNCs as the reinforcing phase, a number of challenges have presented themselves including poor dispersion of CNCs and degradation of mechanical properties upon exposure to moisture. One method to address these shortcomings is surface modification of CNCs to inhibit their hydrophilic nature via direct grafting of synthetic polymer chains in an effort to create high-performance nanocomposites while maintaining moisture-resilient mechanical properties. In this work, the effect of polymer grafting on individual CNCs is investigated using fully atomistic molecular simulation. Using grand canonical Monte Carlo (GCMC) simulations, the effect of polymer grafts on moisture adsorption is explored to determine how grafting parameters such as polymer chain length, grafting density, and polymer species impact the adsorption characteristics of CNCs.
Breen-Lyles, Mary Elizabeth, "Direct Polymer Grafting as a Method of Maintaining the Mechanical Properties of Cellulose Nanocrystals in the Presence of Moisture" (2019). Graduate Research Theses & Dissertations. 6881.
Northern Illinois University
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