Recycled PET Nanofiber Mask Filters

ISEF Category: Materials Science

Subcategory: Nanomaterials  ·  Difficulty: Advanced  ·  Setup: University Lab  ·  Time: Full Year

The Hook

A thin fiber mat can catch tiny particles better than a much thicker sheet. That is the basic promise of nanofiber filters. If you can turn recycled plastic bottles into a filter material, you also connect air cleaning with waste reduction. Your project can measure whether the idea works, and how well it works.

What Is It?

This project studies electrospun nanofibers, which are ultra-thin strands pulled from a polymer solution using a strong electric field. Think of it like making cotton candy with electricity instead of heat. The result is a web of tiny fibers with lots of empty space between them. Air can pass through, but particles can get trapped by the maze of fibers.

In this case, the polymer comes from recycled PET, the same plastic used in many drink bottles. You turn waste into a filter material, then test how well it blocks particles from incense aerosol. A PMS5003 sensor reads particle levels in the air, so you can compare conditions before and after the filter. You are not just asking, "Does it work?" You are asking how structure, thickness, and setup change performance.

Why This Is a Good Topic

This is a strong science fair topic because you can change one design factor at a time and measure a real output. You can compare filter thickness, fiber quality, layering, or airflow conditions, then connect those choices to particle capture. The project links pollution control, recycling, and materials design, so the result has a real-world purpose. You can also learn how to turn raw sensor data into graphs, efficiency values, and a clear claim.

Research Questions

• How does nanofiber mat thickness affect particle-filtration efficiency for incense aerosol?
• What is the effect of fiber diameter on PMS5003 particle reduction across a filter sample?
• Does blending recycled PET with another polymer change filtration efficiency and airflow resistance?
• To what extent does the number of nanofiber layers improve capture of fine particles?
• Which filter orientation, tight or loose mounting, gives the best balance of particle removal and airflow?
• How does humidity change the measured filtration performance of recycled PET nanofiber filters?

Basic Materials

• Clean recycled PET bottles or PET pellets from a trusted source.
• Electrospinning setup with a high-voltage power supply and collection target.
• Solvent system approved for PET handling and disposal by your lab supervisor.
• Syringe pump or other controlled feed system.
• Conductive needle, tubing, and syringe compatible with the setup.
• Filter frame or holder for mounting test samples.
• PMS5003 particle sensor.
• Microcontroller such as Arduino or Raspberry Pi for logging sensor output.
• Incense sticks or another consistent aerosol source.
• Digital balance with at least 0.01 g resolution.
• Calipers or a micrometer for sample thickness.
• Safety goggles, lab coat, gloves, and proper ventilation equipment.

Advanced Materials

• Scanning electron microscope access for fiber diameter and morphology.
• Universal testing machine or airflow resistance setup for pressure-drop measurements.
• Analytical balance for precise sample mass tracking.
• FTIR or DSC access to verify PET recovery and polymer properties.
• Cleanroom or fume hood-rated electrospinning enclosure.
• Particle counter or reference aerosol instrument for validation against the PMS5003.
• Software for image analysis of fiber diameter distributions.
• Humidity and temperature data logger.
• Tensile test grips or custom mounting frames for fabric-like samples.
• Statistical analysis software for comparing multiple filter designs.

Software & Tools

• Excel or Google Sheets: Organizes sensor readings, calculates averages, and builds comparison graphs.
• Python: Cleans time-series data, computes filtration efficiency, and runs statistics.
• ImageJ: Measures fiber diameters and pore features from microscope images.
• Arduino IDE: Uploads code and reads PMS5003 sensor data from a microcontroller.
• R: Tests whether differences between filter designs are statistically meaningful.

Experiment Steps

1. Define the exact filter property you want to improve, such as particle removal, airflow, or both.
2. Choose one design variable to change first, such as fiber thickness, layer count, or polymer blend.
3. Plan a particle-measurement setup that compares the air before and after the filter under the same conditions.
4. Build a calibration plan so your sensor readings can be compared across trials and days.
5. Decide which structural measurements, such as fiber diameter or mat thickness, will explain your filtration results.
6. Map out the statistics you will use to compare groups and defend your conclusion.

Common Pitfalls

• Using inconsistent incense output, which makes particle readings change for reasons that have nothing to do with the filter.
• Mounting the filter with gaps around the edges, which lets air bypass the nanofiber mat and inflates performance.
• Trusting raw PMS5003 numbers without checking background drift, which can hide small but real differences between samples.
• Comparing filters with different thicknesses or masses without normalizing the data, which makes one design look better just because it contains more material.
• Ignoring humidity and airflow, which can change particle behavior and make two runs look different even when the filter is the same.

What Makes This Competitive

A stronger project goes beyond a simple before-and-after test. You can compare several controlled designs, measure the fibers themselves, and connect structure to performance. A good entry also checks pressure drop or airflow resistance, not just particle removal. That gives you a more complete picture of whether the material could work in a real mask or filter system.

Project Variations

• Test recycled PET nanofibers against a commercial mask layer to compare particle removal and airflow resistance.
• Compare incense aerosol with another safe particle source, such as chalk dust or outdoor air after a short walk, to see how particle type changes results.
• Add an image-analysis angle by linking SEM or microscope fiber data to filtration efficiency across different spinning conditions.

Learn More

• NIH PubMed: Search review articles on electrospun nanofiber filters, aerosol filtration, and PET recycling.
• NASA Earthdata: Find background on particulate pollution, aerosol behavior, and air-quality measurement concepts.
• NOAA Air Resources Laboratory: Read about atmospheric particles, transport, and monitoring basics.
• University of Washington OpenCourseWare or MIT OpenCourseWare: Search for materials science, polymers, and transport phenomena course notes.
• Journal of Membrane Science: Search for peer-reviewed papers on nanofiber filtration performance and pressure drop.