Fabrication and multifunctional properties of marigold-like nanostructured beta-Ni(OH)(2) coated cotton fabric

Oil spillage from petroleum industry and also the mixing of industrial wastewater into water bodies are some of the major ways of water pollution. Low cost, biodegradable and biocompatible materials are highly required for tackling the pollution problem without causing further indirect pollution. In this work, a superamphiphilic nanomarigold-like beta-Ni(OH)(2) based coating on commercial cotton fabric (bNH-CF) has been fabricated by a simple one pot hydrothermal process. The fabric is able to simultaneously separate oil and water from oil-water mixtures where the sample is pre-wetted by either oil or water. The coated fabric shows under-oil superhydrophobicity and underwater superoleophobicity. The sample is able to separate both light and heavy oils from oil-water mixtures, oil-alkaline/acidic/salt/hot water mixtures with similar to 99% separation efficiency. In addition, it shows an excellent reusability (up to 50 cycles) with superior mechanical and chemical durability under harsh conditions without affecting the nanomarigold-like structure of beta-Ni(OH)(2) that developed upon the cotton fabric. The presence of beta-Ni(OH)(2) coated fabric shows significant bacterial (E. coli and S. aureus) and fungal (C. albicans) reduction in contaminated water. Hence, the coated cotton fabric fabricated by cost effective process can be useful for hassle-free simultaneous separation of oil-water mixtures as well as removal/growth inhibition of microbes from wastewater. The coated fabric also shows significant electrical conductivity. On the other hand, hexadecyltrimethoxysilane modified beta-Ni(OH)(2) coated fabric (bNHS-CF) shows excellent in-air superhydrophobicity, self-cleaning and anti-staining properties.Thus, the versatility of coated fabric can broaden the domain of practical applications as antimicrobial and superwetting multifunctional textiles. GRAPHICS]

Green synthesis of hierarchically structured Ag-Cu2O on cotton fabric with sustained antimicrobial activity and on-demand oil-water separation ability

Film deposition/modification of cotton fabric surface is an effective way to impart multiple functionalities towards a broad range of applications. In this work, we demonstrate a facile approach for the green fabrication of hierarchical hollow structures of Ag-Cu2O on cotton fabric (ACN). The effect of key parameters such as time, temperature, precursor concentrations, and type of substrates upon the formation of a unique mud-dauber wasp nest-like structure has been studied and also the formation mechanism of the structure has been proposed. The fabric shows underwater superoleophobicity owing to the presence of hierarchical surface structures and after modification with hexadecyltrimethoxysilane (ACNS), it also shows superhydrophobicity. By virtue of switchable super-wettability, the fabric has been used for on-demand separation of light oil-water and heavy oil-water mixtures with similar to 99% separation efficiency and superior reusability. In addition, the coated fabric, ACNS exhibits an excellent self-cleaning ability towards solid and liquid contaminants. Moreover, the coated fabric, ACN shows antimicrobial activity towards bacteria E. coli and S. aureus and fungi C. albicans with 100% microbial reduction efficiency. The superhydrophobic cotton fabric (ACNS) has been employed to enhance the longevity of antimicrobial activity by hindering the uninhibited release of copper and silver ions. As a result, an efficient and sustainable antimicrobial activity up to 90 days has been achieved. This modification strategy could be useful for advancing research in the field of surface science

Fabrication and multifunctional properties of fluorine-free durable nickel stearate based superhydrophobic cotton fabric

A fluorine-free superhydrophobic cotton fabric based on nickel stearate with multifunctional properties has been fabricated by a two step simple solution process. The cotton fabric (aNS-CF) exhibits static water contact angle, similar to 160 degrees, and water shedding angle, < 10 degrees, due to in-situ formation of hierarchical (micro and nano) broccoli-like structures of nickel stearate. The superhydrophobic cotton fabric, having superoleophilic property, has been used for separation of a series of light/heavy oil-water mixtures, and similar to 99% separation efficiency has been achieved after 10 cycles of separation process and it has been found to be slightly reduced to similar to 98% after 50 cycles. Antifouling and self-cleaning performance of the fabric has been evaluated effectively using solid and liquid contaminants as well as some common food liquids. The coating exhibits significant mechanical and chemical robustness and laundering durability in harsh conditions. The coated fabric possesses antibacterial (gram-negative E. coli and gram-positive S. aureus) and antifungal (C. albicans) properties leading to similar to 99.99% reduction in microbial growth, which has been remarkably sustained after 50 cycles of washing, abrasion and separation of oil-water mixtures. The stable multifunctional properties of the fabric exhibits a great potential towards a huge domain of practical implementations in smart textiles. GRAPHICS]

Development of superhydrophobic coating from biowaste and natural wax

Nowadays, superhydrophobic coatings (SHCs) fabricated from eco-friendly and sustainable materials are high in demand as they do not contribute to additional carbon footprint. In the present work, biowaste eggshell powder and food grade natural beeswax based SHC with static water contact angle, SCA ti 156 degrees, and sliding angle, SA 150 degrees) and also prevents adherence of the liquids. The fabricated coating also exhibits significant stability towards handling. In addition, the SHC inhibits protein adsorption on its surface. Thus, the fabricated eco-friendly SHC can be used as a potential liquid anti-adhesive food packaging coating to prevent wastage of common drinks consumed in our daily life.Copyright (c) 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Smart and Sustainable Developments in Materials, Manufacturing and Energy Engineerin

Hierarchically structured alpha-nickel hydroxide based superhydrophobic and antibacterial coating on cellulosic materials for oil-water separation

Inspired by hierarchical surface structure of lotus leaf and insect wings, a uniform coating of disorderly oriented semi crystalline alpha-Ni(OH)(2) nanosheets for creating dual scale (micro-nano) has been developed on cellulosic materials (cotton and wood) by a one-step facile solution process. The coating shows an innate superhydrophobic nature with a static water contact angle (SCA) similar to 157 degrees and water shedding angle (WSA) similar to 10 degrees. Growth pattern, morphology and microstructure, thermogravimetric mass loss behaviour and chemical bonding of alpha-Ni(OH)(2) with commercially available cotton fabric as well as antibacterial activity of the coated fabric towards gram positive and negative bacteria have been studied systematically. For long term use as a filter cloth for oil-water separation, the coating is further modified with hexadecyltrimethoxysilane (HDTMS) restoring the hierarchical structure of alpha-Ni(OH)(2). The dual scale surface roughness as well as low surface energy long chain HDTMS layer renders the coating a stable SCA similar to 162 degrees and WSA similar to 8 degrees. The superhydrophobic and superoleophilic alpha-Ni(OH)(2)-HDTMS coating shows self-cleaning ability, similar to 99% oil-water separation efficiency including reusability over 50 separation cycles. The coated sample also shows excellent chemical and mechanical stability as well as laundering fastness. This facile fabrication process can make an avenue for development of other transition metal hydroxides based superhydrophobic and superoleophilic coatings on cellulosic materials

Antimicrobial activity study of Ag-ZnO nanoflowers synthesised from neem extract and application in cotton textiles

Zinc oxide has gained a tremendous attention from materials researchers owing to its availability, ease of synthesis, biocompatibility, low cytotoxicity and widespread applications. A few green synthesis methods are available in the literature for making hierarchically structured ZnO (ZO)/metal doped ZnO. In this work, a green synthesis of Ag-ZnO flowers (AZO) has been performed from neem extract (Azadiracta indica) by low temperature solution method. Material properties of the samples such as crystallinity/crystal phase, morphology and optical property have been investigated systematically. In addition, the effect of AZO upon the growth of gram positive/negative bacteria has been studied. As prepared AZO along with a biocompatible and chitosan having antimicrobial property has been used for deposition of a robust coating on commercial cotton fabric. The morphology, chemical bond vibrations and antimicrobial activity of the coated fabric against E. coli, S. aureus and fungi C. albicans have been studied. The coated fabric shows excellent antibacterial and antifungal activities. Thus, the material can be used as medical textile in research laboratory and/or other health sectors

Fabrication and photoelectrochemical activity of hierarchically Porous TiO2-ZnO heterojunction film

For the first time, we report the fabrication of hierarchically (macro with nested meso) porous nanocrystalline TiO2-ZnO heterojunction film onto fluorine-doped tin oxide-coated glass substrate by colloidal crystal templating technique using poly(methyl methacrylate) (PMMA) spheres as template. Accordingly, the precursor solutions of titanium isopropoxide and zinc acetate dihydrate in the presence of Pluronic P123 were used to impregnate the individual solution into the template. Initially, nanocrystalline TiO(2)inverse opal mesoporous film was deposited using the titanium precursor. The film was cured at 450 degrees C in an air atmosphere. A similar process was adopted to deposit nanocrystalline ZnO inverse opal mesoporous film onto the TiO(2)to obtain hierarchically porous TiO2-ZnO heterojunction nanocrystalline film. Morphology of the fabricated films showed a periodic arrangement of macropores, whereas the microstructural analysis confirmed the presence of nested mesopores in the film network. Chemical interaction existed between TiO(2)with ZnO forming the heterojunction film was ascertained by X-ray photoelectron spectroscopy. Light harvesting efficiency of the samples was studied, and the photoelectrochemical (PEC) performance of the hierarchically porous heterojunction films as photoanode showed about 5 times enhancement in photocurrent density compared to the pristine metal-oxide-semiconductor film under visible light exposure. The porous nanocrystalline hierarchically porous inverse opal heterojunction film could be used as an efficient photoanode in PEC cell

Nano gold-coated surface patterned mesoporous titanium tin oxide sol-gel thin film: fabrication, optical and photoelectrochemical properties

Nano noble metal coating on surface patterned mesoporous semiconductor thin film can play an important role in enhancing visible light harvesting efficiency (LHE) towards improvement in photoelectrochemical (PEC) activity of the material. In this work, one-dimensional (1D) and two-dimensional (2D) mesoscale surface patterns have been created on sol-gel-based titanium tin oxide (TSO) nanostructured thin film on pure silica/indium tin oxide-coated glass by soft lithography. The TSO film matrix is observed to be mesoporous and semicrystalline as evidenced from the structural characterization by transmission electron microscopy and measurement of atmospheric ellipso-porosimetry, respectively. The 2D patterned film exhibits maximum LHE value in visible wavelength region. Further film surface modification has been carried out by depositing nano Au coating onto the bare patterned TSO films by a low temperature solution technique. Under visible light, a significant improvement in PEC activity is found and the gold-coated patterned 2D film shows higher visible LHE as well as >2.7 times higher photocurrent density than bare 2D film. This facile fabrication strategy can create an avenue toward improvement in LHE vis-a-vis the PEC activity of mesoporous mixed metal oxide semiconductor thin film. GRAPHICS] HighlightsFabricated 1D/2D patterned mesoporous tin titanium oxide sol-gel thin films.Deposited nano Au onto the patterned films.Au-coated 2D patterned film showed better visible light harvesting efficiency.The 2D patterned film exhibited an improved photoelectrochemical activity

Nano gold coated hierarchically porous zinc titanium oxide sol-gel based thin film: fabrication and photoelectrochemical activity

In this work, for the first time homogeneously distributed near periodic macroporous (HDPM) with nested mesoporous (hierarchically porous) semicrystalline zinc titanium oxide (ZTO) thin film on pure silica glass and fluorine doped tin oxide coated glass substrates was deposited by sol-gel dip coating technique from an optimized precursor solution of zinc nitrate hexahydrate and titanium isopropoxide with acetylacetone in low boiling solvents. The HDPM film formation was carried out by simple breath figure method where the pore formation occurred from the generated water droplets via molecular condensation onto the as-deposited cold solution film surface owing to solvent evaporation. Zinc to titanium ratio in precursor solution, room relative humidity and other critical parameters were tailored towards optimization of the periodic macropores formation. Gold nanoparticles (NPs) were further deposited onto the ZTO thin films by solution technique. Crystallinity, surface morphology and microstructure of the thin films were critically analyzed by X-ray diffraction, atomic force, scanning, and transmission electron microscopic studies. The photoelectrochemical (PEC) performance of the films was examined under visible light irradiation. A significant improvement in PEC activity was observed in nano Au coated hierarchically porous thin film. This facile fabrication process could be applied in different mixed metal oxide thin films for improving the PEC activity of the materials

Facile fabrication of fluorine free zirconium zinc stearate based superhydrophobic and superoleophilic coating on cotton fabric with superior antibacterial property

A simple solution technique has been adopted to fabricate in situ generated zirconium zinc stearate based superhydrophobic and superoleophilic fluorine-free coating on cotton fabric with superior antibacterial and excellent photocatalytic properties. The materials properties of the specimen such as crystallinity/crystal phase, chemical bonding, surface morphology, and surface roughness have been characterized systematically. The coated cotton derived from an optimized precursor composition shows the retention of superhydrophobicity with static water contact angle \~163 degrees after several cycles of machine laundering and mechanical abrasion. It is seen that zirconium species may have caused an enhancement in laundering durability and mechanical robustness while hierarchical morphology of zinc stearate is responsible for acquiring superior antibacterial property along with self cleaning ability of the coating to make the coated fabric promising for real life application such as military uniform, biomedical clothing/devices. In addition, the coated cotton is found to be suitable for separation of oil from oil-water mixtures with high efficiency (\~99%) even after 10 cycles of repeated use. Thus, the material can be used for separation of oil from oil-contaminated industrial wastewater/marine water. Moreover, AgBr modified superhydrophobic cotton fabric shows excellent photocatalytic activity towards degradation of organic dye. This facile process can be up-scaled for commercial u