13 Self-interpretation of Symptoms in Pediatric Brain Tumor High Throughput Experimentation and Data Analysis

Revealing the Intricate Interplay of Oil Spills and Microplastics Across Diverse Conditions

Faculty Mentor: Samira Shiri (Mechanical Engineering, University of Utah)

Microplastics, plastics smaller than 5 mm, and oil spills, which happen when liquid hydrocarbons and related petroleum products are released into marine or terrestrial ecosystems, are two major environmental pollutants.^[1]. This summer, under the mentorship of Samira Shiri, PhD, in the IT Physics Lab at the University of Utah, I studied how polyethylene (PE) and polystyrene (PS) microplastics influence the behavior of oil droplets in water. This project combined experimental design, image analysis, and data interpretation to better understand how these pollutants interact at the microscale. The knowledge gained from this research can contribute to the development of smarter, eco-friendly technologies for oil spill remediation, especially in scenarios where microplastics and oil coexist and influence each other’s behavior.^[2]

Our core research question was: How do polyethylene (PE) and polystyrene (PS) microplastics of varying sizes and concentrations affect oil droplet shape, evaporation, and particle distribution over time in aqueous environments?

To address this, we prepared microplastic suspensions using two common polymer types: PE and PS, each with two different size ranges (9.5-20 µm and 500-600 µm). We tested three concentrations:10 g/L, 50 g/L, and 100 g/L, and deposited droplets of these suspensions, with a small amount of vegetable oil, onto a SPOTs (Surface Patterned Omniphobic Tile) platform.^[3] Using a high- resolution camera, we captured images of each droplet every 20 minutes.

We processed these images using ImageJ and MATLAB. By converting the images to grayscale and analyzing pixel intensity across the droplet radius, we could quantify how microplastics influenced evaporation and particle dispersion throughout the droplet over time.

Our analysis of polyethylene (10 – 20 µm) samples revealed that microplastic concentration strongly influenced droplet behavior over time. At lower concentrations (10 g/L), particles remained evenly distributed throughout evaporation, with minimal change in pixel intensity. In contrast, higher concentrations (especially 100 g/L) showed clear signs of particle aggregation and migration toward the droplet edges over time, as reflected by pronounced peaks in pixel intensity. This suggests that concentration plays a critical role in particle mobility and distribution, with implications for how microplastics behave during environmental evaporation processes.

In contrast to PE, polystyrene (9.5 -11 µm) samples generally exhibited more consistent pixel intensity profiles across different concentrations and time points, indicating relatively stable particle distribution during evaporation. However, at the highest concentration (100 g/L), we observed subtle visual changes over time, including increased opacity and slight fluctuations in pixel intensity. These suggest a degree of microplastic accumulation or redistribution not seen at lower concentrations. While less pronounced than in PE, these findings highlight that PS behavior may also change under more saturated conditions, possibly due to concentration-dependent interfacial effects.

This project was a valuable opportunity to apply computational thinking to real-world environmental challenges. Through it, I gained hands-on experience in experimental design, image analysis, and data visualization, and I hope to continue this project in the near future.