A comparison of collector plate materials for electrostatic capture of tire wear particles

This study compares the effect of applying −5 kV to four electrostatically charged metal materials (aluminum, brass, copper, and stainless steel) on capturing tire wear particles (TWPs) behind the wheel. A smooth-tread bicycle tire was spun against sandpaper while two metal plates collected the TWPs. Particles were measured in ImageJ by the percentage of the plate surface covered and the number of particles. Across the materials, charging raised surface coverage 23.2-fold and particle count 15.8-fold (both p < 0.001). The size of the gain depended on the material for both metrics (interaction p = 0.007 for coverage; p < 0.001 for count). All four materials improved significantly on surface coverage. Brass, copper, and stainless steel improved on particle count. Copper gained the most at 114 times the surface coverage and 53.6 times the count. For aluminum, surface coverage increased 5.5 times (p = 0.001) but particle count only increased 2.0 times and did not reach significance. When charged, copper and brass yielded about twenty times more TWP material than aluminum or stainless steel. In every charged trial for all materials, particles were only collected on the negatively charged plate, suggesting that the generated TWPs had a net positive charge. The results emphasize the importance of plate material in electrostatic TWP collector designs.