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• The Sol-Gel method followed by spin coater was used to fabricate the copper heating surface with TF. • Refrigerant R141b was used as a working fluid and heat transfer coefficient was investigated based on saturation temperature or pressure and heat flux. • Experimental results were validated with established correlations and qualified with excellent agreement. • A mathematical model was formulated, and it predicts the optimal heat transfer coefficient for various coating thicknesses under the nucleate pool boiling configuration. Experimental investigations were conducted to study the significance of surface modification on the heat transport phenomena under nucleate pool boiling configuration of saturated R-141b at ambient condition over SiO 2 thin film (TF) nanocoated surfaces. The experiments were conducted within the heat flux variation of 50 to 185 kW/m2 at an interval of 15 kW/m2. The diameter of the heating surface was 9 mm, and the thickness was 3 mm. Five Cu heating surfaces of circular shape having zero (Emery polished surface (S1)), 125 (S2), 250 (S3), 375 (S4), and 500 (S5) nm coating thicknesses were fabricated employing the Sol-Gel approach accompanied by spin coater and characterized by surface profilometer and field emission scanning electron microscopy (FE-SEM). The current experimental results were verified with the existing correlations proposed in the literature. It was found that the heat transfer coefficient increased with an increase in the heat flux, and it is also witnessed here that modification in the surface significantly contribute towards the improvement in the heat transfer coefficient. The maximum and the minimum heat transfer were revealed at 375 (S4) and 500 (S5) nm coating thickness, respectively. Modification of the surface leads to an increase in the heat transfer coefficient due to the existence of a large number of dynamic nucleation sites. Finally, a mathematical model to predict the optimum nucleate pool boiling heat transfer coefficients for different coating thicknesses was proposed which reflects the effects of surface thickness, coating thickness, and the imposed heat flux. The model predicts good agreement with the experiment of R-141b and other existing findings within an accuracy of ± 5 %. [ABSTRACT FROM AUTHOR]

Herein, the influence of the substrate in the formation of zirconium oxide monolayer, from an aqueous hexafluorozirconic acid solution, by chemical conversion and by electro-assisted deposition, has been approached. The nanoscale dimensions of the ZrO2 film is affected by the substrate nature and roughness. This study evidenced that the mechanism of Zr-EAD is dependent on the potential applied and on the substrate composition, whereas conversion coating is uniquely dependent on the adsorption reaction time. The zirconium oxide based nanofilms were more homogenous in AA2024 substrates if compared to pure Al grade (AA1100). It was justified by the high content of Cu alloying element present in the grain boundaries of the latter. Such intermetallic active sites favor the obtaining of ZrO2 films, as demonstrated by XPS and AFM results. From a mechanistic point of view, the electrochemical reactions take place simultaneously with the conventional chemical conversion process driven by ions diffusion. Such findings will bring new perspectives for the generation of controlled oxide coatings in modified electrodes used, as for example, in the construction of battery cells; in automotive and in aerospace industries, to replace micrometric layers of zinc phosphate by light-weight zirconium oxide nanometric ones. This study is particularly addressed for the reduction of industrial waste by applying green bath solutions without the need of auxiliary compounds and using lightweight ceramic materials. [ABSTRACT FROM AUTHOR]

Molecularly thin two-dimensional (2D) nanomaterials are attractive building blocks for constructing anticorrosion nanocoatings as an ultimate pursuit in the metal-related industry. However, the nanocoating of prefocused graphene is far from industrial demands due to its high cost, low scalability, and insufficient quality. We propose all requirements to realize rational anticorrosion nanocoating of metal oxide nanosheets. The proof-of-concept study with Ti 0.87 O 2 and Ca 2 Nb 3 O 10 nanosheets demonstrates that the 10 and 20 nm thick coatings fabricated by a facile layer-by-layer (LbL) self-assembly on stainless steel (SUS) give perfect inhibition efficiency (IE) values of 99.92% and 99.89%, respectively. A driving test with a nanosheet-coated car-baffle demonstrated suitable corrosion resistance and mechanical and thermal robustness for industrial applications. The revealed and controlled thermal oxidation mechanisms are critical toward high-temperature application of the 2D oxide anticorrosion nanocoating. The advantages of nanosheet coating and extensible materials design will open a solid but exciting route to anticorrosion nanotechnology.

Microbial inoculants can enhance soil quality, promote plant nutrient acquisition, and alleviate problems caused by the excessive use of chemical fertilizers. However, susceptibility to harsh conditions during transport and storage, as well as the short shelf-life of plant growth-promoting rhizobacteria (PGPR), limit industrial application. Herein, a novel strategy to form nanocoating on bacterial surfaces to enhance viability was proposed. The nanocoating was composed of N -hydroxysuccinimide (NHS)-modified poly (γ-glutamic acid) (γ-PGA) and calcium ions, which could adhere to the surface of bacteria by forming covalent bonds and ionic bonds with the bacteria. The bacteria encapsulated in the coating had better resistance against harsh conditions than bare bacteria. The viability of coated bacteria was also increased by 2.38 times compared with bare bacteria after 4 weeks of storage. The pot experiment showed that coated Pseudomonas stutzeri NRCB010 had better growth-promoting properties compared with free P. stutzeri NRCB010. These results indicate that cell surface engineering is an effective method to enhance the resistance of bacteria against harsh conditions and is expected to promote the widespread use of PGPR.

Engineered nanomaterials (ENMs) have an enormous economic impact. In the surface coating industry, titanium dioxide (TiO2) and silicon dioxide (SiO2) nanoparticles are commonly incorporated into varnishes, paints, and finishing products. These ENMs are used for UV-active properties and self-cleaning activities, as well as for the durability and resistance they provide. However, several health concerns are associated with the inhalation of some ENMs. In this case study, occupational exposures to engineered nanoparticles were investigated in an industrial hardwood floor manufacturing plant during the finishing task of an automated spraying equipment. A combination of air and surface sampling was carried out during two workdays. Airborne and deposited particles were measured using a combination of real-time and filter-based sampling methods and analyzed by microscopy and spectrometry. Results indicate that the wood floor coating process generates airborne TiO2 and SiO2 nanoparticles which include individual particles in the nanoscale range (lower than 100 nm) and agglomerated particles of several hundred nanometers containing individual nanoparticles. Finishing activities significantly increased total particle number concentrations (45 620 and 117 880 particles cm-3) and surface-specific mass concentrations (154 µm2 cm-3). Concentrations of TiO2 ranged from 13 to 97 µg m-3 for personal measurements and from 36 to 55 µg m-3 for ambient measurements in the finishing location. Characterization of the deposited particles indicated the dispersion of the engineered airborne nanoparticles from the finishing location to the packaging area. Using a multimetric approach, this study shows high evidence that the worker was exposed to engineered TiO2 and SiO2 nanoparticles during the finishing process of the wood floor production facility. In addition, this study indicates that workers outside the finish spray area could be exposed to airborne engineered TiO2 and SiO2 nanoparticles coming from the finishing process., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

The change induced in some parameters of a nanocoating by 0.1 N solutions of hydrochloric and nitric acids was studied. It was found that swelling is more intense in hydrochloric than in nitric acid. The intensity of the dissolution of a nanocoating in a 0.1 N solution of nitric acid is directly proportional and in hydrochloric acid inversely proportional to the etch time. [ABSTRACT FROM AUTHOR]

A one-pot strategy was developed to coat micro- and nanomaterials with crystalline nanoparticles. Three Li-based materials were coated by a solution combustion synthesis method. By this procedure, we obtained LiCoO 2 nanoparticles covered with nanocrystals of NiO and Ag; LiMn 2 O 4 nanoparticles covered with Ag, and LiNi 0·5 Mn 1·5 O 4 microparticles covered with ZnO. The results confirm that the coating of the nano- and micro-particles was successful. The materials obtained were characterized morphologically and structurally. Using X-ray diffraction, Transmission Electron Microscopy (TEM), Scanning Electron Microscope (SEM), and Energy-dispersive X-ray Spectroscopy Mapping, the morphological uniformity and high crystallinity of the nano-coatings were confirmed. Therefore, this method makes it possible to obtain different coatings by varying the weight percentage of the coating material, yielding homogeneously coated materials, even at percentages as low as 0.5 wt%. The developed method has great advantages as it is simple, inexpensive, and easily scalable. Image 1 • Homogeneous coating with crystalline nanoparticles using a liquid method. • Solution combustion as an efficient method to coat micro and nano size materials. • Materials coated with crystalline nanoparticles in controlled weight ratios. • Method used to coat cathode materials for Li-ion batteries. • Simple, time- and energy-saving method. [ABSTRACT FROM AUTHOR]

Abstract: In order to suppress fast degradation of ZnS-type phosphors applied in field emission displays (FEDs), the surface coating and encapsulation are expected to be an effective way. The titania nanocoatings are obtained by a sol–gel route using tetrabutyl titanate (TBT) as the precursor in this paper. With the addition of the glacial acetic acid (HAc), due to the formation of Ti(OC4H9) x (Ac)4– x ligand, the hydrolysis process is inhibited. When the molar ratio of HAc to TBT is 2, the appropriate gelation rate is obtained. The coating process is perhaps related to the electrostatic forces and chemical bonding between ZnS phosphor and Ti(OH)2(Ac)2 ligand. [Copyright &y& Elsevier]

• Nanostructured tubes had higher and lower heat transfer coefficients than plain. • Nanostructured tubes had up to 200% higher heat transfer coefficients than plain. • Pool boiling of nanostructured tubes is unique compared to plain tubes. • The critical heat flux of nanostructured tubes was lower than plain tubes. • Wickable surfaces may lose their wettability when boiling organic fluids. This study investigated the heat transfer performance of three nanostructured surfaces and two plain surfaces: one roughened and one polished during the saturated pool boiling of refrigerants R-134a at 5 and 25 °C and R-245fa at 20 °C. Nanocoatings were applied to polished copper tubes through a layer-by-layer (LbL) process that deposited silica nanoparticles, a chemical oxidation process where an intertwined mat of sharp copper oxide (CuO) structures were generated and a commercial nanocoating process (nanoFLUX). A polished copper tube and a roughened copper tube were tested as comparison cases. All tubes were tested in the horizontal position in pool boiling over heat fluxes of 20 to 100 kW/m2, followed by a further increase in heat flux in an attempt to reach critical heat flux. The tubes were internally water heated and Wilson plots were conducted to characterise the internal heat transfer characteristics. The nanoFLUX surface had the highest heat transfer coefficients, the LbL and polished surfaces had the lowest heat transfer coefficients, and the CuO and roughened surfaces had intermediate heat transfer coefficients. The nanoFLUX surface had between 40 and 200% higher heat transfer coefficients than those of the polished tube. Both roughened tubes and nanocoated tubes showed typical exponentially increased heat transfer coefficients as heat flux was increased. However, the nanoFLUX and CuO surfaces displayed more heat flux sensitivity compared with the other surfaces. The nanoFLUX surfaces outperformed the other nanostructured surfaces due to a higher nucleation site density and outperformed the roughened tube due to a unique heat transfer mechanism. The nanoFLUX and CuO surfaces also experienced reduced critical heat flux compared with plain surfaces, thought to be caused by the trapping of vapour in the fibrous nanostructures, resulting in reduced wetting in the Cassie-Baxter state. [ABSTRACT FROM AUTHOR]

Relatively poor adhesion of carbon fibers with matrix leads to various serious concerns in high performance composites. Interface debonding during loading is the most vulnerable among them particularly when polymer matrix is used. This paper presents the results of electron microscopy investigation of four different techniques that are beneficial for improving interfacial bonding. These techniques were based on modifying the fiber surface by way of both; coating a film on the fiber and ablating a layer from it. The former employed growth of nanostructures of carbon and zinc oxide by thermal catalytic chemical vapor deposition and magnetron sputtering respectively and depositing a layer of pyrolytic carbon by CVD while the latter involved ablation of an outer layer of fiber using femtosecond laser treatment. Both the approaches relied on introducing mechanical anchoring on the fiber surface by micro roughening anticipating an improved fiber- matrix interfacial bonding. Carbon fiber surface prior and post treatment was investigated microscopically using FESEM and TEM. CNTs growth formed network like structure around the fiber, while PyC coating showed continuous layer around the fiber. HRTEM images of ZnO nanostructures; both nanowires and nanowalls possessed crystalline structure revealed by the presence of Moiré fringes formed due to overlapping of two crystals with different orientation. Laser treated fiber surface showed formation of LIPSS with average periodicity of 147 ± 10 nm. Unlabelled Image • Surface modification of carbon fiber at nano-scale for interface strengthening in composites by; (i) PyC coating, (ii) MWCNTs growth, (iv) ZnO nanowires, nanowalls growth and (v) Femtosecond laser machining • FESEM imaging revealing uniform growth • HRTEM shows crystalline structure of grown nanostructures [ABSTRACT FROM AUTHOR]

Nanocoatings have numerous potential applications in the indoor environment, such as flooring finishes with increased scratch- and wear-resistance. However, given concerns about the potential environmental and human health effects of nanomaterials, it is necessary to develop standardized methods to quantify nanomaterial release during use of these products. One key choice for mechanical wear studies is the abrasion wheel. Potential limitations of different wheels include the release of fragments from the wheel during abrasion, wearing of the wheel from the abrasion process, or not releasing a sufficient number of particles for accurate quantitative analysis. In this study, we evaluated five different wheels, including a typically used silicon oxide-based commercial wheel and four wheels fabricated at the National Institute of Standards and Technology (NIST), for their application in nanocoating abrasion studies. A rapid, nondestructive laser scanning confocal microscopy method was developed and used to identify released particles on the abraded surfaces. NIST fabricated a high performing wheel: a noncorrosive, stainless-steel abrasion wheel containing a deep cross-patch. This wheel worked well under both wet and dry conditions, did not corrode in aqueous media, did not release particles from itself, and yielded higher numbers of released particles. These results can be used to help develop a standardized protocol for surface release of particles from nanoenabled products using a commercial rotary Taber abraser. [ABSTRACT FROM AUTHOR]

Commercial hernia mesh is commonly made from polypropylene (PP), due to its inertness, biocompatibility, physical properties, ease of processing and versatility for conversion into flexible shape. However, reportedly hernia mesh prepared from PP experienced issues such as diminished long-term strength, foreign body rejection, lack of biocompatibility and high adhesion to the abdomen wall. Infiltration of the mesh by soft tissue (called remodeling) results in an integration of mesh into the body, leading to a rapid reduction in mesh mechanical properties and potential infection. Here, this study addresses these issues through the incorporation of nanodiamond (ND) into PP filament and coating on the surface of plasma-treated PP-ND mesh. The results show that the dynamic modulus of the PP-ND mesh increased significantly, without compromising its flexibility. Coating PP-ND mesh with hydroxylated ND led to a reduction in nonspecific protein adsorption onto the surface of nanocomposite, which is an important characteristic for hernia mesh to prevent foreign body reaction, attachment of mesh to the abdominal wall and nearby organs. In-vitro study with mammalian cells shows that coated PP-ND mesh with functionalized ND exhibits a significant increase in the number of adhered cells with more elongated morphology in comparison with other PP meshes, due to the better hydrophilicity. Therefore, the ND coated nanocomposite mesh can be a promising candidate for hernia repair in the future; however, more investigation is required. Unlabelled Image • Developed Polypropylene–nanodiamond (PP-ND) composite hernia mesh developed is the first reported in the literature. PP-ND provided exceptional long-term stability performance, mechanical and biological properties. • Plasma treated PP-ND mesh supported attachment of hydroxylated ND to the surface resulting in a durable ND coating. • PP-ND exhibited excellent stability and performance properties, that lead to a durable and biocompatible implanted mesh • PP-ND exhibited significant reduction in protein absorption consistent with lower inflammatory responses • No cytotoxicity was observed that indicated PP-ND scaffold could be ideal for complex hernia repair management. [ABSTRACT FROM AUTHOR]

This paper presents the results of corrosion and tribological analysis of pure and nanocomposite zinc coatings. Coatings were electroplated using commercially available products—zinc acidic bath and a nanoparticle carrying plating additive. Electrochemical measurements were carried out to compare the anticorrosion performance of coatings. An investigation into the influence of nanoparticles on the mechanical properties was performed. The zinc nanocomposite coating exhibited better wear resistance and higher hardness than the plain zinc coating. The application of confocal laser scanning microscopy (CLSM) allowed the detailed description of friction/wear marks. The electrochemical studies revealed that the introduction of nanoparticles into the coating did not compromise its protective properties—a similar resistance of plain and nanocomposite coatings to corrosion was obtained. [ABSTRACT FROM AUTHOR]

A new strategy through coating inorganic adhesive as the "nano-armor" to enhance the existing surface microstructure and related surface wettability was advanced. The method can strengthen the surface microstructure while simultaneously keep the original microstructure and related function unchanged, which can further be used to protect and enhance lots of other surface microstructure-dependent functions. • Underwater superoleophobic copper microstructure was prepared by eletrodeposition. • Rigid aluminum dihydrogen phosphate coating can act as a layer of nano-armor. • The nano-armor can enhance the mechanical stability of the copper microstructure. • The nano-armor coated copper film has a robust underwater superoleophobicity. Recently, enhancing the stability of surface microstructure becomes a research focus due to its significant effect on various interfacial properties, such as the wettability. A new strategy that can improve the stability of existing microstructure without changing its morphology is desirable since it can keep original surface functions that are dependent on the microstructure, but it is still a challenge. Herein, we report such a strategy through dip coating and heat treatment of a layer of rigid aluminum dihydrogen phosphate (ADP) on the existing fragile copper micro/nanostructure. SEM results and the mechanical wear tests including sand abrasion and tape peeling test results demonstrate that the ADP coating can act as a layer of "nano-armor" to protect the inner microstructure without changing its morphology, as a result, the stability of both surface microstructure and corresponding underwater superoleophobicity are improved remarkably. Specifically, the hardness of microstructure is improved by a factor about 10. Theoretical simulations analysis reveals that the enhanced effect results from the nanocoating, which decreases the maximum transverse deformation and stress on the microstructure. Finally, the method was also applied on some other surfaces with particular functions including anisotropic wettings and oil/water separating properties, further confirming the universality for strengthening the microstructure-dependent surface functions. This work advances a strategy through strengthening existing surface microstructure to obtain stable superwetting performance, which starts fresh ideas for the design of robust functional interfacial materials. [ABSTRACT FROM AUTHOR]

Recently, carbon allotropes have received tremendous research interest and paved a new avenue for optical fiber sensing technology. Carbon allotropes exhibit unique sensing properties such as large surface to volume ratios, biocompatibility, and they can serve as molecule enrichers. Meanwhile, optical fibers possess a high degree of surface modification versatility that enables the incorporation of carbon allotropes as the functional coating for a wide range of detection tasks. Moreover, the combination of carbon allotropes and optical fibers also yields high sensitivity and specificity to monitor target molecules in the vicinity of the nanocoating surface. In this review, the development of carbon allotropes-based optical fiber sensors is studied. The first section provides an overview of four different types of carbon allotropes, including carbon nanotubes, carbon dots, graphene, and nanodiamonds. The second section discusses the synthesis approaches used to prepare these carbon allotropes, followed by some deposition techniques to functionalize the surface of the optical fiber, and the associated sensing mechanisms. Numerous applications that have benefitted from carbon allotrope-based optical fiber sensors such as temperature, strain, volatile organic compounds and biosensing applications are reviewed and summarized. Finally, a concluding section highlighting the technological deficiencies, challenges, and suggestions to overcome them is presented. [ABSTRACT FROM AUTHOR]

• Synthesis of G/C PVP-AgNPs was characterized by the XRD, PSA, FTIR, FE-TEM, EDS. • The G-PVP-AgNPs was exhibited the excellent antibacterial activity. • Nanocoating of G/C PVP-AgNPs was expand the shelf life of Fresh-cut pepper (FCP). • The G-PVP-AgNPs was increase the shelf life of FCP than the C-PVP-AgNPs. • This work recommended that G-PVP-AgNPs is a promising preservative agent for FCP. The present work reported the comparative analysis on the preparation and characterization of chemically and green synthesized silver nanoparticles polyvinylpyrrolidone (PVP) based glycerosomes (C/G-PVP-AgNPs) and their function as antimicrobial nanocoating agent to augment the shelf life of the fresh cut pepper (FCP). The UV Spectrophotometer results revealed peak at 400–420 nm indicating the formation of G-AgNPs and C-PVP-AgNPs. The Fourier-transform infrared spectroscopy (FTIR) results indicated the involvement of phytomolecules from the pedicel extracts on the synthesis of G-AgNPs and this analysis displayed the peaks corresponding to copolymers PVP and glycerol in G/C-PVP-AgNPs. The X-ray diffractometer (XRD) results confirmed G-AgNPs followed the occurrence of the Ag in G/C-PVP-AgNPs. The particle size analyzer (PSA) and field emission transmission electron microscopy- Energy Dispersive X-ray Spectroscopy (FETEM-EDS) revealed the mean size of 37.01 nm for G-AgNPs, 123 nm for G-PVP-AgNPs and 45.26 nm for C-PVP-AgNPs. The G-PVP-AgNPs showed more antibacterial activities than the C-PVP-AgNPs as evident by low minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The application of the nano coating of G-PVP-AgNPs extended the shelf life of the red or yellow FCP (Fresh Cut bell Pepper) for 12 d at 4 °C without causing any harm to cellular or physicochemical properties of FCP. The G/C-PVP-AgNPs coated FCP juices did not cause any toxicity to the survival of roundworms while the uncoated FCP juice caused the cellular damage in the roundworm. These results suggested the potential application of G-PVP-AgNPs as a preservative agent to augment the shelf life of FCP in food industry for the future. [ABSTRACT FROM AUTHOR]

A critical challenge to the development of tissue engineering small-diameter vascular grafts is to achieve rapid endothelialization and long-term anticoagulation. It is necessary to graft both adhesion and antithrombus factors onto the surface of polycaprolactone without burst release to promote endothelial cell affinity and antithrombogenicity. A bionic structure with a nanocoating that allows a biologically responsive, long-term release was employed in this work to enable the grafting of various bioactive molecules such as gelatin, polylysine, and heparin. This approach involved orienting the biomimetic vascular structures; the self-assembly grafting of gelatin, polylysine, and heparin nanoparticles; and genipin crosslinking to form a multiphase crosslinked nanocoating. In this biologically inspired design, vascular endothelialization and long-term anticoagulation were successfully induced through a matrix metallopeptidase 2 regulative mechanism by delivering both adhesion and antithrombus factors with a responsive, long-term release without burst release. The method provided a simple and effective approach for delivering dual factors for tissue engineering small-diameter vascular grafts. • Surface functionalization of polycaprolactone by multiphase crosslinked nanocoating to achieve a long-term release of antithrombus factors was proposed. • The long-term release profile of heparin reached up to 35 days. • Long-term anticoagulation and rapid endothelialization were successively induced through a matrix metallopeptidase 2 regulative mechanism. [ABSTRACT FROM AUTHOR]

Abstract: In order to apply ZnS-type phosphors in field emission displays (FEDs), their poor ageing performance, resulting from their surface oxidation at high current densities, should be improved. In this study, the green emitting ZnS:Ag,Cl phosphors are covered with uniform and continuous SiO2 coatings via a sol–gel route, which is expected to inhibit their surface oxidation. During the gelation process, cetyltrimethylammonium chloride (CTAC), a cationic surfactant, is added to increase the dispersibility of phosphors in suspension. Furthermore, the addition of CTAC promotes uniform distribution of charges on the whole phosphor surfaces, thus benefit the formation of continuous and uniform coatings. [Copyright &y& Elsevier]

Modification by intumescent flame retardants is an effective way to impart antiflame properties to fabric materials. Polyphosphazene elastomers contain all three elements required by intumescent flame retardants: an acid source, a gas source, and a carbon source, making them all-in-one integrated intumescent flame retardants. In this work, halogen-free poly(dimethoxy)phosphazene (PDMP) loaded with 29.0 wt % phosphorus and 13.1 wt % nitrogen is shown to be an ideal flame retardant for fabric materials. For the first time, transparent and elastic PDMP was applied as an intumescent flame retardant for cotton fabric. The PDMP-coated cotton shows remarkable high-efficiency flame-retardant properties: (1) a self-extinguishing property during the vertical flame test is obtained when the add-on level reaches 5.3 wt %, with a lower smoke release character; (2) the limiting oxygen index (LOI) values of coated cotton are improved with increasing add-on level, and the thickness of the coating is measured to be at the nanolevel, 2540 nm when 10.9 wt % PDMP is coated. The coated cotton shows enhanced carbonization ability at lower temperatures, which is the key to imparting flame-retardant properties to cotton, and the PDMP-coated cotton shows remarkably lower peak heat release rate and total heat release compared to the control cotton during combustion. The durability of modified cotton was tested after 50 laundering cycles, which showed that the coating maintains 80% of its initial mass, and the after-laundering sample preserves the characteristics of self-extinguishing and a high LOI. Thus, the PDMP nanocoating-modified flame-retardant cotton fabric is sufficiently durable for practical application.

Contact lenses are widely used for visual corrections. However, while wearing contact lenses, eyes typically face discomforts (itching, irritation, burning, etc.) due to foreign object sensation, lack of oxygen permeability, and tear film disruption as opposed to a lack of wetting agents. Eyes are also prone to ocular infections such as bacterial keratitis (BK) and fungal keratitis (FK) and inflammatory events such as contact lens-related acute red eye (CLARE), contact lens peripheral ulcer (CLPU), and infiltrative keratitis (IK) caused by pathogenic bacterial and fungal strains that contaminate contact lenses. Therefore, a good design of contact lenses should adequately address the need for wetting, the supply of antioxidants, and antifouling and antimicrobial efficacy. Here, we developed multifunctional gallic acid (GA), phytomolecules-coated zinc oxide nanoparticles (ZN), and phytomolecules-coated zinc oxide nanoparticles + gallic acid + tobramycin (ZGT)-coated contact lenses using a sonochemical technique. The coated contact lenses exhibited significant antibacterial (>log 10 5.60), antifungal, and antibiofilm performance against BK-causing multidrug resistant bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia. coli) and FK-related pathogenic fungal strains (Candida albicans, Aspergillus fumigatus, and Fusarium solani). The gallic acid, tobramycin, and phytomolecules-coated zinc oxide nanoparticles have different functionalities (-OH, -NH 2 , -COOH, -COH, etc.) that enhanced wettability of the coated contact lenses as compared to that of uncoated ones and further enabled them to exhibit remarkable antifouling property by prohibiting adhesion of platelets and proteins. The coated contact lenses also showed significant antioxidant activity by scavenging DPPH and good cytocompatibility to human corneal epithelial cells and keratinocytes cell lines. STATEMENT OF SIGNIFICANCE: • Multifunctional coated lenses were developed with an efficient sonochemical approach. • Lens surface was modified with nanocoatings of ZnO nanoparticles, gallic acid, and tobramycin. • This synergistic combination endowed the lenses with remarkable antimicrobial activity. • Coated lenses also showed noteworthy antifouling and biofilm inhibition activities. • Coated lenses showed good antioxidant, biocompatibility, and wettability characteristics., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Strategic advances in the single-cell nanocoating of mammalian cells have noticeably been made during the last decade, and many potential applications have been demonstrated. Various cell-coating strategies have been proposed via adaptation of reported methods in the surface sciences and/or materials identification that ensure the sustainability of labile mammalian cells during chemical manipulation. Here an overview of the methodological development and potential applications to the healthcare sector in the nanocoating of mammalian cells made during the last decade is provided. The materials used for the nanocoating are categorized into polymers, hydrogels, polyphenolic compounds, nanoparticles, and minerals, and the corresponding strategies are described under the given set of materials. It also suggests, as a future direction, the creation of the cytospace system that is hierarchically composed of the physically separated but mutually interacting cellular hybrids., (© 2021 Wiley-VCH GmbH.)

Viscous oil adherence onto solid surfaces is ubiquitous and has caused intractable fouling problems, impairing the function of solid surfaces in various areas such as optics and separation membranes. Materials with superhydrophilicity and underwater superoleophobicity are very effective in elimination of oil fouling. However, most of them cannot dewet viscous oils and may malfunction without prehydration treatment. Herein, we report a facile and environmental strategy to prepare barium sulfate (BaSO 4 ) nanocoating to dewet viscous oils on dry surfaces. Abundant surface polar groups (surface hydroxyl) on BaSO 4 nanocoating enhance both hydrophilicity after oil fouling (underoil water contact angle <10°) and underwater superoleophobicity (underwater-oil contact angle >155°) and then facilitate oil dewetting ability. Different oils with viscosity up to 900 mPa·s can be easily eliminated after immersion into water. The results and force analysis also demonstrate that small surface roughness and ultrahydrophilicity under oil are beneficial to achieve oil dewetting property on dry surfaces. Furthermore, BaSO 4 nanocoating displays excellent mechanical, thermal and chemical stability and can maintain oil repellency through various harsh conditions. Outstanding antioil fouling ability also enables the fabric coated by BaSO 4 nanocoating to separate crude oil/water with flux higher than 28 000 Lm 2- h -1 and separation efficiency larger than 99.9% and maintain effective separation performance even after 100 times of separation. Thus, the robust superhydrophilic BaSO 4 nanocoating is potential in oil dewetting and waste oil remediation.

Light plays paramount functions for living beings in nature. In addition to color, the polarization of light is used by many animals for navigation and communication. In this study, we describe the light polarizing role of special nanostructures coating cuticular surfaces of diverse arthropods. These structures are built as parallel nanoscale ridges covering the eyes of the sunlight-navigating spider Drassodes lapidosus and of the water pond-swarming black fly Simulium vittatum , as well as the light-emitting abdominal lantern of the firefly Aquatica lateralis . Exact topography and dimensions of the parallel nanoridges provide different light polarizing efficiencies and wavelength sensitivity. Optical modeling confirms that the nanoscale ridges are responsible for the spectral polarization dependency. Co-opting from our recent work on the self-assembly of Drosophila corneal nanostructures, we engineer arthropod-like parallel nanoridges on artificial surfaces, which recapitulate the light polarization effects. Our work highlights the fundamental importance of nanocoatings in arthropods for the light polarization management and provides a new biomimetic approach to produce ordered nanostructures under mild conditions.

Polyphenolic molecules have become attractive building blocks for bioinspired materials due to their adhesive characteristics, capacity to complex ions, redox chemistry, and biocompatibility. For the formation of tannic acid (TA) surface modifications based on silicate-phenolic networks, a high ionic strength is required. In this study, we investigated the effects of NaCl, KCl, and LiCl on the formation of TA coatings and compared it to the coating formation of pyrogallol (PG) using a quartz-crystal microbalance. We found that the substitution of NaCl with KCl inhibited the TA coating formation through the high affinity of K + to phenolic groups resulting in complexation of TA. Assessment of the radical formation of TA by electron paramagnetic resonance spectroscopy showed that LiCl resulted in hydrolysis of TA forming gallic acid radicals. Further, we found evidence for interactions of LiCl with the Si aq crosslinker. In contrast, the coating formation of PG was only little affected by the substitution of NaCl with LiCl or KCl. Our results demonstrate the interaction potential between alkali metal salts and phenolic compounds and highlight their importance in the continuous deposition of silicate-phenolic networks. These findings can be taken as guidance for future biomedical applications of silicate-phenolic networks involving monovalent ions.

A coating must remain intact to perform its inherent functions on a surface, and often functional organic coatings fail due to deterioration because of their intrinsic vulnerabilities. In this work, we present a biomimetic material based on a glass sponge to provide a robust silica composite nanocoating with an antifog effect. The silica composite nanocoating was constructed with a binary film structure consisting of (1) a Fe(III)-tannic acid (TA) nanofilm for adhesion to coat the substrates and (2) a SiO 2 layer to enhance the durability of the coating. Due to the universal coating property of Fe(III)-TA nanofilms, we demonstrated that the silica composite nanocoating was effective regardless of the substrate. By layer-by-layer assembly of the silica composite, it is possible to precisely control the nanocoating thickness. The superhydrophilic nature of the SiO 2 layer showed an exceptional antifog effect that remained intact against multiple deteriorative conditions, including acid treatment, peroxide degradation, sudden temperature change, severe heat conduction, and oil contamination. In addition, the silica composite nanocoating is scalable for surfaces of different shapes and sizes with the aid of a spray-assisted deposition technique. The bioinspired, multicomposite nanocoating strategy herein contributes to the improvement of organic coatings for uses in applications to tackle current technological problems.

We report the surface-energy-dependent wetting transition characteristics of an evaporating water droplet on surface-energy-controlled microcavity structures with functional nanocoatings. The droplet wetting scenarios were categorized into four types depending on the synergistic effect of surface energy and pattern size. The silicon (Si) microcavity surfaces ( γ Si = 69.8 mJ/m 2 ) and the polytetrafluoroethylene (PTFE)-coated microcavity surfaces ( γ PTFE = 15.0 mJ/m 2 ) displayed stable Wenzel and Cassie wetting states, respectively, irrespective of time. In contrast, diamond-like carbon (DLC)-coated ( γ DLC ) surfaces demonstrated a time-dependent transition of wetting states. In particular, the DLC-coated surface showed random filling of microcavities at the earlier time point, while the FDLC-coated surface displayed directional filling of microcavities at the late stage of drop evaporation. Such dynamic wetting scenarios based on surface energy, in particular, the random and directional wetting transitions related to surface energy of nanocoatings have not been explored previously. Furthermore, the microscopic role of nanocoating in the wetting scenarios was analyzed by monitoring the time-dependent deformation and movement of the air-water interface (AWI) at individual cavities using the fluorescence interference-contrast (FLIC) technique. A coating-dependent depinning mechanism of the AWI was responsible for variable filling of cavities leading to time-dependent wetting scenarios. A capillary wetting model was used to relate this depinning event to the evaporation-induced internal flow within the droplet. Interestingly, FLIC analysis revealed that a hydrophilic nanocoating can induce microscopic hydrophobicity near the cavity edges leading to delayed and variable cavity filling. The surface energy-dependent classification of the wetting scenarios may help the design of novel evaporation-assisted thermodynamic and mass-transfer processes.2 ) and fluorinated diamond-like carbon (FDLC)-coated ( γ FDLC = 36.2 mJ/m 2 ) surfaces demonstrated a time-dependent transition of wetting states. In particular, the DLC-coated surface showed random filling of microcavities at the earlier time point, while the FDLC-coated surface displayed directional filling of microcavities at the late stage of drop evaporation. Such dynamic wetting scenarios based on surface energy, in particular, the random and directional wetting transitions related to surface energy of nanocoatings have not been explored previously. Furthermore, the microscopic role of nanocoating in the wetting scenarios was analyzed by monitoring the time-dependent deformation and movement of the air-water interface (AWI) at individual cavities using the fluorescence interference-contrast (FLIC) technique. A coating-dependent depinning mechanism of the AWI was responsible for variable filling of cavities leading to time-dependent wetting scenarios. A capillary wetting model was used to relate this depinning event to the evaporation-induced internal flow within the droplet. Interestingly, FLIC analysis revealed that a hydrophilic nanocoating can induce microscopic hydrophobicity near the cavity edges leading to delayed and variable cavity filling. The surface energy-dependent classification of the wetting scenarios may help the design of novel evaporation-assisted thermodynamic and mass-transfer processes.

Clinically related infection is a critical risk for human health and is usually caused by biofilm formation on medical devices. Herein, typical polyphenols, catechin (Cat), and rare-earth ions (Re 3+ ) were used for self-assembled Cat-Re nanoparticles that can be facilely coated on the surface of a polyamide (PA) membrane to synergistically prevent bacterial adhesion and subsequent biofilm formation. The antibacterial adhesion feature of the assembled Cat-Re nanoparticles coated on the PA membrane surface was assessed using Pseudomonas aeruginosa , one of the most common pathogenic bacteria, as probe bacteria under static and dynamic simulation flow conditions. The Cat-Re nanocoating showed excellent antibacterial and anti-adhesion activities against P. aeruginosa and successfully prevented biofilm formation on the material's surface. Regardless of the conditions, the Cat-Re nanocoating significantly suppressed the growth and attachment of P. aeruginosa and maintained >90% inhibition activity with favorable reusability and long-term stability. The results suggest that the self-assembled rare-earth-phenolic nanocoating has promising application potential in the prevention of medical device-related biofilm formation.

All-solid-state lithium batteries (ASLBs) are promising for the next generation energy storage system with critical safety. Among various candidates, thiophosphate-based electrolytes have shown great promise because of their high ionic conductivity. However, the narrow operation voltage and poor compatibility with high voltage cathode materials impede their application in the development of high energy ASLBs. In this work, we studied the failure mechanism of Li 6 PS 5 Cl at high voltage through in situ Raman spectra and investigated the stability with high-voltage LiNi 1/3 Mn 1/3 Co 1/3 O 2 (NMC) cathode. With a facile wet chemical approach, we coated a thin layer of amorphous Li 0.35 La 0.5 Sr 0.05 TiO 3 (LLSTO) with 15-20 nm at the interface between NMC and Li 6 PS 5 Cl. We studied different coating parameters and optimized the coating thickness of the interface layers. Meanwhile, we studied the effect of NMC dimension to the ASLBs performance. We further conducted the first-principles thermodynamic calculations to understand the electrochemical stability between Li 6 PS 5 Cl and carbon, NMC, LLSTO, NMC/LLSTO. Attributed to the high stability of Li 6 PS 5 Cl with NMC/LLSTO and outstanding ionic conductivity of the LLSTO and Li 6 PS 5 Cl, at room temperature, the ASLBs exhibit outstanding capacity of 107 mAh g -1 and keep stable for 850 cycles with a high capacity retention of 91.5% at C/3 and voltage window 2.5-4.0 V (vs Li-In).

• Ti 3 C 2 ultra-thin nanosheets were prepared via etching and ultrasonic exfoliation. • PUFs with chitosan/Ti 3 C 2 nanocoating were fabricated via layer-by-layer approach. • Remarkable fire and smoke suppressions was achieved with inexpensive weight gain. MXene/chitosan nanocoating for flexible polyurethane foam (PUF) was prepared via layer-by-layer (LbL) approach. MXene (Ti 3 C 2) ultra-thin nanosheets were obtained through etching process of Ti 3 AlC 2 followed by exfoliation. The deposition of MXene/chitosan nanocoating was conducted by alternatingly immersing the PUF into a chitosan solution and a Ti 3 C 2 aqueous dispersion, which resulted in different number of bilayers (BL) ranging from 2, 5 and 8. Owing to the utilization of ultra-thin Ti 3 C 2 nanosheets, the weight gain was only 6.9% for 8 BL coating of PUF, which minimised the unfavourable impact on the intrinsic properties of PUF. The Ti 3 C 2 /chitosan coating significantly reduced the flammability and smoke releases of PUF. Compared with unmodified PUF, the 8 BL coating reduced the peak heat release rate by 57.2%, alongside with a 65.5% reduction in the total heat release. The 8 BL coating also showed outstanding smoke suppression ability with total smoke release decreased by 71.1% and peak smoke production rate reduced by 60.3%, respectively. The peak production of CO and CO 2 gases also decreased by 70.8% and 68.6%, respectively. Furthermore, an outstanding char formation performance of 37.2 wt.% residue was obtained for 8 BL coated PUF, indicating the excellent barrier and carbonization property of the hybrid coating. [ABSTRACT FROM AUTHOR]

A method of forming a self-cleaning hydrophobic nanocoating (SCHN) on glass substrates utilizing a scalable manufacturing process is described. The process initiates with roughening of planar glass surfaces using diamond micro-/nano-particle abrasives, which creates microscopic tortuous grooves. After cleaning the substrates, the roughened surface is vapor deposited with trichloro (1H,1H,2H,2H-perfluorooctyl)silane (TCPFOS) under enclosure with controlled humidity. TCPFOS chemically binds with the substrate via covalent linkage. Due to the greatly reduced surface tension between water and the self-cleaning surface, the water droplet slides down leaving no trail (sliding angle of 14° for 0.1 mL water droplet). Due to the reduced adhesion of dirt to the self-cleaning surface, the dirt particles are washed away by sliding or rolling water droplets. The SCHN shows a negligible change in transmission as compared to the original glass substrate. The coating is resistant to multiple environmental factors including abrasion cycles, acid rain (pH = 3), saline exposure (10% w/v), alkali solution (pH 11, NaOH), and extreme temperature cycling (−10 to 60 °C). Image 10367 • A scalable process for the manufacturing of self-cleaning hydrophobic nanocoating (SCHN) on glass was demonstrated. • The fabrication process included a mechanical abrasion of glass, followed by the deposition of chemical vapor of TCPFOS. • SCHN coated glass showed excellent self-cleaning behavior, resulting sliding angle of 14° for 0.1 mL water droplet. • SCHN coated glass also exhibited strong resistant to various environmental elements. [ABSTRACT FROM AUTHOR]

Electrospinning, as a promising platform in multidisciplinary engineering over the past two decades, has overcome major challenges and has achieved remarkable breakthroughs in a wide variety of fields such as energy, environmental, and pharmaceutics. However, as a facile and cost-effective approach, its capability of creating nanofibers is still strongly limited by the numbers of treatable fluids. Most recently, more and more efforts have been spent on the treatments of liquids without electrospinnability using multifluid working processes. These unspinnable liquids, although have no electrospinnability themselves, can be converted into nanofibers when they are electrospun with an electrospinnable fluid. Among all sorts of multifluid electrospinning methods, coaxial electrospinning is the most fundamental one. In this review, the principle of modified coaxial electrospinning, in which unspinnable liquids are explored as the sheath working fluids, is introduced. Meanwhile, several typical examples are summarized, in which electrospun nanofibers aimed for the environment remediation were prepared using the modified coaxial electrospinning. Based on the exploration of unspinnable liquids, the present review opens a way for generating complex functional nanostructures from other kinds of multifluid electrospinning methods. [ABSTRACT FROM AUTHOR]

The superamphiphobic 1060 aluminum alloy mesh with nano-villus coating on surface was prepared by chemical micro-engraving method. NaOH solution was used to form micro-sized roughness on the mesh substrate, and PFMS (1H, 1H, 2H, 2H-perfluoroalkyltrimethoxysilane) was used to reduce the surface energy of the mesh matrix and combined with –OH on the surface to form nanocoating of superamphiphobicity. When water was used as test liquid, the contact angle on the surface was 158°, and glycerol was used as test liquid, the contact angle on the surface was 163°. In order to test the performance of superamphiphobic surface, the experiments of ice resistance, corrosion resistance, self-cleaning and wear resistance were carried out in this paper. The experimental results show that the superamphiphobic aluminum alloy mesh with nanocoating has excellent anti-icing performance at −18 °C for the first 26 h, good corrosion and wearing resistance. It can replace the traditional aluminum material in low temperature environment to ensure the normal operation of precision electronic devices. • PFMS coating is found to have low surface energy and nanostructure. • Micro and nano roughness make the surface superamphiphobic. • Superamphiphobic surface can keep the matrix from freezing in 26 h at −18 °C. • Anti-corrosion and self-cleaning properties are also excellent. [ABSTRACT FROM AUTHOR]

In order to improve osseointegration, polyetheretherketone (PEEK) interbody fusion cages are frequently surface coated. The bonding strength of the coatings is mostly investigated under unrealistic loading conditions. To close this gap, in this study, uncoated and coated cages were loaded in a clinical setup in order to investigate their real resistance against abrasion. Six uncoated, six calcium phosphate (CaP) nanocoated, and six titanium (Ti) nanocoated PEEK cages were tested in this study. The experimental setup was designed to mimic cage impaction into the intervertebral disc space using polyurethane (PU) foam blocks as vertebral body substitutes. The cage surface was inspected before and after impaction, and their weight was measured. Impaction resulted in abrasion at the tip of the ridges on the implant surface. The mean weight loss was 0.39 mg for the uncoated cages, 0.57 mg for the CaP nanocoated cages, and 0.75 mg for the Ti nanocoated cages. These differences were statistically significant. In conclusion, differences between the three cage types were found concerning the amount of abrasion. However, all three cages lost less weight than a comparative Ti plasma spray coated cage, which showed a mean weight loss of 2.02 mg. This may be because the plasma spray coating is significantly thicker than the two nanocoatings. If compared with the permitted amount of weight loss derived from an FDA guidance document, which is approximately 1.7 mg, the wear of the Ti plasma spray coated cage is above this limit, whereas the wear for all other cage types is below. [ABSTRACT FROM AUTHOR]

Inorganic–organic multilayer films consisting of polymers coated with thin inorganic oxidic layers (e.g., SiOx) ensure very high barrier performances against gas and vapor permeation, what makes them packaging materials suitable for sophisticated technical applications, including the encapsulation of photovoltaic devices or quantum dots, barrier films for optical displays, and transparent greenhouse screens. In these fields, surface coating or texturing of the multilayer protective films are effective technologies to improve their self-clean ability, thus reducing the required maintenance and ensuring longer durability and better performances. In this work, we used the self-assembled monolayer (SAM) technique to modify the surface and wetting properties of commercial polyethylene terephthalate-silicon oxide substrate (PET-SiOx) films developed for technical applications requiring a combined high barrier and transparency. The selected surface modifier was the 1H,1H,2H,2H-per-fluorodecyltrichlorosilane (FDTS). The reagent mixture composition was optimized for the lowest water and oil wettability, as well as the highest self-cleaning capacity and performance stability. In particular, for the used PET-SiOx film the best FDTS/film surface for both the lowest water and oil wettability was found to be equal to 26.5 mM/dm2, which changes the surface behavior from very hydrophilic (static water contact angle (CAw) = 21.5°) to hydrophobic (CAw = 101°), and gives a significant increment of the static oil contact angle (CAo) from 27° to 60°. Interestingly, the results demonstrated that the SAM reaction occurred also on the uncoated the PET side. After the SAM treatment, a small increase of the water vapor permeability is observed, probably due to a crack or defect onset of the SiOx coating of the SAM modified films. On this point, atomic force measurements demonstrated an increment of the SiOx coating layer roughness after the SAM treatment execution. Finally, the transparency changes of the SAM treated films, measured in the wavelength range 400–800 nm, were always small, so that the results were acceptable for the films' use in applications where high transparency is required. [ABSTRACT FROM AUTHOR]