Dual-functional Al-MOF/polysiloxane nano-composite sizing agent for enhanced thermomechanical properties and amphiphobicity of basalt fibers

Traditional sizing agent coated on the surface of Basalt Fibers(BFs) limits its heat-resistance and surface wettability in the application field of special functional textiles, such as fire-retardant apparel and high-temperature-resistant dustproof bag, etc., especially affects the display of BFs' original excellent heat resistance. A novel nanocomposite sizing agent combining NH₂-MIL-53(Al) metal-organic frameworks (MOFs) with a water-soluble polysiloxane (POS) has been prepared to improve both the thermomechanical and amphiphobic properties of BFs. The composition mimics the main compositions of BFs to construct a topology, where the inorganic part of Al-MOFs is mainly responsible for enhancing roughness and heat-resistance and the organic part of POS is needed to mediate chemical heterogeneity and film forming property. The sized BFs exhibit significantly enhanced mechanical properties compared to the naked BFs, with the breaking force and elongation increasing from 8.04 cN to 21.1 cN and from 1.58 % to 2.64 % at room temperature, about 162.4 % and 67.1 %, respectively. The retention rate of thermomechanical properties of the sized BFs maintains over 95 % at 250 °C and over 85 % even at 400 °C, while those of the naked BFs diminishes drastically to 50 % at 250 °C and 40 % at 400 °C, comparing with their original value at room temperature. Simultaneously, the surface amphiphobicity of BFs is achieved with the contact angles of water and diiodomethane being 140.1° ± 0.6° and 111.2° ± 0.9°, respectively. This work provides engineering implications for constructing multi-functional surfaces and thereby extensively broadens the application potential of BFs in the realm of textiles.