BS in Materials Engineering
Materials Engineering Department
The purpose of this work was to investigate methods to produce consistent, reliable, and testable thin films of arabinan-cellulose nanocomposites. Mechanical properties and composition of the Opuntia ficus-indica cactus spines served as motivation for this research. The high specific strength and stiffness, biodegradability, and sustainability of these spines inspired the creation of composites fabricated from the same materials found in cactus spines: arabinan and nanocrystalline cellulose (NCC). Arabinan serves as the matrix material and NCC as the reinforcement. To explore the feasibility of using a non-toxic solvent, different solution casting techniques with water as a solvent were investigated. Ultrasonication was used to disperse the NCC particles within an arabinan-water solution. A straightforward procedure using silicone molds yielded consistent samples that were suitable for tensile testing. SEM imaging showed signs of aggregation NCC particles. Composite stiffness, strength, and strain to break were found to be dependent on drying time, temperature, water content, and weight percent NCC. To obtain samples at similar water content, samples were monitored until any tacky spots on the film surface had completely dried. Composite samples with greater NCC content were found to have a higher strength and modulus compared to pure arabinan. Arabinan reinforced with 5 wt.% NCC had an average tensile strength of 7.66 MPa and stiffness of 309.03 MPa, while pure arabinan had 4.62 MPa and 211.37 MPa, respectively.