# In Situ Synthesis of ZnO Nanoparticles Using Soy Protein Isolate for Sustainable and Multifunctional Finishing of Hemp Fabrics

## TL;DR

This paper introduces a sustainable method to finish hemp fabrics using soy protein and zinc oxide nanoparticles, providing UV protection and antibacterial properties.

## Contribution

A novel eco-friendly finishing technique using soy protein isolate and IR-assisted ZnO NP synthesis for multifunctional hemp textiles.

## Key findings

- ZnO nanoparticles were successfully synthesized in situ on hemp fabrics using IR heating and soy protein isolate.
- Treated fabrics showed UV protection factor (UPF) of 50+ and 99.99% antibacterial efficiency against Staphylococcus aureus.
- SPI pretreatment improved fabric hydrophilicity and wettability by 2 wt% addition.

## Abstract

This study presents an environmentally sustainable finishing approach for hemp fabrics by combining soy protein isolate (SPI) pretreatment with an in situ infrared (IR)-assisted synthesis of zinc oxide nanoparticles (ZnO NPs). IR heating was employed to reduce energy consumption while promoting efficient nanoparticle formation compared to conventional thermal processing, while SPI acted as a bio-based stabilizer to enable uniform ZnO NP distribution on the fabric surface. Transmission electron microscopy revealed predominantly spherical to polyhedral ZnO NPs with minimal agglomeration, and X-ray diffraction confirmed their characteristic wurtzite crystalline structure. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy mapping further verified the homogeneous deposition of ZnO NPs on hemp fibers. The treated fabrics exhibited multifunctional performance, showing significantly enhanced ultraviolet (UV) protection with a UV protection factor (UPF) of 50+ compared with untreated hemp. Antibacterial activity against Staphylococcus aureus and Escherichia coli was confirmed by the AATCC TM147 test, while a quantitative AATCC TM100 assessment demonstrated an excellent antibacterial efficiency of 99.99% bacterial reduction against S. aureus. Additionally, the incorporation of 2 wt% SPI significantly improved fabric hydrophilicity and wettability. Overall, this work demonstrates a green and effective strategy for producing antibacterial and UV-protective hemp textiles.