Properties Of Nanocomposite Films Research Articles

Optimization of optical properties of nanocomposite films incorporating CWO and ITO nanoparticles for energy-saving window applications

Cesium tungsten oxide (CWO) and indium tin oxide (ITO) nanoparticles are potential candidates for application in energy-saving windows. However, most optical studies on these nanocomposite films lack systematic evaluation and design methods. In this work, the optical properties of spherical and cylindrical CWO and ITO nanoparticles under different geometric parameters based on the Lorenz–Mie and T-matrix theories are investigated, and spectral responses of CWO-PDMS and ITO-PDMS windows are calculated by solving the radiative transfer equation (RTE) using the Monte Carlo method. By evaluating and optimizing the geometric parameters of the nanocomposite films, energy-saving windows exhibit excellent optical performance, with a visible light transmittance that meets the indoor needs of the human eye (Tlum is about 0.6), and can shield most near-infrared light, especially CWO-PDMS windows (TNIR=0.04). Finally, a building energy consumption simulation analysis based on Energy Plus is conducted in three different cities: Jinan, Hong Kong, and Singapore. The results indicate that by adjusting the geometric parameters of nanoparticles, energy-saving windows can effectively reduce energy consumption in tropical and subtropical regions. This work provides guidance for the subsequent commercialization and experimental analysis of spectral selective composite films.

Enhancing PBAT nanocomposite films: The impact of AgVO3 nanorods on mechanical, hydrophobicity, and antibacterial properties

AbstractPoly(butylene adipate‐co‐terephthalate) (PBAT) is popular because of its low cost, biodegradability, good processing properties, flexibility, and mechanical features. In this study, we explore the potential of PBAT‐based bioplastics by adding AgVO3 nanorods with PBAT to reduce costs. We produced nanocomposite films of PBAT reinforced with 1, 3, and 5 wt% of AgVO3 nanorods using solvent casting. The inclusion of AgVO3 in the structure of PBAT was investigated through Fourier transform infrared spectroscopy, x‐ray diffraction, and scanning electron microscopy. The nanocomposite films demonstrate excellent properties, surpassing those of single‐component blends, enhancing mechanical properties, and improving the barrier properties of nanocomposite films. The water vapor transmission rate of AgVO3 reinforced (5 wt%) nanocomposite films improved by 42.45% compared to pure PBAT films. The tensile strength of the PBA‐3 film was 37.19 MPa, exhibiting higher strength than the films produced from clean PBAT (19.73 MPa). The AgVO3‐reinforced films demonstrated increased resistance to moisture and water, as indicated by their higher water contact angle values (88.04°). Food‐borne bacteria like Staphylococcus aureus and Escherichia coli have been stable to the antibacterial activity of the nanocomposites on the addition of AgVO3.The potential applications of these nanocomposite films in food packaging are promising, offering a sustainable and effective solution to food preservation.Highlights The AgVO3‐filled poly(butylene adipate‐co‐terephthalate) (PBAT) nanocomposite films exhibit superior mechanical, barrier, and resistance to moisture and water compared to neat PBAT films. The water vapor transmission rate of the film is significantly enhanced, with a 42.45% enhancement in films reinforced with 5 wt% AgVO3. AgVO3‐filled PBAT nanocomposites demonstrate effective antibacterial activity against Escherichia coli and Staphylococcus aureus.

Investigating the morphological, mechanical, barrier, and antibacterial properties of the polycaprolactone nanocomposite films reinforced with hybrid zinc oxide/polyhedral oligomeric silsesquioxane nanoparticles

ABSTRACT The importance of biopolymer-based nanocomposites in food packaging is growing significantly. Therefore, in the present study, we aim to examine the impact of zinc oxide (ZnO), polyhedral oligomeric silsesquioxanes (POSS), and, for the first time, their hybrid on polycaprolactone (PCL) nanocomposites. For this matter, different concentrations of 1, 3, and 5 wt% of each nanoparticle and the hybrid were incorporated into the PCL nanocomposites via the solution casting method. Their chemical structures and interactions, crystalline structures, and morphology were investigated by FT-IR, WAXD, and SEM. Moreover, it was observed through contact angle and surface free energy experiments that an increase in the nanoparticle concentration corresponded to an increase in the contact angle values. The incorporation of hybrid POSS and ZnO equilibrated well between Young’s modulus, tensile strength, and elongation of the samples in their single status. Accordingly, the addition of the hybrid nanoparticles up to 3 wt% significantly increased the modulus and yield strength of PCL nanocomposites without any significant sacrifice in toughness. Also, PPZ3 (containing an optimal 3%wt. of hybrid nanoparticles) demonstrated the lowest permeability against both water vapor and O2 gas, exhibiting reductions of approximately 30 and 55% when compared to pristine PCL. Finally, the antibacterial properties of the nanocomposite films were investigated for S. aureus and E. coli bacteria and revealed. In addition to the antibacterial properties of ZnO and POSS nanoparticles, increasing the concentration of hybrid nanoparticles up to 5 wt% expanded S. aureus’s inhibitory zone. The balanced mechanical, and barrier characteristics, enhanced morphologies, and antibacterial effects of the novel hybrid nanocomposites present novel opportunities in the field of food packaging.

Preparation of Poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide)/Zinc Oxide Nanocomposite Bioplastics for Potential Use as Flexible and Antibacterial Food Packaging.

High-molecular-weight poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-PEG-PLLA) is a flexible and biodegradable bioplastic that has promising potential in flexible food packaging but it has no antibacterial ability. Thus, in this work, the effect of zinc oxide nanoparticles (nano-ZnOs) which have antimicrobial activity on various properties of PLLA-PEG-PLLA was determined. The addition of nano-ZnOs enhanced the crystallization, tensile, UV-barrier, and antibacterial properties of PLLA-PEG-PLLA. However, the crystallization and tensile properties of nanocomposite films decreased again as the nano-ZnO increased beyond 2 wt%. The nano-ZnO was well distributed in the PLLA-PEG-PLLA matrix when the nano-ZnO content did not exceed 2 wt% and exhibited some nano-ZnO agglomerates when the nano-ZnO content was higher than 2 wt%. The thermal stability and moisture uptake of the PLLA-PEG-PLLA matrix decreased and the film's opacity increased as the nano-ZnO content increased. The PLLA-PEG-PLLA/ZnO nanocomposite films showed good antibacterial activity against bacteria such as Escherichia coli and Staphylococcus aureus. It can be concluded that nano-ZnOs can be used as a multi-functional filler of the flexible PLLA-PEG-PLLA. As a result, the addition of nano-ZnOs as a nucleating, reinforcing, UV-screening, and antibacterial agent in the flexible PLLA-PEG-PLLA matrix may provide protection for both the food and the packaging during transportation and storage.

Enhanced optical, dielectric, and mechanical properties of starch-based nanocomposite films reinforced with layered double hydroxide

In this study, we present the optical, electrical, dielectric, and mechanical properties of nanocomposite films containing different inorganic filler content. Starch is used as the biopolymer while the carbonate intercalated Mg-Al layered double hydroxide (LDH) is used as the inorganic filler. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDS) are used to characterize and evaluate the dispersion of LDH in the biopolymer matrix. Increasing the filler content was found to improve the optical properties by increasing the light absorption coefficients, reducing the optical gap energy and increasing the refractive index. Improved dielectric properties were demonstrated by the significant decrease in the dielectric energy dissipation with increasing filler content. In addition, mechanical properties were enhanced by increasing the Young’s modulus when the filler content reached 5 wt %.

Investigation on structural, optical, thermal, and dielectric properties of nanocomposite films based on chitosan containing vanadium pentoxide/zinc oxide and their potential for optoelectronics devices

Chitosan (Cs), zinc oxide (ZnO), and vanadium pentoxide (V2O5) nanoparticles (NPs) have been used to create ternary nanocomposite materials to improve their optical and electrical characterization. Physical methods have been used to investigate the effects of varying vanadium pentoxide nanoparticle contents on the optical and electrical characterization of the prepared films. In XRD results obtained, the characteristic peaks of pure chitosan are seen to be broken and vanished (especially at 15 wt.% V2O5 NPs). This means that when chitosan is filled with different concentrations of V2O5 nanoparticles, chitosan is very weak and simply broken, and only characteristic peaks of V2O5 appear. The average crystal size of V2O5 has been determined to be 25.4 nm. FTIR spectra approve the strong complexation between the nanoparticles and hydrogen bonds in the composite. The study suggests that the addition of zinc and vanadium nanoparticles to chitosan-based films can improve their thermal stability, which has potential applications in various industries, including packaging, biomedical, and environmental. Electrical studies indicate that as the content of embedded zinc/vanadium-filled-in chitosan rises, the ε′ value decreases. The observed decrease in the insulating behavior of chitosan aligns with the notion that doping reduces its insulating properties. This aligns with the enhanced electrical conductivity evident from the DC conductivity measurements. The study demonstrates that incorporating zinc oxide (ZnO) and vanadium pentoxide nanoparticles effectively influences the dielectric properties and relaxation behavior of chitosan. The given results suggest Ternary nano-composite chitosan-ZnO/V2O5 films for specific requirements in optical, optoelectronic applications.

Mechanical properties, sustained release, and oxygen scavenging properties of nanocomposite films loaded with bimetallic nanoparticles (Fe2O3/TiO2) in extra virgin olive oil.

The aim of this study was the synthesis of bimetallic nanoparticles based on Fe2O3/TiO2 and its use in the poly(lactic acid) (PLA) films as an oxygen scavenger in extra virgin olive oil (EVOO) packaging. Bimetallic nanocomposites were prepared by two different precipitation methods (precipitation with ammonia and sodium hydroxide). The characteristics of bimetallic nanoparticles precipitated with sodium hydroxide (Na-Ti0.01Fe0.048O0.08) and bimetallic nanoparticles precipitated with ammonia (NH-Ti0.01Fe0.022O0.09) were compared. Relative amounts of elements in bimetallic nanocomposites and their morphological characteristics were determined using field emission scanning electron microscopy coupled with energy-dispersive X-ray spectrometer. Porosity volume and surface area of bimetallic nanoparticles were calculated using adsorption-desorption isotherms and the Brunauer-Emmett-Teller method. The formation/characterization of bimetallic nanoparticles and their location in the matrix of PLA-based nanocomposite film was studied using X-ray diffraction and Fourier transform infrared. In nanocomposite films based on PLA, bimetallic nanoparticles lead to better oxidative stability (peroxide value, p-anisidine index, K232, and K270) of the EVOO and oxygen scavenging during storage compared to free nanoparticles. Mechanical properties of nanocomposite films were improved due to bimetallic nanoparticles, which were better for Na-Ti0.01Fe0.048O0.08. In vitro release modeling of the bimetallic nanoparticles in EVOO proved that Fickian diffusion is the dominant mechanism, and the Peleg model was the best description of the release behavior of nanoparticles.

Biphasic nanocomposite films of polypyrrole and poly(3,4-ethylene dioxythiophene) using a surface-tethered dopant strategy

Using a newly invented surface-tethered dopant approach for the electrochemical polymerization growth of conductive polymer films, nanocomposites are created consisting of two distinct phases of polypyrrole (PPy) and Poly(3,4-ethylene dioxythiophene) (PEDOT). The growth of the conductive nanocomposite films takes advantage of the unique way in which a conductive polymer film forms when grown using a surface-tethered dopant, starting out as a highly nanoporous film that gradually becomes more and more solid as additional polymer deposition occurs preferentially within the nanopores rather than at the films outer surface. Nanocomposite films can thus be fabricated simply and controllably by first growing one nanoporous conductive polymer film followed by the deposition of a second conductive polymer within the nanopores of the first. This study investigates the morphological and electrochemical properties of nanocomposite films grown using a surface-tethered dopant and how these properties are affected by simple changes in electrochemical polymerization parameters.

Synthesis of cobalt nanoparticles in polystyrene matrix enhanced optical, dielectric, and magnetic properties

Recently, the development of particles fortified polymer composites has grown significantlydue to their intelligent uses in many fields.Cobalt nanoparticles' impact on the dielectric, optical, and magnetic properties of cobalt/polystyrene (Co/PS) nanocomposite films has been investigated. Co-NPs were preparedusing the reduction method and loadedintothepolystyrenematrixwith different concentrations(2, 5, 8, and 10 wt.%),forming nanocompositefilms. X-ray diffraction XRD was used to describe the structure of the produced films. The results showed a hexagonal (hcp) structure with ε phase of the Co-NPs in the PS matrix. The topography of the cross-section of nanocomposite films was scanned through a field emission electron microscope (FE-SEM). The high-resolution transmission electron microscope (HR-TEM) was used to examine the morphology of the produced Co-NPs. Zetasizer considered the charge and particle size distribution of the prepared Co-NPs powder. At room temperature, dielectric spectroscopy looked at the dielectric characteristics over a frequency range from 10−1 - 107 Hz. The UV analyzed the optical properties of nanocomposite films–VIS technique. The optical bandgap of the nanocomposite films is a direct allowed transition and decreases from 4.51 to 3.69e, which increases the absorption coefficient. A vibrating sample magnetometer (VSM) was used to measure the magnetic hysteresis loops of the produced films at room temperature. The ferromagnetic behavior of all samples was evident, and there was an apparent magnetic hysteresis. All samples exhibited high coercivity, where the exchange bias decreased from 28.02 Oe to 1.42 Oe with increasing Co wt% in PS. The present work found that the Co/PS nanocomposite films loaded with various concentrations of Co-NPs and tuned properties may be suitable for use in electrical energy storage, photonic devices, and some magnetic applications, such as spintronic devices.

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.

Role of nano SiC in enhancement of mechanical, barrier, and flame-retardant properties of PANI-co-PAA films

ABSTRACT Herein, polyaniline-copolyacryclicacid(PANI-co-PAA) nanocomposite films are prepared via in situ polymerization technique with dispersion of functionalized-nano silicon carbide(f-SiC). The morphological analysis evidences reduction in voids due to the presence of SiC Nps. PANI-co-PAA/f-SiC films show significant improvement in thermal stability, chemical resistance, and flame retardancy by increasing the concentration of nanofiller. The oxygen barrier properties of nanocomposite films increase sevenfolds, compared to PANI-co-PAA matrix. The films show considerable biodegradation in sludge water treatment which diminishes with increase in concentration of nano SiC. The mechanical, thermal, gas barrier, flame retardancy, chemical-resistant, and biodegradation properties render the PANI-co-PAA/f-SiC films effective for packaging applications.

Enhancing saturable absorption in a Au-decorated MoS2/PEDOT:PSS nanocomposite through plasmon resonance and Pauli blocking.

We have effectively demonstrated a technique for substantial alteration of the nonlinear saturable absorption (SA) properties in nanocomposite films (NCF) composed of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT:PSS) and molybdenum disulfide (MoS2) decorated with gold nanoparticles (AuNPs). This control is achieved by adjusting the AuNP concentration on the MoS2 surface and varying the input pulse energy of the laser. The simple drop-casting method is used to create the nanocomposite films (NCFs) on a glass substrate with different amounts of Au-decorated MoS2. The Kramers-Kronig equations are employed for determining the refractive index and extinction coefficient values of the resulting NCFs. Nonlinear investigations reveal that adding Au-decorated MoS2 to pure PEDOT:PSS alters its optical nonlinearity. Surface plasmon resonance and Pauli blocking have been observed in Au-decorated MoS2/PEDOT:PSS NCFs. This increases NCF's saturable absorption. An open aperture Z-scan method is utilized to study nonlinear optics, with excitation achieved using a nanosecond (ns) pulsed laser operating at a 532 nm wavelength. The findings reveal the noteworthy saturable absorption characteristics of the NCFs.

Co-encapsulation of anthocyanin and cinnamaldehyde in nanoparticle-filled carrageenan films: Fabrication, characterization, and active packaging applications

Nanoparticle-filled films were fabricated as smart and active packaging materials to monitor and preserve the freshness of foods (fish). Antisolvent precipitation was used to produce zein nanoparticles containing anthocyanin in their hydrophobic cores and cinnamaldehyde on their surfaces. These nanoparticles were then coated with a layer of carrageenan, resulting in the formation of anthocyanin-zein-cinnamaldehyde-carrageenan (AZCC) composite nanoparticles. Dynamic light scattering, electrophoresis, infrared spectroscopy, and scanning electron microscopy were used to characterize the properties of these composite nanoparticles. The particles formed were spherical and had relatively small diameters (563 nm) and high negative charges (−24.6 mV). The particles were mainly held together by hydrophobic, hydrogen bonding, and electrostatic interactions. The impact of nanoparticle concentration on the physical, structural, and functional properties of nano-composite films was investigated. Increasing the nanoparticle concentration led to changes in the opacity (17.42 A mm−1), microstructure, thermal stability (65.3%), and antioxidant activity of the films, as evaluated through DPPH (48.39%) and ABTS (92.77%) assays. The changes in color (SLab: 16.98%–85.98%) of the nanoparticle-loaded films was sensitive to pH and ammonia content, which meant that they could be used as quality sensors. The release of anthocyanins from the films depended on the polarity of the model food they were in contact with. Optimized films significantly extended the freshness of Mandarin fish, resulting in a 13.3% reduction in total volatile base-nitrogen levels, which highlights their potential for monitoring and controlling the freshness of packaged foods.

Role of Pauli blocking for enhancement of saturable absorption in MoS2/PEDOT:PSS nanocomposite films

We have effectively shown a technique for significantly altering the nonlinear saturable absorption (SA) properties of nanocomposite films (NCFs) based on poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT:PSS) and molybdenum disulfide (MoS2) by regulating MoS2 concentration and input pulse energy of the laser. The NCFs are made using the straightforward drop-cast process on a glass substrate with varying quantities of MoS2. The produced NCFs’ refractive index (n) and extinction coefficient (k) values are determined using the Kramers–Kronig equations. Nonlinear studies show that the optical nonlinearity of pure PEDOT:PSS changes when mixed with MoS2. The Pauli blocking has been observed in MoS2/PEDOT:PSS NCFs. This leads to enhanced SA in NCF. The open-aperture Z-scan approach is used for the nonlinear optical research, and a nanosecond pulsed laser with a wavelength of 532 nm is used for the excitation. The findings obtained show the NCFs’ strong SA qualities.

A novel green synthesis approach for shape memory polymer nanocomposites decorated with silver nanoparticles

AbstractA new, low‐cost, and direct green synthesis strategy was developed for the preparation of polymer composites composed of silver nanoparticles (AgNPs) decorated on a shape memory polymer blend using Rubus caesius L. leaves. X‐ray powder diffraction, ultraviolet‐visible spectroscopy (UV–vis), scanning electron microscopy, and energy dispersive X‐ray spectroscopy (EDS) elemental composition were applied to characterize the crystal size, morphology, and elemental composition of Ag‐NPs. UV–vis spectra detected the characteristic absorbance signal of AgNPs at about 430 nm, and the average crystal size of nanoparticles was calculated as about 12.60 nm. When nanocomposite films were characterized by attenuated total reflectance infrared spectroscopy, characteristic polylactic acid, and poly ethylene glycol (PEG) signals were determined. From the thermogravimetric analysis curves, it was determined that the amount of residue of nanocomposites increased as the amount of AgNP increased. It was seen that AgNPs did not affect the Tg temperature of the nanocomposite films, while it was also a proof that the polymer blend was immiscible. It was observed that the shape recovery properties of nanocomposite films were better with increasing AgNPs content. Finally, both green synthesized AgNPs and nanocomposites prepared with shape memory polymers showed very good antibacterial activity against Gram‐positive and Gram‐negative bacteria.Highlights Green synthesis of silver nanoparticles (AgNPs) was carried out with Rubus caesius L. leaves. The synthesized AgNPs were characterized by ultraviolet visible spectroscopy and x‐ray powder diffraction. Composite films were prepared with poly lactic acid/poly ɛ‐caprolactone blend by solvent casting method. The amount of residue of nanocomposites increased with increasing AgNPs percentage. The nanocomposite film containing 10% AgNPs has good activity.

Enhancement of the mechanical properties and water barrier properties of thermoplastic starch nanocomposite films by chitin nanofibers: Biodegradable coating for extending banana shelf life

Starch-based films have limited applications due to their hydrophilicity and poor mechanical performance. Herein, thermoplastic starch (TPS) nanocomposite films with chitin nanofibers (ChNFs) extracted from shrimp-shell waste were successfully fabricated using a solvent casting method. We investigated the effects of the ChNF loadings on the physical, mechanical, and water vapor barrier properties of the nanocomposite films. The well-dispersed ChNFs within the soft matrix associated with the formation of interfacial bonding between ChNFs and starch facilitated the efficient stress transfer from the soft matrix to the stiff ChNFs. Additionally, the presence of ChNFs created tortuous pathways within the films, which could impede the diffusion of water molecules. This resulted in a significant improvement in the mechanical properties, wettability, water resistance, and water vapor barrier properties of the nanocomposites. Compared to the results obtained from the neat TPS films, the TPS nanocomposites reinforced with ChNFs exhibited a 300% higher tensile stress, a 603% Young's modulus, and a considerable increase in the water contact angle, shifting from 86.2° to 98.6°. Furthermore, the ChNF-reinforced nanocomposite films showed no fragmentation after being soaked in water for 12 h under vigorous stirring, whereas the neat TPS films disintegrated under the same conditions. Interestingly, we found that coating a suspension of TPS and ChNFs on bananas effectively delayed their aging, preventing the color change from green to yellow. This promising result demonstrates the potential of the developed coating to extend the shelf life of fresh food produce, reducing food waste and the reliance on single-use petroleum-based packaging.

EFFECT OF NANOCELLULOSE TYPE AND MATRIX MATERIAL ON PRODUCTION OF NANOCOMPOSITE FILMS

The objective of this study has been to investigate the chemical structure, thermal and mechanical properties of nanocomposite films, which were produced by combining cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs) with different ratios of boric acid (BA) and polyvinyl alcohol (PVA) as a matrix. Nanocomposites reinforced with BA had B–O–B, and B–O–C ether bonds, while the addition of PVA did not influence the chemical bonds of the films. Furthermore, the addition of BA to CNF and CNC films enhanced the thermal resistance of the films at high temperatures, but the addition of PVA declined the thermal properties of these films. Considering the mechanical properties of nanocomposite films, it was determined that adding PVA to CNF and CNC films had a positive impact, unlike BA. Consequently, it was concluded that each BA and PVA have their advantages and can be preferred for specific industrial applications.

Tuning the stoichiometry of the pulsed laser deposited composite films

Graphene-based composite thin films were deposited on glass substrates using a laser-based approach, anointed Pulsed Laser Deposition (PLD), at room temperature. To eliminate some technical fabricating hurdles, we studied the annealing temperature effects on the chemical properties of nanocomposite films and their photocatalytic activity. Results indicate that the stoichiometry of the composite films and their optical characteristics can be adjusted accurately through an optimized annealing temperature. We thoroughly investigated the characteristics of the layers using various analyses, x-ray diffraction analysis, scanning electron microscopy, energy dispersive x-ray spectroscopy, and optical spectroscopies. We analyzed the film's functional groups and their alterations under different annealing temperatures using confocal Raman spectroscopy. Raman's results affirm the formation of a composite film with combined features of both precursors (ZnO and GQDs) at 300°C. We recorded a high degradation percentage of 84% for the sample to show a high photocatalytic ability to degrade dyes for optimized nanocomposite film. Under visible light irradiation, all ZnO-GQDs composite thin films showed a higher photocatalytic degradation of Rhodamine 6 G than pristine ZnO. We found dye degradation to be of the first order, following the Langmuir-Hinshelwood mechanism.

Effect of cellulose nanocrystals and green synthesized silver nanoparticles on mechanical properties and antimicrobial activity of banana flour/agar composite films

This study characterized the physicochemical and functional properties of nanocomposite films synthesized by incorporating cotton linter cellulose nanocrystals (CN) and green silver nanoparticles (AgNPs) into banana flour/agar. The results showed that CN could not enhance the tensile strength of the B/A nanocomposite films, but it did prolong the antibacterial activity against the Gram-positive bacterium Listeria monocytogenes when combined with AgNPs. However, the binary blend of CN and AgNPs resulted in a flocculated morphology on the film surface, causing an increase in the film brittleness and a decrease in the water solubility, elongation, and final decomposition temperature. Unfortunately, none of the nanocomposite films were found to inhibit the growth of the Gram-negative species Escherichia coli within 12 h. Further research is needed to assess the migration release of CN/AgNPs in nanocomposite films and to determine their potential for use as active food packaging.

Dielectric Properties of (GO-MgO-PoPDA- PVA) nanocomposite films

In this work, a pure (PVA) polymer film reinforced with magnesium oxide, graphene oxide poly (o-phenylene diamine) (GO-MgO-PoPDA) was created utilizing the solution casting process in various weight ratios (0, 2, 4, 6, 8, 10 wt%). It was investigated how varied weight ratios of the nanoparticles magnesium oxide (MgO) and graphene oxide (GO) affected the Dielectric Properties of nano composite films. FTIR, SEM,X-RAY were used to characterized the nanocomposite. The results of the dielectric properties showed that the values of the alternating electrical conductivity of the prepared films increase when adding (GO-MgO-PoPDA) nanoparticles and with the increase of the frequency of the applied electric field and the increase of the particle content, while the values of the dielectric constant increase with the increase of each of the content of (GO-MgO- PoPDA) nanoparticles, but it decreases with increasing frequency. Whereas, the dielectric loss coefficient of the prepared films decreases when nanoparticles are added and with increasing frequency.