Ocean oil spills, resulting from accidents with oil supertankers and drilling rigs, damage the environment and pose serious immediate and long-term health risks to exposed organisms. Current oil spill remediation makes wide use of chemical dispersants, which dissolve or break up oil masses into smaller particles, allowing the oil to sink and be slowly digested by microorganisms. Unfortunately, these powerful solvents maintain acute toxicity in combination with the oil itself, sacrificing deep ocean health to protect shorelines. To better remediate ocean oil spills, alternative methods of cleanup are being explored.

This project utilizes microcrystalline cellulose(MCC) to synthesize an ultra-lightweight, highly porous aerogel in order to absorb oil and allow for re-collection while using naturally-derived materials and efficient methods of production. MCC is a naturally occurring polymer with long chains of cellulose microfibrils that exhibit a high degree of three-dimensional bonding, resulting in a highly crystalline substance that is resistant to dissolution in water and many strong reagents. My goal is to use the microcrystalline cellulose as a green way to selectively clean up oil spills in a simple, sponge-like cleanup method. The aerogel actively adsorbs oil film onto their multifaceted surfaces, and maintains structure to allow for easy removal during cleanup.

The microcrystalline cellulose was dissolved using tetrabutylammonium fluoride(TBAF) in dimethyl sulfoxide and tetrahydrofuran, producing a liquid crystalline phase material that preserved the microcrystalline polymerization and aggregated into a solid gel overnight. These hydrogels were then pre-frozen and placed under complete vacuum to allow for lyophilization, resulting in an ultra-lightweight aerogel with an incredibly high oil adsorption capacity. Concentrations of TBAF were varied(1.5%, 2.5%, 3.5%, and 4.5%, w:v) with 2.5% MCC(W:V) to achieve the strongest possible aerogel. The strongest ratio of MCC to TBAF, 1:1 by weight, was used to vary concentrations of MCC from 2.5% to 1.25%, 0.8%, and 0.5% while maintaining ideal strength characteristics in order to synthesize high oil-adsorbing aerogels without compromising strength. A hydrogel compression strength test was used to indicate relative strength of the aerogels, which determined the feasibility of each group for oil spill remediation. Dry weight measurements determine the actual mass of the aerogel, which were related to the mass of the sample after absorbing silicone oil to determine relative masses of oil absorbed per gram of aerogel material.

The 0.8% MCC concentration with 0.8% TBAF catalyst resulted in an optimal balance between strength and oil adsorption, absorbing up to 20 times its weight it oil while maintaining a feasible compressive strength. The novel method of production, as a result, was tested with an oil/water mixture and the aerogels shown to maintain oil specific adsorption. This study proved effective in producing a material ideal for applications in oil spill remediation with easy cleanup by absorption and subsequent removal.