Nanocomposite Films Research Articles

Investigation on structural, optical, thermal, and dielectric properties of cellulose propionate/styrene-maleic anhydride copolymer/molybdenum nanocomposite prepared by pulsed laser ablation

Polymer nanocomposite films of cellulose propionate/styrene-maleic anhydride copolymer/molybdenum (CP/SMAC/Mo) were fabricated by pulsed laser ablation of Mo in the polymer solution for 10, 20, and 30 min. The films were then characterized by various analytical methods. X-ray diffraction (XRD) revealed that the addition of Mo to CP/SMAC removed the crystalline peaks of Mo without changing the amorphous nature of the copolymer. According to the scanning electron microscopy (SEM) and atomic force microscopy (AFM) patterns, Mo atoms were trapped in the amorphous polymer stacks. The energy-dispersive X-ray (EDX) spectrum features C, O, and Mo. FTIR confirmed the embedding of Mo in the polymers. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were carried out on the samples. The pristine polymer film exhibited a band gap energy of 2.9 eV, which decreased to 2.05 eV because of the loading of the Mo nanoparticles. The intensity of the photoluminescence (PL) peak of the films increases with ablation time such that the absorption intensity of the film at a λmax of 426 nm increases by trifold during the 30 min of irradiation, which is consequently due to the increased amount of Mo in the nanostructure. The incorporation of Mo in the polymer matrix enhances the dielectric constant (ε') (6.28–18.13) and ac conductivity (σac) (3.19 × 10−5–1.12 × 10−4 S/cm) of the polymer with negligible dielectric loss. The results suggest possible technological utilization of these materials in such applications as supercapacitors, light-emitting diodes, and organic optoelectronic devices, among others.

Exploring the biomedical potential of chitosan‐ceria nanocomposites: synthesis and characterizations

The objective of this study was to synthesize and evaluate the biological effectiveness of cerium oxide (CeO2) against various bacterial and fungal strains. The chitosan‐CeO2 nanocomposite was comprehensively characterized. The Fourier transform infrared (FTIR) spectra displayed a combination of bands that provided evidence for the existence of a composite complex between the chitosan (CS) structure and the Ce–O bands originating from CeO2 nanoparticles. SEM measurements showed uniform dispersion across the whole CS surface, and the morphological changes were clearly observed as the CeO2 nanoparticle content was increased. In contrast, CS‐CeO2 demonstrates enhanced antibacterial efficacy against both Gram‐positive and Gram‐negative pathogens. The MTT method was utilized to assess the cytotoxicity of the examined CS‐CeO2, with the aim of evaluating the cell viability of various cancer cell lines under varying ultraviolet (UV) exposures. The enhanced penetration of CS and CeO2 nanocomposites into cancer cells during their anticancer activity, even in the absence of UV light, led to an increased rate of cell death. The administration of greater dosages of CS and its CeO2 nanocomposites led to an increased generation of reactive oxygen species (ROS), which was observed to be associated with an enhancement in the efficacy of anticancer activity. The impact was additionally amplified through exposure to UV radiation. The nanocomposite thin films demonstrated much higher antioxidant activity against the DPPH radical as compared to ordinary vitamin C. The aforementioned observation was derived from an evaluation of the antioxidant properties of the subject utilizing the DPPH free radical scavenging technique.

Enhanced field emission characteristics of WS2 nano-films by diamond film and Mo film

WS2 is a type of transition metal chalcogenide materials (TMDCs) that exhibits exceptional photoelectric properties. Due to its atomically sharp edges, WS2 has the capability to enhance the electric field around its edges, thus presenting significant potential in field emission applications. In this study, the electron beam vapor deposition (EBVD) system and microwave plasma chemical vapor deposition (MPCVD) system were used to prepare a series of single-layer WS2 films，single-layer diamond films and diamond/WS2 nano-composite films on N-type highly doped Si substrate, and Mo/WS2 nano-composite films were prepared on Al2O3 ceramic substrate. Based on the characterization and analysis of the microstructure and chemical composition of each thin film layer in the above film devices, the field emission (FE) characteristics of each thin film device are compared and studied. The results demonstrate that the maximum FE current density of diamond/WS2 nano-composite film device is 912 μA/cm2, which is 2.7 times of the maximum FE current density of Mo/WS2 nano-composite film device 330 μA/cm2, and 3.4 times of the maximum FE current density of the single-layer diamond thin film device 267 μA/cm2. The single layer WS2 film did not exhibit measurable FE performance. The working principles of thin film field emission devices with various structures are introduced. It is considered that the diamond layer plays the role of electron accelerating layer, which not only effectively improves the FE characteristics of diamond/WS2 nanocomposite film, but also improves the repeatability and long-term stability of diamond/WS2 nanocomposite film FE devices.

A self-healing crosslinked-xanthan gum/soy protein based film containing halloysite nanotube and propolis with antibacterial and antioxidant activity for wound healing

Traumatic multidrug-resistant bacterial infections are the most threat to wound healing. Lower extremity wounds under diabetic conditions display a significant delay during the healing process. To overcome these challenges, the utilization of protein-based nanocomposite dressings is crucial in implementing a successful regenerative medicine approach. These dressings hold significant potential as polymer scaffolds, allowing them to mimic the properties of the extracellular matrix (ECM). So, the objective of this study was to develop a nanocomposite film using dialdehyde-xanthan gum/soy protein isolate incorporated with propolis (PP) and halloysite nanotubes (HNTs) (DXG-SPI/PP/HNTs). In this protein-polysaccharide hybrid system, the self-healing capability was demonstrated through Schiff bonds, providing a favorable environment for cell encapsulation in the field of tissue engineering. To improve the properties of the DXG-SPI film, the incorporation of polyphenols found in PP, particularly flavonoids, is proposed. The synthesized films were subjected to investigations regarding degradation, degree of swelling, and mechanical characteristics. Additionally, halloysite nanotubes (HNTs) were introduced into the DXG-SPI/PP nanocomposite films as a reinforcing filler with varying concentrations of 3 %, 5 %, and 7 % by weight. The scanning electron microscope (SEM) analysis confirmed the proper embedding and dispersion of HNTs onto the DXG-SPI/PP nanocomposite films, leading to functional interfacial interactions. The structure and crystallinity of the synthesized nanocomposite films were characterized using Fourier Transform Infrared Spectrometry (FTIR) and X-ray diffraction (XRD), respectively.Moreover, the developed DXG-SPI/PP/HNTs nanocomposite films significantly improved cell growth of NIH-3T3 fibroblast cells in the presence of PP and HNTs, indicating their cytocompatibility. The antibacterial activity of the nanocomposite was evaluated against Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus), which are commonly associated with wound infections. Overall, our findings suggest that the synthesis of DXG-SPI/PP/HNTs nanocomposite scaffolds holds great promise as a clinically relevant biomaterial and exhibits strong potential for numerous challenging biomedical applications.

Structural, thermal and optoelectrical study of PVA/iron oxide nanocomposite films

AbstractThe work reported here deals with fabricating iron oxide nanoparticles incorporated polyvinyl alcohol nanocomposite films via the solution‐casting green route, characterized using various characterization techniques. X‐ray diffraction analysis shows interaction of nanoparticles with the polyvinyl alcohol matrix, scanning electron microscopy shows surface morphology of crack‐free films, energy dispersive spectroscopy indicates elemental purity, tensiometer analysis shows changing behavior of hydrophilic to hydrophobic, thermogravimetric analysis shows improved thermal stability, ultraviolet‐visible spectroscopy shows tunable optical properties, and frequency response analysis shows improved electrical properties. A small incorporation (1 wt. %) of iron oxide nanoparticles has induced significant alternations in structural, wetting, thermal, optical, and electrical properties of the polyvinyl alcohol‐based nanocomposite films. Results showed notable changes in the structural phases, water contact angle (39.5° to 97.7°), optical absorption edge (5.12 eV to 4.84 eV), indirect band gap (4.99 eV to 4.68 eV), direct bandgap (5.41 eV to 5.21 eV), and band tail (0.57 eV to 0.89 eV) from native polyvinyl alcohol to polyvinyl alcohol/iron oxide nanocomposite films. Enhancements were observed in refractive indices, optical conductivity, optical dielectric loss, thermal stability, dielectric constant, and dielectric loss on incorporating iron oxide nanoparticles into the polyvinyl alcohol matrix. The fabricated nanocomposite films might be a potential material for optoelectronic and microelectronics applications.

Structural and Optical Properties of PMMA-MgO Nanocomposite Film

This study investigates the structural, morphological, and optical properties of poly(methyl methacrylate) (PMMA) films incorporated with magnesium oxide (MgO) nanoparticles. The PMMA-MgO polymer nanocomposite (PNC) films were fabricated via solution casting method using varying weight percentages (1-4 wt%) of MgO nanoparticles. X-ray diffraction analysis confirmed the integration of MgO nanofillers in the PMMA matrix. Fourier transform infrared spectroscopy revealed interactions between PMMA and MgO nanoparticles. Atomic force microscopy demonstrated increased surface roughness in PNC films with higher MgO loading. Optical characterization using UV-visible spectroscopy showed enhanced absorption in the UV region and a noticeable peak at 280 nm due to MgO nanoparticles. The refractive index of PMMA-MgO PNCs increased with rising MgO content while the optical bandgap marginally decreased. The study highlights the potential of PMMA-MgO PNC films for advanced optoelectronic applications requiring high optical transparency and tuneable refractive index.

Fabrication of Poly(ethylene furanoate)/Silver and Titanium Dioxide Nanocomposites with Improved Thermal and Antimicrobial Properties.

Poly(ethylene furanoate) (PEF)-based nanocomposites were fabricated with silver (Ag) and titanium dioxide (TiO2) nanoparticles by the in-situ polymerization method. The importance of this research work is to extend the usage of PEF-based nanocomposites with improved material properties. The PEF-Ag and PEF-TiO2 nanocomposites showed a significant improvement in color concentration, as determined by the color colorimeter. Scanning electron microscopy (SEM) photographs revealed the appearance of small aggregates on the surface of nanocomposites. According to crystallinity investigations, neat PEF and nanocomposites exhibit crystalline fraction between 0-6%, whereas annealed samples showed a degree of crystallinity value above 25%. Combining the structural and molecular dynamics observations from broadband dielectric spectroscopy (BDS) measurements found strong interactions between polymer chains and nanoparticles. Contact angle results exhibited a decrease in the wetting angle of nanocomposites compared to neat PEF. Finally, antimicrobial studies have been conducted, reporting a significant rise in inhibition of over 15% for both nanocomposite films against gram-positive and gram-negative bacteria. From the overall results, the synthesized PEF-based nanocomposites with enhanced thermal and antimicrobial properties may be optimized and utilized for the secondary packaging (unintended food-contact) materials.

The local potential variation mapping including thermoelectromotive force in nanocomposite materials under non-thermal equilibrium

Thermoelectric nanocomposite materials are attracting much attention due to their high thermoelectric performance brought by effectively combining thermoelectric properties of the matrix and introduced nanostructures. However, understanding the mechanism of Seebeck coefficient enhancement brought in nanocomposite materials is difficult because there are no measurement methods of thermoelectromotive force V TE on the nanoscale. In this study, we demonstrate that the controlled temperature gradient Kelvin force microscopy (T-KFM) measurement we developed in 2021 can be applied to nanocomposite films. We observe temperature difference ΔT-induced vacuum level V vac variation, which is related to V TE, in PEDOT:PSS/Si nanowire nanocomposite films using T-KFM. The large ΔT-induced V vac variation at the tops of Si nanowires is generated, which is mainly explained by the larger Seebeck coefficient value of the Si nanowire. This application of T-KFM to the nanocomposites highlights that T-KFM will be a powerful tool for the development of nanocomposite materials with controlled thermoelectric properties on the nanoscale.

Poly(vinyl alcohol)/graphene nanoplatelet nanocomposites: Elucidation of the nanofiller, dispersing agent, and interphase effects on thermomechanical properties

AbstractPoly(vinyl alcohol) (PVA)/graphene nanoplatelet (GnP) nanocomposite films were fabricated by a solution casting method. High loadings (30–40 wt.%) of two GnP grades, that is, xGnP C300 (low surface area/large size) and C750 (high surface area/small size), were utilized in combination with three commercial dispersing agents, that is, DISPERBYK‐161, DISPERBYK‐162 TF, and DISPERBYK‐2014, to yield films with desirable stiffness and energy dissipation characteristics (dynamic mechanical analysis, DMA), as well as thermal properties (thermogravimetric analysis, TGA) for potential impact resistance applications. The addition of GnPs and dispersing agents to PVA leads to a maximum six‐fold increase in its Young's modulus for the PVA sample containing 40 wt.% C300 GnPs and DISPERBYK‐162 TF. However, the modulus of resilience drops dramatically for the same sample (about 18‐fold decrease), as expected. Also, C300 GnPs yield nanocomposites with higher Young's moduli that those obtained using C750 GnPs. The atomic force microscopy stiffness maps illustrate that C300 GnPs disperse better in the PVA matrix. Furthermore, the average interphase thickness in the PVA‐C300 nanocomposites (~300 nm) is almost double that of PVA‐C750 nanocomposites. Based on the TGA results, the addition of GnPs and dispersing agent to the PVA matrix leads to a moderate increase (an average of 3.5%) in the value of the neat PVA, while its char yield increases by an average 8.5‐fold. Specifically, the PVA/GnP nanocomposites containing DISPERBYK‐162 TF yield the largest and char yield values than the other systems. The insights gained in this work can guide the design of coatings for impact resistance applications.

Investigations on Impact of YSZ Nanoparticles on Morphology & Electrical conductivity of PEDOT: PSS

Conductive polymer nanocomposites, which combine the flexibility and conductivity of polymers with the unique properties of nanofillers, have generated interest in various fields such as energy storage, sensors, coatings, and corrosion protection. This study discusses the effect of Yttria-stabilized zirconium nanoparticles (YSZ NPs) on the morphology and electrical conductivity of poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT: PSS). Thin films of PEDOT: PSS and PEDOT: PSS: YSZ were fabricated using spin coating technique. FTIR and XRD characterizations confirmed the interaction between YSZ nanoparticles and the PEDOT: PSS matrix, leading to changes in chemical morphology and film crystallinity. The investigation of the current-voltage (I-V) relationship showed improved electrical conductivity in PEDOT: PSS films with the addition of YSZ nanoparticles, with respective conductivities of 0.028×10−6 S cm−1 and 0.0885×10−4 S cm−1 for pristine and YSZ-containing films. Additionally, the sensing properties of the PEDOT: PSS: YSZ film in detecting organic vapours were studied. These findings suggest that these conducting polymer nanocomposite thin films could potentially be used as electrolyte components in battery cells, supercapacitors, and fuel cells, as well as serve as sensors for certain organic vapours.

Physicochemical and optical activity of chitosan based ternary nanocomposites for food packaging applications

Chitosan (CS)-based ternary bionanocomposite materials have applications in the food packaging industry owing to their excellent properties. We fabricated chitosan/polyvinyl alcohol/graphene oxide (CS/PVA/GO) ternary bionanocomposites for food packaging using an environmentally friendly approach involving solution casting and solvent evaporation method. The physiochemical characteristics of the prepared ternary bionanocomposite films were elucidated using FTIR, Raman, XRD, TGA, DSC, FE-SEM, UV–visible, PL, and CD analysis. The viability assay revealed that the bio-based nanocomposite films are superior to native CS and PVA films. Water uptake and porosity of bionanocomposite films were evaluated. Tomatoes (Solanum lycopersicum) were used to evaluate the shelf-life-enhancing capability of the CS/PVA/GO composite. The results indicate that the biocompatible and eco-friendly CS/PVA/GO bionanocomposites are promising for food packaging applications.

Incorporation of Magnetic Filler (Co0.2Zn0.2Cd0.6Fe2O4) in PVA Matrix and Studying the Structural, Optical and Mechanical Properties of Nanocomposite Films

AbstractThe goal of this study is to synthesize nanocomposite PVA/ Co0.2Zn0.2Cd0.6Fe2O4 films with varying contents of Co0.2Zn0.2Cd0.6Fe2O4 nanoparticles (x = 0, 0.2, 0.4, 0.6, 0.8) to improve the structural, optical, and mechanical characteristics of the examined materials. Casting technique is used to prepare PVA/ Co0.2Zn0.2Cd0.6Fe2O4 films. X-ray diffraction, FTIR, UV–Vis spectroscopy, and Vickers Hardness were used to examine the effect of magnetic nanoparticle content on the structural, optical, and mechanical characteristics of PVA nanocomposite films. The refractive index rises from 1.4967 for pure PVA to 7.6511 for PVA + 0.8Co0.2Zn0.2Cd0.6Fe2O4, allowing it to be employed in a variety of applications such as solar cell construction. Because of the presence of ferrite in the glass matrix, the average hardness values enhanced and increased from 90.7 to 114.2 MPa. The stress exponent (n) varies from 1.12 to 3.33, with grain boundary sliding as the deformation mechanism for x = 0, viscous glid for x = 0.2, 0.4, and 0.6, and dislocation climb for x = 0.8 nanocomposite thin films.

Multifunctional Ti3C2Tx MXene-reinforced thermoplastic starch nanocomposites for sustainable packaging solutions

Starch-derived films exhibit significant potential for packaging applications owing to their low cost, biodegradable characteristics, and natural abundance. Nonetheless, there is a demand to enhance their mechanical properties and moisture resistance to broaden their use. In this study, high performing sorbitol-plasticized starch/Ti3C2Tx MXene nanocomposites, reinforced with ultra-low filler contents, were fabricated for the first time in literature. The MXene nanoplatelets were well-dispersed within the starch matrix while there was a tendency for the fillers to align in-plane, as revealed by polarized Raman spectroscopy. The produced nanocomposite films demonstrate remarkable effectiveness in blocking UV light, offering an additional valuable attribute in food packaging. The Young's modulus and tensile strength of starch films containing 0.75 wt% MXene increased from 439.9 and 11.0 MPa to 764.3 and 20.8 MPa, respectively. The introduction of 1 wt% MXene nanoplatelets reduced the water vapour permeability of starch films from 2.78 × 10−7 to 1.80 × 10−7 g/m h Pa due to the creation of highly tortuous paths for water molecules. Micromechanical theories were also implemented to understand further the reinforcing mechanisms in the biobased nanocomposites. The produced starch nanocomposites not only capitalize on the biodegradable and renewable nature of starch but also harness the unique properties of nanomaterials, paving the way for sustainable and high-performance packaging solutions that align with both consumer and environmental demands.

Enhanced antibacterial properties of polyvinyl alcohol/starch/chitosan films with NiO–CuO nanoparticles for food packaging

Packaging is very important to maintain the quality of food and prevent the growth of microbes. Therefore, the use of food packaging with antimicrobial properties protects the food from the growth of microorganisms. In this study, antibacterial nanocomposite films of polyvinyl alcohol/starch/chitosan (PVA/ST/CS) together with nickel oxide-copper oxide nanoparticles (NiO–CuONPs) are prepared for food packaging. NiO–CuONPs were synthesized by the co-precipitation method, and structural characterization of nanoparticles (NPs) was carried out by XRD, FTIR, and SEM techniques. Composites of PVA/ST/CS, containing different percentages of NPs, were prepared by casting and characterized by FTIR and FESEM. The mechanical properties, diffusion barrier, and thermal stability were determined. The nanoparticles have a round structure with an average size of 6.7 ± 1.2 nm. The cross-section of PVA/ST/CS film is dense, uniform, and without cracks. In the mechanical tests, the addition of NPs up to 1% improved the mechanical properties (TS = 31.94 MPa), while 2% of NPs lowered TS to 14.76 MPa. The fibroblast cells toxicity and the films antibacterial activity were also examined. The films displayed stronger antibacterial effects against Gram-positive bacteria (Staphylococcus aureus) compared to Gram-negative bacteria (Escherichia coli). Furthermore, these films have no toxicity to fibroblast cells and the survival rate of these cells in contact with the films is more than 84%. Therefore, this film is recommended for food packaging due to its excellent mechanical and barrier properties, good antibacterial activity, and non-toxicity.

Improved performance of polyamide nanofiltration membrane embedded with zeolite beta

In this study, zeolite beta nanoparticles were incorporated into an interfacial polymerization procedure for the fabrication of thin film nanocomposites (TFNs). The successful introduction of zeolite beta into the polyamide (PA) selective layer was confirmed by surface attenuated total reflection infrared spectroscopy (ATR-FTIR), and x-ray photoelectron spectroscopy (XPS). The introduction of porous structured zeolite beta improved the water flux and rejection rate of the TFN membrane compared to the PA thin film composite (TFC) membrane. A quantitative performance coefficient is further proposed in this work, comprehensively considering the flux and rejection rate to evaluate the performance of TFNs. For five salt solutions, we found that the TFN0.3 membrane with 0.3 wt% of zeolite particles had a high coefficient of performance. With the help of zeolite particles, the TFN0.3 membrane achieved a high flux of 92.53 L/(m2·h) under an operating pressure of 5 bar. For ion separation from binary solutions, the TFN0.2 membrane with 0.2 wt% zeolite content was a better choice for a wide range of binary mixtures, which is because the addition of zeolite beta resulted in smaller pore sizes, the strongest zeta potential, and the thickest thickness (scanning electron microscope, SEM determined) of the TFN0.2 membrane. All these factors contribute to the selectivity of the TFN0.2 membrane. Our study provides an efficient and cost-effective method to simultaneously improve the permeability and rejection of nanofiltration membranes, facilitating the development of nanofiltration for water recovery.

Investigation into thermoelectric performance of a flexible n-type nanocomposite film from the AgxSe nanotube composited with PPy

Silver selenide (Ag2Se) has turn up as a promising n-type thermoelectric (TE) material. Especially, the Ag2Se nanotubes may be more attractive in view of their one-dimensional hollow tubular nanostructure. Regrettably, the TE application of Ag2Se nanotubes has not yet been reported so far, probably due to their hard accessibility and poor processability. In this work, we developed a simple and efficient template-free electrochemical deposition method for preparing AgxSe nanotubes, and thus investigated the TE application of the AgxSe-nanotube films electrochemically composited with polypyrrole (PPy). It was found that the incorporation of PPy into the n-type AgxSe-nanotube films not only settled the issues of their high brittleness and easy oxidation, but also significantly improved their TE performance through the synergistic effects. Consequently, the AgxSe nanotube/PPy composite film achieved a maximum power factor of 282.8 ± 16.5 μW m−1 K−2, which is nearly twice that of the pure AgxSe-nanotube film.

Exploiting sulfonated covalent organic frameworks to fabricate long-lasting stability and chlorine-resistant thin-film nanocomposite nanofiltration membrane

Incorporating hydrophilic and charged porous nanofillers to prepare high-performance thin film nanocomposite (TFN) nanofiltration (NF) membranes is an effective method to achieve efficient water treatment. In this study, we synthesize the sulfonated covalent organic framework nanosheets (S-CONs) with higher hydrophilicity and electronegativity by immobilizing sulfonic acid groups (–SO3H) on TpPa-1 nanosheets. The S-CONs are incorporated in the PA layer by interfacial polymerization (IP) reaction. The results indicated that the S-CONs could modulate the hydrophilicity, thickness, and electronegativity of TFN-NF membranes. At the optimal addition of S-CONs (0.006 g), the pure water permeance increases to 8.84 L⋅m−2⋅h−1⋅bar−1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\rm{L}}\\cdot{\\rm{m}}^{-2}\\cdot{\\rm{h}}^{-1}\\cdot{\\rm{bar}}^{-1}$$\\end{document}, which is about 1.75 times than the TFC membrane, with a high Na2SO4 rejection reaching 98.97%. The improvement of the separation performance mainly results from the reduction of PA layer thickness (from ~178.00–198.00 to ~100.00–128.00 nm) and the increase of surface electronegativity (from −20.37 to −44.41 mV at pH = 7.00). More interestingly, the amide bond formed between the S-CONs and TMC improved the chlorine resistance of the membranes. This study reveals the potential of using functionalized 2D CONs as nanofillers to modify TFC membranes for efficient nanofiltration.

Sweet cherry tree (Prunus avium) exudate gum-based film modification in a photoreactor: Effects of hydrogen peroxide oxidation, UV irradiation, and TiO2 nanoparticles

The fabrication possibility of nanocomposite film from sweet cherry tree exudate gum (SCG) was studied. To improve SCG film properties, oxidation with hydrogen peroxide, ultraviolet irradiation (UV-A and UV-C), and TiO2 nanoparticles (T-NPs) were used. Hydrogen peroxide oxidation at higher amounts decreased the water vapor permeability (WVP) and thickness and increased the mechanical properties and transparency. In comparison with the UV-A, UV irradiation of the C-type increased permeability, and elongation at break (EAB) and thickness, but reduced the tensile strength (TS), solubility, and transparency. The permeability and tensile strength were increased and elongation at break was decreased at a longer time of irradiation. The transparency values of fabricated films ranged from 65.3 to 79.5 % and WVP were in the range of 2.32–4.72 (×10−10 g/m.s.Pa). The measured TS of the SCG films were between 2.2 and 5 MPa and the EAB of the SCG films was between 35 and 68.7 %. The FTIR spectrum and SEM images revealed that the treatments could affect the bonds and the smoothness of the film surface, respectively. Images provided by AFM showed that the roughness of the films was increased by the addition of T-NPs. The incorporation of T-NPs increased the TS and decreased EAB and WVP. These results indicated that oxidation, UV irradiation and nanomaterials incorporation could be used to improve SCG film properties that are related to food packaging material.

Nanocomposite film combines polyvinyl alcohol and iron oxide capped in silica for optical applications

Nanocomposite film combines polyvinyl alcohol and iron oxide capped in silica for optical applications

Structural engineering of vertically aligned nanocomposite films fabricated via magnetron and pulsed laser co-deposition for microwave application

Microwaves are often used in communication engineering, including in microwave relays as well as multichannel, mobile, and satellite communications. To meet the demand for a “small, light, thin, and precise” modern electronic machine, developing highly tunable microwave materials to manufacture miniaturized microwave devices has become a top priority. Ferroelectric materials are excellent microwave materials, showing outstanding dielectric properties and tunability. Introducing low dielectric loss oxides in the construction of vertical self-assembly nanocomposites (VSNs) effectively improves their tunability and reduces dielectric loss. However, the optimal doping content of simple VSN films limits further improvement of tunability. Herein, we propose a strategy-gradient VSN to achieve combined improvement in tunability and dielectric constant by designing a sputtering and pulsed laser co-deposition. The resulting VSN composite film has a dielectric constant of 428.08, a dielectric loss of 0.0212, and a tunability of 78.69 %. Our results contribute to the development of filters and have broad application prospects in the microwave industry.