Climate Shifts and the Role of Nano Structured Particles in the Atmosphere

A global net sum equilibrium in heat exchange is a fact and thus a global climate change doesn’t exist, but climate shifts in climate cells, especially in the northern temperate cell, do. The global climate has been ever since homeostatic, and has recuperated far huger climate impacts in the past. Current climate models need a drastically revision on the focus of carbon dioxide as main driver. Carbon dioxide and other carbon gasses do influence albedo patterns, but provide globally a homeostatic effect with a commonly accepted increase impact of 0.3 degrees Celsius. Carbon dioxide does not trigger the climate shifts, but is an indicator of exhaust of combustion processes that emit very small particles which drive these climate shifts. They are the fine dust and nano structured particles that cause the shifts of the climate in cells, as demonstrated in this article and results i.e. in more thunder and lightning, extreme weather, distinct droughts and precipitation patterns. The causes underlying these shifts are nano structured particles in the upper troposphere and lower stratosphere, especially largely produced and remain in the temperate climate northern hemisphere cell and get dispersed by jet streams and low and high pressure areas. However, because of electrical charge, caused by friction or due to anthropogenic negatively charged nano structured particle, emissions will travel up to the lower stratosphere and become neutralized at the electro sphere level, and they do also have a tendency to move to the Arctic. The southern hemisphere climate faces limited anthropogenic emissions, because only 10 percent of the world population can contribute with less pollutant providing activities, and hasn’t changed, but that could well be because it is equally influenced and driven, like the northern hemisphere, by the variation of sun activity in diverse cycles. The present problem is that we produce huge amounts of air borne nano structured particles from combustion processes that never exist before. The only nano particles known in nature are those who are limited produced from volcano eruptions and natural forest fires. The natural feedback systems that moderate climate shifts and influence global climate are: convection by cumulonimbus clouds, sea currents and vegetation adaptation. A novel ultra-fine dust electric reduction device (UFDRS-System), created by the author, diminishs to a size of less than 10 nano particles in diameter and thus prevents major electrical drift of nano structured particulates in the upper troposphere and lower stratosphere and contributes largely in purifying the air and thus reduces the effects of climate shifts. Like solving the acid rain problems with sulphuric acid reduction and ozone depletion with CFCs proscription in the past, the present climate shifts can be mitigated via a reduction of the anthropogenic nano structured particulates in the atmosphere. The UFDRS-System together with the given nature’s solutions can re-balance our atmosphere in a period of two years or a little bit longer due to extension of the lifespan of a particle in the stratosphere.

Localized in‑situ deposition:a new dimension to control in fabricating surface micro/nano structures via ultrafast laser ablation

Controllable fabrication of surface micro/nano structures is the key to realizing surface functionalization for various applications.As a versatile approach,ultrafast laser ablation has been widely studied for surface micro/nano structuring.Increasing research eforts in this feld have been devoted to gaining more control over the fabrication processes to meet the increasing need for creation of complex structures.In this paper,we focus on the in-situ deposition process following the plasma formation under ultrafast laser ablation.From an overview perspective,we frstly summarize the diferent roles that plasma plumes,from pulsed laser ablation of solids,play in diferent laser processing approaches.Then,the distinctive in-situ deposition process within surface micro/nano structuring is highlighted.Our experimental work demonstrated that the in-situ deposition during ultrafast laser surface structuring can be controlled as a localized micro-additive process to pile up secondary ordered structures,through which a unique kind of hierarchical structure with fort-like bodies sitting on top of micro cone arrays were fabricated as a showcase.The revealed laser-matter interaction mechanism can be inspiring for the development of new ultrafast laser fabrication approaches,adding a new dimension and more fexibility in controlling the fabrication of functional surface micro/nano structures.

Preface: Advanced Thin Film Developments and Nano Structures

In this special issue, we invited a few leading materials researchers to present topics in thin films, coatings, and nano structures. Readers will find most recent developments in topics, including recent advances in hard, tough, and low friction nanocomposite coatings; thin films for coating nanomaterials; electroless plating of silver thin films on porous Al2O3 substrate; CrN/Nano Cr interlayer coatings; nano-structured carbide derived carbon （CDC） films and their tribology; predicting interdiffusion in high-temperature coatings; gallium-catalyzed silica nanowire growth; and corrosion protection properties of organofunctional silanes. Authors are from both national laboratories and academia.

Nano Structure Plays an Important Role in the Present and Future Anode Materials of Li-ion Batteries

1 ResultsLi-ion batteries are the most promising secondary batteries for IT and EV applications, where it is required to increase the capacity and power capability to a great extent. In responding to the demand we have been studied on the anode materials especially paying attention on the improved graphite active materials and modified silicon. In both cases we realized that the nano-structured design plays an important role. In this paper the examples of nano-size structure working in the actual materi...

Controlled Synthesis of SnO_2 with Hierarchical Micro/Nano Structure

Preparing SnO2 with hierarchical micro/nano structures by hydrothermal, coordination, templating and electrochemical deposition methods and their mechanisms are investigated. The result shows that the echinus-like SnO2 prepared by Method 1 is a typical Ostwald mechanism that develops from internally to externally. The cabbage-like SnO2 by Method 2 is produced with oxalic acid as complexing agent to set-up precursor of SnO2, and then precursors are bocked around the body that is around the body being bocked. The nest-like SnO2 by Method 3 is controlled by citric acid as coordinator for the nucleation as well as the grow rate and setup process. Spongy-like SnO2 by Method 4 is produced using PST as template, PST is be infiltered into SnO2 precursor by gravity and capillary and treated thermally to form a multiporous structure. The petal-like SnO2 by Method 5 is formed with crystal deposition emergence due to oxidation-reduction reactions of two electrodes in an electric field. XRD analyses shows that the five results are all pure phase SnO2. It provides basic data for SnOE industrial application.

Superhydrophobic surfaces via controlling the morphology of ZnO micro/nano complex structure

ZnO micro/nano complex structure films, including reticulate papillary nodes, petal-like and flake-hole, have been self-assembled by a hydrothermal technique at different temperatures without metal catalysts. The wettability of the above film surfaces was modified with a simple coating of heptadecafluorodecyltrimethoxy-silane in toluene. After modifying, the surface of ZnO film grown at 50℃ was converted from superhydrophilic with a water contact angle lower than 5° to superhydrophobic with a water contact angle of 165° Additionally, the surface of reticulate papillary nodes ZnO film grown at 100 ℃ had excellent superhydrophobicity, with a water contact angle of 173° and a sliding angle lower than 2° Furthermore, the water contact angle on the surface of petal-like and flake-hole ZnO films grown at 150℃ and 200℃ were found to be 140° and 120°, respectively. The wettability for the samples was found to depend strongly on the surface morphology which results from the growth temperature.

Energy barrier for configurational transformation of graphene nanoribbon on nanotube

A graphene nanoribbon （GNR） has two basic configurations when winding on the outer surface of a carbon nanotube （CNT）： helix and scroll. Here the transformation between the two configurations is studied utilizing molecular dynamics simulations. The energy barrier during the transformation as well as its relationship with the interfacial energy and the radius of CNT are investigated. Our work offers further insights into the formation of desirable helix/scroll of GNR winding on nanotubes or nanowires, and thus can enable novel design of potential graphene-based electronics.

Preparation of Scratch-Resistant Nano-Porous Silica Films Derived by Sol-Gel Process and Their Anti-reflective Properties

Structural strengthening of the nano porous silica films has been reported. The films were prepared with a base/acid two-step catalyzed TEOS-based sol-gel processing and dip-coating, and then baked in the mixed gas of ammonia and water vapor. The silica films were characterized with TEM, AFM, FTIR, spectrophotometer, ellipsometer, and abrasion test, respectively. The experimental results have shown that the films have a nanostructure with a low refractive index and can form an excellent scratch-resistant broadband anti-reflectance. The two-step catalysis noticeably strengthens the films, and the mixed gas treatment further improves mechanical strength of the silica network. Finally the strengthening mechanism has been discussed.

Generation of micro/nano hybrid surface structures on copper by femtosecond pulsed laser irradiation

The delamination of copper lead frames from epoxy molding compounds(EMC)is a severe problem for microelectronic devices,as it leads to reduced heat dissipation or circuit breakage.The micro/nanoscale surface structuring of copper is a promising method to improve the copper-EMC interfacial adhesion.In this study,the generation of micro/nano hybrid structures on copper surfaces through femtosecond pulsed laser irradiation is proposed to improve interfacial adhesion.The micro/nano hybrid structures were realized by generating nanoscale laser-induced periodic surface structures(LIPSS)on microscale parallel grooves.Several types of hybrid surface structures were generated by changing the laser polarization direction,fluence,and scanning speed.At a specific aspect ratio of microgrooves,a latticed structure was generated on the sides of microgrooves by combining LIPSS formation and direct laser interference patterning.This study provides an efficient method for the micro/nanoscale hybrid surface structure formation for interfacial adhesion improvement between copperand EMC.

Effect of martensitic transformation on nano/ultrafine-grained structure in 304 austenitic stainless steel

304 austenitic stainless steel was cold rolled in the range of 20%-80%reductions and then annealed at 700-900°C for 60 sto obtain nano/ultrafine-grained（NG/UFG）structure.Transmission electron microscopy,electron backscatter diffraction and X-ray diffraction were used to characterize the resulting microstructures.The results showed that with the increase of cold reduction,the content of martensite was increased.The steel performed work hardening during cold-working owing to the occurrence of strain induced martensite which nucleated in single shear bands.Further rolling broke up the lath-type martensite into dislocation-cell type martensite because of the formation of slip bands.Samples annealed at 800-960°C for 60 swere of NG/UFG structure with different percentage of nanocrystalline（60-100 nm）and ultrafine（100-500 nm）grains,submicron size（500-1000 nm）grains and micron size（〉1000 nm）grains.The value of the Gibbs free energy exhibited that the reversion mechanism of the reversion process was shear controlled by the annealing temperature.For a certain annealing time during the reversion process,austenite nucleated first on dislocation-cell type martensite and the grains grew up subsequently and eventually to be micrometer/submicrometer grains,while the nucleation of austenite on lath-type martensite occurred later resulting in nanocrystalline/ultrafine grains.The existence of the NG/UFG structure led to a higher strength and toughness during tensile test.

Construction of Zn-incorporated Micro/Nano Hierarchical Structure Coatings on Tantalum

Tantalum(Ta)alloys have been widely used as bone repair materials duc to their excellent biocompatibility.In present work,zinc(Zn)incorporated ceramic coatings with micro/nano hierarchical structure were successfully fabricated on Ta by micro-arc oxidation and hydrothermal treatment.The content of Zn ions is about(1.35士0.3)wt%.Cortex-like rough morphology(Ra:1.504μm)with irregular vermiform slots can be clearly observed on the surface of Ta.More importantly,the coatings resembling the structure of natural bone can release Zn,Ca,and P ions in a controlled and sustained manner.The corrosion resistance ofTa is greatly improved after functionalized with ceramic coatings,confirming by potentiodynamic polarization tests.The bonding strength between the coatings and substrates can be up to 18.9 N.Furthermore,the surface of MAOs-HT@Ta is covered by bonelike apatite after immersed in Simulated Body Fluid(SBF)for three weeks,showing excellently bioactivity.These results suggest that the innovative Zn-incorporated micro/nano hierarchical coatings on Ta may be used as promising candidates for orthopedic implants.

Fabrication,characterization,and electrical conductivity properties of Pr_6O_(11) nanoparticles

PrrOll nanoparticles were obtained by subsequent thermal decomposition of the as-prepared precipitate formed under ambient temperature and pressure using NaOH as precipitant. The calcination process was affected, for 1 h in static air atmosphere, at 400-700 ℃ temperature range. The different samples were characterized using X-ray diffraction （XRD）, transmission electron microscopy （TEM）, field emission scanning electron microscopy （FE-SEM）, thermogravimetric analysis （TGA）, in situ electrical conductivity, and N2 adsorption/desorption. The obtained results demonstrated that nano-crystalline Pr6O11, with crystallites size of 6-12 nm, started to form at 500 ℃. Such value increased to 20-33 nm for the sample calcined at 700℃. The as-synthesized PrrOll nanoparticles presented high electrical conductivity due to electron hopping between Pr（III）-Pr（IV） pairs.

An Improved Method for Synthesizing LiV3O8 Nanorods

This paper reports on the synthesis, characterization and electrochemical performance of LiV3O8 nanorods which were prepared through a very facile hydrothermal route. The diameters of the LiV3O8 nanorods are about 150 nm. The morphology of LiV3O8 can be controlled by adjusting the reaction conditions such as the reaction time and temperature. Electrochemical measurements reveal that the as-prepared LiV3O8 nanorods display high initial dis- charge capacities （292.5 mAohg-1 ） and excellent cyclability. This result indicates that the nanorods are a promising cathode candidate material for lithium batteries.

Research progress in improving the performance of PEDOT:PSS/Microand Nano-textured Si heterojunction for hybrid solar cells

Silicon-based hybrid solar cells(HSCs),especially PEDOT:PSS/Si HSC,have attracted the interest of researchers because they combine the advantages of organic and inorganic materials.A high quality PEDOT:PSS/Si heterojunction is the key to the good performance of PEDOT:PSS/Si HSC.However,as generally requisite to enhance light absorption for HSCs,Si Micro/Nano structures will reduce the interface contact quality between PEDOT:PSS and Si surface.The inferior interface contact quality will limit the separation efficiency of the photogenerated carriers.In this paper,we summarize the research progress in improving the interface contact between Si Micro/Nano structures and PEDOT:PSS film from three aspects:the optimization of Si Micro/Nano structures aimed to improve the fluid properties of PEDOT:PSS solution,the material modification of PEDOT:PSS and interface modification with the purpose to enlarge the heterojunction area and improve the electrical contact,and the specific deposition process of PEDOT:PSS solution developed to achieve the high filling rate of PEDOT:PSS on Si Micro/Nano structures.The insight of this paper is helpful for the preparation of high-quality heterojunction,which is vitally important for the development of high efficiency PEDOT:PSS/Si HSCs.

Formation of Nano/Ultrafine Grains in AISI 321 Stainless Steel Using Advanced Thermo-Mechanical Process

Production of nano/ultrafine grains through deformation-induced martensite formation and its reversion to austenite in an AISI 321 stainless steel was studied. The repetitive cold rolling and subsequent annealing were conducted to obtain nanocrystalline structure. Heavy cold rolling （90% reduction） at ＋20 and -20 ℃ was carded out to induce the formation of α′-martensite from metastable austenitic material. The process was followed by annealing treatment at 700-900 ℃ for 0.5-30 min. Effects of process parameters, i.e., ＂reduction percentage,＂ ＂rolling temperature,＂ ＂annealing temperature＂ and ＂annealing time＂, on the microstructural development were considered. Microstructural evolutions were conducted using feritscope, X-ray diffractometer and scanning electron microscope. Hardness of the specimens was measured by Vickers method. Results revealed that the higher thickness reduction and lower rolling temperature provided more martensite volume fraction and further hardness. X-ray diffraction patterns and feritoscopic results indicated that saturated strain （εs） was reduced from 2.3 to 0.9 when temperature declined from ＋20 to -20 ℃. The smallest grain size （about 70 nm） was achieved in the condition of cold rolling at -20℃followed by annealing at 750 ℃for 5 min.

Effective strategy to achieve a metal surface with ultralow reflectivity by femtosecond laser fabrication

An effective and simple method is proposed for fabricating the micro/nano hybrid structures on metal surfaces by adjusting femtosecond laser fluence,scanning interval,and polarization.The evolution of surface morphology with the micro/nano structures is discussed in detail.Also,the mechanism of light absorption by the micro/nano hybrid structures is revealed.Compared with the typical periodic light-absorbing structures,this type of micro/nano hybrid structures has an ultralow average reflectivity of 2%in the 250–2300 nm spectral band and the minimum 1.5%reflectivity in UV band.By employing this method,large areas of the micro/nano hybrid structures with high consistency could be achieved.

Progress of passive daytime radiative cooling technologies towards commercial applications

Global warming has become one of the major environmental problems facing mankind in the 21st century,The existing refrigeration technology of buildings,like air conditioning,consumes a lot of energy.Passive daytime radiative cooling technology works without consuming energy.nor emitting carbon dioxide and other greenhouse gases.This review summarizes the development of daytime passive radiative cooling technologyfrom the basic principles,structure and materials of radiative coolers;analyses and evaluates the various existing radiative coolers.The core of radiative cooling lies in the combination of multi-scale micro/nano structures.The cooler reflects sunlight thus preventing the building from being heated up;while allows the building toradiate its own heat out thus being cooled down;meanwhile maintains the temperature difference by the heat insulation effect ofthe porous structure in theflm.The common challenges and potential solutions for the commercialization of radiative cooling technologies are analyzed,which may promote the applications of the technology in the near future.

Fabrication and multiscale characterization of 3D silver containing bioactive glass-ceramic scaffolds

In this work,we fabricated and characterized bioactive 3D glass-ceramic scaffolds with inherent antibacterial properties.The sol-gel(solution-gelation)technique and the sacrificial template method were applied for the fabrication of 3D highly porous scaffolds in the 58.6SiO2-24.9CaO-7.2P2O5-4.2Al2O3–1.5Na2O−1.5K2O–2.1Ag2O system(Ag-BG).This system is known for its advanced bioactive and antibacterial properties.The fabrication of 3D scaffolds has potential applications that impact tissue engineering.The study of the developed scaffolds from macro-characteristics to nano-,revealed a strong correlation between the macroscale properties such as antibacterial action,bioactivity with the microstructural characteristics such as elemental analysis,crystallinity.Elemental homogeneity,morphological,and microstructural characteristics of the scaffolds were studied by scanning electron microscopy associated with energy dispersive spectroscopy(SEM-EDS),transmittance electron microscopy(TEM),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FTIR),and UV-visible spectroscopy methods.The compressive strength of the 3D scaffolds was measured within the range of values for glass-ceramic scaffolds with similar compositions,porosity,and pore size.The capability of the scaffolds to form an apatite-like phase was tested by immersing the scaffolds in simulated body fluid(SBF)and the antibacterial response against methicillin-resistant Staphylococcus aureus(MRSA)was studied.The formation of an apatite phase was observed after two weeks of immersion in SBF and the anti-MRSA effect occurs after both direct and indirect exposure.

Multishelled CuO/Cu_(2)O induced fast photo-vapour generation for drinking water

Solar thermal interfacial water evaporation is proposed as a promising route to address freshwater scarcity,which can reduce energy consumption and have unlimited application scenarios.The large semiconductor family with controllable bandgap and good chemo-physical stability are considered as good candidates for photo-evaporation.However,the evaporation rate is not satisfactory because the rational control of nano/micro structure and composition is still in its infancy stage.Herein,by systemically analyzing the photo-thermal evaporation processes,we applied the hollow multishelled structure(HoMS)into this application.Benefiting from the multishelled and hierarchical porous structure,the light absorption,thermal regulation,and water transport are simultaneously optimized,resulting in a water evaporation rate of 3.2 kg·m^(-2)·h^(-1),which is among the best performance in solar-vapour generation.The collected water from different water resources meets the World Health Organization standard for drinkable water.Interestingly,by using the CuO/Cu_(2)O system,reactive oxygen species were generated for water disinfection,showing a new route for efficient solar-vapour generation and a green way to obtain safe drinking water.