Green and sustainable fabrication of a durable superhydrophobic cotton fabric with self-cleaning properties

Designing a superhydrophobic cotton fiber coating exploiting TiO2@g-C3N4 layered structure for augmented photocatalysis and efficient water-oil separation

This study introduces a novel approach to develop a multifunctional coating on cotton fabric, emphasizing the utilization of cotton fiber as a biological macromolecule, by integrating a TiO2@g-C3N4 layered structure to confer superhydrophobic properties and multiple functionalities. The engineered structure not only enhances fabric roughness but also incorporates non-fluoro hydrophobic agents, thereby imparting diverse capabilities such as photocatalysis, oil-water separation, and self-cleaning to the cotton substrate. Fabrication of the TiO2@g-C3N4 layered structure involved ultrasonic dispersion of TiO2 and g-C3N4, subsequently deposited onto cotton fabric. Sequential hydrophobic treatment with polydimethylsiloxane (PDMS) and isophorone diisocyanate (IPDI) achieved superhydrophobicity, exhibiting an exceptional water contact angle (WCA) of 157.9°. Comprehensive characterization via scanning electron microscopy (SEM), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), and thermogravimetric validated the composite's structural and chemical properties. The introduced TiO2@g-C3N4 structure significantly enhanced fabric roughness, while PDMS treatment lowered surface energy and IPDI hydrolysis facilitated cross-linking, ensuring durability. The resultant TiO2@g-C3N4/PDMS cotton exhibited outstanding self-cleaning properties and demonstrated oil adsorption capacity, accommodating both heavy and light oils. Notably, this superhydrophobic cotton efficiently separated water-oil mixtures, achieving 96.8 % efficiency even after 10 cycles. Moreover, under simulated light, it displayed outstanding photocatalytic degradation (93.2 %) of methylene blue while maintaining a WCA of 150° post-degradation, highlighting sustained functionality. This innovation holds promise for sustainable applications, offering robust physical and chemical durability within the realm of biological macromolecules. The amalgamation of TiO2@g-C3N4 layered structure and PDMS treatment on cotton fabric underscores a sustainable approach to address water-oil separation challenges and enable efficient self-cleaning. This research demonstrates a significant step towards sustainable material applications and addresses pertinent real-world challenges in diverse technological domains.

A universal eco-friendly flame retardant strategy for polylactic acid fabrics and other polymer substrates

Various polymer substrates have their particular combustion features, therefore, developing an effective universal flame retardant strategy for various polymer substrates is of great practical importance. Meanwhile, as substitutes for petroleum-based products, bio-based flame retardants and biodegradable polylactic acid (PLA) meet the requirements of sustainable development. In this work, a fully bio-based flame retardant coating (PAGS) was prepared using phytic acid (PA) and guanosine (GS). PAGS was used as a universal flame retardant coatings for polylactic acid (PLA) fabrics and other substrates, including cotton fabrics, polyethylene terephthalate (PET) fabrics, polyamide (PA) fabrics, polyurethane (PU) foams, polyethylene terephthalate (PET) films, and woods. The PAGS-treated substrates were able to self-extinguish and eliminate molten droplets. Similarly, the PAGS coating significantly suppressed the heat release of each substrate. The P-containing free radicals in the gas phase were able to interact with highly reactive H, HO and alkyl radicals, blocking the chain reaction during combustion. The flammable gas density was also diluted by nonflammable gases. The formed continuous porous and dense intumescent char layer hindered heat and oxygen. It is suggested that this work provides a simple and efficient flame retardant strategy for improving the fire safety of various polymer substrates.

Up to Date Review of Nature-Inspired Superhydrophobic Textiles: Fabrication and Applications

In recent years, with the rapid development of the economy and great progress in science and technology, people have become increasingly concerned about their quality of life and physical health. In order to pursue a higher life, various functional and biomimetic textiles have emerged one after another and have been sought after by people. There are many animal and plant surfaces with special wettability in nature, and their unique "micro-nano structures" and low surface energy have attracted extensive attention from researchers. Researchers have prepared various textiles with superhydrophobic features by mimicking these unique structures. This review introduces the typical organisms with superhydrophobicity in nature, using lotus, water strider, and cicada as examples, and describes their morphological features and excellent superhydrophobicity. The theoretical model, commonly used raw materials, and modification technology of superhydrophobic surfaces are analyzed. In addition, the application areas and the current study status of superhydrophobic surfaces for textiles are also summarized. Finally, the development prospects for superhydrophobic textiles based on bionic technology are discussed.