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

## TL;DR

This paper introduces a new method to strengthen electrospun nanofiber mats using light-induced welding with gold nanocages, improving their mechanical strength and opening up new applications.

## Contribution

A controllable technique using the photothermal effect of gold nanocages to weld nanofibers under near-infrared laser irradiation.

## Key findings

- Nanofibers are permanently welded at junction points after 2 seconds of laser irradiation.
- After 5 seconds of irradiation, the mat transforms into a transparent solid film.
- The technique enhances mechanical strength and enables new applications like patterning and printing.

## Abstract

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.

The light‐induced heating enabled by Au nanocages offers a simple and effective method for selectively welding poly(ε‐caprolactone) nanofibers at their junction points, reinforcing the mechanical property of a fibrous mat. By controlling the extent of welding, the fibrous mat can be transformed into a solid film with high transparency, expanding the scope of applications.