Deposition Of Multilayer Films Research Articles

Magnetron sputtering process for deposition of multilayered thin diamond-like carbon films with silver nanoparticles for anti-reflective coatings and refractometric sensing

Multilayered film stacks serving optical applications usually require multiple target sources for deposition. In this work, we present a convenient method for the deposition of single- and multilayered thin films with varying diamond-like carbon (DLC) and silver content employing a single magnetron in the deposition system. For this, a reactive magnetron sputtering system was utilized and the silver target was poisoned based on desired structure: clean target and argon gas resulted in a pure silver film, completely poisoned target and acetylene and argon gas resulted in a DLC film, and anything in between resulted in a nanocomposite DLC:Ag film. The films were deposited on fused quartz, crystalline silicon, and porous anodized aluminum oxide substrates. We investigated the optical properties of these films and showed their applications for anti-reflective, black-appearing coatings and refractometric sensors, both experimentally and by simulation methods.

Influence of plasma kinetic energy during the pulsed laser deposition of borophene films on silicon (100).

Developing borophene films with good structural stability on non-metallic substrates to maximize their potential in photosensitivity, gas detection, photothermia, energy storage, and deformation detection, among others has been challenging in recent years. Herein, we succeeded in the pulsed laser deposition of multilayered borophene films on Si (100) with β12 or χ3 bonding by tuning the mean kinetic energy in the plasma during the deposition process. Raman and X-ray photoelectron spectroscopies confirm β12 and χ3 bonding in the films. Borophene films with β12 bonding were obtained by tuning a high mean kinetic energy in the plasma, while borophene with χ3 bonding required a relatively low mean kinetic energy. Atomic force microscopy (AFM) micrographs revealed a granular and directional growth of the multilayered borophene films following the linear atomic terraces from the (100) silicon substrate. AFM nanofriction was used to access the borophene surfaces and to reveal the pull-off force and friction coefficient of the films where the surface oxide showed a significant contribution. To summarize, we show that it is possible to deposit multilayered borophene thin films with different bondings by tuning the mean kinetic energy during pulsed laser deposition. The characterization of the plasma during borophene deposition accompanies our findings, providing support for the changes in kinetic energy.

Sub-5 nm AFM Tip Characterizer Based on Multilayer Deposition Technology

Atomic force microscope (AFM) is commonly used for three-dimensional characterization of the surface morphology of structures at nanoscale, but the “Inflation effect” of the tip is an important factor affecting the accuracy. A tip characterizer has the advantages of in situ measurement, higher accuracy of probe inversion results, and relatively simple fabrication process. In this paper, we developed a rectangular tip characterizer based on multilayer film deposition technology with protruding critical dimension parts and grooves parts. And the tip characterization is highly consistent across the line widths and grooves, and still performs well even in the sub-5 nm line width tip characterizer. This indicates that tip characterizers produced by this method can synergistically meet the combined requirements of standard rectangular structure, very small line edge roughness, very small geometry dimension, and traceable measurements.

Tyrosinase-Based Paper Biosensor for Phenolics Measurement

Environmental pollution resulting from various industrial activities is still a problem for developing countries. The high content of phenolics such as phenols, polyphenols, bisphenol A, catechol, m- and p-cresol from industrial activities are discharged into surface water, soil, and air. Periodic monitoring of the impact of these toxic pollutants is needed for proper control and handling. These detrimental chemicals are usually measured using conventional methods with many drawbacks such as expensive analysis costs, long measurement times, requiring competent analysts, and complicated instrument maintenance. However, the presence of tyrosinase-based paper biosensors is now considered the most promising tool in overcoming the challenges mentioned earlier because they can detect these components quickly, precisely, accurately, inexpensively, and can be measured in situ. The working principle of this biosensor sees optical changes such as dyes, redox processes, and physicochemical properties (aggregation or dispersion) due to the presence of analytes accompanied by the occurrence of color changes that appear. This biosensor uses a layer-by-layer electrostatic method, which causes the deposition of multi-layered films on solid surfaces. In this paper, we review the development of the tyrosinase-based paper biosensor method for phenolic measurement in water, air, and food that gives better results than the conventional methods.

Multilayers in mixed perfluorocarbon-hydrocarbon surfactant films: Yes or no?

Mixtures of perfluorotetradecanoic acid and arachidic acid form highly structured, phase-separated monolayers at the air-water interface, which can subsequently be deposited onto various solid substrates through Langmuir Blodgett deposition. While deposited monolayers in these systems are well-established and characterized, the ability to deposit multilayers remains entirely unexplored. The key complicating factor is that while pure fatty acids deposit with good efficiency in multilayers, pure perfluorinated fatty acid films do not, and the role this difference plays in mixed multilayer film deposition remains an unknown quantity. The transfer efficiency to solid substrates, resulting morphology and crystallographic structure of these mixed films has been assessed under a variety of conditions to evaluate if and how multilayer films can be produced in these systems. Under typical conditions used for Langmuir Blodgett multilayer deposition, including deposition from pure water or Cd2+(aq) enriched sub-phases, mixed multilayer films would not deposit with any substantial efficiency onto solid substrates. A combination of surface characterization techniques indicates traditional multiple pass Langmuir Blodgett deposition (Y-type films) at the air-water interface results in repeated deposition and removal of the perfluorocarbon component of the mixed films with successive up-strokes and down-strokes, respectively. The inability to deposit mixed multilayer films using this approach appears to be an implication of the weak adhesion between putative layers of perfluorocarbon, and the ability of the hydrogenated fatty acid to fill in void regions left by stripping of the weakly adhered perfluorocarbon off the hydrophilic substrate.

Multipurpose Solar Photoelectrochemical Hybrid Multilayer Films Based on Porphyrin and Preyssler Type Polyoxometalates for Solar Cell and Ag Nanomaterial Synthesis

Multilayer films with electrostatic interaction between Preyssler,s Polyanions (NH4)14[NaP5W30O110]14- .31H2O and tetracationic free base porphyrin [H2TN+(Me)3PyP]4+ have been alternately deposited on quartz and ITO substrates. and characterized by UV-visible absorption spectroscopy to follow the successive deposition of multilayer film. Solution phase interaction of both components revealed the stiochiometric ratio of the electrostatic complex formed . The morphology and composition of films were studied by atomic force microscopy and X-ray photoelectron spectroscopy (XPS ) .While permeability to cations in aqueous media and redox behavior were studied by cyclic voltametry . The solar photoctalytic activity of hybrid films is identified by TEM images obtained after heterogeneous aqueous photoreduction of Ag2SO4(aq) and KAuCl4 (aq) to yield diversified nanostructures . The study is first and initial report on preyssler type polyanions and porphyrin based heterogenous photocatalysis that provide a green, solar and multiple applications for precious metal recovery as nanoparticle ,sustainable wastewater purification and solar photocurrent generation.Polyoxometalates (POMs) are metal−oxygen framework of early metal elements in their highest oxidation state , able to undergo reversible, stepwise, multielectron-transfer reactions, which are the basis for many catalytic processes[1].These polyanions clusters exhibit applications in catalysis, medicine, materials science [2]. They offer effective photocatalytic properties in oxidation and reduction processes. On photolysis, the high oxidizing ability of excited POMs can lead to the degradation of a variety of organic compounds such as pollutants, leading to a process for water purification [3]. In the presence of a sacrificial electron donor , their photolysis lead to the formation of reduced POMs which can in turn reduce metallic ions. It could be a good alternative for precious metals recovery or synthesis of metal nanoparticles. [4,5]. However, polyoxometalates absorb in the uv part of spectrum, thus they require UV excitation, which cease its large-scale environmental application. One of obvious strategy is to couple it with some chromophore group which can be sensitized by visible light. Metal porphyrins are attractive components in materials because of their appealing chemical and photochemical properties: high stability, intense visible absorption bands, long-lived excited states, and tunability by chemical derivatization [2]. Figure 1.1 R.H.S. Representation of the porphyrin used 5, 10, 15, 20-Tetrakis (4-trimethylammoniophenyl) porphyrin tetra(p-toluenesulfonate), namely [H2TN+(Me)3PyP]4+) used with the Preyssler type (NH4)14[NaP5W30O110]14- .31H2O . L.H.S. UV-visible record on quartz and ITO shows layer by layer absorbance. Formation of Multilayer Films :H2TN+(Me)3PyP4+] / [(NH4)14[NaP5W30O110]14- .31H2O ] The alternate deposition of positively charged porphyrin, H2TN+(Me)3PyP4+, and negatively charged [NaP5W30O110]14-on slides of quartz and Indium tin Oxide (ITO) lectrodes by layer-by-layer were performed.

Corrosion behavior of Al-containing MAX-phase coatings exposed to oxygen containing molten Pb at 600 °C

Four types of MAX-phase coating samples (Cr2AlC, V2AlC, Ti2AlC, and Ti3AlC2), synthesized via physical vapor deposition and post-annealing of elemental multilayer films, have been investigated toward their potential corrosion protection in 10-6 wt% oxygen-containing molten Pb for 3200 h at 600 °C. Three MAX-phase coatings (Cr2AlC, Ti2AlC, and Ti3AlC2) are corrosion resistant against the molten Pb, via formation of a protective oxide layer. Specifically, various oxide scales formed on each sample: an Al2O3 scale, containing a low amount of Cr2O3 was formed in case of the Cr2AlC coating; a mixed Al2O3 and TiO2 oxide scale was observed for both Ti2AlC and Ti3AlC2 coatings. A more complex mixed oxide layer consisting of VO2, V4O7, and Pb3(VO4)2 phases is formed on the V2AlC coating, while the MAX-phase coating was almost entirely consumed. According to their corrosion performance against oxygen containing molten Pb, the order of corrosion resistance is: Cr2AlC > Ti2AlC > Ti3AlC2 > V2AlC.

Corrosion behaviour of Zn-Co alloy and multilayered metallic coatings: a comparative insight

ABSTRACT Zinc layers are widely used for the protection of various classes of steel in atmospheric conditions. An improvement in corrosion performance of these layers may qualify them to be used in harsh marine conditions. In this study, two practical approaches, including alloying Zn with Co at different current densities and electrolyte temperatures, as well as deposition of multilayered Zn-Co films with various numbers of interlayers, were applied to fabricate corrosion barrier coatings on St 37 steel. The surface and cross-sectional morphologies of the coatings were studied using scanning electron microscopy (SEM). Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarisation tests were employed to compare the corrosion resistance of the alloy and multilayered coatings. Results illustrated that the best protection performance is obtained for multilayered coatings with top Co layer showing promise to be used in marine applications.

VACUUM UNIT WITH ELECTRON-BEAM EVAPORATOR AND VACUUM LOADING OF GROUP SUBSTRATE HOLDERS, "Электронная техника. Серия 3. Микроэлектроника"

A new vacuum unit (ELU TM 1Sh) with mult-crucible electron beam evaporation (EBE) and lock loading of group substrate holders for 100-150 mm wafers has been developed. The unit is intended mainly for deposition of single-layer or multilayer films in explosive photolithography technology.

Biocompatible Exfoliation and Modified Self-Assembly Deposition of Graphene Films for Electrodes Fabrication: Processing Parameters Vs. Electrochemical Performance

Liquid Phase Exfoliation (LPE) of graphite has been proposed as a scalable and low-cost method for graphene (G) production (A. O’Neill, U. Khan et al. Phys. Chem. C, 115, 5422–5428 (2011)). Ultrasonic mixing coupled with polymeric stabilizers effectively overcomes Van Der Walls forces between graphitic planes and isolating graphene flakes. The absence of strong oxidizing/reducing agents in the synthesis process allows the graphenic basal plane to preserve its sp2 character, with defects mainly concentrated at the flakes’ edges. In this work, we investigate the use of biocompatible solvents, ethanol (EtOH) and water, and stabilizing agents (cellulose acetate butyrate, CAB) to form stable liquid dispersions of graphene. Centrifugation of the EtOH/CAB/G mixture and removal of excess polymeric stabilizer followed the Ultrasonic Assisted Liquid Phase Exfoliation (UALPE) to obtain an optimal graphene dispersion. The resulting material is employed for the self-assembly-driven deposition of multi-layer graphene films on SiO2/Si substrates. According to the Marangoni effect principle, the low surface tension value of the graphene liquor can be exploited to induce a mass flow at the interface with a secondary high surface tension solvent (H2O). This phenomenon results in the formation of stable films of “compressed” graphene (X. Li et al., Adv. Funct. Mater., 26, 1322–1329 (2016)). Said material is deposited on the Si/SiO2 surface by a Langmuir-Shaefer/Blodgett hybrid approach with an ad hoc 3D printed sample holder. The graphene films are characterized via Raman, XPS, and SEM. Raman spectroscopy was the primary tool for the evaluation of the quality of graphene and its characteristics. The I(D)/I(G) and I(D)/I(D’) ratios confirm low-defectivity concentrated at the edges. The 2D peak shape and fit were instead used to indicate the number of graphene layers, estimated at 5-7. The same parameters were employed to analyze multi-layer graphene films, identifying the stacking of the material as electronically decoupled. The electrical properties are analyzed as a function of the coating iterations and UALPE duration to obtain conductivity data, showing the best results to be in the range of the 103 Sm.Electrochemical characterization of the deposits is evaluated by redox probing graphene in an appropriate electrolyte. A coordination complex couple like ferro/ferricyanide is used to evaluate the electrochemical performance of the graphene films as electrodes in standard cyclic voltammetry. The reversible nature of the [Fe(CN)6]3-/[Fe(CN)6]4- redox reaction allows the calculation of the Electrochemical Surface Area (ESA) by analyzing the voltammetric current1. (Y. Lei et al., J. Electroanal. Chem., 887, 115084 (2021)). The exfoliation parameters and iterations of self-assembly-driven electrode fabrication are related to the electrochemically active surface area (D. A. C. Brownson and C. E. Banks, The Handbook of Graphene Electrochemistry, p. 201, Springer London, London, (2014)). Electrochemical AFM (EC-AFM) is also utilized to assess the behavior of the carbonaceous deposits. EC-AMF in situ analysis is employed to investigate the evolution of the electrochemical phenomena on a micro/nanoscale and trace a correlation between the graphene synthesis variables and the response of the multi-layer graphene films.

Pulsed laser deposition of multilayer diamond-like carbon film grown on stainless steel

The amorphous SiC layers played an essential role of improving adhesive property in the pulsed laser deposition-grown multilayer DLC coating. Comparison of several experiments exhibited that the adhesive SiC layer enhanced the adhesive strength of the DLC layer on the transitional Ti layer. Meanwhile, the ‘inserted’ buffer thin SiC layers, which had strong binding force with the DLC layers, divided the thick DLC layer (about 1.2 μm) into several relatively thin layers. It's thought that the buffer SiC layers reduced accumulation of internal stress in each finite thickness and then prevented the cracking of the DLC layer. And the total thickness of optimized multilayer DLC coating reached to 2 μm. The multilayer DLC coating with the adhesive SiC layer and buffer SiC layers showed an excellent adhesive performance on the stainless steel. The similar tribological property of SiC layer to the DLC layer conferred this multilayer DLC coating a low friction coefficient and a low wear rate.

DEPOSITION OF Al/SnAl OHMIC CONTACT ON SILICON FROM A LIQUID PHASE

Background. Single- and multi-layer metal films are widely utilized in modern electronics and optoelectronics as ohmic contacts. As a rule, the films are deposited by thermal evaporation, ion sputtering and chemical vapour deposition. However the methods of deposition from a liquid phase are the most simple and cost-effective. Thus the ohmic contact deposition by these methods is still an actual problem. Objective. The purpose of the paper is to study the possibility of deposition of multi-layer ohmic metal films over a semiconductor wafer surface from a liquid phase, particularly by scanning liquid phase epitaxy technique. Methods. In this work we considered the influence of a long-term temperature gradient at the interface metallic solution-melt – semiconductor wafer on the possibility of deposition of multi-layer ohmic metal films on the semiconductor wafer surface during segmental contact between the solution-melt and the wafer. For this purpose we carried out the simulation of heat transport process, wafer wetting process as well as the process of wafer cleansing off the solution-melt taking into account capillary phenomena in the mask openings using the method of scanning liquid phase epitaxy. For experimental confirmation of adequacy of the model proposed we carried out the deposition of Al/SnAl layer on silicon wafer in the above mentioned conditions. Results. We have deposited the contact layer Al/SnAl on the surface of silicon wafer from Al-Sn solution-melt by scanning liquid phase epitaxy technique using supplementary heater for the wafer and mask installed in the apparatus. The contact layer is made as three identical pads located at different distance one from each other. By the analysis of current-voltage characteristic we determined that the metallic film contact with the semiconductor is a non-rectifying, i.e. ohmic contact. The specific contact resistance was determined by the Transmission Line Method using linear configuration of the contact pads (LTLM). Its value was 7.2∙10-4 Ohm·cm2. Conclusions. The principal possibility of obtaining of multi-layer ohmic contacts to the semiconductor by scanning liquid phase epitaxy technique in conditions of segmental contact between the solution-melt and the wafer as well as long-term gradient at the contact interface was shown. The conditions were realized by using extra heating of the wafer back side and the high-temperature mask through which the solution-melt contacted the wafer.

Enhanced Electrical Properties of AZO/IZO Multilayered Thin Film with Post Laser Annealing Process.

In this research, alternative deposition process of ZnO-based thin films have been studied for transparent conducting oxide (TCO) application. To improve the electrical and optical properties of transparent oxide thin films, alternatively stacked Al-doped ZnO and In-doped ZnO thin films were investigated. Multilayer structure of alternative 6 layers of thin films were prepared in this research. Especially, Aluminum and Indium were chosen as dopant materials. Thin films of Al-doped ZnO (AZO) and In-doped ZnO (IZO) were alternatively deposited by spin coating with sol-gel method. After deposition of multilayered thin films, multi steps of furnace (F), rapid thermal annealing (R) and CO₂ laser annealing (L) processes were carried out and investigated thin film properties by dependence of post-annealing sequence and thin film structures. The electrical and optical properties of thin films were investigated by 4-point probe and UV-vis spectroscopy and its shows the greatest sheet resistance value of 0.59 kΩ/sq. from AZO/IZO multilayered structure and upper 85% of transmittance. The structural property and surface morphology were measured by X-Ray Diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The Al- and In-doped ZnO thin film shows the highest intensity value at (002) peak of AZO/IZO multilayer structure which was performed FRL process.

Deposition of MoS2-TiN Multilayer Films on 1045 Steel to Improve Common Rail Injection System

In this study, plasma treatment was performed to increase the surface hardness, followed by the deposition of MoS2-TiN multilayer films by magnetron sputtering to reduce friction and facilitate sliding contact. The tribological test was performed with a tribometer (cylinder-disc type) developed exclusively to simulate the behavior of these components under pressure and movement conditions similar to those present in the common rail injection system (CRIS). The results obtained in this work showed a considerable increase in surface hardness due to the formation of iron nitrides caused by the plasma treatment, which slightly decreased by solid lubrication coating (MoS2). The increase in cycles in the tribological test causes a reduction in surface roughness due to the softness of the MoS2 layers by plastic deformation. The combination of plasma treatment and MoS2-TiN multilayer films contributed to the decrease in mass loss and better performance of the studied components.

Nacre inspired tailoring of mechanically strong hydrophobic coatings through Layer-by-Layer assembly

Nacre has been an extensively studied biomaterial exhibiting remarkable and myriad strength, stiffness, and toughness. Inspired by its mechanical property, bricks and mortar structure of seashell nacre was replicated by alternatively embedding building blocks into hybrid films using. Layer-by-Layer (LbL) deposition technique. The prepared artificial nacre-like hybrid films show enhanced mechanical property and solvent resistance. Synthesis of desired oligomeric siloxane was evident via FTIR and VPO, while FTIR, ellipsometer, XPS and SEM analysis indicated a successful deposition of multilayered thin films comprising polyethyleneimine (PEI), montmorillonite (MMT) and oligomeric siloxane. A strong electrostatic and hydrogen bonding enabled the nanostructured film to reach reduced modulus of ~65 GPa which is higher than previously prepared PEI-Clay coatings. The films exhibit high hardness (H), reduced modulus (Er) with a smooth surface, henceforth durable. When combined with hydrophobicity and chemical resistance of multilayered thin films, these mechanical properties indicate their promising feature for several potential applications as protective coatings in heavy mechanics, transportation, surface-sensitive substrates and adsorption of hydrophobic agents from water.

Layer-by-layer growth of molecular self-assembled monolayers /sputtered gold thin films/graphene oxide on glass substrate

In the present study, 1-dodecanethiol self-assembled monolayers (SAMs) on graphene oxide (GO) –Au (Gold) thin films as molecular templates for the selective deposition of multilayer films was performed. Thus, heterostructured GO/Au/DDT and DDT/Au/GO thin film are fabricated by sputtering Au target onto modified GO structure or self-assembled 1-dodecanethiol (DDT) arrays. It has been shown that a new device concept can be made by completing the glass substrate with the surface heterostructures; i.e. layer GO sheet or DDT with Au nanoparticles (Au NPs). In the light of the performed study, the layer-by-layer assembling of DDT on the GO sheet-Au thin films template has been proved for the distinct conjugation. Also, Optical and morphological characterizations are coherent with the instantaneous nucleation and growth model over the modified DDT-Au NPs-GO or GO-Au NPs-DDT thin films in the aspect of surface roughness, the phonon transport, and other multilayer films properties. As a consequence, the multilayer films of DDT-capped Au thin films and GO sheets have shown a better hybrid nanostructure with higher consistency, hierarchy and surface area. In addition, this work will present a new perspective for template preparation based on nanostructured thin films due to its unique properties resulting from nanoscale properties.

Deposition of Multilayer Films of ZnO by Sol-gel Process on Stainless Steel Substrates for Energy Harvesting Devices

The mechanical vibrations surrounding the environment can be converted in electrical energy by piezoelectric energy harvesters (PEH). The increase on the availability of Wireless Sensor Networks (WSN) increases the need for power supply that replaces ordinary batteries. In this paper, an electromechanical modelling and a deposition of multilayer zinc oxide (ZnO) films for an PEH are presented. The aim of the study is to obtain the thickness of the multilayer ZnO films in different conditions, in order to improve the energy harvesting capacity for a PEH device. The ZnO synthesis was performed by the sol-gel method with dehydrated zinc acetate as a precursor, making deposits of 5, 10 and 15 layers. The depositions were made at room temperature by spin coating at 1440 revolutions per minute for 16 s. An UV-Vis test showed that ZnO were present, with a percentage of peak reflectance at 370 nm and a XRD test showed a preferential crystalline orientation at (002). Also, a Finite Element Modelling (FEM) simulation of the substrate behaviour was performed, functioning as a cantilever beam. When adding a seismic mass and oscillating in the resonance frequency of 103.31 Hz and with 15 layers of ZnO deposited, 2.67 volts were obtained.

Physical, electrochemical and biological evaluations of spin-coated ε-polycaprolactone thin films containing alumina/graphene/carbonated hydroxyapatite/titania for tissue engineering applications.

Composite structures are at the frontier of materials science and engineering and polymeric/ceramic composites present one of their most prospective subsets. Prior studies have shown both improvements and deteriorations of properties of polymers upon the addition of ceramic phases to them, but not many studies have dealt with the direct comparison of chemically distinct inorganic additives. The goal of this study was to compare the properties of ε-polycaprolactone (PCL) thin films supplemented with alumina, graphene, carbonated hydroxyapatite or titania particles, individually, in identical amounts (12wt%). The composite films were analyzed for their phase composition, grain size, morphology, surface roughness, porosity, cell response, mechanical properties and electrochemical performance. Each additive imparted one or more physical or biological properties onto PCL better than others. Thus, alumina increased the microhardness of the films better than any other additive, with the resulting values exceeding 10MPa. It also led to the formation of a composite with the least porosity and the greatest stability to degradation in simulated body fluid based on open circuit potential (OCP) measurements and electrochemical impedance spectroscopy (EIS). Titania made the surface of PCL roughest, which in combination with its high porosity explained why it was the most conducive to the growth of human fibroblasts, alongside being most prone to degradation in wet, corrosive environments and having the highest Poisson's ratio. Graphene, in contrast, made the surface of PCL smoothest and the bulk structure most porous, but also most conductive, with the OCP of -37mV. The OCP of PCL supplemented with carbonated hydroxyapatite had the highest OCP of -134mV and also the highest mechanical moduli, including the longitudinal (781MPa), the shear (106MPa), the bulk (639MPa), and the elastic (300MPa). The only benefit of the deposition of multilayered PCL films supplemented with all four inorganic additives was to enable a relatively high resistance to degradation. This study demonstrates that the properties of thin PCL films could be effectively optimized through the simple choice of appropriate inorganic additives dispersed in them. There is no single additive that proves ideal for improving all the properties of interest in PCL thin films, but their choice should be adjusted to the actual application. One such method of compositional optimization could prove crucial in the effort to develop biocomposites for superior performance in tissue engineering applications.

Fabrication of Self-Assembled Nanoporous Structures from a Self-Templating M13 Bacteriophage

In this work, a model for self-assembled nanopore formation based on multilayer film deposition was devised. The laminated film with the self-assembled nanoporous surface was fabricated by utilizing a nanofiber-like M13 bacteriophage from a simple fabrication method. The fabricated laminated structure containing nanopores agreed well with the model and was well supported by optical results. This optical result confirms the structural transitions from a poor initial surface layer to a final nanoporous surface layer and was verified by experiment and simulation. The study shows that the M13 bacteriophage acts as a self-templating layer helping in a formation of self-assembled nanoporous structures. Successful fabrication of laminated films with a porous surface consists of a uniform distribution of nanopores with a width of ∼150–500 nm and a depth of 15–30 nm on a large scale. Our fabrication approach based on simplicity and easy fabrication along with low-cost, large-scale manufacturing will open the path ...

Durable UV-protective cotton fabric by deposition of multilayer TiO2 nanoparticles films on the surface

Durable ultraviolet (UV)-protective cotton fabric has great application potential in outdoor cotton clothing. In this study, oppositely charged TiO2 nanoparticles were deposited onto cotton fabric through the layer-by-layer self-assembly technique, resulting in multilayer films with UV-protective properties. The mechanism of the technology has been investigated through characterization of the structure and properties using different techniques including FTIR, UV–Vis spectroscopy, and a scanning electron microscope with an energy-dispersive X-ray spectrum. The results showed that TiO2 nanoparticles distributed uniformly on the surface of cotton fibers. The TGA results indicated that the TiO2 nanoparticles deposit on cotton fabrics had little effect on the thermal stability of cotton fabrics. The tensile strength and air permeability of the cotton samples were tested by a universal material testing machine and automatic ventilation instrument. The UV protection property of cotton fabric after assembled multilayer films was measured by an ultraviolet transmittance analyzer, and the laundering experiments were carried out to determine the durability of TiO2 nanoparticles on cotton fabric. The results showed that the UV protection property of cotton fabrics after assembled TiO2 nanoparticles was still maintained at a high level after five launderings.