Durable Superhydrophobic Cotton Textiles with Ultraviolet-blocking Property and Photocatalysis Based on Flower-Like Copper Sulfide

Surface Modification of Cotton Fabric Using TiO2 Nanoparticles for Self-Cleaning, Oil-Water Separation, Antistain, Anti-Water Absorption, and Antibacterial Properties

Superhydrophobicity is of interest for practical applications such as water repellency, self-cleaning, stain resistance, antibacterial properties, and oil-water separation. In this work, a superhydrophobic coating on cotton fabric is prepared by simple immersion in TiO₂ nanoparticles and perfluorodecyltriethoxysilane solution. Its antiwetting properties, surface morphology, and functionality are characterized. The cotton fabric shows superhydrophobicity with a water static contact angle of 169.3 ± 2.1° and tilt angle of 6.3 ± 2.0°. The coating is also characterized by performing stability tests, and it shows excellent mechanical durability, chemical stability, and thermal stability. Additionally, the water droplet dynamic on the coated surface is also studied. The coated cotton fabric exhibits excellent self-cleaning, stain resistance, rust stain resistance, anti-water absorption, and antibacterial properties. It can also be used in oil-water separation with a high separation efficiency and excellent reusability.

Electrochemical Fingerprint of CuS-Hexagonal Chemistry from (Bis(N-1,4-Phenyl-N-(4-Morpholinedithiocarbamato) Copper(II) Complexes) as Photon Absorber in Quantum-Dot/Dye-Sensitised Solar Cells

The main deficit of quantum dot/dye-sensitised solar cells (QDSSCs) remains the absence of a photosensitiser that can absorb the entire visible spectrum and increase electrocatalytic activity by enhancing the conversion efficiency of QDSSCs. This placed great emphasis on the synthesis route adopted for the preparation of the sensitiser. Herein, we report the fabrication of hexagonal copper monosulfide (CuS) nanocrystals, both hexadecylamine (HDA) capped and uncapped, through thermal decomposition by thermogravimetric analysis (TGA) and a single-source precursor route. Morphological, structural, and electrochemical instruments were used to assert the properties of both materials. The CuS/HDA photosensitiser demonstrated an appropriate lifetime and electron transfer, while the electron back reaction of CuS lowered the electron lifetime in the QDSSCs. The higher electrocatalytic activity and interfacial resistance observed from current density-voltage (I–V) results agreed with electrochemical impedance spectroscopy (EIS) results for CuS/HDA. The successful fabrication of hexagonal CuS nanostructures of interesting conversion output suggested that both HDA capped and uncapped nanocrystals could be adopted in photovoltaic cells.

Advances in photocatalytic self-cleaning, superhydrophobic and electromagnetic interference shielding textile treatments

The use of nanomaterials in textiles provides many new opportunities and advantages for users and manufacturers; however, it comes with some of its downsides and challenges which need to be understood and overcome for enhancing the applicability of these products. This review article discusses the recent progress in developing self-cleaning and conductive textiles as two of the leading research fields of smart textiles. In particular, different aspects of fabricating nanocoatings for photocatalytic self-cleaning, superhydrophobic and electromagnetic interference (EMI) shielding effect will be brought to light. The theoretical concepts, mechanisms, latest fabrication methods along with their potential applications will be discussed. Moreover, the current drawbacks of these fields will be underlined and some recommendations for future research trajectories in terms of performance, current limitations, sustainability and safety will be proposed. This review article provides a comprehensive review on the state-of-the-art achievements in the field, which will be a valuable reference for researchers and decision makers.

Environmentally benign non-wettable textile treatments: A review of recent state-of-the-art

Among superhydrophobic materials, non-wettable textiles are probably the ones that come in contact or interact with the human body most frequently. Hence, textile treatments for water or oil repellency should be non-toxic, biocompatible, and comply with stringent health standards. Moreover, considering the volume of the worldwide textile industry, these treatments should be scalable, sustainable, and eco-friendly. Due to this awareness, more and more non-wettable textile treatments with eco-friendly processes and green or non-toxic chemicals are being adopted and reported. Although fluorinated alkylsilanes or fluorinated polymers with C8 chemistry (with ≥ 8 fluorinated carbon atoms) are the best performing materials to render textiles water or oil repellent, they pose substantial health and environmental problems and are being banned. For this reason, water/solvent-borne, C8-free vehicles for non-wettable treatment formulations are probably the only ones that can have commercialization prospects. Hence, researchers have come up with a variety of new, non-toxic, green formulations and materials to render fabrics liquid repellent that constitute the focus of this review paper. As such, this review article discusses and summarizes recent developments and techniques on various sustainable superhydrophobic treatments for textiles, with comparable performance and durability to formulations based on fluorinated C8 compounds. The current state-of-the-art technologies, potential commercialization prospects, and relevant limitations are discussed and summarized with examples. The review also attempts to indicate promising future strategies and new materials that can transform the process for non-wettable textiles into an all-sustainable technology.

NiO x Nanoflower Modified Cotton Fabric for UV Filter and Gas Sensing Applications

Integration of multifunctional nanomaterials with textiles could be a significant value addition to the bright future of the growing technology "Technical Textiles". Development of textiles with antielectromagnetic radiation and in particular antiultraviolet features could be one of the best solutions to the ozone depletion induced ultraviolet pollution of the environment, which is a major concern in the context of surging skin cancer cases. In this background, multifunctional nanoflower structured partial hydroxide nickel oxide (NiO _x) was grown on cotton fabric using a chemical bath deposition technique for the development of UV filter and flexible gas/chemical sensor. X-ray diffraction patterns of bare and NiO _x modified cotton fabrics confirmed the micro and poly crystalline nature, respectively. Field emission scanning electron microscopic images revealed the growth of 3D green button chrysanthemum flower-like morphology on the surface of cotton fabric. In addition, X-ray photoelectron spectra revealed the presence of nickel, carbon, and oxygen elements in the NiO _x modified cotton cellulose. The increase in hydrophobic nature of surface-treated fabric was observed using a goniometer. A differential scanning calorimeter trace for bare and surface modified cotton fabrics exhibited endothermic behavior at the characteristic onset temperature. The results of thermogravimetric analysis revealed the enhanced thermal stability of up to 800 °C for the surface-treated fabric compared to bare cotton. Further, the ultraviolet protection factor (UPF) of the NiO _x nanoflower modified cotton fabric was measured using an in vitro method following the AATCC 183:2004 standard using a UV transmittance analyzer. The enhanced absorbance of ultraviolet rays at 388 nm resulted in the UPF of 2000. The chemical/gas sensing features of the surface modified textile samples were investigated using the homemade gas testing chamber. NiO _x modified fabric showed a selective response of 12431 toward trimethylamine at room temperature.

Robust Superhydrophobic Cotton Fibers Prepared by Simple Dip-Coating Approach Using Chemical and Plasma-Etching Pretreatments

The preparation of superhydrophobic textiles with high mechanical and chemical durability is challenging. Here, facile and fluorine-free methods, using alkali and plasma-etching treatments, followed by the addition of silica nanoparticles and tetraethyl orthosilicate (TEOS), were used to prepare superhydrophobic cotton surfaces. With different input variables and etching techniques, superhydrophobic cotton fabrics with high chemical and mechanical durability were successfully prepared, with contact angles up to 173°. A control of the surface architecture at the nanoscale in combination with a homogeneous repellent layer of TEOS in the cotton surface was achieved. The repellent properties of the as-prepared cotton remain stable under accelerated laundering and abrasion test conditions. The etching pretreatment by alkali or plasma plays a key role in obtaining superhydrophobic cotton surfaces.

RN, Rajamathi JT, Rajamathi M. Microwave-Assisted Synthesis of Porous Aggregates of CuS Nanoparticles for Sunlight Photocatalysis

Solvated two-dimensional nanosheets of copper hydroxy dodecylsulfate in 1-butanol react with thiourea under microwave irradiation to yield surfactant-free porous aggregates of CuS nanoparticles. These aggregates exhibit excellent photocatalytic activity toward degradation of methylene blue, methyl orange, and 4-chlorophenol in natural sunlight. While the high surface area (14.74 m² g^-1) and porosity increase the active reaction centers for adsorption and degradation of organic molecules, quantum confinement results in a low recombination of photogenerated electrons and holes. Chemical and photogenerated hydroxyl radicals cause the oxidation of the dyes and 4-chlorophenol.