Fluorine‐free synthesis of ultra‐thin, high aspect ratio Ti3C2Tx MXene nanosheets for high‐efficiency ultraviolet‐shielding applications

• Published in: Polymer engineering and science Vol. 65; no. 5; pp. 2513 - 2524
• Main Authors: Zhong, Huolin, Fang, Hui, Yan, Zhao, Wu, Fangjuan
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.05.2025; Blackwell Publishing Ltd
• Subjects: alkaline etching; Etchants; Etching; Fluorine; green synthesis; Grinding; High aspect ratio; Light transmittance; Membranes; Metal carbides; MXenes; Nanosheets; Polyvinyl alcohol; PVA nanocomposites; Shielding; Stone; Synthesis; Tensile strength; Ti3C2Tx MXene; Transition metals; Ultraviolet radiation; UV‐shielding
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.27164

MXenes, two‐dimensional transition metal carbides and nitrides, show great potential in various applications. However, traditional synthesis methods often involve toxic fluorine‐containing etchants, limiting large‐scale production. This study introduces a novel, environmentally friendly approach for synthesizing Ti3C2Tx MXene nanosheets using stone grinding‐assisted exfoliation and mild alkaline etching at 80°C. The synthesized MXene nanosheets exhibited high aspect ratios with transverse dimensions mostly on the micrometer scale and a thickness of approximately 3 nm, corresponding to one to two layers of Ti3C2. MXene/polyvinyl alcohol (PVA) composite membranes were fabricated to demonstrate practical applications. The composite membrane containing 1 wt% MXene achieved a 99.9% UV shielding rate while maintaining 67% visible light transmittance. Furthermore, it significantly enhanced PLA's UV resistance, with protected samples retaining 98.1% tensile strength after 48 hours of UV exposure, compared with 47.8% for unprotected PLA. This fluorine‐free synthesis method addresses environmental concerns and enables large‐scale MXene production for advanced UV protection applications. Highlights Ti3C2Tx MXene is made via stone grinding and alkaline etching. MXene nanosheets are produced in the micron range and are 1–2 layers thick. The fluorine‐free synthesis enables green, large‐scale production of MXene. MXene/PVA films show 99.99% UV shielding with 67% visible light transmittance. MXene/PVA coating improves PLA's UV resistance, keeping 98.1% of tensile strength. Stone grinding‐assisted preparation of Ti3C2Tx MXene nanosheets for transparent UV‐shielding applications.