Light‐Induced Welding of Electrospun Poly( <i>ε</i> ‐caprolactone) Nanofibers in a Nonwoven Mat by Leveraging the Photothermal Effect of Gold Nanocages

Nonwoven mats of electrospun nanofibers are widely used in an array of applications, including those related to filtration, textiles, and tissue engineering. The performance of the mats is often plagued by their relatively weak mechanical strength due to the lack of bonding at the junction points between fibers. To address this issue, here a controllable technique is demonstrated for welding a nonwoven mat of poly(ε-caprolactone) fibers into an interconnected network by leveraging the photothermal effect of Au nanocages under the irradiation of a near-infrared laser. Upon irradiation for 2 s only, the poly(ε-caprolactone) fibers in a nonwoven mat are permanently welded at the junction points. When the irradiation time is increased to 5 s, the fibers fused together transforming the porous and opaque mat into a transparent solid film. In addition to strengthening nonwoven mats of electrospun nanofibers, this technique may open the door to new applications such as masking, patterning, and printing.