As-prepared Nanocomposite Films Research Articles

Fabrication and Characterization of Activated Carbon/ZnO Nanocomposite Films for Use as a Photocatalyst in Degradation of Organic Compounds

The activated carbon/ZnO nanocomposite films were successfully prepared by a simple doctor blade method. The obtained films were characterised by X-ray diffraction, scanning electron microscopy, Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy and Photoluminescence techniques. The photocatalytic properties of all films were carried out by degrading rhodamine B (RhB) dye under solar light irradiation. From the study, it was found that an increment of the efficacy of photocatalytic activities showed in activated carbon/ZnO nanocomposite films as compared to the pure activated carbon and pure ZnO. Moreover, the effect of concentration of activated carbon on the photocatalytic activity of as-prepared nanocomposite films was studied. Results were found that the optimal concentration of 5 wt% activated carbon on the surface of ZnO exhibited the highest efficiency.

Structural and Magnetic Properties of Ni Nanoparticles Embedded in Vinyl Polymer Nanocomposite Films

Ni nanoparticles layer of nominal thickness in the range of 5–40[Formula: see text]nm were deposited on polyvinyl alcohol (PVA) film by using the ion beam sputtering (IBS) technique. PVA films were made on a quartz substrate by the solution casting technique. Grazing incidence X-ray diffraction (GIXRD) results reveal Ni is present in a metallic form in the FCC phase. AFM shows that roughness increases with increase in thickness of Ni layer and corresponding MFM images of magnetic domains were recorded. Soft X-ray absorption spectroscopy (SXAS) studies on the PVA/Ni nanocomposites films were recorded using synchrotron radiation. This study is used to study the electronic structure of the as-prepared nanocomposite films and reveals that Ni nanoparticles are present in their metallic form. Magnetic properties were measured using the magneto-optical Kerr effect (MOKE) magnetometer and the films were found to be magnetically soft with higher value of coercivity at lower thickness of Ni nanoparticles layer. The results of magnetic studies are discussed in light of the microstructure and morphological features of PVA/Ni nanocomposite films. The PVA/Ni nanocomposites showed interesting anisotropic magnetic behavior; thus the investigative results may be useful for the development of futuristic flexible functional magnetic material system.

A shape programmable MXene-based supermolecular nanocomposite film

Stimulus-responsive MXene films demonstrate extensive application scenarios, such as artificial muscles and biomedical devices. However, the shape deformation of such materials entails continuous stimulation, thus limiting their implementation in specific fields when temporary shapes have to be maintained without external stimuli. This work fabricates a kind of shape-programmable MXene-based supermolecular nanocomposite film by integrating MXene and polyvinyl alcohol. In this film, MXene provides extra intermolecular hydrogen bond interaction between polyvinyl alcohol and acts as cross-linking points in the nanocomposite, thus endowing this film with a good shape-fixing property. Furthermore, with the osmotic plasticization of water on the polyvinyl alcohol chains, the as-prepared nanocomposite film demonstrates excellent water-responsive shape-memory performance. This material cannot only overcome the inability of traditional stimulus-responsive MXene films to maintain temporary structures without continuous stimulation, but also expands potential applications in some fields including controlled release and intelligent bio-robots.

Microstructure, Mechanical, and Nanotribological Properties of Ni, Ni-TiN, and Ni90Cu10-TiN Films Processed by Reactive Magnetron Cosputtering

In this study, nanocrystalline Ni, Ni-TiN, and Ni90Cu10-TiN coatings were processed using reactive magnetron cosputtering of Ni, Cu, and Ti targets under Ar and N2 gas environment. The phase evolution and structure of coatings were analyzed by the X-ray diffraction (XRD) technique. The morphology of the as-prepared nanocomposite films were investigated by high-resolution transmission electron microscopy (HRTEM). The elastic modulus, nanohardness, and scratch resistance of the investigated films were measured using the nanoindentation technique and compared. The results showed that Ni, Ni-TiN and Ni90Cu10-TiN coatings exhibited nanocrystalline structure. The Ni90Cu10-TiN nanocomposite films showed optimum nanohardness and tribological properties due to the additional TiN additives which enhanced the dispersion hardening of the composite matrix significantly.

Impact of Multi-Walled CNT Incorporation on Dielectric Properties of PVDF-BaTiO3 Nanocomposites and Their Energy Harvesting Possibilities

The current study investigated the fabrication of multi-walled carbon nanotubes (MWCNTs) adhering to Barium titanate (BaTiO3) nanoparticles and poly(vinylidene fluoride) (PVDF) nanocomposites, as well as the impact of MWCNT on the PVDF-BaTiO3 matrix in terms of dielectric constant and dielectric loss with a view to develop a high performance piezoelectric energy harvester in future. The capacity and potential of as-prepared nanocomposite films for the fabrication of high-performance flexible piezoelectric nanogenerator (PNG) were also investigated in this work. In particular, five distinct types of nanocomposites and films were synthesized: PB (bare PVDF–BaTiO3), PBC-1 (PVDF–BaTiO3-0.1 wt% CNT), PBC-2 (PVDF–BaTiO3-0.3 wt% CNT), PBC-3 (PVDF–BaTiO3-0.5 wt% CNT), and PBC-4 (PVDF–BaTiO3-1 wt% CNT). The dielectric constant and dielectric loss increased as MWCNT concentration increased. Sample PBC-3 had the optimum dielectric characteristics of all the as-prepared samples, with the maximum output voltage and current of 4.4 V and 0.66 μA, respectively, with an applied force of ~2N. Fine-tuning the BaTiO3 content and thickness of the PNGs is likely to increase the harvester’s performance even more. It is anticipated that the work would make it easier to fabricate high-performance piezoelectric films and would be a suitable choice for creating high-performance PNG.

Integrating waste fish scale-derived gelatin and chitosan into edible nanocomposite film for perishable fruits

Petroleum-based plastics (such as polyethylene, polypropylene, polyvinyl chloride, polystyrene, etc.) as white waste have caused great concern in the environment. It is urgent to develop a kind of biodegradable, biocompatible and non-toxic materials to replace them. Herein, an environmental-friendly edible film for postharvest fruits refreshing application was prepared by combining the waste fish scale-derived gelatin, chitosan as well as CaCO3 nanoparticles. The as-prepared nanocomposite film showed the multifunctional features, such as UV absorption, antimicrobial, oxygen screening, excellent mechanical properties and non-toxic. In addition, the protein-polysaccharide based nanocomposite film was hydrophilic and can be easily washed away on fruits before eating. In order to inspect its preservative effect on fruits, longan and banana were chosen as the testing object. Our results showed that the edible multifunctional nanocomposite film can effectively extend the shelf life of longan by more than 3 days and banana by more than 5 days, compared with the control groups. Integrating natural biological macromolecules gelatin and chitosan into a multifunctional nanocomposite film with series of advantages of biodegradability, sustainability as well as multifunction is expected to be a potential preservative material for food packaging applications.

Novel MAPbBr3 perovskite/ polymer nanocomposites with luminescence and self-healing properties: In suit fabrication and structure characterization

Flexible luminescence materials have recently attracted increasing attention for their applications in the next generation intelligent devices. We developed an in situ fabrication approach to prepare MAPbBr 3 nanocrystals embedded in 2-methoxyethylacrylate (MEA) and N -isopropylacrylamide (NIPAM) copolymers matrix through controlling the crystallization of MAPbBr 3 . The as-prepared nanocomposite films exhibited luminescent self-healing properties. By means of X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), and X-ray absorption fine structure spectroscopy (XAFS), we demonstrated that the copolymer acts as a unique medium to control the growth process of MAPbBr 3 perovskite nanocrystals. It is surface interaction between MAPbBr 3 nanocrystals and copolymer that play a key role in the luminescent and self-healing properties of nanocomposites. These work offers deep insights into the correlation between their structure and properties, which provides a novel approach to design the next generation smart optical materials. • In situ fabrication of MAPbBr 3 /copolymer nanocomposites. • XAFS and FTIR reveal the surface interaction between MAPbBr 3 and copolymer. • Surface interaction are beneficial for the luminescent self-healing nanocomposites.

Constructing robust chain entanglement network, well-defined nanosized crystals and highly aligned graphene oxide nanosheets: Towards strong, ductile and high barrier Poly(lactic acid) nanocomposite films for green packaging

It is a great challenge to develop a feasible strategy for reconciling barrier performance and mechanical ductility of environmentally friendly poly(lactic acid) (PLA) in the application of packaging industry. In the current study, the combination of manipulating the amorphous chain entanglement network of PLA and constructing “dual barrier walls” of highly aligned GONSs and well-defined PLA crystals simultaneously enhanced barrier properties and ductility of PLA nanocomposite films via “biaxial stretching-constrained annealing” method. The intense extensional field during biaxial stretching induced highly aligned GONSs as the first barrier wall and regulated the amorphous chain entanglement network. Constrained annealing promoted the growth and perfection of PLA crystals as the second effective barrier wall and strengthened amorphous chain entanglement network to some extent. More interestingly, GONSs were first verified as contributors to stabilize the enhanced amorphous chain entanglement network of PLA and benefited for the mechanical ductility of PLA nanocomposite films. As a result, this synergetic structure manifested excellent comprehensive ability in ameliorating the intrinsic drawbacks of brittle and poor barrier PLA films, exhibiting low oxygen permeability coefficient of 0.712 × 10−14 cm3 cm cm−2 s−1 Pa−1, excellent ductility with elongation at break of 147.8%, high yield strength of 83.1 MPa and good dimensional stability with deformation ratio of as low as 3%. The as-prepared PLA nanocomposite films with excellent comprehensive properties hold great potential prospects in the application of packaging industry. The methodology proposed here opens up a new avenue to fabricate environmentally friendly PLA films for promoting the sustainable development of packaging industry.

Simultaneous enhancement of breakdown strength and discharged energy efficiency of tri-layered polymer nanocomposite films by incorporating modified graphene oxide nanosheets

Developing high dielectric performance of polymer nanocomposites is still a long-standing issue to simultaneously inherit the high dielectric constant of nanofillers and maintain the high breakdown strength of polymer matrix. In the current study, a tri-layered nanocomposite film is fabricated by a simple and effective solution-casting and dip-coating method, where graphene oxide nanosheets (GONSs) were modified by insulating SiO2 layer (SiO2@GONSs) and polyvinylidene fluoride (PVDF)/SiO2@GONS nanocomposite inner layer was sandwiched by polycarbonate (PC) layers. The surface modification could minimize the local electric field concentration and block conductive path. Furthermore, the sandwich or tri-layered structure inhibited the relaxation and migration of space charge or impurity ions and suppressed the charge injection, thus achieving enhanced breakdown strength and discharged energy efficiency. As a result, the as-prepared tri-layered nanocomposite film exhibited a dielectric constant of 5.2 and a low dielectric loss (tanδ) of 0.013 at 1 kHz, and breakdown strength of 219 MV m−1, which was significantly higher than single-layered nanocomposite films and its counterpart without SiO2 modification. The corresponding discharged energy density was 1.20 J cm−3 with an excellent efficiency of 86.2% at 200 MV m−1. More interestingly, the insulating SiO2 modification layer and PC outer layers could also effectively restrict the relaxation or migration of impurity ions at a high temperature of 120 °C, endowing excellent high-temperature dielectric performance to the as-prepared tri-layered nanocomposite film. The combination of surface modification and sandwich structure opens up an avenue to fabricate GONS-based dielectric nanocomposites with low dielectric loss, high breakdown strength, high efficiency and high temperature tolerance.

Optical characterizations of PMMA/metal oxide nanoparticles thin films: bandgap engineering using a novel derived model

We synthesize and optically characterize pure PMMA and PMMA incorporated with metal oxides nanoparticles (MO NPs) such as ZnO, CuO, TiO2 and SiO2 NPs nanocomposite thin films with weight concentration of 10% using dip-coating technique. SEM images of MO NPs show that all NPs have nearly an average size of around 50 nm. The optical parameters such as, optical parameters (n and k), optoelectronics properties, dispersion, band-gap energy and band structure of as-prepared nanocomposite thin films were determined by analyzing the transmittance and reflectance spectra. Mainly, optical band-gap energy (Eg) and the thickness of thin films are evaluated to a high degree of accuracy by utilizing Q-functional derived using a mathematical model recently published. The Q(E) is a functional containing experimental transmission and reflection data and the incident photon energy. The Eg value of un-doped PMMA thin films is found to be 4.273 eV. This value decreases as pre-selected MO NPs are introduced into thin films. These values are in excellent agreement with those determined using Tauc method. The FTIR technique is employed to elucidate the vibrational bands of the nanocomposites and the intermolecular bonding between PMMA matrix and the MOs NPs. Thermal stability is investigated by employing thermogravimetric analysis (TGA) at temperatures up to 400 °C. The obtained TGA thermograms indicate that adding MOs NPs to PMMA yield thin films of better thermal stability. The obtained doped thin films show a great promise for fabricating high-efficient optoelectronic devices.

Improved mechanical, water vapor barrier and UV-shielding properties of cellulose acetate films with flower-like metal-organic framework nanoparticles

Flower-like metal-organic frameworks (Cu-MOF) nanoparticles are successfully synthesized and incorporated into cellulose acetate (CA) matrix to prepare CA-based functional nanocomposite films via a simple solution-casting method. The effect of the incorporation of flower-like Cu-MOF on the morphological, mechanical, thermal, surface wettability, water vapor barrier, cytotoxicity, photostability and UV-shielding properties of CA films is fully investigated. Results reveal that the flower-like Cu-MOF has good compatibility with CA, providing uniform and compact nanocomposite films. The as-prepared nanocomposite films show improved mechanical properties, surface hydrophobicity, water vapor barrier ability compared to neat CA film, and exhibit super UV-shielding capability through the entire UV regions meanwhile retaining a high visible transparency. Moreover, the high transparency and UV-shielding ability of the nanocomposite films can be still maintained even after continuous UV-light (365 nm) irradiation for 12 h. In addition, MTT cytotoxicity assays towards normal human liver cells (HL-7702) reveal high cell viability (over 80%) and good biocompatibility for the CA/Cu-MOF nanocomposite films. These results indicate that the CA/Cu-MOF nanocomposite films with obviously improved physical and functional performances hold significant potential for transparent packaging and UV-protection applications.

Charge transfer induced excitons and nonlinear optical properties of ZnO/PEDOT:PSS nanocomposite films.

In this current work, we have prepared zinc oxide (ZnO) nanorods by sol-gel method, and its composite films with a conducting polymer poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) also have been prepared by drop-casting method on the glass substrate. UV-Vis absorption and steady-state fluorescence studies revealed exciton dissociation and recombination at the interface of polymer chain and wide-bandgap semiconductor ZnO. Also, nonlinear optical properties of as-prepared nanocomposite films have been reported by employing an open aperture z-scan technique. A predominantly two-photon induced saturable absorption behavior, when excited with 532nm, 10ns laser pulses, appeared in nonlinear optical measurements. These results indicate that our as-synthesized composites can be useful in fabricating optical switch and saturable absorbers.

Preparation of antibacterial film-based biopolymer embedded with vanadium oxide nanoparticles using one-pot laser ablation

An environmentally and cost effective film based on poly(vinyl alcohol)/chitosan (PVA/CS) embedded with vanadium oxide nanoparticles (V2O5 NPs) was fabricated. In our research work, we aimed to utilize one step pulsed laser ablation in liquids (PLAL) pathway for the preparation of V2O5 NPs followed by mixing the prepared nanoparticles with polymer solution prior film formation. The target for using V2O5 NPs is to enhance the antibacterial properties of the produced PVA/CS film. The as-prepared nanocomposite films of PVA/CS/V2O5 NPs were extensively examined in terms of their structural, optical, morphological features and thermogravimetric analysis in order to clarify the effect of the added V2O5 NPs with two different concentrations. The interaction between V2O5 NPs and PVA/CS was confirmed by means of XRD and FTIR-ATR techniques. The data obtained depicted that the number of charges carried in the synthesized nanocomposite film that causing an increase in the density of and thus, yield high refractive index via increasing the concentration of V2O5 NPs and laser ablation time. The findings also illustrated that the antibacterial efficacy of the PVA/CS/V2O5 NPs was increased with increasing V2O5 NPs concentration. Based on the obtained resultant, the doping of V2O5 NPs inside the nanocomposite film played an important role for enhancing the antibacterial activity suggesting the potential use of this nanocomposite film in several antibacterial applications.

Photodeposition of Ag Nanocrystals onto TiO2 Nanotube Platform for Enhanced Water Splitting and Hydrogen Gas Production

Current work reports the study of Ag nanocrystals (NCs) decorated doubly anodized (DA) TiO2 nanotubes (NTs) thin film as an efficient photoelectrode material for water splitting and photocatalytic hydrogen gas production. DA process has been shown to be capable of producing less defective NTs and creating additional spacious gaps in between NT bundles to allow efficient and uniform integration of Ag NCs. By employing photoreduction method, Ag NCs can be deposited directly onto NTs, where the size and density of coverage can be maneuvered by merely varying the concentration of Ag precursors. Field emission scanning electron microscope (FESEM) images show that the Ag NCs with controllable size are homogeneously decorated onto the walls of NTs with random yet uniform distribution. X-ray diffraction (XRD) results confirm the formation of anatase TiO2 NTs and Ag NCs, which can be well indexed to standard patterns. The decoration of metallic Ag NCs onto the surface of NTs demonstrates a significant enhancement in the photoconversion efficiency as compared to that of pristine TiO2 NTs. Additionally, the as-prepared nanocomposite film also shows improved efficiency when used as a photocatalyst platform in the production of hydrogen gas. Such improvement in the performance of water splitting and photocatalytic hydrogen gas production activity can be credited to the surface plasmonic resonance of Ag NCs present on the surface of the NTs, which renders improved light absorption and better charge separation. The current work can serve as a model of study for designing more advanced nanoarchitecture photoelectrode for renewable energy application.

Highly Efficient Three-Dimensional Gas Barrier Network for Biodegradable Nanocomposite Films at Extremely Low Loading Levels of Graphene Oxide Nanosheets

A simple and facile method was proposed to successfully build a three-dimensional (3D) gas barrier network of graphene oxide nanosheets (GONSs) in the biodegradable poly(lactic acid) (PLA) matrix, in which GONSs were first self-assembled on the surface of PLA microspheres and then preferentially distributed at the interface of PLA domains. Polyethylene oxide was introduced as a flow accelerator and interfacial adhesive for favorable interfaces. As a result, the as-prepared PLA nanocomposite films exhibited a significant enhancement in barrier performance with ∼78.6% reduction in the O₂ permeability coefficient at a low GONS loading of 0.0344 vol %. The modified Bharadwaj model by introducing an effective stacking factor indicated an efficient assembly of GONSs in the form of “edge-to-edge” stacking. The new insight into the relationship between the stacking efficiency of nanoplatelets and barrier performance provides a valuable clue in developing high-barrier polymer nanocomposite films.

Cu–Co‐codoped titanate/TiO2nanocomposite thin films for enhanced visible light absorption

Titanate nanotube thin (TNT) films were synthesised by alkaline hydrothermal method using titanium (Ti) plates as precursors. Copper–cobalt (Cu–Co)-codoped titanate/Ti dioxide (TiO2) nanocomposite thin films were prepared by doping Cu and Co to TNT films through ion exchange method and annealed at 500°C for 120 min. The as-prepared nanocomposite films were characterised by scanning electron microscopy, transmission electron microscopy, X-ray diffractometer, and ultraviolet–visible absorption spectra. The results show that anatase TiO2 particles were grown on the surface of titanate nanomaterial films. The composite materials mainly consisted of anatase TiO2 particles and titanate nanotubes/nanosheets. Cu–Co-codoped titanate/TiO2 nanocomposite thin films exhibited superior visible height adsorption property due to the reduced energy bandgap of composites introduced by additional Cu and Co 3d orbitals.

Hydrophobic Graphene Oxide as a Promising Barrier of Water Vapor for Regenerated Cellulose Nanocomposite Films.

Regenerated cellulose (RC) films exhibit poor water barrier performance, which seriously restricts its applications. To address this issue, an impermeable and hydrophobic graphene oxide modified by chemically grafting octadecylamine (GO-ODA) was utilized to enhance the water vapor barrier performance of RC nanocomposite films. Compared to the neat RC film, more than 20% decrease in the coefficient of water vapor permeability (PH2O) was achieved by loading only 2.0 wt % GO-ODA. The promising hydrophobicity of GO-ODA effectively retarded the formation of hydrogen bonding at the relatively weakened interface between GO and RC, compensating for the diffusion of water vapor molecules at the interface; on the other hand, the fully exfoliated GO-ODA nanosheets were inclined to align with the surface of the as-prepared RC nanocomposite films during hot-pressure drying, creating a much more tortuous pathway for diffusion of water molecules. The new insights could be valuable for widening application of cellulose such as packaging.

Bioinspired enhancement of chitosan nanocomposite films via Mg-ACC crystallization, their robust, hydrophobic and biocompatible

Amorphous calcium carbonate/chitosan (ACC/CS) nanocomposite films containing Mg-ACC (0–100 wt%) are prepared by simple natural evaporation-induced assembly. The influence of Mg-ACC content on the mechanical properties as well as cross-section of ACC-CS nanocomposite films were systematically investigated. The nanocomposite films exhibit an excellent mechanical property at Mg-ACC contents of 80 wt% compared to ordinary calcium carbonate/chitosan composites. With content of Mg-ACC increasing, the mechanical properties of ACC-CS nanocomposite films were further increased, reaching a maximum when the content of Mg-ACC to 80 wt%. Strength and Young's modulus of the 80 wt% ACC-CS nanocomposite film reach 121.67 MPa and 31.96 GPa, respectively, which is 2.3 and 5.1 times higher than that of the pure CS film. After undergoing Mg-ACC crystal transformation when the Mg-ACC content is greater than 80 wt%, the smooth structure was transformed into crystal-like agglomerates, which deteriorates mechanical properties. Furthermore, the as-prepared nanocomposite films show excellent hydrophobicity and high biocompatibilities for boosting the growth of Cell-293T. In addition, we also proposed a physical model for the dispersion of Mg-ACC in CS matrix, which could better explain the enhancement of the mechanical properties of nanocomposite films. The above results provide a comprehensive understanding of the development of high-performance bionic nanocomposites loaded with high nanofillers.

Community Refinery Wastewater Photodegradation by Fe-Doped TiO2 Films

Photocatalytic treatment of real community wastewater using Fe-doped TiO2 nanofilm was prepared by modified sol-gel method together with a simple dip-coating technique. The process was investigated in a home-made batch photoreactor. The as-prepared nanocomposite film was characterized by UV-Vis diffuse, XRD, BET, and Fe-SEM analysis. The poultry processing wastewater was collected from Nakhonsawan Municipality. Subsequently, the photocatalytic treatment of the wastewater was performed using a home-made photoreactor operated in batch mode to demonstrate the effects of Fe-dopant concentration with various layer numbers. The catalysts were irradiated using four lamps of 15 W power that emitted visible light and performed at room temperature. The samples were collected every 15 min and analyzed for biochemical oxygen demand (BOD) and chemical oxygen demand (COD) removal efficiency compared to pure TiO2 nanofilm and direct photolysis. From the results, the mixture of rutile and anatase was obtained with the maximum specific surface area of 150.12 mg2/g and the average particle size of 39.95 nm for 3 layers of 0.15% wt/v Fe-doped TiO2. The BOD and COD value at 90 min time treatment was presented to be 8.87 and 32 mg L−1, respectively, in the presence of 0.15% wt/v Fe-doped TiO2 film photocatalysts. Moreover, atomic absorption spectrometric result ensured that no Ti contamination was detected in all parts of plants after watering by the treated water. Hence, the photocatalytic treatment markedly improved the quality of the community wastewater.

Crosslinked PVA/PVP Supported Silver Nanoparticles: A Reusable and Efficient Heterogeneous Catalyst for the 4-Nitrophenol Degradation

Well-organized and stable silver nanoparticles (AgNPs) were successfully prepared within polymeric film of polyvinyl alcohol and Polyvinylpyrrolidone as supporting matrix. The free-standing film was obtained by using the casting technique. Electron microscopy techniques confirmed the formation of spherical AgNPs of 15 nm size. The prepared AgNPs were crystallized in face-centered cubic structure as indicated by X-ray diffraction. The as-prepared nanocomposite film exhibited good catalytic properties in the complete catalytic degradation of 4-nitrophenol using sodium borohydride as a reducing agent. The AgNPs are tightly held within a polymeric matrix which facilitates their recovery and reuse for several cycles.