Generating micro/nanostructures on magnesium alloy surface using ultraprecision diamond surface texturing process

The lightness and high strength-to-weight ratio of the magnesium alloy have attracted more interest in various applications.However,micro/nanostructure generation on their surfaces remains a challenge due to the flammability and ignition.Motivated by this,this study proposed a machining process,named the ultraprecision diamond surface texturing process,to machine the micro/nanostructures on magnesium alloy surfaces.Experimental results showed the various microstructures and sawtooth-shaped nanostructures were successfully generated on the AZ31B magnesium alloy surfaces,demonstrating the effectiveness of this proposed machining process.Furthermore,sawtooth-shaped nanostructures had the function of inducing the optical effect and generating different colors on workpiece surfaces.The colorful letter and colorful flower image were clearly viewed on magnesium alloy surfaces.The corresponding cutting force,chip morphology,and tool wear were systematically investigated to understand the machining mechanism of micro/nanostructures on magnesium alloy surfaces.The proposed machining process can further improve the performances of the magnesium alloy and extend its functions to other fields,such as optics.

Development of micro/nanostructured‒based biomaterials with biomedical applications

Natural biomaterials are now frequently used to build biocarrier systems,which can carry medications and biomolecules to a target region and achieve a desired therapeutic effect.Biomaterials and polymers are of great importance in the synthesis of nanomaterials.The recent studies have tended to use these materials because they are easily obtained from natural sources such as fungi,algae,bacteria,and medicinal plants.They are also biodegradable,compatible with neighborhoods,and non-toxic.Natural biomaterials and polymers are chemically changed when they are linked by cross linking agents with other polymers to create scaffolds,matrices,composites,and interpenetrating polymer networks employing microtechnology and nanotechnology.This review highlights how microengineered and nanoengineered biomaterials are utilized to produce efficient drug-delivery systems and biomedical and biological therapies and how innovative sources of biomaterials have been identified.

A review of the techniques for the mold manufacturing of micro/nanostructures for precision glass molding

Micro/nanostructured components play an important role in micro-optics and optical engineering,tribology and surface engineering,and biological and biomedical engineering,among other fields.Precision glass molding technology is the most efficient method of manufacturing micro/nanostructured glass components,the premise of which is meld manufacturing with complementary micro/nanostructures.Numerous mold manufacturing methods have been developed to fabricate extremely small and high-quality micro/nanostructures to satisfy the demands of functional micro/nanostructured glass components for various applications.Moreover,the service performance of the mold should also be carefully considered.This paper reviews a variety of technologies for manufacturing micro/nanostructured molds.The authors begin with an introduction of the extreme requirements of mold materials.The following section provides a detailed survey of the existing micro/nanostructured mold manufacturing techniques and their corresponding mold materials,including nonmechanical and mechanical methods.This paper concludes with a detailed discussion of the authors recent research on nickel-phosphorus(Ni-P)mold manufacturing and its service performance.

Simple Fabrication of Hierarchical Micro/Nanostructure Superhydrophobic Surface with Stable and Superior Anticorrosion Silicon Steel via Laser Marking Treatment

To improve the weak corrosion resistance of silicon steel to acid solution and alkaline solution with high temperature,a stable hierarchical micro/nanostructure superhydrophobic surface with myriad irregular micro-scale hump and sheet-like nanostructure was successfully prepared on silicon steel by a simple,efficient and facile operation in large-area laser marking treatment.The morphology,composition,wettability of the as-prepared surface were studied.The superhydrophobic performance of the surface was investigated as well.Additionally,the corrosion resistance of the superhydrophobic surface to acidic solutions at room temperature and alkaline solutions at high temperature (80 ℃) was carefully explored.The corrosion resistance mechanism was clarified.Moreover,considering the practical application of the surface in the future,the hardness of the hierarchical micro/nanostructure superhydrophobic surface was studied.The experimental results indicate that the hierarchical micro/nanostructure surface with texture spacing of 100 μm treated at laser scanning speed of 100 mms/ presents superior superhydrophobicity after decreasing surface energy.The contact angle can be as high as 156.6°.Additionally,the superhydrophobic surface provide superior and stable anticorrosive protection for silicon steel in various corrosive environments.More importantly,the prepared structure of the surface shows high hardness,which ensures that the surface of the superhydrophobic surface cannot be destroyed easily.The surface is able to maintain great superhydrophobic performance when it suffers from slight impacting and abrasion.

Strongly coupled N-doped carbon/Fe3O4/N-doped carbon hierarchical micro/nanostructures for enhanced lithium storage performance

A strong interface coupling is of vital importance to develop metal oxide/carbon nanocomposite anodes for next-generation lithium ion batteries.Herein,a rational N-doped carb on riveting strategy is designed to boost the lithium storage performance of Fe3O4/N-doped carbon tubular structures.Poly pyrrole(PPy)has been used as the precursor for N-doped carbon.N-doped carbon-riveted Fe3O4/N-doped carbon(N-C@Fe3O4@N-C)nanocomposites were obtained by pyrolysis of PPy-coated FeOOH@PPy nanotubes in Ar atmosphere.When tested as an anode for LIBs,the N-C@Fe3O4@N-C displays a high reversible discharge capacity of 675.8 mA h g-1 after 100 cycles at a current density of 100 mA g-1 and very good rate capability(470 mA h g_1 at 2 A g-1),which significantly surpasses the performance of Fe3O4@N-C.TEM analysis reveals that after battery cycling the FeOx particles detached from the carbon fibers for Fe3O4@N-C,while for N-C@Fe3O4@N-C the FeOx particles were still trapped in the carbon matrix,thus preserving good electrical contact.Consequently,the superior performance of N-C@Fe3C)4@N-C is attributed to the synergistic effect between Fe3O4 and N-doped carbon combined with the unique structure properties of the nanocomposites.The strategy reported in this work is expected to be applicable for designing other electrode materials for LIBs.

Superhydrophobic Micro/Nanostructured Copper Mesh with Self-Cleaning Property for E ective Oil/Water Separation

In this work, a simple method was carried out to successfully fabricate superoleophilic and superhydrophobic N-dodecyltrimethoxysilane@tungsten trioxide coated copper mesh. The as-fabricated copper mesh displayed prominent superoleophilicity and superhydrophobicity with a huge water contact angle about 154.39° and oil contact angle near 0° Moreover, the coated copper mesh showed high separation efficiency approximately 99.3%, and huge water flux about 9962.3 L·h^-1·m-2, which could be used to separate various organic solvents/ water mixtures. Furthermore, the coated copper mesh showed favorable stability that the separation efficiency remained above 90% after 10 separation cycles. Benefiting from the excellent photocatalytic degradation ability of tungsten trioxide, the coated copper mesh possessed the self-cleaning capacity. Therefore, the mesh contaminated with lubricating oil could regain superhydrophobic property, and this property of self-cleaning permitted that the fabricated copper mesh could be repeatedly used for oil and water separation.

Anticorrosion Coatings from Poly(Aniline-co-2-Ethylaniline) Micro/Nanostructures

PANI copolymer micro/nanostructures with different surface wettability were obtained from the chemical oxidation copolymerization of aniline(Ani)with 2-ethyl aniline(EA)at diverse[EA]/[Ani+EA]molar ratios,by employing ammonium persulfate as an oxidant.The results revealed that the poly(aniline-co-2-ethyl aniline)(PANI-EA)copolymer micro/nanostructures exhibited satisfactory anticorrosion performance for carbon steel,and the corrosion protection efficiency increased with the increase of water repellent property.Poly(2-ethyl aniline)(PEA)showed the largest contact angle(CA=145°)and show the best corrosion protection for the carbon steel(h=87.29%).It is found that the superior anticorrosion property of PEA is attributed to its high hydrophobicity,low conductivity and low porosity.

Hierarchically Micro/Nanostructured Current Collectors Induced by Ultrafast Femtosecond Laser Strategy for High-Performance Lithium-ion Batteries

Commercial Cu and Al current collectors for lithium-ion batteries(LIBs)possess high electrical conductivity,suitable chemical and electrochemical stability.However,the relatively flat surface of traditional current collectors causes weak bonding strength and poor electrochemical contact between current collectors and electrode materials,resulting in potential detachment of active materials and rapid capacity degradation during extended cycling.Here,we report an ultrafast femtosecond laser strategy to manufacture hierarchical micro/nanostructures on commercial Al and Cu foils as current collectors for high-performance LIBs.The hierarchically micro/nanostructured current collectors(HMNCCs)with high surface area and roughness offer strong adhesion to active materials,fast electronic delivery of entire electrodes,significantly improving reversible capacities and cyclic stability of HMNCCs based LIBs.Consequently,LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM523)cathode with Al HMNCC generated a high reversible capacity after 200 cycles(25%higher than that of cathode with Al CC).Besides,graphite anode with Cu HMNCC also maintained prominent reversible capacity even after 600 cycles.Moreover,the full cell assembled by graphite anode with Cu HMNCC and NCM523 cathode with Al HMNCC achieved high reversible capacity and remarkable cycling stability under industrial-grade mass loading.This study provides promising candidate for achieving high-performance LIBs current collectors.

Bioinspired micro/nanostructured surfaces prepared by femtosecond laser direct writing for multi-functional applications

manufacturing of biomimetic micro/nanostructures due to its specific advantages including high precision,simplicity,and compatibility for diverse materials in comparison with other methods(e.g.ion etching,sol-gel process,chemical vapor deposition,template method,and self-assembly).These biomimetic micro/nanostructured surfaces are of significant interest for academic and industrial research due to their wide range of potential applications,including self-cleaning surfaces,oil-water separation,and fog collection.This review presents the inherent relationship between natural organisms,fabrication methods,micro/nanostructures and their potential applications.Thereafter,we throw a list of current fabrication strategies so as to highlight the advantages of FLDW in manufacturing bioinspired microstructured surfaces.Subsequently,we summarize a variety of typical bioinspired designs(e.g.lotus leaf,pitcher plant,rice leaf,butterfly wings,etc)for diverse multifunctional micro/nanostructures through extreme femtosecond laser processing technology.Based on the principle of interfacial chemistry and geometrical optics,we discuss the potential applications of these functional micro/nanostructures and assess the underlying challenges and opportunities in the extreme fabrication of bioinspired micro/nanostructures by FLDW.This review concludes with a follow up and an outlook of femtosecond laser processing in biomimetic domains.

Fabrication of Ordered Micro/Nanostructures Using Probe‑Based Force‑Controlled Micromachining System

This paper presents a probe-based force-controlled nanoindentation method to fabricate ordered micro/nanostructures.Both the experimental and finite element simulation approaches are employed to investigate the influence of the interval between the adjacent indentations and the rotation angle of the probe on the formed micro/nanostructures.The non-contacting part between indenter and the sample material and the height of the material pile-up are two competing factors to determine the depth relationship between the adjacent indentations.For the one array indentations,nanostructures with good depth consistency and periodicity can be formed after the depth of the indentation becoming stable,and the variation of the rotation angle results in the large difference between the morphology of the formed nanostructures at the bottom of the one array indentation.In addition,for the indentation arrays,the nanostructures with good consistency and periodicity of the shape and depth can be generated with the spacing greater than 1μm.Finally,Raman tests are also carried out based on the obtained ordered micro/nanostructures with Rhodamine probe molecule.The indentation arrays with a smaller spacing lead to better the enhancement effect of the substrate,which has the potential applications in the fields of biological or chemical molecular detection.

Facile Synthesis of 3D Porous Flower-like ZnO Micro/nanostructure Films and Their Photocatalytic Performance

3D porous flower-like ZnO micro/nanostructure films grown on Ti substrates are synthesized via a very facile electrodeposition technique followed by heat treatment process. The ZnO architecture is assembled with ultra thin sheets, which consist of numbers of nanoparticles and pores, and the size of the nanoparticles can be controlled by adjusting the electrodepo- sition time or calcination temperature. It is worth noting that this synthetic method can provide an effective route for other porous metal oxide nanostructure films. Moreover, the photocatalytic performance shows the porous ZnO is an ideal photocatalyst.

Fabrication and Applications of Micro/Nanostructured Devices for Tissue Engineering

Nanotechnology allows the realization of new materials and devices with basic structural unit in the range of1–100 nm and characterized by gaining control at the atomic, molecular, and supramolecular level. Reducing the dimensions of a material into the nanoscale range usually results in the change of its physiochemical properties such as reactivity,crystallinity, and solubility. This review treats the convergence of last research news at the interface of nanostructured biomaterials and tissue engineering for emerging biomedical technologies such as scaffolding and tissue regeneration. The present review is organized into three main sections. The introduction concerns an overview of the increasing utility of nanostructured materials in the field of tissue engineering. It elucidates how nanotechnology, by working in the submicron length scale, assures the realization of a biocompatible interface that is able to reproduce the physiological cell–matrix interaction. The second, more technical section, concerns the design and fabrication of biocompatible surface characterized by micro- and submicroscale features, using microfabrication, nanolithography, and miscellaneous nanolithographic techniques.In the last part, we review the ongoing tissue engineering application of nanostructured materials and scaffolds in different fields such as neurology, cardiology, orthopedics, and skin tissue regeneration.

Controllable Hydrothermal Synthesis and Properties of ZnO Hierarchical Micro/Nanostructures

A simple hydrothermal route has been developed for the fabricating Zn O hierarchical micro/nanostructure with excellent reproducibility. SEM and TEM analysis show that the hierarchical rod is a single-crystal, suggesting that many single-crystal micro/nanorods are assembled into Zn O hierarchical micro/nanostructures. The morphologies of the hierarchical rods can be conveniently tailored by changing the reaction parameters. And we also found citric acid plays a crucial role in the formation process of Zn O micro/nanostructures. Room-temperature photoluminescence spectra reveals that the Zn O hierarchical micro/nanostructures have a strong emission peak at 440 nm and several weak emission peaks at 420, 471 and541 nm, respectively.

Polypyrrole Micro/Nanostructure Prepared Using Azo Dyes with Different Substituents

This contribution deals with simple way of polypyrrole structure modification. Using azo dyes in polymerization reaction as soft-template with similar molecular structure but different type and distribution of substitution groups lead to formation of one-dimensional and newly also three-dimensional polypyrrole micro/nanostructures. These structures are characteristic with geometrical symmetry and uniformity. Geometry of prepared structures was studied by scanning electron microscopy (SEM) and by methods of image analysis;nanotubes are hundreds of nm in diameter and units of μm in length, new tree-dimensional structures have units of μm in diameter. Infrared spectra (ATR-FTIR) confirmed that azo dyes work only as intermediate supporting structures without reaction with polypyrrole.

Sphere-shaped SiGe micro/nanostructures with tunable Ge composition and size formed by laser irradiation

SiGe spheres with different diameters are successfully fabricated on a virtual SiGe template using a laser irradiation method.The results from scanning electron microscopy and micro-Raman spectroscopy reveal that the diameter and Ge composition of the SiGe spheres can be well controlled by adjusting the laser energy density.In addition,the transmission electron microscopy results show that Ge composition inside the SiGe spheres is almost uniform in a well-defined,nearly spherical outline.As a convenient method to prepare sphere-shaped SiGe micro/nanostructures with tunable Ge composition and size,this technique is expected to be useful for SiGe-based material growth and micro/optoelectronic device fabrication.

Mass-Based Environmental Factor and Energy Assessment of Microwave-Assisted Synthesized Transition Metal Nanostructures

This paper describes mass-based energy phase-space projection of microwave-assisted synthesis of transition metals (zinc oxide, palladium, silver, platinum, and gold) nanostructures. The projection uses process energy budget (measured in kJ) on the horizontal axes and process density (measured in kJg−1) on the vertical axes. These two axes allow both mass usage efficiency (Environmental-Factor) and energy efficiency to be evaluated for a range of microwave applicator and metal synthesis. The metrics are allied to the: second, sixth and eleventh principle of the twelve principle of Green Chemistry. This analytical approach to microwave synthesis (widely considered as a useful Green Chemistry energy source) allows a quantified dynamic environmental quotient to be given to renewable plant-based biomass associated with the reduction of the metal precursors. Thus allowing a degree of quantification of claimed “eco-friendly” and “sustainable” synthesis with regard to waste production and energy usage.

Micro/nanostructured amorphous TiNbZr films to enhance the adhesion strength and corrosion behavior of stainless steel

To improve the corrosion resistance of key components and ensure the service safety of marine equipment,here we combined femtosecond(fs)laser fabrication and magnetron sputtering deposition to develop micro/nanostructured amorphous TiNbZr films.Analysis of the compositional,microstructural,corrosion,and mechanical properties was conducted.The results showed that the TiNbZr films were amorphous,and spherical TiNbZr nanoparticles uniformly covered the fs laser-induced periodic fringe structure.A complex hierarchical micro/nanostructure was formed that was hydrophobic and showed enhanced adhesion strength.The TiNbZr films deposited on fs laser-treated substrates provided the best corrosion resistance,showing a self-corrosion current density of 116 nA/cm^(2),excellent passive ability,and pitting resistance.The microscratch test revealed that the micro/nanostructures doubled the binding strength of the TiNbZr/316L interface due to the compositional and structural gradients induced by an approximately 20 nm transition layer formed during fs laser processing.This work provides a new method for obtaining anti-corrosion films with a high adhesion strength for marine applications.

Ambient-Condition Strategy for Production of Hollow Ga_(2)O_(3)@rGO Crystalline Nanostructures Toward Efficient Lithium Storage

Crystallineγ-Ga_(2)O_(3)@rGO core-shell nanostructures are synthesized in gram scale,which are accomplished by a facile sonochemical strategy under ambient condition.They are composed of uniformγ-Ga_(2)O_(3)nanospheres encapsulated by reduced graphene oxide(rGO)nanolayers,and their formation is mainly attributed to the existed opposite zeta potential between the Ga_(2)O_(3)and rGO.The as-constructed lithium-ion batteries(LIBs)based on as-fabricatedγ-Ga_(2)O_(3)@rGO nanostructures deliver an initial discharge capacity of 1000 mAh g^(-1)at 100 mA g^(-1)and reversible capacity of 600 mAh g^(-1)under 500 mA g^(-1)after 1000 cycles,respectively,which are remarkably higher than those of pristineγ-Ga_(2)O_(3)with a much reduced lifetime of 100 cycles and much lower capacity.Ex situ XRD and XPS analyses demonstrate that the reversible LIBs storage is dominant by a conversion reaction and alloying mechanism,where the discharged product of liquid metal Ga exhibits self-healing ability,thus preventing the destroy of electrodes.Additionally,the rGO shell could act robustly as conductive network of the electrode for significantly improved conductivity,endowing the efficient Li storage behaviors.This work might provide some insight on mass production of advanced electrode materials under mild condition for energy storage and conversion applications.

Formation of Natural Melanin/TiO_(2) Nanostructure Hybrids with Enhanced Optical,Thermal and Magnetic Properties as a Soft Material

The natural Melanin/TiO_(2) was synthesized by the use of ultrasonication under UV radiation.The influence of natural melanin on the structural,optical and thermal properties of TiO_(2) nanoparticles was investigated by using Fourier transform infrared spectroscopy,thermogravimetric analysis and UV-Vis spectroscopy.It was observed that incorporating natural melanin on TiO_(2) nanoparticles(TiO_(2)-Mel)occurred at 2.01 eV with a low value of Urbach energy around 100 meV indicating improvement in the crystalline structure.Magnetic measurement at room temperature showed diamagnetic behavior.Furthermore,thermal results showed that TiO_(2)-Mel is stable even at temperatures up to 400℃.According to the results obtained by the thermal stability of melanin with titanium dioxide,it can be a good candidate in many applications such as solar cells and optoelectronics.

Green Chemistry Allometry Test of Microwave-Assisted Synthesis of Transition Metal Nanostructures

Microwave irradiation is considered an important approach to Green Chemistry, because of its ability to rapidly increase the internal temperature of polar-organic compounds that lead to synthesis times of minutes rather than hours when compared to conventional thermal heating. This works describes a dual allometry test for the discrimination between the solvents and reagents used in the microwave-assisted synthesis of transition metal (zinc oxide, palladium silver, platinum, and gold) nanostructures. The test is performed in log-log process energy phase-space projection, where the synthesis data (kJ against kJ·mol-1) has a power-law signature. The test is shown to discriminate between recommended Green Chemistry, problematic Green Chemistry, and Green Chemistry hazardous solvents. Typically, recommended Green chemistry exhibits a broad y-axes distribution within an upper exponent = 1 and lower exponent = 0.5. Problematic Green Chemistry exhibits a y-axes narrower distribution with an upper exponent = 0.94 and lower exponent = 0.64. Non-Green Chemistry hazardous data exhibits a further narrowing of the y-axes distribution within upper exponent = 0.87 and lower exponent = 0.66. In all three cases, the y-axes is aligned to original database power-law signature. It is also shown that in the x-axes direction (process energy budget) the grouped order of magnitude decreases from four orders for recommended Green Chemistry solvent and reagent data, through two orders for non-Green Chemistry hazardous material and down to one order for problematic Green Chemistry.