Determination of the Adhesion Between Electrospun Mats through Peel tests

Electrospinning is an interesting technique widely used in industry to produce complex fibrous structures with tunable porosity and morphology. Yet, little is known about possible delamination between electrospun layers. In the present work, we studied the adhesion between PCL electrospun mats of similar porosity and investigated the effect of different morphologies, solvents and post-treatment on adhesive strength using a T-peel test. The objective is to establish guiding rules for improving the adhesive strength when fabricating multilayered electrospun systems. The effect of fiber diameter was found to be clearly dominant, large diameter fibers (3.6 µm) showing almost 7-fold increase (p<0.0001) of the adhesive strength compared to smaller ones (0.5 µm), while the use of different solvents for the two layers didn’t induce any major change. Heat treatment was also found to improve the adhesive strength. Further study is needed to better understand adhesion mechanisms between electrospun materials. Finally, this T-peel test was found to be an adequate simple tool to test electrospun bilayer materials and evaluate their adhesive strength.