Alcohol Composite Films Research Articles

Preparation and properties of calcium oxide and calcium peroxide from eggshell waste for enhanced antimicrobial activity

Calcium peroxide (CaO2), which releases hydrogen peroxide (H2O2) upon contact with water, has garnered attention as a potential alternative to liquid H2O2. Researchers have explored various methods to enhance the production of CaO2 with reduced environmental impact. This study focuses on the preparation of two potent antimicrobial agents, calcined calcium oxide (C-CaO) and synthesized calcium peroxide (S-CaO2) from eggshell waste. These agents were then incorporated into ethylene vinyl alcohol (EVOH) composite films for antimicrobial packaging. The synthesized CaO and CaO2 were analyzed using Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA) and Scanning electron microscopy (SEM). The results confirmed the successful synthesis of high-purity CaO and CaO2 from eggshell waste. Compared to CaO (a well-known antimicrobial agent), CaO2 exhibited approximately 1.6 to 2 times higher antimicrobial activity, which is attributed to its release of H2O2. EVOH films containing 3% of CaO2 demonstrated significant microbial growth deactivation, reaching 99.99% and 97.24% for gram-negative and gram-positive bacteria, while EVOH films containing 3% of CaO exhibited relatively low deactivation ability of 79.01% and 48.82, respectively. This study underscores the potential of eggshell waste as a valuable resource for producing high-value materials. Moreover, CaO2 emerges as an effective antimicrobial agent, particularly in antimicrobial packaging applications, showcasing its versatility across various sectors.

Triboelectric Nanogenerator Based on Tin Doped Zinc Oxide and Polyvinyl Alcohol Composite Thin Film for Energy Harvesting Applications

The triboelectric nanogenerator (TENG) collects mechanical energy from its surroundings and converts it to electrical signals that can be used in sustainable energy harvesting technologies to help maintain the social ecosystem. However, TENG operation with pure triboelectric material may not be sufficient to power a small electronic system without modification. The optimal material capable of producing significant electrical energy with flexible structures remains a major barrier to practical application. In this study, tin-doped zinc oxide (Sn:ZnO) and polyvinyl alcohol (PVA) composite thin films were prepared using a simple solution immersion technique at various Sn atomic percentage (at.%) concentrations for use in TENG devices. The crystalline quality of a composite thin film made of Sn:ZnO and PVA was identified using x-ray diffraction. The microstructure changes of the composite thin film were found to be influenced by Sn doping, as studied using optical microscopy. The TENG with 2.5 at.% Sn:ZnO/PVA composite thin film and Kapton film achieved the highest peak voltage of 8.5 V in open circuit and 90 µW output power at 1 MΩ. The produced electrical output was then used to store energy in capacitors. According to its TENG properties, the Sn:ZnO/PVA composite thin film-based TENG has the potential to be used in low power electronic devices.

The effect of NaY‐zeolite on mechanical, thermal, and spectroscopic behavior of crosslinked polyvinyl alcohol films

AbstractThe effects of sodium y zeolite (NaY‐zeolite) on crosslinked Polyvinyl alcohol (CrPVA) composite films were investigated. The spectroscopic analysis showed that crosslinks were formed between PVA, Tartaric acid (TA), and NaY‐zeolite particles. The thermal stability of the CrPVA film was improved with the addition of zeolite. Optimum thermal stability was observed for 5 wt % zeolite content. It can be seen that the mechanical properties also improved for 5 wt % zeolite‐doped CrPVA composite films when compared with CrPVA. It was observed that Young's modulus increased 54.14 to 74.49 MPa. While the degree of crystallinity of the composite film decreased from 20.42 to 14.77% due to zeolite content. This is thought to be due to the increase in the structure's crosslinking rate. The utilization of TA and NaY zeolite in membrane applications may be considered an advantage for improving the mechanical characteristics and the recyclability of membrane technology.

Sustainable solution for wastewater management: Fabrication of cost-effective β-cyclodextrin incorporated chitosan polyvinyl alcohol composite hydrogel film for the efficient adsorption of anionic congo red and tartrazine dyes

Dyes are an integral part of leather, textiles, food, and packaging materials, providing aesthetic appeal to the finished article. These industries use large amounts of water, creating wastewater with harmful, toxic, and hazardous pollutants, posing significant health and environmental risks to the public and ecological system. Therefore, to resolve this issue, a superabsorbent β-cyclodextrin incorporated chitosan polyvinyl alcohol cross-linked with citric acid composite hydrogel film (β-CD/Ch/PVA) has been developed for the effective adsorption of congo red (CR) and tartrazine dyes (TG). The Fourier-transform infrared spectroscopic (FTIR) analysis confirmed the presence of –OH, –NH2 functional groups in hydrogel film. The rough surface morphology was obtained through Field emission scanning electron microscopic (FESEM) analysis. Brunauer-Emmett-Teller (BET) method gave the surface area of hydrogel, which is 17.34 m2/g with pore diameter of 4.12 nm, indicating its mesoporous nature. Adsorption parameters like contact time, temperature, pH, initial concentration of dyes, and dosage of hydrogel have been optimized by batch adsorption studies and the Box-Behknen Design Model. In batch experiments, the hydrogel film effectiveness was confirmed, achieving high removal efficiencies of 95.38 % and 96.3 % for CR and TG dyes at pH 7 and 6, respectively. The adsorption process followed the pseudo-second-order kinetics and Langmuir model at room temperature for both dyes, and the maximum adsorption capacity was found to be 366.34 mg/g, 1436.04 mg/g for CR and TG dyes, respectively. The thermodynamic study revealed that the adsorption of dyes was spontaneous and endothermic in nature. The electrostatic interactions and hydrogen bonding between the hydrogel and dye molecules were responsible for the adsorption. This hydrogel film can be reused for 5 consecutive adsorption–desorption cycles for both dyes, maintaining upto 85 % in removal efficiency. Hence, the synthesized β-cyclodextrin incorporated chitosan polyvinyl alcohol composite hydrogel film holds great potential for the remediation of wastewater effluents and addressing environmental issues.

Green Extraction of Reed Lignin: The Effect of the Deep Eutectic Solvent Composition on the UV-Shielding and Antioxidant Properties of Lignin.

Lignin, the second most abundant natural polymer, is a by-product of the biorefinery and pulp and paper industries. This study was undertaken to evaluate the properties and estimate the prospects of using lignin as a by-product of the pretreatment of common reed straw (Phragmites australis) with deep eutectic solvents (DESs) of various compositions: choline chloride/oxalic acid (ChCl/OA), choline chloride/lactic acid (ChCl/LA), and choline chloride/monoethanol amine (ChCl/EA). The lignin samples, hereinafter referred to as Lig-OA, Lig-LA, and Lig-EA, were obtained as by-products after optimizing the conditions of reed straw pretreatment with DESs in order to improve the efficiency of subsequent enzymatic hydrolysis. The lignin was studied using gel penetration chromatography, UV-vis, ATR-FTIR, and 1H and 13C NMR spectroscopy; its antioxidant activity was assessed, and the UV-shielding properties of lignin/polyvinyl alcohol composite films were estimated. The DES composition had a significant impact on the structure and properties of the extracted lignin. The lignin's ability to scavenge ABTS+• and DPPH• radicals, as well as the efficiency of UV radiation shielding, decreased as follows: Lig-OA > Lig-LA > Lig-EA. The PVA/Lig-OA and PVA/Lig-LA films with a lignin content of 4% of the weight of PVA block UV radiation in the UVA range by 96% and 87%, respectively, and completely block UV radiation in the UVB range.

Structural, optical, and electrical characteristics of HPMC/PVA-I2O5 composites: Fabrication and performance analysis for energy storage applications

Polymer composites (PCs) are increasingly utilized in energy storage applications, notably in dielectric capacitors, due to their distinct properties and advantages over conventional liquid electrolytes. In this study, we investigate the structural, optical, electrical, and dielectric properties of hydroxypropyl methylcellulose (HPMC)/polyvinyl alcohol (PVA) composite films filled with varying concentrations of iodine pentoxide (I2O5), prepared via a solution casting method. Incorporating I2O5 into the polymer matrix significantly impacted the composite's properties. FTIR and XRD analyses revealed disturbances in molecular structure, crystallization order, and the presence of I2O5 crystal phases in the composite films. Calculations of crystallinity percentage indicated a reduction with I2O5 addition, leading to increased amorphous phase content suitable for enhancing electrical conductivity (σ). UV/vis spectroscopy studies demonstrated decreased optical energy gaps, suggesting improved charge storage capability. The σ analysis revealed enhanced values with I2O5 addition, indicative of improved charge mobility within the composite films. Frequency-dependent behaviors in complex permittivity (ε′ and ε″) highlighted the potential of these composites for efficient charge storage across different frequency ranges. Impedance analysis provided insights into space charges and conductive paths within the composites, influencing their electrical characteristics. Capacitors fabricated from the HPMC/PVA-I2O5 composites exhibited enhanced energy storage capacity and controlled conductance characteristics, demonstrating promising performance for energy storage applications. Our findings demonstrate that the HPMC/PVA-I2O5 composites are potential dielectric materials for capacitor technology.

Characteristics of corn starch/polyvinyl alcohol composite film with improved flexibility and UV shielding ability by novel approach combining chemical cross-linking and physical blending

With the aim of effectively improving the performance of bio-friendly food packaging and circumventing the hazards associated with petroleum-based plastic food packaging, composite films of corn starch and polyvinyl alcohol were prepared using a new method that involved chemical cross-linking of glutaraldehyde and blending with cinnamon essential oil nanoemulsion (CNE). Glutaraldehyde and CNE enhance the film's network structure by chemical bonding and hydrogen bonding, respectively. This results in improved surface smoothness, mechanical properties, and UV shielding ability of the film. However, the films' surface hydrophilicity increased as a result of CNE, which is harmful for food preservation in high humidity. Overall, glutaraldehyde and CNE have a synergistic effect on some of the properties of the film which is mainly attributed to the films' structure improvement. The films have great potential for preparing flexible and UV-shielding films and offer new ideas for developing biodegradable films.

Cation-Modified Poly(vinyl alcohol) Film to Optimize the Bistability of Transparent Electrophoretic Display Based on Charge Adsorption Behavior in Nonpolar Solvent.

Electrophoretic displays (EPDs) utilize the electrophoretic particles in electronic ink (e-ink) to display different color states with bistability. Bistability of EPDs is achieved by placing colloidal particles in a highly viscous solvent to keep the distribution of colloidal particles stable without sustaining the external field, so it only consumes power when updating the image. The feature of low power consumption makes it suitable for applications such as advertising boards, price tags, etc. Apart from these applications, recent research on lateral-driving EPDs extends its applications to smart windows, privacy control, and so on. However, achieving bistability by simply increasing the viscosity of solvent is inefficient in the case of lateral driving operation. Therefore, it is deserving to have intensive study on the mechanism of bistability from other aspects. Herein, we propose a mechanism to investigate the charge adsorption behavior on the electrode to affect the bistability of particles, which is based on the "Stern layer adsorption/desorption" model. Based on the above mechanism, we further fabricated a hexadecyl trimethylammonium bromide (CTAB)/poly(vinyl alcohol) (PVA) composite film on the electrode to improve the bistability of lateral-driving EPD by reducing the diffusion current caused by unabsorbed charges. This developed lateral-driving EPD can significantly improve the bistability, which is enhanced from 40 s to 7 min, an increase by a factor of approximately 10. This work gives a way to consider the bistability of colloidal particles in nonpolar solvent.

High-compatibility properties of Aronia melanocarpa extracts cross-linked chitosan/polyvinyl alcohol composite film for intelligent food packaging

Although the active and intelligent properties of rich in anthocyanin extracts added to films have been extensively studied, there remains a sparsity of research pertaining to the miscibility of blended films. This work focused on the miscibility of the chitosan/polyvinyl alcohol (CP) film caused by the addition of Aronia melanocarpa extracts (AME), which are rich anthocyanins and phenolic acids, and its effect on physicochemical and functional properties. AME facilitated the amidation reaction and ionic interaction of chitosan in CP films, leading to loss of the crystallinity degree of chitosan. Furthermore, the crystal disruption promoted the formation of hydrogen bonds with polyvinyl alcohol (PVA) with the promoted miscibility. CP film incorporated with 8 % AME possessed the highest tensile strength (26.79 MPa), and elongation at break (66.38 %) as well as excellent ultraviolet–visible (UV–vis) light barrier property, water vapor barrier properties, due to its high miscibility degree. Moreover, this film also showed excellent antioxidant, antibacterial activity, and pH response function, which could be used to monitor the storage of highly perishable shrimp. Hence, the AME provided extra functionality and improved miscibility between chitosan and PVA, which showed great potential for the preparation of high-performance bioactive-fortified and intelligent food packaging films.

Fabrication of PVA-based electromagnetic interference shielding composite film by improving the dispersibility of carbon nanomaterial via m-LDH modification

A good dispersion of carbon (C) nanoparticles is a crucial factor to ensure good electrical conductivity and electromagnetic interference shielding effectiveness (EMI SE) performance of polymer-based composite films. In the present work, water-dispersed monolayer layered double hydroxides (m-LDH) was used to modify the C nanoparticles via an in-situ growth method and applied as the conductive fillers for polyvinyl alcohol (PVA) composite films. The prepared C@m-LDH hybrids displayed good water dispersibility due to the in-situ growth of m-LDH with high dispersibility and small particle size on the surface of C nanoparticles, as well as the synergistic effect of styrene-maleic anhydride copolymer attached to the m-LDH surface. The property testing experiments for the PVA composite films demonstrated that compared with pristine C nanoparticles, as-prepared C@m-LDH hybrids exhibited greatly enhanced the electrical conductivity and higher EMI SE performance. Moreover, PVA/C@m-LDH composite film exhibit remarkably low permeation thresholds, especially PVA/CB@m-LDH composite film, CB@m-LDH content is only 0.4 wt%. In order to further improve the electrical conductivity and EMI SE performance, hybrid fillers of CB@m-LDH/CNT@m-LDH were added in the composite films with different mass ratios. Among, the polymer composite films containing 30 wt% CB@m-LDH/CNT@m-LDH with a mass ratio of 12:1 achieves a high EMI SE value up to 29 dB at a thickness of 0.2 mm, indicating the potential use of these materials for electromagnetic shielding application in the X-band frequency region. The present study paves the way for designing high-performance polymer-based composite film by Cnanoparticles functionalization and altering processing conditions for efficient microwave shielding material.

Sustainable chitosan/polyvinyl alcohol composite film integrated with sulfur-modified montmorillonite for active food packaging applications

Sulfur-functionalized montmorillonite (S-MMT), which has strong antioxidant and antibacterial activities, was prepared by forming a sulfur-amine complex using ethylenediamine (EDA). S-MMT was added to the chitosan/polyvinyl alcohol (Chi/PVA) blend polymer to develop an active food packaging film. The composite film, especially 4 wt% S-MMT-added Chi/PVA film (Chi/PVA/S-MMT4%), showed significant increases in tensile strength (∼25.1 %), elongation at the break (∼94.1 %), and UV-blocking ability (98.2 % UV-A and 100 % UV-B) compared to the neat Chi/PVA film. The Chi/PVA/S-MMT4% film also exhibited remarkable antioxidant properties (100 % ABTS and 65.4 % DPPH scavenging activity) and potent antibacterial activity (stopped the growth of L. monocytogenes and E. coli). Chicken packaged in the composite film showed a significant reduction in quality changes, including appearance, pH, thiobarbituric acid reactive substances (TBARS), and total viable colonies (TVC) over 20 days of storage. Multifunctional Chi/PVA/S-MMT films have high potential in active food packaging applications.

Flaxseed Mucilage/Hydroxypropyl Methylcellulose and Sodium Alginate/Polyvinyl Alcohol Composite Bilayer Film as a Promising Drug Carrier for Periodontal Treatment.

The present study focused on the formulation of mucoadhesive bilayer composite films for the treatment of periodontitis and evaluation of their physicochemical properties. The solvent casting technique was used to prepare films. The primary layer (D) was prepared with flaxseed and hydroxypropyl methylcellulose composite to sustain the release of doxycycline hyclate. The second layer (S) comprised sodium alginate and polyvinyl alcohol composite for faster release of clove oil. Both layers were combined to generate the bilayer film (B). All formulations were characterized further to obtain an optimized formulation. Attenuated total reflection-Fourier transform infrared radiation results showed intactness of drug and clove oil in the presence of excipients. The pH of the films was compatible with the periodontal cavity and the thickness was suitable for inserting into the cavity. The immediate release layer showed faster disintegration and swelling. The content of clove oil was above 80%. The rate of swelling of the primary layer was slow and drug content complied with the United States Pharmacopoeia. Scanning electron microscope analysis revealed intact, non-porous and smooth films. Films exhibited better mechanical strength and bioadhesiveness. Clove oil was released from the immediate release layer within 10 min, and doxycycline hyclate release was retarded to a minimum of up to 8 h in the primary layer as well as the bilayer. Formulation also had a significant effect on both Escherichia coli and Staphylococcus aureus. In the current study, bilayers were successfully prepared and characterized. The optimized formulation can be effectively used for the treatment of periodontitis.

STUDYING THE PHYSICAL PROPERTIES OF PVA-PEG LOADED WITH DIFFERENT CONCENTRATIONS OF LIGNOSULFONATE

Polyvinyl Alcohol (PVA) and Polyethylene Glycol (PEG) blend composite films were prepared using the casting technique. The study aims to investigate the effect of the addition of various Lignosulfonate (LS) concentrations at (0.01, 0.02, and 0.04 wt %) on the optical and structural properties of the PVA/PEG using UV–VIS spectroscopy and X-ray diffraction (XRD). The results showed that the addition of LS led to a more compact structure of PVA/PEG, which increased its refractive index and amorphous phase. This resulted in a reduction in the optical energy gap that could be attributed to the increase in the disordered structure of the composites. Additionally, the Absorbance of PVA/PEG/LS composite film increased as the LS doping concentration increasedin the matrix. These results reflect the proper dispersion of LS into the PVA/PEGmatrix, causing a strong intermolecular interaction between LS and PVA/PEG blends, suggesting strong hydrogen bond formation between the hydroxyl group in PVA chains and the outer site groups of LS.This study has yielded significant insights that may aid in the advancement of polymer applications in industries by reducing costs. Theseresults could be instrumental in enhancing production processes and making the use of polymers a more viable and cost-effective option for industrial operations.

Polydiacetylene/Poly(vinyl alcohol) Composite Films as a Low-Temperature Irreversible Indicator for Drug Storage Applications

Polydiacetylene/Poly(vinyl alcohol) Composite Films as a Low-Temperature Irreversible Indicator for Drug Storage Applications

Investigating the annealing effects on the performance of polyvinyl alcohol-graphite-based triboelectric nanogenerator

Annealing plays a crucial role in enhancing the performance, stability, and durability of triboelectric nanogenerators (TENGs). By carefully controlling the annealing parameters, the material properties can be optimized and improve the overall efficiency of TENG devices for various practical applications. Herein, graphite (Gr) embedded polyvinyl alcohol (PVA) composite films are prepared by a solution casting technique and subjected to annealing at various temperatures below the glass transition temperature (Tg) of PVA. The annealed effects are thoroughly examined through characterizations involving PXRD, SEM, EDS, FTIR, and TGA. Subsequently, TENGs are fabricated utilizing the annealed composite films as the tribopositive material, polypropylene as the tribonegative material, and the impact of annealing on the device performance is investigated. At an annealing temperature of 80°C, the PVA-Gr TENG exhibited notably higher output voltage (VOC) and short-circuit current (ISC) of 200.24 V and 12.68 µA, respectively. In addition, the PVA-Gr TENG successfully charges electrolytic capacitors, powers a digital watch, operates a humidity and temperature sensor, and lights a series of green LEDs. Thus, the present study highlights the significant impact of annealing on the performance of PVA-Gr TENG, leading to enhanced output power and stability.

Synthesis of poly(maleic anhydride-co-vinyl chloride) crosslinked microspheres and its superior enhancement in mechanical strength and antibacterial activity for poly(vinyl alcohol) composite films

Poly(vinyl alcohol) (PVA) is an attractive raw material and widely applicated in multiple fields owing to its unique features. However, the poor mechanical strength and without intrinsic antimicrobial activity severely restrained its further use. Herein, we proposed a novel strategy to fabricate PVA-based composites film with excellent mechanical properties and superior antibacterial activity by employing functional polymeric microspheres as a hydrogen bonding cross-linker and bactericide loading platform. Firstly, we synthesized poly(maleic anhydride-co-vinyl chloride) cross-linked microspheres (PDVM) via self-stabilized precipitation polymerization and subsequently the PDVM microspheres were reacted with gaseous ammonia to endow the microsphere surface with abundant carboxyl and amidogen group. As a result, uniform PDVM microspheres with diameters ranging from 175 to 685 nm and controlled gel content (25.3–91.8%) were prepared successfully and aminolyzed PDVM microsphere (NPDVM) were obtained. By incorporating 5 wt% NPDVM in PVA matrix, the composite film has a significant increment in tensile strength (63.9 MPa) and elongation at break (107 %) in comparison to neat PVA (51.8 MPa, 80%) mainly attributed to the formation of multiple hydrogen bonding network. Furthermore, by immobilizing Zn2+ on the surface of NPDVM/PVA film via complexation, the composite film exhibited outstanding antibacterial efficiency against E. coli and S. aureus.

Modification of starch-derived graphene quantum dots as multifunctional nanofillers to produce polymer starch/polyvinyl alcohol composite films for active packaging

Here we reported a facile and green route to prepare graphene quantum dots (GQDs) by using corn starch as a nanofiller for the preparation of starch-based active films. The aqueous solution of GQDs displayed excitation wavelength-independent emission, stable photoluminescence, and good bio-safety. And the results demonstrated that the starch-derived GQDs have good compatibility with the natural polymer starch/polyvinyl alcohol (PVA) matrix. With the addition of GQDs over 50 μg/mL, the composite film has a very satisfactory UV blocking capacity. Moreover, 100 μg/mL of GQDs significantly increases the elongation at break and tensile strength of the obtained film to 1.79 and 2.94 times respectively, while the water solubility is only 53.9% of that of the starch/PVA film. The maximum scavenging rates of 2,2-diphenyl-1-picrylhydrazyl free radical by the starch/PVA film containing 150 μg/mL of GQDs was 83.3%. As the amount of GQDs added increases, the inhibitory effect of the composite film on Staphylococcus aureus and Escherichia coli becomes more and more significant. The starch-sourced composite film's eco-friendly nature and superior performance make it a promising alternative to traditional plastic materials for active packaging.

Preparation and Properties of Polyvinyl Alcohol (PVA) Composite Films by Incorporation of Octadecylamine Polyoxyethylene Ether Modified Carbon Black Particles as Filler

In our research described here, a strong acid oxidizing agent was selected to modify the surface of carbon black (CB) to obtain oxidized carbon black (OCB) particles. These OCB particles were then subjected to an ionic bonding reaction with alkaline amine groups present on the surface of octadecylamine polyoxyethylene ether (AC1830) in the form of a paste, resulting in the production of polyether amine-modified oxidized carbon black particles (A-CB). FTIR confirmed the successful production of the A-CB particles. The PVA composite films were prepared using the casting method with varying amounts of A-CB as filler and PVA as the matrix. The films were then analyzed using tensile, scanning electron microscopy, dynamic thermo-mechanical analysis, DSC, and water absorption testing. The results showed that the tensile strength was highest at 3% A-CB, reaching 154.85 MPa. A-CB was well dispersed in PVA at low contents (1% and 3%). The loss modulus, energy storage modulus, crystallinity, and crystallization rate of the A-CB/PVA films improved compared to PVA films. Additionally, the issue of excessive water absorption in A-CB/PVA has been improved.

Biodegradable starch-polyvinyl alcohol composite films by the incorporation of lignin for packaging applications

In this work, firstly, the optimal performance ratio of potato starch and polyvinyl alcohol (PVA) was selected, and then the sustainable high-grade food packaging film was developed by adding different amounts (0, 5, 10, 15, 20, and 25 wt% based on the starch mass) of functional additive lignin into the starch - PVA film matrix. Starch - PVA based films with different amounts of lignin were studied from the aspects of morphology, physical and chemical properties, barrier properties, mechanical properties and antioxidant properties. Mechanical tests showed that lignin significantly improved the tensile strength (TS) of the film and effectively blocked the passage of water vapor. Lignin, starch and PVA were linked by hydrogen bond to form polymer network structure, which improved the interfacial compatibility between polymers. The interaction between polymer molecules and the distribution of lignin particles were confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The high content of phenolic hydroxyl in lignin undergoes proton coupled electron transfer mechanism, which endows the composite film with high antioxidant activity, which is proved by DPPH radical scavenging activity experiment. At the same time, it also gives the film excellent UV barrier and antibacterial properties. The introduction of lignin in this study provides a valuable way for the preparation of multifunctional composite films using biomass as raw materials, and has a potential application prospect in food packaging.

Nano boron nitride laminated poly(ethyl methacrylate)/poly(vinyl alcohol) composite films imprinted with silver nanoparticles as gas barrier and bacteria resistant packaging materials

AbstractHerein, nano boron nitride (BN) laminated poly(ethyl methacrylate) (PEMA)/poly(vinyl alcohol) (PVA) nanocomposite films are fabricated by using a simple in situ polymerization technique with incorporation of silver nanoparticles (Ag NPs). Structural investigations of PEMA/PVA/Ag@BN nanocomposite thin films are carried out by Fourier‐transform infrared spectroscopy, dynamic light scattering, X‐ray diffraction analysis, 1H nuclear magnetic resonance, 13C nuclear magnetic resonance, and mass spectrometry. The change in morphology of PEMA/PVA matrix due to the reinforcement of BN platelets are identified by electron microscopic studies. The unique tortuous paths are achieved by the dispersion of BN platelets by which gas penetration is restricted with enhancing the barrier properties of the material by 6.5 folds at 5 wt% BN content as compared with neat PEMA/PVA. Acid and alkali resistant along with biodegradability behavior of as‐synthesized nanocomposites are studied. From limiting oxygen index (LOI) results, it is found that the prepared materials are fire retardant in nature owing to effective reinforcement of BN layers. Antibacterial activities of PEMA/PVA/Ag@BN nanocomposite are studied by Xanthomonas citri or axonopodis pv. Citri, Escherichia coli, and Xanthomonas oryzae pv. Oryzae because of Ag NPs reinforcement. The substantial improvements in gas barrier, fire retardant, and antibacterial properties enable the materials for packaging application.