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This work presents an economic and controllable fabricating method of high numerical aperture (NA) polymer microlens array (MLA) based on ink-jetting technology. The MLAs are ink-jetted to align on micro platforms patterned flexible PDMS substrate. The shape of a sole lens is constructed by the ink-jetted pre-cured polymer volume confined on a micro platform. In this way, MLAs with targeted geometries—as well as tailored optical characteristics—can be printed, leading to freely designed optical properties. High NA from 0.446 to 0.885 and focal lengths between 99.26 μm and 39.45 μm are demonstrated, confirming theoretical predictions. Particularly, both the simulations and experimental measurements in optical properties are carried out, demonstrating that microlenses with shapes beyond a hemisphere (CA > 90°) exhibits higher light utilization efficiency and wider viewing angle. Meanwhile, the MLAs are fabricated on flexible PDMS substrates and can be attached to other curved surfaces for wider field of view imaging and higher sensitivity. [ABSTRACT FROM AUTHOR]

Highlights: [•] The nitride uranium metal surfaces were formed by SGPN and PIII methods. [•] The initial oxidation behaviors of surfaces were analyzed by XPS in detail. [•] A comparative study was performed to clarify the initial oxidation processes. [ABSTRACT FROM AUTHOR]

Fluorinated hybrid films composed of fluorinated polymethylsiloxane (PMHS– x FMA, x = 6, 13, 17) and octavinyl-polyhedral oligomeric silsesquioxanes (OVPOSS) were prepared for icephobic applications. PMHS– x FMA with diverse fluorinated side groups were synthesized via hydrosilylation of polymethylhydrosiloxane (PMHS) with fluorinated methacrylate ( x FMA), i.e. , hexafluorobutyl methacrylate (6FMA), tridecafluorooctyl methacrylate (13FMA) and heptadecafluorodecyl methacrylate (17FMA), respectively. Characterizations of atomic force microscope and scanning electron microscope indicated that surfaces of the hybrid films consisted of submicron/nano-scaled OVPOSS aggregates, and the root-mean-square roughness ( S q ) could vary from 42.6 nm to 145.2 nm with various OVPOSS content (5–20 wt%). Wettability measurements of the prepared films demonstrated that the relatively longer fluorinated side groups in PMHS–17FMA were beneficial for decreasing surface energy and enhancing hydrophobic properties. However, the fluorinated hybrid films with PMHS–17FMA presented higher ice shear strengths due to the stronger interfacial interactions between the film surface and ice/water. The film prepared by PMHS–13FMA and 10 wt% of OVPOSS with proper roughness (90.2 nm) performed the lowest ice shear strength (188.2 ± 13.4 kPa) among all the samples. Dynamic water droplet impact measurement revealed that the rougher surface with the mass fraction of OVPOSS more than 10 wt% and S q larger than 90 nm could repel water droplets. The submicron/nano-structured surface of PMHS– x FMA and OVPOSS was expected for anti-icing applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • In situ DRIFTS distinguishes CO adsorption on mesoporous CeO 2 -supported Pt catalysts. • Various structures of mesoporous Pt/CeO 2 catalysts are correlated with Pt-CO ads bands. • CeO 2 -supported Pt catalysts synthesized from SBA-15 have the strongest CO adsorption. CeO 2 -supported Pt (1 wt%) catalysts have been synthesized using three ordered mesoporous silica templates, SBA-15, KIT-6, and COK-19, with the representative pore structures listed as 2D hexagonal, bicontinuous cubic and face-centered cubic structures. The effect of pore structure on surface and adsorption properties of those ordered mesoprous CeO 2 -supported Pt catalysts have been studied by in situ variable temperature diffuse reflectance infrared Fourier transform spectroscopy (VT-DRIFTS) using carbon monoxide (CO) as the probing molecule to study the Pt – CO ads and carbonate/formate surface species. VT-DRIFT spectra demonstrate that the mesoporous Pt-CeO 2 catalyst synthesized from the SBA-15 template shows the largest amount of Pt – CO ads , indicating that mesoporous Pt-CeO 2 synthesized from SBA-15 possesses the largest number of active metal sites, due to its larger pore volume and pore size, compared to the ones synthesized from KIT-6 and COK-19. The VT-DRIFT results of CO adsorption and desorption from ordered mesoporous CeO 2 -supported Pt catalysts will assist in understanding the surface chemistry of reactions with CO as a reactant, such as water–gas shift reaction; and help design effective mesoporous catalysts for CO reactions, under operando conditions. [ABSTRACT FROM AUTHOR]

Transition between superhydrophilicity and superhydrophobicity is primarily important in the modification of the wettability of the material surface. The significant transition between the superhydrophilicity and the superhydrophobicity is realized from the surface made up of zinc oxide (ZnO) nanorod arrays on a silicon substrate with different annealing temperatures by the post-annealing process. Surprisingly, a critical temperature (300 °C) existed for ZnO nanorod arrays to achieve the transition from the increase in contact angle to its reduction. As the annealing temperature increases, the initial hydrophilic surface is gradually converted to the superhydrophobic one, whereas the surface property reverses back to the hydrophilic one as the critical annealing temperature is surpassed. Oxygen vacancies and carbon adsorptions are examined to be responsible for this extraordinary wettability variation. We establish a simple theoretical model to describe the novel mechanism of the transition between the superhydrophilicity and the superhydrophobicity. The facile method to achieve the transition reported here will supply the great facile applications to control the wetting properties of materials, without employing the destroyable chemical coating or external stimulation by electrowetting and ultra-violet (UV) illumination. [ABSTRACT FROM AUTHOR]

Micro/nanostructures are fabricated on the stainless steel surfaces by a nanosecond laser in different gaseous environments, including air, O 2 , N 2 and Ar. Our results indicate that the dimensional feature of the micro/nanostructures is greatly affected by laser scanning speed as well as gaseous environment. The chemical composition of the structures can be flexibly adjusted by laser processing parameters. Oxygen-rich environment is found to boost the growth of the nanostructures. The coloring by the laser processing can be achieved on the laser treated stainless steel surfaces. The multicolor effect on the surfaces is found to be attributed to both feature dimension and chemical composition of the structures. The coloring of the metal surfaces has promising applications in surface marking and code identifying. [ABSTRACT FROM AUTHOR]

CeO 2 thin films were deposited on Si (1 1 1) substrates by laser molecular-beam epitaxy (LMBE). The thermal stability and surface behaviors of CeO 2 /Si samples were investigated by X-ray photoelectron spectroscopy during in-situ vacuum annealing. Temperature dependency of surface compositions was identified. At the temperature from 700 K to 1000 K, CeO 2 was reduced gradually, but incomplete transformation of CeO 2 to Ce 2 O 3 was found even when the sample was annealed at 1000 K for an hour. When the sample was exposed to oxygen ambience, the enhanced thermal stability of the partially reduced surface was revealed by the slight variation of Ce3d and Ce4d spectra. Si2p peak at 102.7 eV was detected on the top surface after the whole heating treatments, while not for the sub-surface during sputtering till to the interface. The Si signal at the outmost surface is induced by surface segregation due to the decreasing solid solubility of Si atoms in CeO 2 matrix with the decreasing temperature. At the interface, Si2p peaks at 99.9 eV with the presence of Ce4d peaks at 122.2 eV and 125.6 eV are attributed to the formation of cerium silicates with Ce–Si–O matrix during annealing due to interfacial reactions, which are supposed to stabilize the partially reduced ceria system. [ABSTRACT FROM AUTHOR]

Highlights: [•] Adsorptive geometry and energy on perfect and defective surface have been calculated. [•] The electronic structure has been analyzed by CDD and DOS. [•] Adsorption rate has been deduced employing a model of grand canonical ensemble. [•] The transition temperate of nuclide from adsorption to desorption has been obtained. [ABSTRACT FROM AUTHOR]

Abstract: This study investigates the surface fractal dimensions (SFDs) of pore structure of cement pastes and mortars with/without ground granulated blast-furnace slag (GGBS) incorporated into binder. The samples were subject to water curing and sealed curing. The fractal dimensions of samples are determined by Zhang’s model (Ind Eng Chem Res, 34 (1995):1383–1386) on the basis of mercury intrusion porosimetry (MIP) data. The results confirm the scale-dependent property of fractal dimension of pore structures and the micro-fractal, transition and macro-fractal regions are identified for all samples. The upper pore size range for micro-fractal regions is around 30nm, the transition regions cover 0.5–2 magnitude orders of pore size and macro fractal regions cover 1.5–3 magnitude orders. Both curing conditions and GGBS in binder have impact on the fractal properties of pore structure, and samples incorporating GGBS have substantially larger values for micro-fractal regions. [Copyright &y& Elsevier]

Highlights: [•] CdTe nanotrees are prepared by one-step sputtering method. [•] CdTe nanotrees are constructed by the trunk and branches nanorods. [•] CdTe nanotrees have stable superhydrophobic surface. [ABSTRACT FROM AUTHOR]

Highlights: [•] The numerical aperture of micro-lens arrays increases with the droplet curvatures. [•] Expected micro-lens arrays of numerical aperture and fill factor can be fabricated through morphology of ZnO nanopillars and arrangements of nozzle in ink-jetting process. [•] The anti-reflection property of ZnO nanopillars leads to better performance of the micro-lens arrays. [Copyright &y& Elsevier]

Abstract: The influence of pregrowth surface morphology and reconstruction upon the growth of In0.15Ga0.85As alloy layers was investigated. After obtaining different pregrowth surfaces, depositions of InGaAs were carried out by molecular-beam epitaxy (MBE). The real space ultrahigh vacuum scanning tunneling microscopy (STM) images showed the disciplinary changes between GaAs and InGaAs surface morphology. Reflection high energy electron diffraction (RHEED) has also been used to estimate InGaAs deposition. As STM images and RHEED oscillations showed, heteroepitaxial surface quality greatly depends on initial state of surface even form the earliest stages of deposition. Two reasons of the effects are proposed, a conjecture for the formation of surfaces morphology and its influence on subsequent growth is also proposed. [Copyright &y& Elsevier]

Abstract: A novel fluorine-contained random copolymer (2,3,4,5,6-pentafluorostyrene)-r-poly(4-vinyl benzocyclobutene) (P(PFSt-r-4-VBCB)) was synthesized, and then spin-coated onto Si substrates followed by thermal cross-linking to produce the copolymer ultra-thin films. Although the surface modification with the P(PFSt-r-4-VBCB) film was simple and did not rely on special surface chemical reactions, the film could decrease the surface energy significantly, more importantly; the film demonstrated excellent stability and corrosion resistance. This random copolymer film could find broad applications in modifying various solid surfaces to enhance the properties such as corrosion resistance and solvent resistance. [Copyright &y& Elsevier]

• In x Ga 1-x N/GaN core/shell NWs can be formed spontaneously via a Ni-catalyzed CVD growth. • The thickness of the GaN shells can be tuned according to a two-step growth mechanism. • In x Ga 1-x N NWs without GaN shells can be applied for photocatalytic hydrogen generation. In x Ga 1-x N nanowires (NWs) have drawn great attentions as a promising photocatalyst for H 2 generation via solar water splitting. In this article, m-axial NWs with In x Ga 1-x N/GaN core/shell structure can be formed spontaneously on the n-type Si (1 1 1) substrate via Ni-assisted chemical vapor deposition (CVD) method. CVD growth conditions were adjusted by tuning the duration and pressure. The microstructures, surface chemistry, and optical properties of the obtained NWs were characterized using various techniques. The growth mechanism is identified as a two-step process. The In x Ga 1-x N cores with a high density of basal stacking faults were grown by a vapour-liquid-solid (VLS) mode, while the GaN shells were grown on the sidewalls of In x Ga 1-x N core through a vapor-solid (VS) mode. The photocatalytic activities of the NWs were evaluated by the amount of H 2 generated from water splitting. A thicker GaN shell was revealed to decrease the photoactivity by hindering the charge separation and transfer of electron-hole pairs generated inside the In x Ga 1-x N cores. A strategy can be proposed to improve the photocatalytic performance of NWs by terminating the VS growth of the GaN shells during the CVD process. [ABSTRACT FROM AUTHOR]

Enhanced glow discharge plasma immersion ion implantation and deposition (EGD-PIII&D) have been proved to be highly effective for depositing diamond-like carbon (DLC) films on the inner surface of the slender quartz tube with a deposition rate of 1.3 μm/min. Such a high-efficiency DLC films deposition was explained previously as the short electrons mean free path to cause large collision frequency between electrons and neutral particles. However, in this paper, we found that the inner surface material of the tube itself play a vital role on the films deposition. To disclose the mechanism of this phenomenon, the effect of different inner surface materials on plasma discharge was experimentally and theoretically investigated. Then a self-enhancing plasma discharge is discovered. It is found that secondary electrons emitted from the inner surface material, whatever it is the tube inner surface or deposited DLC films, can dramatically enhance the plasma discharge to improve the DLC films deposition rate. [ABSTRACT FROM AUTHOR]

A novel approach has been developed to prepare an efficient visible-light photocatalyst using Ag 3 PO 4 and TiO 2 sol as precursors. First, Ag 3 PO 4 particles were dipped into TiO 2 sol for 5 min and were filtered quickly. Second, Ag 3 PO 4 particles adsorbing a small amount of TiO 2 sol were aged for 24 h to form TiO 2 gel on their surface. Finally, Ag 3 PO 4 particles covered by TiO 2 gel were calcined at 450 °C for 2 h to obtain the surface-modified Ag 3 PO 4 sample. The surface-modified Ag 3 PO 4 was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, UV–vis diffuse reflection spectroscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy. The visible-light photocatalytic performances of the surface-modified Ag 3 PO 4 were evaluated by the photodegradation of methyl orange or phenol solution. The results showed that the surface-modified Ag 3 PO 4 exhibited much higher visible-light photocatalytic activity and stability than pure Ag 3 PO 4 . As the amount of TiO 2 gel on the Ag 3 PO 4 surface increased, the visible-light photocatalytic activity increased first and then decreased. The surface-modification of Ag 3 PO 4 obviously decreased its solubility in water environment due to the protection of TiO 2 and Ag nanocrystals on the surface. The visible-light photocatalytic mechanism of the surface-modified Ag 3 PO 4 has been discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Acid etching and polymer coating were used to prepare a superhydrophilic and superhydrophobic surface on aluminum alloy. [•] The facile transition from hydrophilicity to superhydrophilicity and superhydrophobicity was readily realized by the simple method. [•] The superhydrophobic surfaces with a high water contact angle of 157̊ were obtained by the simple coating. [ABSTRACT FROM AUTHOR]

Abstract: Molecular dynamic simulation was applied in analyzing the difference of surface damage during the impact of a large silica cluster on a crystal silicon substrate in dry and wet condition, respectively. The simulation results show that the damage of silicon substrate under the dry impact is more severe than that under the wet impact. A reason is that the water film buffers the impact of the incident cluster at the init stage under the wet impact. The more important reason is that the water film might be solidified into a continuous thin film at the cluster deformation stage. So, the considerable great impact energy of the cluster will be absorbed by the water film and transformed into thermal dissipation of energy between the simulation ensemble and the water film. [Copyright &y& Elsevier]

Abstract: The grafting number of surfactant coating on magnetite nanoparticles in a magnetic colloid (magnetic fluid), defined as the number of surfactant molecules adsorbed per surface area of nanoparticles, was successfully obtained from the atomic absorption spectroscopy and transmission electron microscopy. We found that the increases of grafting number with the molar concentration of surfactant and the adsorption temperature can be quantitatively measured, making it possible to produce well controlled, stable magnetic colloids that are precursors for many magnetic nanostructures. [Copyright &y& Elsevier]

CeO 2 with four different morphologies (sphere, rod, octahedron, cube) are used as the supports to synthesize the CuCe catalysts for the CO preferential oxidation in the H 2 -rich gas and characterized by various techniques (TEM, HR-TEM, SEM, XRD, N 2 physisorption, XPS, Raman spectra, CO-TPD, CO-DRIFTS, O 2 -TPD, CO pulses, H 2 -TPR) to obtain an insight into the impact of the CeO 2 morphology on the surface structure, composition and redox properties, especially the active species. The four supports expose {111}, {110} and {100} planes, and sphere-shape CeO 2 has a higher ratio of {111}, which can form more reductive copper species and active oxygen species. And the catalytic performance followed by this order: spheres (28.5 kJ/mol) > rods (31.0 kJ/mol) > octahedrons (34.1 kJ/mol) > cubes (40.3 kJ/mol). By further analysis of the characterization results, a series of structure-activity relationships are established to confirm that the active oxygen species is the decisive factor of preferential oxidation of CO in the H 2 -rich stream. Unlabelled Image [ABSTRACT FROM AUTHOR]

Highlights: • Clarify the effect of vacancy on H 2 S dissociation and H atom diffusion on Fe(1 0 0) surfaces. • Demonstrate the effects of adjacent vacant atom on H atom diffusion. • Reveal the minimum energy-diffusion path of the H atom from the Fe(1 0 0) surfaces into the bulk Fe. Abstract Vacancy defects on an iron surface have a great influence on the occurrence of hydrogen embrittlement. The adsorption/dissociation mechanism of H 2 S and the diffusion behavior of H atoms were calculated by first-principles spin-polarization density functional theory (DFT) on defect-free and vacancy-defective Fe(1 0 0) surfaces. The results show that the maximum dissociation energy barriers of H 2 S on the Fe(1 0 0) surface of defect-free and first-layer vacancy-defective Fe are 0.35 and 0.17 eV, respectively, indicating that the reactivity of the vacancy-defective Fe(1 0 0) surface is moderately increased. The existence of vacancy defects changes the preferential H atom diffusion entrance to the subsurface and shortens the diffusion path. For H diffusion in bulk Fe(1 0 0), it is found that H atoms diffuse via a tortuous path from one tetrahedral-site to a neighboring tetrahedral-site rather than diffusing through a linear trajectory. Moreover, the previously suggested path via the octahedral site is excluded due to its higher barrier and the rank of the saddle point. Diffusion barriers computed for H atom penetration from the surface into the inner-layers are approximately 0.54 eV (except for second-layer vacancy defects), which are all greater than the activation energy for dissociation of H 2 S on the Fe(1 0 0) surfaces. This suggests that H diffusion is more probable than H 2 S dissociation as the rate-limiting step for hydrogen permeation into the bulk Fe(1 0 0). [ABSTRACT FROM AUTHOR]

Expandable graphite is widely used as a new functional carbon material, especially as fire-retardant; however, its practical application is limited due to the high expansion temperature. In this work, preparation process of low temperature and highly expandable graphite was studied, using natural flake graphite as raw material and KMnO 4 /HClO 4 /NH 4 NO 3 as oxidative intercalations. The structure, morphology, functional groups and thermal properties were characterized during expanding process by Fourier transform infrared spectroscopy (FTIR), Raman spectra, thermo-gravimetry differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), and scanning electron microscope (SEM). The analysis showed that by oxidation intercalation, some oxygen-containing groups were grafted on the edge and within the graphite layer. The intercalation reagent entered the graphite layer to increase the interlayer spacing. After expansion, the original flaky expandable graphite was completely transformed into worm-like expanded graphite. The order of graphite intercalation compounds (GICs) was proposed and determined to be 3 for the prepared expandable graphite, based on quantitative XRD peak analysis. Meanwhile, the detailed intercalation mechanisms were also proposed. The comprehensive investigation paved a benchmark for the industrial application of such sulfur-free expanded graphite. [ABSTRACT FROM AUTHOR]

A solid-phase preparation method was applied to obtain a novel, green and effective functional nanoparticle, silica-supported sulfur monochloride (silica-s-S 2 Cl 2 ), by the chemical reaction between chlorine atom and silicon hydroxyl on the silica surface. Through this chemical reaction, silica surface supported with high content of sulfur, and the functional nanoparticles can not only vulcanize the rubber instead of sulfur or other vulcanizing agent with high performance, but also improve the filler-rubber interaction as a modifier due to the improved modification effect. 29 Si NMR, Raman spectroscopy, Element analysis and TGA confirm that the sulfur monochloride is chemically bonded on the silica surface. Cure properties measurement, morphology of filler dispersion, mechanical properties measurement, immobilized polymer layer and oxidation induction time increment together show that the novel vulcanizing agent silica-s-S 2 Cl 2 instead of sulfur in rubber vulcanization gives rise to significant improvement in the crosslinking density and the interfacial adhesion between silica particles and the rubber matrix, which is on account of the promoted vulcanizing on the functional silica nanoparticles surface with the supported sulfur. [ABSTRACT FROM AUTHOR]

Vulcanization accelerant N-cyclohexyl-2-benzothiazole sulfenamide (CZ) was used as a surface modifier and chemically grafted on the surface of halloysite nanotubes (HNTs) to obtain CZ-functionalized HNTs (HNTs-s-CZ). It was found that HNTs-s-CZ could be homogeneously dispersed into styrene-butadiene rubber (SBR). The grafted CZ molecules, exactly located at the filler-rubber interface, reduced the activation energy of vulcanization of SBR/HNTs-s-CZ compounds. Besides, the density of chain segments introduced by the interfacial phase of SBR/HNTs-s-CZ nanocomposites was higher than the other nanocomposites with silane-modified HNTs (m-HNTs) or pristine HNTs, manifesting an indication of enhanced filler-rubber interfacial interaction in SBR/HNTs-s-CZ nanocomposites. Consequently, SBR/HNTs-s-CZ nanocomposites showed excellent mechanical properties. The tensile strength could be enhanced by as much as 38.6% and 102.5% compared to those of SBR/m-HNTs and SBR/HNTs nanocomposites, respectively, though containing equivalent accelerant component. The value of this work lies in the fact that apparent properties improvement of elastomer composites has been achieved by the incorporation of vulcanization accelerant-functionalized HNTs, which may be fruitful for the rational design of filler surface treatment and offer new scientific and technological opportunities for the preparation of high performance elastomer composites. [ABSTRACT FROM AUTHOR]

In this paper, a novel texturing technology by means of electrodepositon is introduced. Textured surface covered with small bumps with the average size of 28 μm in diameter and 10 μm in height was fabricated. The trough around the bumps acts as the pocket to trap the debris. The nitrogen implantation was used to enhance the tribological properties of textured surfaces. The effects of implanted energy and dose on the structures of coating and tribological performances of textured surfaces were studied. The results show that the formation of Cr 2 N or CrN depends on the implanted dose. After nitrogen ion implantation, the friction coefficient of textured surface reduced and the wear resistance of textured surface was improved. The wear resistance enhances with increase of implanted dose, and has little to do with implanted energy. [ABSTRACT FROM AUTHOR]

The adsorption and migration energies of a single carbon atom and the configuration evolution energies of two carbon atoms on a clean diamond (0 0 1) surface were calculated using the first principle method based on density functional theory to investigate the formation of ultra-nanocrystalline diamond (UNCD) film. The activation energy of a single atom diffusing along a dimer row is 1.96 eV, which is almost the same as that of a CH 2 migrating along a dimer row under hydrogen-rich conditions. However, the activation energy of a single atom diffusing along a dimer chain is 2.66 eV, which is approximately 1.55 times greater than that of a CH 2 migrating along a dimer chain in a hydrogen-rich environment. The configuration evolution of the two carbon atoms is almost impossible at common diamond film deposition temperatures (700–900 °C) because the activation energies reach 4.46 or 5.90 eV. Therefore, the high-energy barrier could result in insufficient migration of adatoms, leading to the formation of amorphous in UNCD films in hydrogen-poor CVD environment. [ABSTRACT FROM AUTHOR]

To enhance the biocompatibility or extend the biomedical application of poly(caprolactone) (PCL), protein retention on PCL surface is often required. In this study, poly(acrylamide) (PAAm) brushes were grown from PCL surface via surface-initiated atom transfer radical polymerization (SI-ATRP) and served as a protein-capturing platform. Grafted PAAm was densely packed on surface and exhibited superior protein retention ability. Captured protein was found to be resistant to washing under detergent environment. Furthermore, protein structure after being captured was investigated by circular dichroism (CD) spectroscopy, and the CD spectra verified that secondary structure of captured proteins was maintained, indicating no denaturation of protein happened for retention process. [ABSTRACT FROM AUTHOR]

In this paper, a novel non-noble metal catalyst (Fe-N x /C) is used to improve the removal mass of sapphire as well as obtain atomically smooth sapphire wafer surfaces. The results indicate that Fe-N x /C shows good catalytic activity towards sapphire removal rate. And the material removal rates (MRRs) are found to vary with the catalyst content in the polishing fluid. Especially that when the polishing slurry mixes with 16 ppm Fe-N x /C shows the maximum MRR and its removal mass of sapphire is 38.43 nm/min, more than 15.44% larger than traditional CMP using the colloidal silicon dioxide (SiO 2 ) without Fe-N x /C. Catalyst-assisted chemical–mechanical polishing of sapphire is studied with X-ray photoelectron spectroscopy (XPS). It is found that the formation of a soft hydration layer (boehmite, γ-AlOOH or γ-AlO(OH)) on sapphire surface facilitates the material removal and achieving fine surface finish on basal plane. Abrasives (colloid silica together with magnetite, ingredient of Fe-N x /C) with a hardness between boehmite and sapphire polish the c -plane of sapphire with good surface finish and efficient removal. Fe 2 O 3 , Fe 3 O 4 , pyridinic N as well as pyrrolic N group would be the catalytical active sites and accelerate this process. Surface quality is characterized with atomic force microscopy (AFM). The optimum CMP removal by Fe-N x /C also yields a superior surface finish of 0.078 nm the average roughness (Ra). [ABSTRACT FROM AUTHOR]

The first-principle technique has been employed to determine the structure of hexyl thiolate molecular chains, monolayers and the adsorption system. CASTEP calculation shows that hexyl thiolate monolayer is a self-assembly system. And the molecular orientation of the hexyl thiolate on the surface is not symmetrical, they have the simplex structure. The electron density confirms the result. Hexyl thiolate monolayer is adsorbed on the Au(1 1 1)–(√3 × √3)R30° surface in the bridge site with the angle between the S C6 bond and the surface is 65°. The structural parameters in the adsorption system are the same to those in the monolayer. [ABSTRACT FROM AUTHOR]

Developments of poly(caprolactone) in blood-contacting applications are often restricted due to its intrinsic hydrophobicity. One common way to improve its hemocompatibility is to attach hydrophilic polymers. Here we developed a non-destructive method to graft hydrophilic poly(acrylamide) (PAAm) onto poly(caprolactone) (PCL) surface. In this strategy, azido-ended PCL with low molecular weights was synthesized and blended with PCL to create a surface with “clickable” property. Alkyne-ended poly(acrylamide)s with controlled chain lengths were then synthesized by atom transfer radical polymerization (ATRP), and finally were immobilized onto PCL surface by “click” reaction. The occurrence of immobilization was verified qualitatively by water contact angle measurement and quantitatively by X-ray photoelectron spectroscopy (XPS). The PAAm grafted surface exhibited fouling resistant properties, as demonstrated by reduced bovine serum albumin (BSA) and fibrinogen (Fg) adhesion. [ABSTRACT FROM AUTHOR]

With the development of ultra-large scale integrated circuits, ruthenium has been selected as one of the most promising barrier metals for copper interconnects to replace traditional Ta/TaN bilayer. This paper mainly investigated the effect of ionic strength on the chemical mechanical polishing performance of ruthenium in H 2 O 2 -based slurries. The results show that, the ruthenium removal rate (RR) increases with the increasing concentration of H 2 O 2 due to the formation of ruthenium oxides like Ru(OH) 3 , RuO 2 ·2H 2 O and even RuO 4 2− ; additionally, the ruthenium RR can be further enhanced with the increase of K + ionic strength. It is revealed that the added K + can intensify the electrochemical reactions between H 2 O 2 and the ruthenium surface by increasing the conductivity, meanwhile can also result in the neutralization of the zeta potentials of both silica particles and the ruthenium surface, and thus can lead to the decrease of the electrostatic repulsive force and the increase of the mechanical abrasion intensity between silica particles and the ruthenium surface. Therefore, the ruthenium RR increases with the increase of K + ionic strength. Furthermore, the effects of K + ionic strength on the material removal rate (MRR) selectivity of Ru vs. Cu and the galvanic corrosion of Cu/Ru couple are studied. It is found that, in order to achieve higher MRR selectivity than 1.0, KNO 3 is preferred for the K + source; and with H 2 O 2 as the oxidizer, copper galvanic corrosion problem can be effectively suppressed. [ABSTRACT FROM AUTHOR]

Highlights: [•] The most suitable configuration is Co CO structure in the CoO-terminated LaCoO3 (001) surface. [•] The Co C bond is mainly from the hybrid between the CO and Co-d orbital. [•] The most suitable configuration is the O CO structure and the electrons transfer from the surface to the CO molecule. [•] The LaCoO3 could be used as the sensitive material to detect CO gas. [Copyright &y& Elsevier]

Highlights: [•] The addition of Ir in Ru/ZnO effectively enhances the catalyst stability. [•] The enhanced stability is due to RuIr alloy and weakened surface acidity. [•] Catalyst deactivation is due to deposition of organic compounds on the surface. [•] Strong CO chemisorption on metal surface also accounts for catalyst deactivation. [ABSTRACT FROM AUTHOR]

Abstract: Nickel/Fe3O4 nanoparticle (Ni/Fe3O4-NPs) composite coatings on the surface of carbon fiber were prepared by electrodeposition in a nickel-plating bath containing Fe3O4 nanoparticles (Fe3O4-NPs). The composite of carbon fiber with nanocomposite coatings were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) analysis, thermogravimetric (TG) analysis and vibrating sample magnetometer (VSM). The microstructure observation reveals that the Fe3O4-NPs distribute uniformly in the coatings. TG and VSM analysis show that the carbon fibers with Ni/Fe3O4-NPs composite coatings exhibit higher thermal stability and saturation magnetization than carbon fiber with Ni coatings. The result is attributed to the homogeneous distribution of magnetic Fe3O4 in the composite coatings. [Copyright &y& Elsevier]

Abstract: Organic phosphonic acid system abrasive free slurry for copper polishing is developed in our earlier work. Since material removal rate is too high to be applied as precision polishing slurry for copper, inhibitors are needed. Experiment results also show us that the most commonly used inhibitor benzotriazole is unsuitable for this abrasive free slurry, and then another kind of compound inhibitors for this organic phosphonic acid system abrasive free slurry are developed. The compound inhibitors, consisting of ascorbic acid and ethylene thiourea, can control the material removal rate and also reduce surface roughness. XPS results show that, in the compound inhibitors, ascorbic acid participates in the surface chemical reaction, forms passivating layer on copper surface and helps to control the material removal rate. Corrosion current calculated from polarization curve is consistent with material removal rate. Ethylene thiourea contributes to the reduction of surface roughness, which can be indicated by the peak shape change of S2p in XPS results. [Copyright &y& Elsevier]

Abstract: A nano-TiO2/hydroxyapatite composite bioceramic coating was developed and applied to the surfaces of pure titanium discs by the sol–gel method. A TiO2 anatase bioceramic coating was utilized in the inner layer, which could adhere tightly to the titanium substrate. A porous hydroxyapatite (HA) bioceramic coating was utilized in the outer layer, which has higher solubility and better short-term bioactivity. Conventional HA coatings and commercially pure titanium were used as controls. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to characterize the crystallization, surface morphology, and thickness of the coatings. The bioactivities of the coatings were evaluated by in vitro osteoblast cultures. Results showed that the nano-TiO2/HA composite bioceramic coating exhibited good crystallization and homogeneous, nano-scale surface morphology. In addition, the nano-TiO2/HA coating adhered tightly to the substrate, and the in vitro osteoblast cultures exhibited satisfactory bioactivity. [Copyright &y& Elsevier]

Abstract: Polyaniline/Prussian blue micro-composites have been synthesized by a low-temperature hydrothermal process. Prussian blue is obtained using the single iron-source precursor K3[Fe(CN)6] in acidic aqueous solution. The composite was characterized by field-emission scanning electron microscopy (FE-SEM), Fourier transmission infrared spectroscopy (FT-IR), and X-ray diffractometer (XRD). The magnetic behavior of polyaniline/Prussian blue composites and the effect of the concentration of K3[Fe(CN)6] on the morphology of polyaniline/Prussian blue micro-composites have been investigated. [Copyright &y& Elsevier]

Abstract: The siloxane microspheres with core-shell structure (PMMA/PMPS) (MMA, methyl methacrylate; MPS, 3-methacryloxypropyl-trimethoxysilane) have been prepared by dispersion polymerization as described in our previous work. In this paper, the developed poly(MMA-MPS) microspheres, as a carrier, are used to investigate the adsorption behavior of bovine serum albumin (BSA) on them. The Langmuir and Freundlich models have been applied to describe the adsorption behavior. The experimental results indicated that the presence of PMPS evidently increases the adsorption rate and the amount of protein, and it also influences the interaction of BSA molecules. The adsorption of BSA on the poly(MMA-MPS) microspheres seems to be sensitive to pH and ionic strength. The fittings curves from Langmuir and Freundlich models showed that the adsorption was actually more complicated than ideal situation because one or more interactions were involved in the process. For understanding the electronic contribution, the Zeta potential was used to measure the reactive system before and after protein adsorption. [Copyright &y& Elsevier]