CALIFORNIA STATE SCIENCE FAIR 2013 PROJECT SUMMARY Name(s) Project Number Karthik Ramachandran 33149 Project Title An A-peeling Solution: The Effect of Citrus Oils and d-Limonene on Polystyrene Abstract Objectives/Goals The purpose of my project is to test the impact of store-bought 100% essential citrus oils, homemade citrus oils, and limonene solutions on polystyrene as bio-friendly alternatives to disposing polystyrene in landfills. I hypothesized that store-bought 100% essential oils would dissolve polystyrene more effectively than homemade oils due to higher concentrations, and that low concentrations of limonene would be sufficient to dissolve polystyrene. Methods/Materials I used 100% citrus essential oils extracted from lemon, grapefruit, and orange peels, and homemade oils hand-pressed from the same fruits, and olive oil as control. I treated 2x2x1 inch polystyrene blocks with these oils and measured the volume of dissolution. To test the effect of diluted limonene on polystyrene, I placed polysterne blocks in 1% and 3% concentration solutions of limonene in water and vinegar and recorded the time it took for the blocks to dissolve. I used water, vinegar, and a shoebox model of a landfill as controls.I conducted three trials for each part of the experiment. Results In the tests for citrus oil, orange oil consistently showed the best results. 100% essential orange oil dissolved 43% of the polystyrene; grapefruit dissolved 41%, while lemon dissolved 36%. Hand-pressed orange oil dissolved an average of 22% of the polystyrene; lemon dissolved 16%, while grapefruit dissolved 7%. Of the limonene solutions, 3% limonene in vinegar dissolved the polystyrene in 22.5 minutes; 3% limonene in water took a minute longer, while the 1% solutions did not completely dissolve the polystyrene. None of the controls impacted polystyrene. Conclusions/Discussion The results confirmed that limonene, a liquid compound found in citrus oils is effective in dissolving polystyrene. Limonene contains a natural oil, citronella, which breaks down the hydrocarbon bonds of polystyrene and dissolves polystyrene. A sticky residue is left behind, which can be easily decomposed by microorganisms in air and water. This project is significant to the real world because polystyrene that currently takes over 500 years to decompose can now be effectively dissolved within minutes. I imagine a future where limonene trucks will collect polystyrene at the curbside and instantaneously dissolve it. Summary Statement My project explores the possibility of using citrus oils and d-limonene to dissolve polystyrene in an eco-friendly manner, thereby reducing the burden on landfills. Help Received Mother asssited me in hand-pressingPreliminary homemade oils and my science teacher, Mrs. Nguyen, for her guidance throughout this project. Ap2/13.