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Graphene oxide (GO) has arisen as an effective adsorbent for water treatment owing to its high removal efficiency for water pollutants. However, separating GO adsorbents from the pollutant solution is difficult after adsorption. The GO adsorbents are unsuitable for various dyes, and can only remove cationic dyes from an aqueous solution. To address these issues, this study utilized a simple and cost-effective layer-by-layer assembly technique to deposit multilayer films onto solid substrates. These films were composed of poly(allylamine hydrochloride)–dextran (PAHD) microgels and GO, and were designed to be highly effective while remaining affordable. The PAHD/GO multilayer films obtained produced an effortless separation process and demonstrated exceptional adsorption capabilities for cationic, anionic and non-ionic dyes. Specifically, the adsorption capacities for carmine and mulberry red were notably high, measuring 337.4 and 417.7 mg g−1, respectively. In addition, the PAHD/GO multilayer films could be regenerated well in sodium chloride solution without obvious compromise of removal efficiency. The adsorption kinetics, isotherms and thermodynamics of dyes on the PAHD/GO multilayer films were also studied. Thanks to the straightforward manufacturing process and outstanding adsorption capabilities of PAHD/GO multilayer films, this study presents a significant opportunity to advance the practical application of GO in water treatment. A composite film composed of poly(allylamine hydrochloride)–dextran microgels and graphene oxide can be employed repeatedly to remove cationic, anionic and non-ionic dyes in water. [ABSTRACT FROM AUTHOR]

Small plastic packaging films make up a quarter of all packaging waste generated annually in Austria. As many plastic packaging films are multilayered to give barrier properties and strength, this fraction is considered hardly recyclable and recovered thermally. Besides, they can not be separated from recyclable monolayer films using near-infrared spectroscopy in material recovery facilities. In this paper, an experimental sensor-based sorting setup is used to demonstrate the effect of adapting a near-infrared sorting rig to enable measurement in transflection. This adaptation effectively circumvents problems caused by low material thickness and improves the sorting success when separating monolayer and multilayer film materials. Additionally, machine learning approaches are discussed to separate monolayer and multilayer materials without requiring the near-infrared sorter to explicitly learn the material fingerprint of each possible combination of layered materials. Last, a fast Fourier transform is shown to reduce destructive interference overlaying the spectral information. Through this, it is possible to automatically find the Fourier component at which to place the filter to regain the most spectral information possible. [ABSTRACT FROM AUTHOR]

Polypropylene (PP) films have been widely used in medical, electronics, and construction fields due to their low cost and excellent comprehensive properties. However, the poor low-temperature toughness of PP films restricts its further applications in extreme cold environments. Here, the nacre-inspired 8-, 32-, 128-, and 512-layer PP/SEBS-based films were constructed via our multilayer blown systems. Compared to the conventional blended films, 128-layer films showed significant improvement under the low-temperature conditions, i.e., 160 %, 150 %, and 136 % in impact toughness, tear toughness, and elongation at break, respectively. The high toughening efficiency of the multilayer films is because of the nacre-inspired multilayer structures, which can develop the multi-stage propagation of the damage behavior such as craze and plastic deformation to dissipate much energy when mechanically broken. Since nacre-inspired PP/SEBS-based multilayer films show high efficiency in low-temperature toughening, this work may provide a possible solution to improving the low-temperature mechanical properties of PP films or even other types of polymeric films. [Display omitted] • PP/SEBS-based microlayer films up to 512 layers with a thickness of 140 μm were fabricated. • Excellent low-temperature toughening efficiency were achieved. • An industrial feasibility for large-scale production of high-toughness PP/SEBS-based films were provided. [ABSTRACT FROM AUTHOR]

In this work, peel tests inside the chamber of an ESEM (in situ peel tests) are described with heat-sealed test specimens of packaging systems made of multilayer films that simulate different flexible packaging types, according to the packaging line used. The in situ peel tests provided evidence to describe the influence of three different main aspects of the packaging process in relation to the opening behavior of the sealing packages. The investigated aspects are the peel angle, the alignment angle between the orientation of the multilayer films and the seal, and the bulge formation as a consequence of inadequate sealing parameters. In situ peel tests enabled the differentiation between peel angle and local (micro) peel angle, which results from the overall stiffness of the multilayer structure film. Alignment angles of 90° and 45° were found to produce similar opening forces. Images showing the formation of various new local micro fissures on new planes during the in situ peel test explained how the opening force can be dramatically increased during the tearing of two sealed multilayer films. [ABSTRACT FROM AUTHOR]

The phenomenon of physical aging of glassy polymers in confined environments has been extensively studied over the last few decades due to its numerous technological and fundamental implications. Understanding aging in confined environments is vital for predicting the long-term performances in applicative conditions for confined glassy polymers. The physical aging of PC/PMMA multilayer films, with layer thicknesses ranging from micro-to-nanoscale, was explored using the Differential Scanning Calorimetry (DSC) technique. Reducing the layer thickness down to 12 nm was shown to have a very different effect on the structural relaxation parameters of the above-mentioned polymers. Recovered enthalpy data for aged films exhibited an acceleration in physical aging under confinement for PC (rigid backbone and rubbery environments), while no change was noted for PMMA (flexible backbone and amorphous environments). A large effect in the amplitude of the structural relaxation process has also been evidenced for confined PC layers. These observations have thoroughly been discussed with respect to the impact of the chemical structure (entanglement), adjacent polymer state (rubbery and amorphous environments) and the nature of molecular mobility (the CRR shape and length are both related to intra-chain and inter-chain relaxation during glass transition),. Moreover, it was found that the accelerated aging of PC was mainly attributed to the dynamic relaxation related to its chemical structure and local modification of intermolecular interactions. [ABSTRACT FROM AUTHOR]

Background: Bacterial proliferation on the endosseous implants surface presents a new threat to the using of the bone implants. Unfortunately, there is no effective constructed antibacterial coating which is bacterial anti-adhesion substrate-independent or have long-term biofilm inhibition functions. Methods: Drug release effect was tested in Chymotrypsin (CMS) solution and S. aureus. We used bacterial inhibition rate assays and protein leakage experiment to analyze the in vitro antibacterial effect of (Montmorillonite/Poly-l-lysine-Chlorhexidine)10 [(MMT/PLL-CHX)10] multilayer film. We used the CCK-8 assay to analyze the effect of (MMT/PLL-CHX)10 multilayer films on the growth and proliferation of rat osteoblasts. Rat orthopaedic implant-related infections model was constructed to test the antimicrobial activity effect of (MMT/PLL-CHX)10 multilayer films in vivo. Results: In this study, the (MMT/PLL-CHX)10 multilayer films structure were progressively degraded and showed well concentration-dependent degradation characteristics following incubation with Staphylococcus aureus and CMS solution. Bacterial inhibition rate assays and protein leakage experiment showed high levels of bactericidal activity. While the CCK-8 analysis proved that the (MMT/PLL-CHX)10 multilayer films possess perfect biocompatibility. It is somewhat encouraging that in the in vivo antibacterial tests, the K-wires coated with (MMT/PLL-CHX)10 multilayer films showed lower infections incidence and inflammation than the unmodified group, and all parameters are close to SHAM group. Conclusion: (MMT/PLL-CHX)10 multilayer films provides a potential therapeutic method for orthopaedic implant-related infections. [ABSTRACT FROM AUTHOR]

In this paper, the synthesized thermoplastic polyimide (TPI) precursor is coated on both surfaces of the surface-treated polyimide (PI) base film, and the TPI/PI/TPI multilayer films is obtained by thermal imidization. The mechanical properties, heat resistance, water absorption of the multilayer film and the interface between the TPI and the PI base film were investigated in detail. Then, multilayer film-2 (MF-2) with excellent comprehensive performance and the two copper foils were pressed together to prepare a double-sided flexible copper clad laminate (FCCL) by thermal lamination method, and the properties of FCCL were studied in detail. The results show that the FCCL has a high peel strength of 1.22 N/mm, passed a solder bath test of 288°C, and the surface condition was good under hot-pressing temperature of 360°C, hot-pressing pressure of 15 MPa and hot-pressing time of 60 s. In addition, the SEM and EDS spectra of the stripped copper foil confirmed that the TPI layer was immersed into the interstitial space of the Cu nodules, forming a strong physical bite with the copper foil. The current work provides a promising solution for the design and fabrication of multilayer printed circuit boards with excellent performance. [ABSTRACT FROM AUTHOR]

WS2/a‐C multilayer films exhibit good friction reduction but relatively low hardness and load‐bearing capacity. To further enhance the tribological properties of WS2/a‐C films, Mo layers with different thicknesses are introduced into WSx/a‐C multilayer films to fabricate WSx/Mo/a‐C/Mo multilayer films by magnetron sputtering. The microstructure and tribological properties of the films are characterized by X‐ray diffractometry, scanning electron microscopy, nanoindentation, and ball‐on‐disk tribotesting. The results show that the WSx/Mo/a‐C/Mo multilayer films have better mechanical and tribological properties than WSx/a‐C multilayer films. With increasing Mo single‐layer thickness, the hardness of the multilayer films initially increases and then decreases slightly; moreover, an increased elastic modulus and decreased adhesion are observed. The multilayer film with an Mo single‐layer thickness of 2 nm demonstrates the optimal set of comprehensive properties (i.e., a maximum hardness (H)/elastic modulus (E) ratio of 0.0793, H3/E2 ratio of 0.0812 GPa, binding force of 30.4 N, minimum friction coefficient of 0.187, and wear rate of 1.01 × 10−14 m3 N−1 m−1). [ABSTRACT FROM AUTHOR]

A novel method for fabricating a nano-Cu/Si 3 N 4 ceramic substrate is proposed. The nano-Cu/Si 3 N 4 ceramic substrate is first fabricated using spark plasma sintering (SPS) with the addition of nanoscale multilayer films (Ti/TiN/Ti/TiN/Ti) as transition layers. The microstructures of the nano-Cu metal layer and the interface between Cu and Si 3 N 4 are investigated. The results show that a higher SPS temperature increases the grain size of the nano-Cu metal layer and affects the hardness. The microstructure of the transition layer evolves significantly after SPS. Ti in the transition layer can react with Si 3 N 4 and with nano-Cu to form interfacial reaction layers of TiN and Ti–Cu, respectively; these ensure stronger bonding between nano-Cu and Si 3 N 4. Higher SPS temperatures improve the diffusion ability of Ti and Cu, inducing the formation of Ti 3 Cu 3 O compounds in the nano-Cu metal layer and Ti 2 Cu in the transition layer. This study provides an important strategy for designing and constructing a new type of ceramic substrate. [ABSTRACT FROM AUTHOR]

A star‐shaped N C N‐pincer tri‐RuII complex 3 with a triarylamine core, capped with three 2,2':6',2''‐terpyridine‐4,4',4''‐tricarboxylic acid terminal ligands, has been synthesized. The single‐crystal X‐ray structure of a precursor ester complex 7 is presented. By using the Zr‐mediated layer‐by‐layer assembly, multilayer films FTO/SnO2:Sb/(3)n(Zr)n‐1 (n = 1–4) have been prepared on Sb‐doped SnO2 nanocrystalline substrates. These films have been characterized by XPS and SEM analysis. The electrochromism of these films in the near‐infrared region were examined by oxidative spectroelectrochemical measurements and douple‐potential‐step chronoamperometry. The two‐layered film displays the best overall performance with a contrast ratio (ΔT%) of 36 % at 1550 nm and response time of shorter than 2 s. After 1000 switching cycles, around 11 % loss of the contrast ratio is observed, suggesting good cyclic stability of these films. In addition, a comparison of the electrochromic performance of these multilayer films with respect to the previously reported electropolymerized films of a related tri‐RuII complex and monolayer films of two mono‐RuII complexes on SnO2:Sb is presented. [ABSTRACT FROM AUTHOR]

Lead-free dielectric film capacitors with fast charge-discharge rates are ideal for pulsed power capacitors, but their energy storage density lags behind. Lead-free epitaxial multilayered BiFeO 3 (BFO)/Na 0.5 Bi 0.5 TiO 3 (NBT)/La 0.7 Sr 0.3 MnO 3 (LSMO) films were designed and fabricated by solution processing and the effects of bottom electrodes as well as BFO thickness on microstructures, electrical properties and energy storage performances were investigated. Compared with the NBT film on Pt/Ti/SiO 2 /Si substrate, the leakage current densities are significantly suppressed and polarizations are obviously improved for the multilayered BFO/NBT/LSMO films. The BFO/NBT/LSMO film with BFO thickness of about 60 nm exhibits a recoverable energy storage density of 37.0 J/cm3 under 2680 kV/cm and excellent performance stability. These results demonstrate that the epitaxial multilayered BFO/NBT/LSMO films are promising candidates for high-power energy storage applications. [Display omitted] • The epitaxial multilayered BiFeO 3 /Na 0.5 Bi 0.5 TiO 3 /La 0.7 Sr 0.3 MnO 3 films were successfully prepared by chemical solution deposition. • Compared with the film deposited on Pt/Ti/SiO 2 /Si substrate, films deposited on La 0.7 Sr 0.3 MnO 3 /LaAlO 3 substrates have significantly improved electrical properties. • By adjusting the thicknesses of BiFeO 3 , the multilayered BFO/NBT/LSMO film exhibits an enhanced recoverable energy storage density of 37.0 J/cm3. [ABSTRACT FROM AUTHOR]

• Multilayers of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and Cu 2 Se through a facile route. • Structural investigation shedding light over transport properties. • A higher power factor value which is about 82 % higher than that of pure PEDOT:PSS. Cu 2 Se is a promising thermoelectric material due to its superionic behavior with superior transport properties. Here we report a facile method of spin coating for the fabrication of multilayers of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and Cu 2 Se thermoelectric materials for mid-temperature range applications. The synthesis of multilayered thin films with a unique organic-inorganic hybrid framework could be used in flexible thermoelectric devices. The detailed investigation of PEDOT:PSS and Cu 2 Se multilayered thin films reveals interaction between organic and inorganic material as inferred by AFM and FTIR. The electronic transport properties were investigated for all specimens, with the highest PF of 20.1 µW/m. K2 at 450 K was achieved from the bilayer stacking of Cu 2 Se and PEDOT:PSS, which is about 82 % higher as compared to that of pure PEDOT:PSS at the same temperature. These improved transport properties are the combined effect of energy filtering and interface effects. The proposed strategy opens up an avenue for research on chalcogenide based composite materials with an organic framework for flexible thermoelectric device applications. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the influence of thermal annealing temperature on the periodic nanostructures and the thermoelectric properties of Sb 2 Te 3 /Au multilayer thin films fabricated by magnetron sputtering. The as-deposited amorphous periodic multilayer films (10 periods, 20 and 7 nm for the Sb 2 Te 3 and Au layers, respectively) show regular and sharp interfaces between Sb 2 Te 3 and Au layers. It was found that the interfaces of periodic films became a little fuzzy and some nanocrystallines could be observed after annealing at relatively lower temperature (373 K) due to atomic diffusion and crystallization. Additionally, obvious crystal grains appeared and the Au layers began to coarsen and even rupture when the annealing temperature was elevated to higher than 423 K. The evolution mechanism has been discussed in the view of grain boundary free energy and interfacial free energy. Furthermore, the experimental results suggest that the resistivity and Seebeck coefficient of the multilayer film sample have not exhibited distinct change until the annealing temperature was increased to as high as 473 K when the periodic nanostructures disappeared. Graphical abstract Image 1 Highlights • Nice periodic layered nanostructure in as-deposited multilayer film. • The Au layers began to coarsen and rupture when annealing at 423 K. • Stable layered structure and thermoelectric performance at lower temperature (below 423 K). [ABSTRACT FROM AUTHOR]

In this study, protein‐based high‐oxygen barrier multilayer films were manufactured at a pilot plant scale by a roll‐to‐roll coating process and an adhesive lamination process. Also, their characteristics were examined to evaluate their industrial feasibility. Oxygen transmission rates (OTRs) of the protein‐based films (polyethylene terephthalate [PET]/pea protein isolate [PPI]/nylon/cast polypropylene [CPP], PET/whey protein isolate [WPI]/CPP, PET/WPI/nylon/CPP, and PET/PPI/nylon/low‐density polyethylene [LDPE]) were significantly lower than OTR of the PET/nylon/CPP film without a protein‐coating layer and that of the commercial high‐barrier multilayer film copolymer (PET/aluminum/CPP). In addition, water vapor transmission rates of the films containing protein layer were significantly lower than that of the commercial high‐barrier film containing ethylene vinyl alcohol [nylon/nylon/EVOH/easy peel layer [EPL]). Among the tested polymers, the PET/WPI/nylon/LDPE film showed the highest heat‐sealing ability, tensile strength, and elastic modulus. Moreover, transparency and haze of the PET/WPI/nylon/CPP film were similar to the film without WPI coating. Taken together, our results indicate that the protein‐based coating films showing high‐oxygen and high‐water barrier properties can be manufactured using industrial facilities and could replace commercial multilayer films based on synthetic materials. Practical Application: Oxygen barrier property is an important feature in food packaging materials. Therefore, protein‐coated high‐oxygen barrier multilayer films were manufactured at a pilot scale to verify the possibility of their mass production. Specifically, high‐oxygen and high‐moisture barrier coating was produced by pea and whey proteins. Finally, the protein‐based multilayer films made by an industrial facility were confirmed to be able to replace current commercial films containing synthetic barrier materials. [ABSTRACT FROM AUTHOR]

Featured Application: The electrospinning coating technology is herein proposed to develop multilayer polylactide (PLA) films with controlled release rates of gallic acid (GA), a natural antioxidant, into saline medium. The bioactivity of the PLA films described here is based on their potential capacity to incorporate a large amount of GA into the packaging structure until its eventual release into the food product either through fast release, by means of coatings, or sustained release, in the form of interlayers, during storage. Therefore, their application in bioactive packaging for both short- and long-term storage of food products can advantageously permit the development of functional food, enhancing the food impact over the consumer's health. The present research reports on the development of bi- and multilayer polylactide (PLA) films by the incorporation of electrospun nanostructured PLA coatings and interlayers containing the antioxidant gallic acid (GA) at 40 wt% onto cast-extruded PLA films. To achieve the bilayer structures, submicron GA-loaded PLA fibers were applied on 200-µm cast PLA films in the form of coatings by electrospinning for 1, 2, and 3 h. For the multilayers, the cast PLA films were first coated on one side by electrospinning, then sandwiched with 10-µm PLA film on the other side, and the resultant whole structure was finally thermally post-treated at 150 °C without pressure. Whereas the bilayer PLA films easily delaminated and lacked transparency, the multilayers showed sufficient adhesion between layers and high transparency for deposition times during electrospinning of up to 2 h. The incorporation of GA positively contributed to delaying the thermal degradation of PLA for approximately 10 °C, as all films were thermally stable up to 345 °C. The in vitro release studies performed in saline medium indicated that the GA released from the bilayer PLA films rapidly increased during the first 5 h of immersion while it stabilized after 45–250 h. Interestingly, the PLA multilayers offered a high sustained release of GA, having the capacity to deliver the bioactive for over 1000 h. In addition, in the whole tested period, the GA released from the PLA films retained most of its antioxidant functionality. Thus, during the first days, the bilayer PLA films can perform as potent vehicles to deliver GA while the multilayer PLA films are able to show a sustained release of the natural antioxidant for extended periods. [ABSTRACT FROM AUTHOR]

Micro-scale surface shape memory effects were investigated on multilayer films that were produced with alternating layers of PVAc and PU. Two different types of micro-scale patterns, including a sharp microprismatic pattern and a smooth microlens pattern, were embossed on the surface of the PVAc/PU multilayer films by a PDMS replica mold using the soft lithography method. The microprismatic pattern as a permanent surface structure on the intrinsically transparent multilayer films renders the films opaque and the microlens surface pattern endows the clear films with focusing properties. The micro-structured surface is programmed by compression and recovery to switch the corresponding optical property of the film. Based on this switchable optical property, the patterned PVAc/PU multilayer film can be employed as an anti-counterfeiting feature in packaging. In this paper, the shape memory effect of the multilayered film was found to be dependent on the composition of the PVAc relative to the PU layers. In addition, the shape memory effect of the layered PVAc/PU films was enhanced compared to the PVAc control film. The recovery mechanism of the shape memory films was interpreted using Burgers viscoelastic model. The effects of the compression pressure, recovery temperature and the geometry of the patterns on the micro-scale shape memory behavior of the PVAc/PU multilayer films were also investigated. [ABSTRACT FROM AUTHOR]

The multiphase coexisting of compositionally graded PbZr x Ti 1- x O 3 multilayer thin films were fabricated using sol-gel method. The giant electrocaloric effect (ECE) has been obtained through regulating the growth sequence of the multilayer thin films. At room temperature (at 298 K), Δ T values of up graded multilayer and down multilayer thin films are 9.1 K (applied electric field E = 755 kV/cm) and 7.3 K ( E = 930 kV/cm), respectively. In addition, both of the films exhibit outstanding ECE at higher temperature, Δ T values of 17.9 K (at 453 K) and 26.8 K (at 393 K) are also obtained for up graded multilayer and down multilayer thin films. The results indicate that the compositionally graded multilayer thin films with a giant ECE could be a potential candidate for the application in cooling devices. [ABSTRACT FROM AUTHOR]

Ultra-stable foams with multilayer films which were similar to the structure of colloidal gas aphrons (CGA) were designed in view of increasing the amount of bound water molecules at molecular level. This liquid films in foams were spontaneously assembled by 1-dodecanol (DDA), sodium dodecyl sulfonate (SDS) and polyvinyl alcohol (PVA) molecular with a remarkable long-term foam lifetime. The states of water molecules as well as the molecular arrangement in foam films have been analyzed via molecular dynamics (MD) simulation to explore microscopic character and stable mechanism of multilayer films of foams. We found that the combined effect of SDS, DDA and PVA could not only increase distribution intensity of bound water molecules in foam film layers, but it also could decrease the gas diffusion rate to balance the pressure of the air layers of the multilayer foams. [ABSTRACT FROM AUTHOR]

[FeCoSiN/SiN x ] 18 multilayer thin films with different SiN x layer thickness ( t ) ranging from 0.75 to 4 nm were fabricated by reactive magnetron co-sputtering without applying an external induced magnetic field. The grain size, morphology, electrical properties, and static and dynamic magnetic properties of [FeCoSiN/SiN x ] 18 multilayer thin films were investigated systematically. The results indicated that SiN x layer thickness had a profound impact on the physical properties of the multilayer thin films. The in-plane uniaxial magnetic anisotropy field (from 114 ± 21 to 163 ± 14 Oe), ferromagnetic resonance frequency (from 4.09 to 4.64 GHz) and resistivity (from 188 to 333 μΩ cm) could be tailored effectively by adjusting the SiN x layer thickness from 0.75 to 4 nm. Moreover, when the SiN x layer thickness reached 2 nm, the continuous growth of FeCoSiN polycrystalline layers was to be interrupted completely and it would result in a minimum grain size of 4.9 ± 0.7 nm. The root mean square roughness of multilayer thin films also acquired a minimum value of 0.8 nm and the corresponding easy axis coercivity achieved a minimum value of 2.8 ± 0.1 Oe. [ABSTRACT FROM AUTHOR]

Biomedical implant failure arises mainly from the degradation caused by tribological processes occurring in the corrosive environment the human body represents, known as tribocorrosion. The material loss and metal ion release resulting from tribocorrosion processes compromise the biocompatibility of metallic implants. The deposition of protective coatings on metallic substrates is a promising solution to overcome this problem. Pure titanium (Ti-cp) is widely used as an implant material due to its excellent corrosion resistance and high biocompatibility. However, its mechanical properties must be improved in order to ensure a longer durability. For this purpose, TaN monolayer and multilayer coatings were deposited on medical grade Ti-cp to enhance its tribocorrosion performance in simulated body fluids. TaN coatings were deposited by recently developed High Power Pulsed Magnetron Sputtering (HPPMS) technique. HPPMS enables the deposition of extremely dense coatings with superior properties compared to the ones grown by conventional sputtering. Columnar-free TaN monolayer and multilayer films were developed exhibiting corrosion resistances in the MΩ range, one order of magnitude higher than for Ti-cp. Friction coefficient of Ti-cp was reduced from 0.58 to 0.25 while wear rate was considerably decreased. The determined material loss after tribocorrosion tests for Ti-cp was 0.4 mm 3 . It was reduced up to 1.55 × 10 − 3 mm 3 by the application of best-performing TaN multilayer film. [ABSTRACT FROM AUTHOR]

This paper reports layer-by-layer films fabricated with hemoglobin (Hb) and gold nanoparticles (AuNPs) as well as their applications in carrying oxygen. The characterization of {Hb/AuNPs} n multilayer films at different layers revealed that the formation of films was step-by-step. Meanwhile, the study showed that the {Hb/AuNPs} n modified glass carbon electrode can maintain the biological activity of Hb. The capacity of carrying oxygen was associated with the number of assembled layers. The {Hb/AuNPs} 3 multilayer films displayed a good storing and releasing ability of oxygen. The study can provide an alternative method for construction of hemoglobin function interface with high-efficiency oxygen carrying capacity. [ABSTRACT FROM AUTHOR]

Atomic force microscopy (AFM) and infrared (IR) spectroscopy have been combined in a single instrument (AFM-IR) capable of producing IR spectra and absorption images at sub-micrometer spatial resolution. This new device enables cross sections of multilayer films to be spectroscopically characterized at levels not previously possible. In particular, it was possible to observe nanoscale IR spectroscopic differences, as well as thermal and mechanical property differences, in the tie layers located between the individual polyethylene and polyamide layers of a multilayer cling film of initially unknown structure. It also appears that a two-μm-thick barrier layer between two polyamide layers near the center of the multilayer cling film consists of an ethylene-vinyl alcohol copolymer. Mechanical stiffness and thermal property differences are also observed between the various layers in the film. This powerful capability should prove generally useful for reverse engineering complex unknown multilayer film materials, as well as in aiding the intelligent design and coextrusion of superior multilayer film materials. [ABSTRACT FROM AUTHOR]

The report focuses on understanding of the mechanism of formation of supported lipid bilayers (SLBs) by vesicle adsorption and rupture on polyelectrolyte multilayer (PEM) films. The PEM films were constructed by sequential adsorption of positively-poly- l -lysine (PLL) and negatively-poly- l -glutamic acid sodium salt (PGA) charged polyelectrolytes (PEs) on charged surface. The adsorption kinetics of small unilamellar vesicles, prepared from mixtures of phospholipids, zwitterionic unsaturated (1-palmitoyl-2-oleoyl- sn -glycero-3-phosphocholine, POPC) and negatively charged unsaturated (1-palmitoyl-2-oleoyl- sn -glycero-3-phospho- l -serine (sodium salt), POPS) was investigated on such PEM polymer cushions, using quartz crystal microbalance with dissipation monitoring (QCM-D). Complementary AFM measurements were performed to verify the morphology of lipid vesicles and isolated bilayer patches on the PEM cushion terminated with positively charged PLL. Properties of solid substrates were characterized with QCM-D and ellipsometry to find information on the layer thickness and water content of these layers. The results suggested that, depending on the number of layers, two pathways of vesicle adsorption may be proposed. We believe that modification of solid surfaces using SLBs is very important for the development of new multifunctional materials for biotechnological applications as cell–membrane models and biosensors and for drug delivery systems. [ABSTRACT FROM AUTHOR]

In this study, coextruded multilayer films with aliphatic (polyamide 6) and aromatic (poly (m-xylene adipamide)) nylons as well as their in-situ polymerized nanocomposites with 4 wt% nanoclay, as an oxygen barrier layer (core), and a linear low-density polyethylene, as a moisture barrier layer (skin), were produced and characterized. Five-layer films were prepared by cast coextrusion and rapidly cooled using an air knife. Dynamic rheological measurements showed that the selected materials can be coextruded with a minimum interfacial instability between the melt flows in the feed block. Type of crystals, crystallinity and thermal transitions of layers were investigated using differential scanning calorimetry and modulated differential scanning calorimetry. The mechanical, optical, oxygen and water vapor barrier properties of the coextruded multilayer films were measured and discussed. Although the crystallinity of the poly (m-xylene adipamide) layer in the multilayer films was lower compared to the polyamide 6 layer, the impermeability to oxygen and water vapor was much better for the former multilayer films. In addition, substituting the neat polyamide 6 and poly (m-xylene adipamide) by their nanocomposites improved the oxygen barrier of the multilayer films by more than 50%. The series resistance model was not able to predict the barrier properties of the multilayer films due to the difference in polymer behavior for the single layer and multilayer, and boundary adjacent layer effects. The coextruded polyamide linear low-density polyethylene multilayer films showed higher toughness, tear and flex crack resistance compared to the poly (m-xylene adipamide)/linear low-density polyethylene samples. The pristine poly (m-xylene adipamide)-based multilayer film showed a lower haze compared to the polyamide 6 films due to very little crystallinity in the former. [ABSTRACT FROM AUTHOR]

Multilayer films of a conventional linear low-density poly(ethylene/α-octene) (LLDPE) and a metallocene linear low-density poly(ethylene/α-hexene) (mLLDPE) copolymers were produced by cast co-extrusion process. Coextruded films were obtained by varying the position and the relative thicknesses of the two polymers. Mechanical (tensile and impact) tests, permeability, haze and hot tack measurements were carried out on the produced films in order to verify the effect of layer composition and position on the performances of the coextruded samples. Thermal and atomic force microscopy characterizations of the three-layer structures were also performed to correlate the resulting morphology with the film properties. The experiments demonstrated that, at fixed composition, the structures having the mLLDPE copolymer as external layers exhibit generally better mechanical performances and a widening in the sealability temperature window due to a lowering of 5℃ in the seal-initiation temperature, with only a small increase (max 3.5%) in the film haze percentages. The oxygen permeability values do not seem to be significantly affected by the structure composition and layout. [ABSTRACT FROM PUBLISHER]

Abstract: We demonstrated fabrication of photo-mechanical materials alternatively-including azobenzene-side-chained acrylate polymer, PMAz6Ac, and polyvinyl alcohol, PVA, without cross-linking. The multi-bilayered (PMAz6Ac/PVA) n films were obtained by alternative spin-coating methods of PVA and PMAz6Ac solutions on glass substrates. After thermal treatment, the azobenzene groups as mesogen were self-organized and were induced out-of-plane orientation. After UV irradiation (λ=375nm), the self-standing films obtained by peeling off was bent to an opposite side of the light source, and the bended film reverted toward the initial position by following visible light irradiation (λ>420nm). Their optical properties of the PMAz6Ac layers indicated that change of molecular orientation, out-of-plane orientation and disordered random, of azobenzene groups in the PMAz6Ac layers closely related with the photo-mechanical behaviors. [Copyright &y& Elsevier]

The goal of this research was to study the potential of polyelectrolyte multilayers as buccal dosage forms for drug delivery and to investigate how the properties of the drugs impact the overall performance of the delivery system. Multilayer films based on the polyelectrolyte interaction between casein and chitosan were developed using benzydamine, tolfenamic acid and betahistine as model drugs. The samples were characterized for surface pH, moisture content and moisture absorption, swelling behavior and mucoadhesion. Additionally, surface morphology was investigated, as well as the drugs' physical state after incorporation in the multilayer films. The samples proved to be non-irritant (pH was within the physiological range), physically stable (moisture content and moisture absorption below 5%) and mucoadhesive, adsorbing from 60 to 70% mucin. The release behavior corelated to the swelling index profiles of the samples and was strongly dependent on the drug solubility. The developed multilayer films appeared to be an optimum delivery system for sparingly soluble drugs due to the high drug loading achieved. [ABSTRACT FROM AUTHOR]

In this study, the thermal stability of the in-plane uniaxial anisotropy field of Fe32Co44Hf12N12/Ti50N50 multilayer films was investigated from room temperature up to 500^\circC with regard to contactless high-frequency sensor applications. The uniaxial anisotropy field of about \mu0Hu\approx 5\ mT was thermally induced by annealing the films in a static magnetic field of 50 mT in vacuum for one hour either at an annealing temperature of Ta=400^{\circ}C or Ta=600^{\circ}C. The films which were annealed at Ta=600^{\circ}C show a clear distinction between the easy and hard axis of polarization up to temperatures of 500^\circC. Hence, the uniaxial anisotropy, thermally induced at Ta=600^{\circ}C, is stable at working temperatures up to 500^\circC. In contrast, films with a uniaxial anisotropy induced at Ta=400^{\circ}C show a different behavior. Here, hysteresis loop measurements indicate that above a working temperature of 200^\circC the uniaxial anisotropy field turns away from its direction at room temperature. In conclusion, only the Fe32Co44Hf12N12/Ti50N50 multilayer films with a uniaxial anisotropy field induced at Ta=600^{\circ}C promise a great potential for contactless high-frequency sensor applications up to 500^\circC. [ABSTRACT FROM AUTHOR]

Abstract: [Fe/Pt/Cu]18 multilayer films with different Cu thicknesses were prepared on thermally oxidized Si (111) substrates at room temperature using dc- and rf-magnetron sputtering. The magnetic properties and microstructure of [Fe/Pt/Cu]18 multilayer films annealed at various temperatures have been investigated. Compared with pure [Fe/Pt]18 multilayer films low-temperature ordering and (001) orientation in the annealed films with Cu volume concentration below 20% can be obtained. During annealing process Cu atoms diffused into FePt lattice which enhanced the diffusion of Fe and Pt atoms and the grain growth of the films. The perpendicular anisotropy and hard magnetic properties of the films deteriorated with increasing Cu volume concentration due to the formation of L10 FeCuPt2 phase. [Copyright &y& Elsevier]

Abstract: The PANI/Pd0 nanocomposite films with Pd nanoparticles embedded in the polyaniline (PANI), were successfully fabricated through the simple layer-by-layer (LBL) adsorption of PANI and PdCl6 2−, followed by the in situ electrochemical reduction of the incorporated PdCl6 2− in the multilayer film. The as-prepared composite films were characterized by X-ray photoelectron spectroscopy, UV–vis spectroscopy, Fourier-transform infrared, atomic force microscope and transmission electron microscopy. The size of Pd nanoparticles in the composite film could be fine-tuned in the range of about 2–22nm by varying the concentration of PdCl6 2−. PANI in the nano-structured PANI/Pd0 composite films still shows the good redox activity in neutral pH solution. The as-obtained PANI/Pd0 nanocomposite film presents an excellent electrocatalytic activity to hydrazine oxidation. And the catalytic performance is not only dependent on film thickness, but also Pd0 size. On the 5-bilayer PANI/Pd0 film with Pd0 particles 2nm in size, two calibration curves were found in the concentration ranges of 3.0×10−7–3.5×10−4 M and 5.0×10−4–1.2×10−2 M. And the minimal detectable concentration was down to 5.0×10−8 M on the electrode with 13 bilayers buildup. The substrate can be used repeatedly for consecutive detection of hydrazine with good stability. [Copyright &y& Elsevier]

Multilayer films for food packaging applications composed of polyvinyl alcohol (PVOH) as the core layer and polyhydroxyalkanoate (PHA) as the outer skin layers were produced by the co-extrusion process. Rheological properties of PVOH and PHA were performed and analyzed before co-extruding into a cast film. Analysis of the rheological data indicated the processing temperatures and grades of the PVOH and PHA polymers that would produce similar viscosity and melt flow properties. To improve adhesion of the layers, PHA was grafted with maleic anhydride using a dicumyl peroxide initiator to provide a tie layer material, which improved the peel strength of the PHA and PVOH layers by over 2×. Oxygen transmission rate (OTR) testing showed that the multilayer sample provided an OTR of 27 cc/m2-day at 0% relative humidity (RH) and rates of 41 and 52 cc/m2-day at relative humidity values of 60% and 90% RH, respectively. This indicates significant barrier performance enhancement over monolayer PVOH that provided an OTR of 60 cc/m2-day at 0% RH and 999 cc/m2-day at 60% RH. Biodegradation testing of the films in the marine environment showed that both the unmodified and maleated PHA polymers displayed high levels of mineralization, whereas the PVOH material did not. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Abstract: First a SiO x layer, as a barrier layer between a photo active anatase TiO2 layer and BOPP substrate, was coated on hydroxylated BOPP film by a sol–gel process. Then, TiO2 layer was formed on SiO x surface through liquid phase deposition. Thus a flexible BOPP/SiO x /TiO2 multilayer film which has photocatalytic activity was fabricated. The coating processes were monitored by FT-IR and UV–vis spectroscopy, scanning electron microscopy, atom force microscopy and water contact angle (CA) measurements. The thickness of SiO x and TiO2 layer was about 600nm and 135nm, respectively. Root mean square (RMS) roughness of the SiO x layer was about 2–3nm while the surface of TiO2 layer was much coarse with RMS roughness about 30nm which offered the large surface area. The TiO2 layer endowed multilayer film photoinduced hydrophilic conversion property evidenced by the fact that its surface water contact angle could reduce to about 5° after 1h of UV irradiation. The photocatalytic degradation ability of multilayer film was evaluated using methyl orange as model contamination and the results indicating that the degradation is efficient. [Copyright &y& Elsevier]

Abstract: In this paper, ITO/Al/ITO multilayer films are fabricated with the variations of Al film thickness and annealing temperature. The effects of Al film thickness and annealing temperature on sheet resistance, optical transmittance, and the figure of merit are analyzed in the aid of the artificial neural network (NNet) models. In order to verify the fitness of NNet model, the root mean square error (RMSE) of training and testing data are calculated. The NNet models well represent the measured sheet resistance, optical transmittance, and the figure of merit. After NNet model is established, genetic algorithm (GA) is used to find the optimum process condition for the ITO/Al/ITO multilayer films to obtain maximum figure of merit in the design space. [Copyright &y& Elsevier]

Abstract: The l-cysteine-modified CdSe/CdS/ZnS nanocrystals were synthesized in aqueous solution by using l-cysteine as stabilizer. The chitosan–CdSe/CdS/ZnS ultrathin multilayer films were fabricated on the pretreated quartz substrate by layer-by-layer electrostatic self-assembly method. The CdSe/CdS/ZnS nanocrystals were characterized by X-ray power diffraction (XRD), fluorescence spectrum and UV–vis spectrum. The UV–vis spectrum, fluorescence spectrum, IR spectrum, contact angle analysis and atomic force microscope analysis were used to characterize the chitosan–CdSe/CdS/ZnS ultrathin multilayer films. The results indicate that chitosan and CdSe/CdS/ZnS nanocrystals are alternatively deposited on the quartz surface, resulting in the buildup of a high quality chitosan–CdSe/CdS/ZnS multilayer films. The prepared ultrathin films of chitosan–CdSe/CdS/ZnS show good fluorescent property, which have potential application in biosensor. [Copyright &y& Elsevier]

Abstract: La0.90Dy0.05Nb2O7 nanosheets were achieved by exfoliating a layered compound HLa0.90Dy0.05Nb2O7. Multilayer films composed of the exfoliated nanosheets were prepared by a layer-by-layer deposition technology, which were subsequently heat-treated at 450°C and exposed under ultraviolet light to obtain the polymer-free nanosheet films, respectively. The resulting La0.90Dy0.05Nb2O7 nanosheet suspension and its films exhibit intense emission by the host excitation and negligibly low emission by the direct Dy3+ excitation, whereas the photoluminescence emissions of the bulk precursors are largely dominated by the direct Dy3+ excitation rather than the host excitation. The comparison between the excitation spectra and the bandgap absorption spectra indicates that the enhanced host excitation-mediated photoluminescence of La0.90Dy0.05Nb2O7 nanosheet results from the efficient energy transfer from the O–Dy charge-transfer transition to Dy3+ within the nanosheet, and that the intensive emission of the multilayer films is attributed to the energy transfer from both of the O–Dy charge-transfer transition and the O–Nb network to Dy3+. Dy3+ in the La0.90Dy0.05Nb2O7 nanosheet and the nanosheet-based films gives two emission peaks at around 480 and 576nm and the blue emission is prominent in the film form. [Copyright &y& Elsevier]

Abstract: In order to investigate microwave damping mechanisms of ferromagnetic films with a structure of [ferromagnetic (FM)/non-magnetic insulator (NMI)] n , a serial of [Fe65Co35/SiO2] n multilayer films was prepared by a magnetron sputtering method on the glass substrate. As-prepared films show excellent soft magnetic properties with tiny coercivities along the easy and hard axis respectively, and remarkable in-plane unixial anisotropies were observed too. The microwave properties were characterized by the ferromagnetic resonance (FMR) and a broadband permeameter. The corresponding theoretical fitting was conducted based on the Landau–Lifshitz–Gilbert (LLG) and two magnon scattering (TMS) theory. Fitting results show the TMS linewidth has a value of 36 times bigger than Landau–Lifshitz intrinsic linewidth, which gives a quantitative and explicit physical picture of microwave damping mechanisms in [Fe65Co35/SiO2] n multilayer films and may be important for the understanding of damping in [FM/NMI] n multilayer films. [Copyright &y& Elsevier]

Abstract: Multiple twins are experimentally observed within Cu grains in nanostructured Cu/Zr multilayer films. Formation of the multiple twins occurs through the sequential emission of partial dislocations not only from the grain boundaries but also from the Cu/Zr interfaces, which are driven by extremely high internal stresses and highly complex stress state caused by the inhomogeneous microstructures. The multilayers with multiple twins exhibit hardness higher than those with single or coplanar twins, indicative of a significant strengthening effect of the multiple twins. [Copyright &y& Elsevier]

Abstract: In the paper, we report on the layer-by-layer self-assembly of multilayer films of polyelectrolyte/Ag nanoparticles (AgNPs). The films were constructed by the alternate adsorption of the oppositely charged poly [(2-ethyldimethylammonioethyl methacrylate ethyl sulfate)-co-(1-vinylpyrrolidone)] (PQ11) and negatively charged citrate-stabilized AgNPs on solid substrates. The multilayer film growth process on quartz slides was monitored by UV-vis absorption spectroscopy. The resulting films exhibit good catalytic activity toward the reduction of hydrogen peroxide (H2O2). The enzymeless H2O2 sensor based on such films exhibits a fast amperometric response time of less than 5s. The linear detection range is estimated to be from 100μM to 110mM (R 2 =0.996), and the detection limit is estimated to be 78μM at a signal-to-noise ratio of 3. [Copyright &y& Elsevier]

Abstract: The Cu/Ni multilayer films were prepared on the titanium alloy surface by ion-assisted magnetron sputtering deposition (IAD) technique. The Cu/Ni multilayer films could significantly improve the resistance of fretting wear and fretting fatigue (FF) of Ti-811 alloy at room temperature. The FF resistance of the titanium alloy substrate did not increase monotonically with increase in the modulation period thickness of the Cu/Ni multilayer films. The Cu/Ni multilayer films with modulation period thickness of 200nm had the highest FF resistance among the prepared Cu/Ni multilayer films for its comprehensive properties with high toughness, high strength and good lubricating action. [Copyright &y& Elsevier]

Abstract: A sensitive sensor for mercury (II) and copper (II) synchronous detection was established via the changed photoluminescence of CdTe quantum dots (QDs) multilayer films in this work. QDs were deposited on the quartz slides to form QDs-multilayer films by electrostatic interactions with poly(dimethyldiallyl ammonium chloride) (PDDA). Hg2+ or Cu2+ could quench the photoluminescence of the QDs-multilayer films, and glutathione (GSH) was used to remove Hg2+ or Cu2+ from QDs-multilayer films due to strong affinity of GSH-metal ions, which resulted in the recovered photoluminescence of QDs-multilayer films. There are good linear relationships between the metal ions concentration and the photoluminescence intensity of QDs in the quenched and recovered process. It was found that the Stern–Volmer constants for Hg2+ are higher than that for Cu2+. Based on different quenching and recovery constant between Hg2+ and Cu2+, the synchronous detection of Hg2+ and Cu2+ can be achieved. The linear ranges of this assay were obtained from 0.005 to 0.5μM for Hg2+ and from 0.01 to 1μM for Cu2+, respectively. And the artificial water samples were determined by this method with satisfactory results, the recoveries for Hg2+ and Cu2+ ions were found in the range of 90.4–106.4%. To the best of our knowledge, it is the first report about the synchronous detection of Hg2+ and Cu2+ by using quenched and recovered photoluminescence of quantum dots multilayer films. [Copyright &y& Elsevier]

Abstract: In this paper a ZnS/Ag/ZnS (ZAZ) nano-multilayer structure is designed theoretically and optimum thicknesses of ZnS and Ag layers are calculated at 35 and 17nm, respectively. Several conductive transparent ZAZ nano-multilayer films are deposited on a glass substrate at room temperature by thermal evaporation method. Changes in the electrical, structural, and optical properties of samples are investigated with respect to annealing in air at different temperatures. High-quality nano-multilayer films with the sheet resistance of 8Ω/sq and the optical transmittance of 83% at 200°C annealing temperature are obtained. The figure of merit is applied on the ZAZ films and their performance as transparent conductive electrodes are determined. [Copyright &y& Elsevier]

Abstract: The reliability characteristics and thermal conductivity of Ga30Sb70/Sb80Te20 nanocomposite multilayer films were investigated by isothermal resistance and transient thermoreflectance (TTR) measurements, respectively. The crystallization temperature and activation energy for the crystallization can be modulated by varying the layer thickness of Ga30Sb70. A data retention time of ten years of the amorphous state [Ga30Sb70 (3nm)/Sb80Te20 (5nm)]13, [Ga30Sb70 (5nm)/Sb80Te20 (5nm)]10, and [Ga30Sb70 (10nm)/Sb80Te20 (5nm)]7 was estimated when ambient temperature is 137, 163, and 178°C, respectively. Ga30Sb70/Sb80Te20 nanocomposite multilayer films were found to have lower thermal conductivity in both the amorphous and crystalline state compared to Ge2Sb2Te5 film, which will promise lower programming power in the phase-change random access memory. [Copyright &y& Elsevier]

The crystallization temperatures of SiO2/Sb80Te20 nanocomposite multilayer films can be modulated by varying the layer thicknesses of SiO2 and Sb80Te20. The reversible phase transition between amorphous and crystalline states can be achieved by using picosecond laser pulses with different fluences. Compared with conventional Ge2Sb2Te5, SiO2/Sb80Te20 multilayer films possess a faster crystallization speed. The existence of a periodic multilayer structure was confirmed by X-ray reflectivity and transmission electron microscopy characterizations. [ABSTRACT FROM AUTHOR]

Abstract: Au nanoparticles (NPs) were synthesized in the one-pot procedure in water at room temperature with the wheel-shaped VV–VIV mixed-valence tungstovanadate [P8W48O184{V4 VV2 IVO12(H2O)2}2]32− (V12) acting as both reducing and stabilizing agents. The V12 stabilized Au NPs (Au@V12 NPs) were characterized by SEM, TEM, DLS, UV–vis spectroscopy, XPS, and XRD analyses and the negatively charged surface of the Au@V12 NPs was proved by the zeta potential analysis. Based on the layer-by-layer assembly (LbL), the Au@V12 NPs-containing multilayer films have been fabricated on ITO-coated glass slide and quartz substrates with poly(ethyleneimine) (PEI). The regular growth of the multilayer films was monitored by UV–vis spectroscopy and cyclic voltammetry, the composition was characterized by XPS. The Au@V12 NPs based composite films showed electrocatalytic activities towards the reduction of dioxygen and the oxidation of methanol. This approach is expected to open the way towards procedures aimed at the one-step fabrication of Au NPs and polyoxometalates (POMs) into the multilayer films. [Copyright &y& Elsevier]

Abstract: We report on the enhancement in impedance and the break-down behavior of room temperature deposited single and multi-layer metal/oxide films of comparable thicknesses. Aluminum–alumina and chromium–chrome oxide thin film structures grown by sputtering were explored as model systems in this study. Electrochemical impedance spectroscopy measurements showed that the resistance of the structure increases with an increase in the number of metal/oxide bi-layers while the total thickness was kept constant. The resistance of the multi-layer system was over an order of magnitude higher than the single bi-layer for an equivalent total thickness for the case of thin film Al–Al2O3. In addition, potentiodynamic polarization measurements exhibited a consistent and reproducible improvement in the break-down potential with an increase in the number of layers. Similar results are obtained for the case of the chromium–chromium oxide bi-layer system as well. Combination of interfaces and lateral current spreading in the multi-layer structure leads to superior overall break-down resistance suggesting the concept of in-situ sacrificial layers for corrosion protection. [Copyright &y& Elsevier]

Abstract: In this work, the effect of modulation period (Λ) on Ti/TiN multilayer films deposited on high-speed-steel (HSS) substrates using pulse biased arc ion plating is reported. The crystallography structures and cross-sectional morphology of Ti/TiN multilayer films were characterized by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM), respectively. Their mechanical properties were determined via nanoindentation measurements, while the film/substrate adhesion via the scratch test. It was found that the highest hardness value reached 43GPa for the modulation period of 54nm, while the film/substrate adhesion also reached the highest value of 83N. Furthermore, the hardness enhancement mechanism in the multilayer films is discussed. [ABSTRACT FROM AUTHOR]

Abstract: The transmission of p-polarized plane wave through Ag/SiO2 multilayer films perforated with periodic subwavelength air slits is investigated by using the finite-difference time-domain (FDTD) method. The results show that the optical transmission property is mediated by the interference among the propagating coupled-SPP modes along the lateral direction inside the SiO2 layers and the conditions of Fabry–Pérot–like resonance along the longitudinal direction together. When some geometric parameters are suitably initialized, the high transmission peaks can split into more peaks as the functional layer (metal/dielectric/metal sandwich stack) number increases, and the wavelength of the same-order transmission peak exhibits a red shift as the grating period increases. [ABSTRACT FROM AUTHOR]

Abstract: The amorphous-to-crystalline transition of Ge/Sb2Te3 nanocomposite multilayer films with various thickness ratios of Ge to Sb2Te3 were investigated by utilizing in situ temperature-dependent film resistance measurements. The crystallization temperature and activation energy for the crystallization of the multilayer films increased with the increase in thickness ratio of Ge to Sb2Te3. The difference in sheet resistance between amorphous and crystalline states could reach as high as 104 Ω/□. The crystallization temperature and activation energy for the crystallization of Ge/Sb2Te3 nanocomposite multilayer films was proved to be larger than that of conventional Ge2Sb2Te5 film, which ensures a better data retention for phase-change random access memory (PCRAM) use. A data retention temperature for 10 years of the amorphous state [Ge (2nm)/Sb2Te3 (3nm)]40 film was estimated to be 165°C. Transmission electron microscopy (TEM) images revealed that Ge/Sb2Te3 nanocomposite multilayer films had layered structures with clear interfaces. [Copyright &y& Elsevier]

Abstract: Depending on the resistivity and transmittance, transparent conductive oxides (TCO) are widely used in thin film optoelectronic devices. Thus doped In2O3 (ITO), ZnO, SnO2 are commercially developed. However, the deposition process of these films need sputtering and/or heating cycle, which has negative effect on the performances of the organic devices due to the sputtering and heat damages. Therefore a thermally evaporable, low resistance, transparent electrode, deposited onto substrates room temperature, has to be developed to overcome these difficulties. For these reasons combination of dielectric materials and metal multilayer has been proposed to achieve high transparent conductive oxides. In this work the different structures probed were: MoO3 (45nm)/Ag (x nm)/MoO3 (37.5nm), with x =5–15nm. The measure of the electrical conductivity of the structures shows that there is a threshold value of the silver thickness: below 10nm the films are semiconductor, from 10nm and above the films are conductor. However, the transmittance of the structures decreases with the silver thickness, therefore the optimum Ag thickness is 10nm. A structure MoO3 (45nm)/Ag (10nm)/MoO3 (37.5nm) resulted with a resistivity of 8×10−5 Ωcm and a transmittance, at around 600nm, of 80%. Such multilayer structure can be used as anode in organic solar cells according to the device anode/CuPc/C60/Alq3/Al. We have already shown that when the anode of the cells is an ITO film the introduction of a thin (3nm) MoO3 layer at the interface anode (ITO)/organic electron donor (CuPc) allows reducing the energy barrier due to the difference between the work function of ITO and the highest occupied molecular orbital of CuPc [1]. This property has been used in the present work to achieve a high hole transfer efficiency between the CuPc and the anode. For comparison MoO3/Ag/MoO3/CuPc/C60/Alq3/Al and ITO/MoO3/CuPc/C60/Alq3/Al solar cells have been deposited in the same run. These devices exhibit efficiency of the same order of magnitude. [Copyright &y& Elsevier]

Thin multilayer films of alternating ultrathin Ni and Ag layers ( L(Ni)=11,15,30 Å, bulk and $L(\mathrm{Ag})=50~{\AA})$ have been prepared by evaporation in ultrahigh vacuum under controlled conditions and have been studied by the magnetic measurements. The critical temperature TC is studied as a function of the surface exchange interaction ( JS). The dependence of TC on the thickness L of the film has been investigated. A critical value of the surface exchange interaction in the film, above which the surface magnetism appears, is obtained. The shift of the critical temperature TC( L) from the bulk value $[\frac{T_{\mathrm{C}}(\infty )}{T_{\mathrm{C}}(L)}-1]$ can be described by a power law L− λ , where $\lambda =\frac{1}{\nu_{\mathrm{b}}}$ is the inverse of the correlation length’s exponent. The effective critical exponent associated with the magnetization M( β) is deduced for different thicknesses of Ni layers, and the thickness L(Ag) was being kept constant at 50 Å. [ABSTRACT FROM AUTHOR]