# Advances in CO2 Laser Treatment of Cotton-Based Textiles: Processing Science and Functional Applications

## TL;DR

CO2 lasers can efficiently modify cotton textiles by altering their surface properties without using water or chemicals, but challenges remain in standardizing the process.

## Contribution

This review consolidates current understanding of CO2 laser effects on cotton and identifies key research gaps for sustainable textile processing.

## Key findings

- CO2 lasers induce controlled dye decomposition, oxidation, and micro-ablation in cotton textiles.
- Laser treatment increases surface energy and wettability through carbonyl and carboxyl group formation.
- Laser-modified cotton supports better adhesion of dyes and nanoparticles compared to untreated fabric.

## Abstract

CO2 laser processing has emerged as an efficient dry-finishing technique capable of inducing controlled chemical and morphological transformations in cotton and denim textiles. The strong mid-infrared absorption of cellulose enables localised photothermal heating, leading to selective dye decomposition, surface oxidation, and micro-scale ablation while largely preserving the bulk fabric structure. These laser-driven mechanisms modify colour, surface chemistry, and topography in a predictable, parameter-dependent manner. Low-fluence conditions predominantly produce uniform fading through fragmentation and oxidation of indigo dye; in comparison, moderate thermal loads promote the formation of carbonyl and carboxyl groups that increase surface energy and enhance wettability. Higher fluence regimes generate micro-textured regions with increased roughness and anchoring capacity, enabling improved adhesion of dyes, coatings, and nanoparticles. Compared with conventional wet processes, CO2 laser treatment eliminates chemical effluents, strongly reduces water consumption and supports digitally controlled, Industry 4.0-compatible manufacturing workflows. Despite its advantages, challenges remain in standardising processing parameters, quantifying oxidation depth, modelling thermal behaviour, and assessing the long-term stability of functionalised surfaces under real usage conditions. In this review, we consolidate current knowledge on the mechanistic pathways, processing windows, and functional potential of CO2 laser-modified cotton substrates. By integrating findings from recent studies and identifying critical research gaps, the review supports the development of predictable, scalable, and sustainable laser-based cotton textile processing technologies.