Osteogenic composite nanocoating based on nanohydroxyapatite, strontium ranelate and polycaprolactone for titanium implants

Titanium and its alloys are commonly used as dental and bone implant materials.Biomimetic coating of titanium surfaces could improve their osteoinductive properties.In this work,we have developed a novel osteogenic composite nanocoating for titanium surfaces,which provides a natural environment for facilitating adhesion,proliferation,and osteogenic differentiation of bone marrow mesenchymal stem cells(MSCs).Electrospinning was used to produce composite nanofiber coatings based on polycaprolactone(PCL),nano-hydroxyapatite(nHAp)and strontium ranelate(SrRan).Thus,four types of coatings,i.e.,PCL,PCL/nHAp,PCL/SrRan,and PCL/nHAp/SrRan,were applied on titanium surfaces.To assess chemical,morphological and biological properties of the developed coatings,EDS,FTIR,XRD,XRF,SEM,AFM,in-vitro cytotoxicity and in-vitro hemocompatibility analyses were performed.Our findings have revealed that the composite nanocoatings were both cytocompatible and hemocompatible;thus PCL/HAp/SrRan composite nanofiber coating led to the highest cell viability.Osteogenic culture of MSCs on the nanocoatings led to the osteogenic differentiation of stem cells,confirmed by alkaline phosphatase activity and mineralization measurements.The findings support the notion that the proposed composite nanocoatings have the potential to promote new bone formation and enhance bone-implant integration.

Highly transparent and super-wettable nanocoatings hybridized with isocyanate-silane modified surfactant for multifunctional applications

Highly transparent and super-wettable nanocoatings for multifunctional applications with outstanding physical properties are in high demanded.However,such nanocoatings resistant to water invasion and Ultraviolet(UV)weathering remain a significant challenge.In this work,physically durable coatings based on inorganic nanoparticles(NPs)and an organic segment(isocyanate-silane modified surfactant)have been synthesized via a sol-gel approach.It is noteworthy the isocyanate-silane with-NH-C=O-functional group creates a strong bonding between the highly hydrophilic surfactant and the inorganic NPs.This in-house synthesized organic segment can render the coating long-lasting wetting properties and resist to be washed away by water,while the inorganic NPs can form sturdy covalent bonds with the nano-scale hierarchical structure on the glazing substrate to improve the durability.This nanocoating demonstrates high transparency with superwetting property(water contact angle,WCA=4.4±0.3°),effective de-frosting performance.Water invasion or UV accelerated weathering tests do not significantly affect the self-cleaning performance of nanocoating.Physical properties,including coating adhesion,hardness,Young's modulus,and abrasion resistance are systematically investigated.Interestingly,this clear coating shows prominent infrared shielding property attributed to Antimony-doped tin oxide(Sb-doped SnO_(2))NPs.The developed nanocoating process is easy to scale up for larger areas that require multipurpose self-cleaning functions.

Visible transparent,infrared stealthy polymeric films with nanocoating of ITO@MXene enable efficient passive radiative heating and solar/electric thermal conversion

Visible transparent yet low infrared-emissivity(ε)polymeric materials are highly anticipated in many applications,whereas the fabrication of which remains a formidable challenge.Herein,visible transparent,flexible,and low-εpolymeric films were fabricated by nanocoating decoration of indium tin oxide(ITO)and MXene on polyethylene terephthalate(PET)film surface through magnetron sputtering and spray coating,respectively.The obtained PET-ITO@MXene(PET-IM)film exhibits lowεof 24.7%and high visible transmittance exceeding 50%,endowing it with excellent visible transparent infrared stealthy by reducing human skin radiation temperature from 32 to 20.8°C,and remarkable zero-energy passive radiative heating capability(5.7°C).Meanwhile,the transparent low-εPET-IM film has high solar absorptivity and electrical conductivity,enabling superior solar/electric to thermal conversion performance.Notably,the three heating modes of passive radiative and active solar/electric can be integrated together to cope with complex heating scenarios.These visible transparent low-εpolymeric films are highly promising in infrared stealth,building daylighting and thermal management,and personal precision heating.

Nanocoating of CsgA protein for enhanced cell adhesion and proliferation

Immune rejection, poor biocompatibility and cytotoxicity have seriously stalled the widespread application of biometallic materials. To overcome these problems, biometallic materials with fast and sufficient osseointegration, antibacterial properties and long-term stability have attracted the attention of researchers worldwide. Surface modification is currently used as a general strategy to develop material coatings that will overcome these challenging requirements and achieve the successful performance of implants. In this study, we proposed a substrate surface-modification strategy based on biofilm Csg A proteins that promote rapid cell attachment, proliferation, and stabilization of the cytoskeleton. Csg A-based nano-coating is easy to fabricate and has superior performance, which is expected to expand the application of medical implants.

Carbon confinement synthesis of interlayer-expanded and sulfur-enriched MoS2+x nanocoating on hollow carbon spheres for advanced Li-S batteries

High energy density and low-cost lithium-sulfur batteries have been considered as one of the most promising candidates for next-generation energy storage systems.However,the intrinsic problems of the sulfur cathode severely restrict their further practical application.Here,a unique double-shell architecture composed of hollow carbon spheres@interlayer-expanded and sulfur-enriched MoS2+x nanocoating composite has been developed as an efficient sulfur host.A uniform precursor coating derived from heteropolyanions-induced polymerization of pyrrole leads to space confinement effect during the in-situ sulfurization process,which generates the interlayer-expanded and sulfur-enriched MoS2+x nanosheets on amorphous carbon hollow spheres.This new sulfur host possesses multifarious merits including sufficient voids for loading sulfur active materials,high electronic conductivity,and fast lithium-ion diffusive pathways.In addition,additional active edge sites of MoS2+x accompanied by the nitrogen-doped carbon species endow the sulfur host with immobilizing and catalyzing effects on the soluble polysulfide species,dramatically accelerating their conversion kinetics and re-utilization.The detailed defect-induced interface catalytic reaction mechanism is firstly proposed.As expected,the delicately-designed sulfur host exhibits an outstanding initial discharge capacity of 1,249 mAh·g^−1 at 0.2 C and a desirable rate performance(593 mAh·g^−1 at 5.0 C),implying its great prospects in achieving superior electrochemical performances for advanced lithium sulfur batteries.

Tea stain-inspired solar energy harvesting polyphenolic nanocoatings with tunable absorption spectra

Discovery and development of new sustainable photothermal materials with tunable light absorption spectra play a key role in solar energy harvesting and conversion.One possible solution to this quest is to check nature as a source of matters or inspiration.Inspired by the formation of tea stains,a unique class of dark stain materials generated by the interfacial reaction between tea polyphenols and metal substance,we reported the facile preparation and screening of a series of photothermal nanocoating layers via the metal ion(i.e.C u(ll)>Fe(lll),Ni(ll),Zn(ll))promoted in situ polymerization of typical phenolic moieties of tea polyphenols(i.e.,catechol and pyrogallol).It was found that those resulting metal-polyphenolic nanocoatings showed various promising features,such as high blackness and strong adhesion,excellent and tunable light absorption properties,good hydrophilicity and long-term stability.We further fabricated the photothermal composite devices by/n s/'fty formation of meta卜polyphenolic nanocoatings on pristine silks for solar desalination,which demonstrated promising durable evaporation behaviors with excellent evaporation rates and steam generation efficiencies.We believe that this work could provide more opportunities towards new types of bio-inspired and sustainable photothermal nanomaterials for solar energy harvesting applications such as water desalination.

Interface engineering of Zn meal anodes using electrochemically inert Al_(2)O_(3)protective nanocoatings

Aqueous rechargeable Zn-ion batteries are regarded as a promising alternative to lithium-ion batteries owing to their high energy density,low cost,and high safety.However,their commercialization is severely restricted by the Zn dendrite formation and side reactions.Herein,we propose that these issues can be minimized by modifying the interfacial properties through introducing electrochemically inert Al_(2)O_(3)nanocoatings on Zn meal anodes(Al_(2)O_(3)@Zn).The Al_(2)O_(3)nanocoatings can effectively suppress both the dendrite growth and side reactions.As a result,the Al_(2)O_(3)@Zn symmetric cells show excellent electrochemical performance with a long lifespan of more than 4,000 h at 1 mA·cm^(−2)and 1 mAh·cm^(−2).Meanwhile,the assembled Al_(2)O_(3)@Zn//V_(2)O_(5)full cells can deliver a high capacity(236.2 mAh·g^(−1))and long lifespan with a capacity retention of 76.11%after 1,000 cycles at 4 A·g^(−1).

Investigation on the electrocatalytic characteristics of SnO_2 electrodes with nanocoating prepared by electrodeposition method

SnO2 electrodes have many advantages in the degradation of toxic or bio-refractory organic wastewater,and SnO2 is a kind of anode material which has the potential to be widely used.Electrocatalytic effi-ciency and service life of Ti\SnO2 electrodes are key factors that can influence its applications.In order to enhance the electrocatalytic characteristics of Ti\SnO2 electrodes,a type of electrocatalytic electrode with nanocoating was prepared by direct current(DC)electrodeposition method and thermal oxidation technique.With phenol as the model pollutant,the electrochemical degradation efficiencies of elec-trodes with nanocoating and non-nanocoating were investigated.It was demonstrated that the elec-trodes with nanocoating have higher efficiency than that of electrodes with non-nanocoating.The degradation time was decreased 33.3% for the same amount of phenol's degradation.The crystal structure of surface coating,the micrograph of electrode surface and the chemical environment of Sn and Sb in the electrode surface were analyzed with the help of XRD,SEM and XPS.The results showed that the surface of electrode was mainly SnO2 crystal with rutile structure and that much adsorbed oxygen in nanocoating was the dominant factor for enhancing the electrocatalytic characteristics.

Phase evolution of plasma sprayed Al_2O_3-13%TiO_2 coatings derived from nanocrystalline powders

Commercial nanosized alumina and titania particles were selected as raw materials to prepare the blended slurry with composition of A1203-13%TiO2 （mass fraction）, which were reconstituted into micrometer-sized granules by spray drying, subsequently sintering at different temperatures to form nanostructured feedstock for thermal spraying, and then A1203-13%TiO2 nanocoatings were deposited by plasma spraying. The evolution of morphology, microstructure, and phase transformation of the agglomerated powder and as-sprayed coatings were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results show that A1203 retains the same a phase as the raw material during sintering, while TiO2 changes from anatase to futile. During plasma spraying, some a-A1203 phases solidify to form metastable y-A1203, and the volume fraction of a-A1203 decreases as CPSP increases. However, peaks of the TiO2 phase are not observed from the as-sprayed coatings except for the coatings sprayed at the lower CPSP. As the CPSP increases, nanostructured TiO2 is dissolved easily in y-A1203 or z-A1203＇TiO2 phase. After heat treatment, y-A1203 in the coatings transforms to a-A1203, and rutile is precipitated.

Effect of Temperature on Pitting Corrosion Resistance of 316 Stainless Steel Coated by Cerium Oxide Film in 3.5% NaCl Solution

One of the main problems of stainless steel is its poor pitting corrosion resistance in the aggressive environment containing Cl-, such as seawater. In this paper we investigated the corrosion behavior of the 316 stainless steel coated by cerium oxide nanocoating prepared by sol-gel process. Potentiodynamic polarization and electrochemical impedance spectroscopy （EIS） were used to study the corrosion behavior of cerium oxide nanocoatings in 3.5% NaCl solution. The microstructure of the cerium oxide was examined by scanning electron microscopy （SEM） and the formed phases was identified by X-ray diffraction （XRD）. The pitting corrosion resistance of the cerium oxide nanocoating was found to be improved after heat treatment of the cerium oxide nanocoating at 300℃ for 30 min.

Ultra-transparent nanostructured coatings via flow-induced one-step coassembly

Polyvinyl alcohol(PVA)/laponite(LP)nanocomposite coatings were fabricated via a facile one-step coassembly process.The formed nanocoatings contain a high concentration of LP nanosheets,which can be well aligned along the substrate surface during the coassembly process.Due to the highly orientated structure,the flexible nanocoatings exhibit ultra-high transparency and superior mechanical properties,and can also act as excellent gas barriers.Such nanocoatings can be exceptional candidates for a variety of applications,such as food packaging.

Anticorrosion of WO₃-Modified TiO₂Thin Film Prepared by Peroxo Sol-Gel Method

The aim of this study was to develop a method to prepare WO3-TiO2 film which has high anticorrosion property when it was coated on type 304 stainless steel. A series of WO3-modified TiO2 sols were synthesized by peroxo-sol gel method using TiCl4 and Na2WO4 as the starting materials. TiCl4 was converted to Ti(OH)4 gel. H2O2 and Na2WO4 were added in Ti(OH)4 solution and heated at 95°C. The WO3-TiO2 sol was transparent, in neutral (pH^7) solution, stable suspension without surfactant, nano-crystallite and no annealing is needed after coating, and very stable for 2 years in stock. WO3-TiO2 sol was formed with anatase crystalline structure. These sols were characterized by XRD, TEM, and XPS. The sol was used to coat on stainless steel 304 by dip-coating. The WO3-TiO2 was anatase in structure as characterized by X-ray diffraction. There were no WO3 XRD peaks in the WO3-TiO2 sols, indicating that WO3 particles were very small, possibly incorporating into TiO2 structure, providing the amount of WO3 was very small. The TiO2 particles were rhombus shape. WO3-TiO2 had smaller size area than pure TiO2. The SEM results showed that the film coated on the glass substrate was very uniform. All films were nonporous and dense films. Its hardness reached 2 H after drying at 100°C, and reached 5 H after annealing at 400°C. The WO3-TiO2 film coated on 304 stainless steel had better anticorrosion capability than the unmodified TiO2 film under UV light illumination. The optimum weight ratio of TiO2: WO3 was 100:4.

Atomic-Scale AES-EELS Analysis of Structure-Phase State and Growth Mechanism of Layered Nanostructures

A review of our experience in range of electron spectroscopy of the physical vapor-phase deposition and growth of single- and multilayer nanostructures with atomic scale interfaces is presented. The foundation of an innovative methodology for the combined AES-EELS analysis of layered nanostructures is developed. The methodology includes: 1) determination of the composition, thickness, and the mechanism of phase transitions in nanocoatings under the probing depth most appropriated for the range of film thickness 1 - 10 ML;2) quantitative iteration Auger-analysis of the composition, thickness and growth mechanism of nanocoating;3) structural and phase analysis of nanocoatings with use of the analysis of position, shape and energy of the plasmon EELS peak and with subtracting the contribution from the substrate;4) analysis of phase transitions with use of the shift of the plasmon Auger-satellite and 5) non-destructive profiling of the composition of nanocoatings over depth with use of a dependence of the intensity and energy of EELS peaks on the value of the primary electron energy.

Near infrared light-induced dynamic modulation of enzymatic activity through polyphenol-functionalized liquid metal nanodroplets

Dynamic manipulation of enzymatic activity is a challenging task for applications in chemical and pharmaceutical industries due to the difficult modification and variable conformation of various enzymes.Here, we report a new strategy for reversible dynamic modulation of enzymatic activity by near-infrared light-induced photothermal conversion based on polyphenol-functionalized liquid metal nanodroplets(LM). The metal-phenolic nanocoating not only provides colloidal stability of LM nanodroplets but also generates nanointerfaces for the assembly of various enzymes on the LM nanodroplets. Upon near infrared(NIR) irradiation, the localized microenvironmental heating through photothermal effect of the LM nanodroplets allows tailoring the enzymatic activity without affecting the bulk temperature. A library of functional enzymes, including proteinase K, glucoamylase, glucose oxidase, and Bst DNA polymerase, is integrated to perform a reversible control and enhanced activities even after five times of cycles, demonstrating great potential in bacterial fermentation, bacteriostasis, and target gene amplification.

Water-Lubricated Ni-Based Composite(Ni-Al_2O_3,Ni-SiC and Ni-ZrO_2)Thin Film Coatings for Industrial Applications

In this work, pure nickel and Ni-based nanocomposite coatings （Ni-AI2O3, Ni-SiC and Ni-ZrO2） were pro- duced on steel substrate by using pulse electrodeposition technique. The industrial performance tests were conducted to evaluate the wear resistance, corrosion resistance, adhesion strength and wettability behaviour of newly developed coat- ings. Rolling contact ball-on-disc tribometer was used to assess anti-wear behaviour of these coatings under water- lubricated contacts. The results showed that the wear- and corrosion resistance properties of nickel alumina and Ni-SiC composite coatings significantly improved than that of pure Ni and Ni-ZrO2 coatings. The adhesion and wettability results of Ni-A1203 composite showed better performance when compared to the rest of the coatings. The effects of incorporating nanoparticles on the surface microstructure, interface adhesion and distribution of the particles were also investigated. The coatings were characterized by using scanning electron microscopy, X-ray diffraction analysis and 3D white light inter- ferometry. The wear failure behaviour of these coatings was further examined by post-test surface observation under optical microscope.

Silica-quaternary ammonium “Fixed-Quat” nanofilm coated fiberglass mesh for water disinfection and harmful algal blooms control

Intensification of pollution loading worldwide has promoted an escalation of different types of disease-causing microorganisms, such as harmful algal blooms(HABs), instigating detrimental impacts on the quality of receiving surface waters. Formation of unwanted disinfection by-products(DBPs) resulting from conventional disinfection technologies reveals the need for the development of new sustainable alternatives. Quaternary Ammonium Compounds(QACs) are cationic surfactants widely known for their effective biocidal properties at the ppm level. In this study, a novel silica-based antimicrobial nanofilm was developed using a composite of silica-modified QAC(Fixed-Quat) and applied to a fiberglass mesh as an active surface via sol–gel technique. The synthesized Fixed-Quat nanocoating was found to be effective against E. coli with an inactivation rate of 1.3 × 10^(-3) log reduction/cm min. The Fixed-Quat coated fiberglass mesh also demonstrated successful control of Microcystis aeruginosa with more than 99% inactivation after 10 hr of exposure.The developed antimicrobial mesh was also evaluated with wild-type microalgal species collected in a water body experiencing HABs, obtaining a 97% removal efficiency. Overall,the silica-functionalized Fixed-Quat nanocoating showed promising antimicrobial properties for water disinfection and HABs control, while decreasing concerns related to DBPs formation and the possible release of toxic nanomaterials into the environment.

Antimicrobial properties of dental cements modified with zein-coated magnesium oxide nanoparticles

The aim of this study was to test the antimicrobial properties of dental cements modified with magnesium oxide(MgO)nanoparticles.Zein-modified MgO nanoparticles(zMgO)in concentrations(0.0,0.3,0.5,and 1.0%)were mixed with dental cements(Fuji II,Rely X Temp E,Ionoglass Cem,Es Temp NE,and System P link).Eight discs were fabricated from each zMgO-cement pair for a total of 32 specimens for each cement.Characterization of the dental cements incorporating zMgO was done by X-ray Diffraction(XRD)and Field Emission Scanning Electron Microscopy(FESEM).The antimicrobial properties of the mixtures were tested using direct contact and agar diffusion assays against Streptococcus mutans,Staphylococcus aureus,Enterococcus faecalis,and Candida albicans.Data was analyzed using two-way analysis of variance and LSD post hoc test at 0.05 significance level.XRD spectra showed sharp peaks of zMgO indicating its high crystalline nature,while the amorphous dental cements with zMgO had broad peaks.FESEM analysis showed a uniform distribution of the zMgO nanoparticles in the cement.There were significant inhibition zone values associated with all concentrations of zMgO-cement mixtures tested compared to controls(p<0.001)with a dose-response recorded only with Fuji II.Optical density values were significantly lower in zMgO groups compared to controls for all microorganisms.The effect was most prominent with Rely X against C.albicans and S.aureus.Dental cements containing zMgO showed significant antimicrobial properties that were dependent on the specific initial cement substrate.