Enhancing wettability and antimicrobial activity of lotus fabric through air plasma treatment and neem extract coating

Abstract

This study investigates the functional enhancement of lotus fibres — a sustainable, environmentally friendly and easily accessible raw material — through atmospheric dielectric barrier discharge (DBD) plasma treatment. The fabric is exposed to air plasma for durations ranging from 1-5 min before being coated with five different concentrations of neem leaf extract. The surface wettability of the treated fabric is assessed through wet-out time analysis, hydrophilicity tests, and contact angle measurements. Structural and chemical modifications are characterised using Attenuated Total Reflectance−Fourier transform infrared (ATR-FTIR) spectroscopy, Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). FTIR and XPS analysis confirms increased polar functional groups (-COOH, -OH, -C=O) on the plasma-treated fabric surface, improving the surface hydrophilicity and functionality. Antimicrobial properties are evaluated using agar plates and modified Hoenste in tests, both qualitatively and quantitatively. Results demonstrate that when coated with neem extract, the plasma-treated lotus fabric exhibits durable antimicrobial activity even after three washing cycles. This suggests that air DBD plasma treatment followed by neem leaf extract application offers a better approach for manufacturing natural antimicrobial textiles, with potential applications in medical and healthcare industries.