# Sandwich-Structured Coating for Ultraviolet Protection and Thermal Management Applications

## TL;DR

A new sandwich-structured coating on polyester fabric provides UV protection and thermal management, making it suitable for protective textiles.

## Contribution

The study introduces a TiO2/Cu–Al/TiO2 multilayer coating with UV shielding and thermal barrier properties on polyester fabric.

## Key findings

- The TCAT coating on polyester fabric achieved near-zero UV transmittance and suppressed light penetration in the visible to near-infrared range.
- Thermal imaging showed reduced surface temperature for coated fabrics, indicating potential thermal shielding effects.
- The coating retained moderate visible transmittance on glass while forming an optically dense barrier on fabric.

## Abstract

During the day, exposure
to UV radiation poses risks to human health,
while managing heat exchange is important for comfort in protective
textiles. Recently, infrared-reflective materials have attracted attention,
particularly for reducing the infrared transmission and moderating
the thermal emission. In this study, titanium dioxide/copper–aluminum/titanium
dioxide (TiO2/Cu–Al/TiO2, TCAT) sandwich-structured
coatings were deposited on polyester fabric using magnetron sputtering.
Deposition times (40 and 90 s) were varied to adjust Al and Cu layer
thicknesses between 20 and 55 nm, and the resulting films were characterized
by X-ray diffraction, scanning electron microscopy, X-ray photoelectron
spectroscopy, UV–vis spectroscopy, and thermal imaging. The
coatings retained moderate visible transmittance on glass, whereas
on woven polyester fabric, they formed an optically dense barrier
with near-zero UV transmittance, suppressing light penetration across
the visible to near-infrared (VIS–NIR) range. In conjunction
with the emissivity-aware interpretation of thermography, these results
substantiate substrate-independent UV shielding and optical/thermal
barrier behavior of the TCAT multilayer. Thermal imaging qualitatively
indicated reduced apparent surface temperature for coated fabrics
compared to uncoated ones, suggesting partial thermal shielding. These
results demonstrate the feasibility of integrating multifunctional
coatings into daily-use polyester textiles, offering effective UV
protection and the potential for thermal management in protective
applications.