Properties Of Composite Films Research Articles

Boosting Performance of Self-Polarized Fully Printed Piezoelectric Nanogenerators via Modulated Strength of Hydrogen Bonding Interactions.

Self-polarized piezoelectric devices have attracted significant interest owing to their fabrication processes with low energy consumption. Herein, novel poling-free piezoelectric nanogenerators (PENGs) based on self-polarized polyvinylidene difluoride (PVDF) induced by the incorporation of different surface-modified barium titanate nanoparticles (BTO NPs) were prepared via a fully printing process. To reveal the effect of intermolecular interactions between PVDF and NP surface groups, BTO NPs were modified with hydrophilic polydopamine (PDA) and hydrophobic 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) to yield PDA-BTO and PFD-BTO, respectively. This study demonstrates that the stronger hydrogen bonding interactions existed in PFD-BTO/PVDF composite film comparative to the PDA-BTO/PVDF composite film induced the higher β-phase formation (90%), which was evidenced by the XRD, FTIR and DSC results, as well as led to a better dispersion of NPs and improved mechanical properties of composite films. Consequently, PFD-BTO/PVDF-based PENGs without electric poling exhibited a significantly improved output voltage of 5.9 V and power density of 102 μW cm−3, which was 1.8 and 2.9 times higher than that of PDA-BTO/PVDF-based PENGs, respectively. This study provides a promising approach for advancing the search for high-performance, self-polarized PENGs in next-generation electric and electronic industries.

Conducting/biodegradable chitosan-polyaniline film; Antioxidant, color, solubility and water vapor permeability properties

In this study, chitosan-polyaniline nanocomposite film was prepared in combination with different concentrations of polyaniline at various synthesis times. Surface morphology, antioxidant properties, water solubility, water vapor permeability (WVP), color properties and light transparency properties of the films were investigated. The size, shape and morphology of the synthesized particles were examined with scanning electron microscopy (SEM) technique. The results indicated that the synthesized polyaniline particles were spherical and in the range of 45–70 nm. The results obtained from the study of the effect of polyaniline on the physical properties of the chitosan film showed that increasing polyaniline concentration and synthesis time causes a decrease in the rate of the water solubility and water vapor permeability. This is an important factor in expanding its use in food packaging. The results of the colorimetric studies showed that the polyaniline sharply changed the surface color of the film. Polyaniline also increased antioxidant properties of composite film. Investigating the light transmission and transparency of the films showed that the polyaniline reduced the transparency and transmission of light, which could be used to package products that are susceptible to oxidation in the light.

Effect of octenylsuccination of pullulan on mechanical and barrier properties of pullulan-chickpea protein isolate composite film

The octenyl succinic anhydride (OSA) modification of pullulan (PU) was applied to improve the blend miscibility, compatibility and water-resistance properties of the PU-chickpea protein isolate (CPI) blend films. For this purpose, the effect of degree of substitution (DS) of the modified PU and also the ratio of CPI to PU-OSA on the physical and mechanical properties of the obtained composite films were evaluated. FTIR and XRD results showed that the molecular interactions between CPI and PU-OSA were more than CPI and PU, indicating that these two polymers had more miscibility because of the hydrophobic nature of PU-OSA which also confirmed by scanning electron microscope (SEM) pictures. The findings indicated that the use of PU-OSA instead of PU can significantly improve the mechanical and water-resistance properties of composite films. In this regard, the octenylsuccination of PU decreased the extensibility, moisture content and water vapor permeability, while increased the tensile strength and water contact angle of the produced composite films. The highest values of the tensile strength (8.90 ± 0.10 MPa) and contact angle (91.48 ± 0.34°) were obtained for CPI50–P3 and CPI70–P3 composite films, respectively. Also, the lowest values of the water solubility (21.23 ± 0.96%), moisture content (15.74 ± 0.47%) and water vapor permeability (2.07 ± 0.06 × 10-10 gm-1s-1pa-1) were obtained for CPI70–P3 blend film. Eventually, it can be deduced that the composite films produced by CPI and PU-OSA with DS of 0.06 are the best and can be used as new biodegradable films with excellent properties.

A High-Efficiency TiO2/ZnO Nano-Film with Surface Oxygen Vacancies for Dye Degradation.

Photocatalytic degradation of organic pollutants in water is a highly efficient and green approach. However, the low quantum efficiency is an intractable obstacle to lower the photocatalytic efficiency of photocatalysts. Herein, the TiO2/ZnO heterojunction thin films combined with surface oxygen vacancies (OVs) were prepared through magnetron sputtering, which was designed to drive rapid bulk and surface separation of charge carriers. The morphology and structural and compositional properties of films were investigated via different techniques such as SEM, XRD, Raman, AFM, and XPS. It has been found that by controlling the O2/Ar ratio, the surface morphology, thickness, chemical composition, and crystal structure can be regulated, ultimately enhancing the photocatalytic performance of the TiO2/ZnO heterostructures. In addition, the heterojunction thin film showed improved photocatalytic properties compared with the other nano-films when the outer TiO2 layer was prepared at an O2/Ar ratio of 10:35. It degraded 88.0% of Rhodamine B (RhB) in 90 min and 90.8% of RhB in 120 min. This was attributed to the heterojunction interface and surface OVs, which accelerated the separation of electron–hole (e–h) pairs.

Citrus Limon L. Peel Powder Incorporated Polyvinyl Alcohol/Corn Starch Antioxidant Active Films

Active food packaging films has gain more significance over conventional packaging. In this study, novel active composite films were prepared by incorporating lemon peel to a polyvinyl alcohol-starch matrix. The morphological, thermal and antioxidant activity evaluation of polyvinyl alcohol-starch-lemon peel composite films were discussed to determine whether the presence and content of lemon peel influenced the film’s characteristics. The results indicated that tested properties of composite films depended on the content of lemon peel. It was found that the thermal stability and antioxidant activity of films considerably improved upon the incorporation of peel. The prepared films with enhanced antioxidant activity may be used for preservation of oxidation-sensitive food products. The results showed that lemon by-product has great potential to be evaluated into added-value products for functional packaging applications. The developed packaging films will be new alternatives for food preservation materials.

The preparation of PVDF-BTO composite film and the influence of polarization intensity on the piezoelectric properties of composite film

In this study, the PVDF-BTO composite film was prepared by the casting method. Through FTIR, SEM and other phase structure and microstructure analysis of the composite film, it was found that the introduction of BTO can promote the growth of β-PVDF. The relative content of β-PVDF in PVDF-BTO composite film reached 62.7%, indicating that BTO acts as a nucleating agent in PVDF. PVDF-BTO composite piezoelectric film is obtained after high temperature stretching and field polarization. After testing the electrical properties of the composite piezoelectric film, it is found that the piezoelectric performance of the PVDF-BTO composite film is higher than that of the pure PVDF film. It shows that the blending of BTO and PVDF to prepare the film promotes the deflection of the electrical properties of the film to the inherent electrical properties of BTO. The influence of different polarization intensities on the piezoelectric properties of composite materials was studied. The results show that the optimal polarization intensity of the PVDF-BTO composite piezoelectric film is 30 KV/mm, and the highest piezoelectric constant d33 is 13 pC/N.

Energy storage properties of composite films with relaxor antiferroelectric behaviors

Here, typical relaxor ferroelectric Ba2Bi4Ti5O18 (BBT) and antiferroelectric PbZrO3 (PZ) were selected to form BBT/PZ/BBT composite films for high energy storage performance. The composite films exhibit relaxor antiferroelectric behavior at 1000 kV/cm. A large recoverable energy storage density (Wrec) of 66.7 J/cm3 and efficiency (η) of 65.6% were achieved at 2500 kV/cm in BBT/PZ/BBT composite films. Additionally, the variation of Wrec and η was less than 4% after 5 × 107 charge-discharge cycles at 1000 kV/cm. What’s more, the energy storage performance of composite films is stable under the temperature range from 20 °C to 160 °C and frequency range from 500 Hz to 2000 Hz.

The effect of cross-linker type on structural, antimicrobial and controlled release properties of fish gelatin-chitosan composite films incorporated with ε-poly-l-lysine

In this study, active antibacterial cross-linked composite films were prepared through incorporating ε-poly-l-lysine (ε-PLL) into Siberian sturgeon gelatin-chitosan mixture. Cross-linking was performed by Glutaraldehyde (G) and/or Cinnamaldehyde (C). The antimicrobial, ε-PLL release, mechanical and morphological properties were then investigated. The addition of G to the biopolymer mixture significantly resulted in lower water vapor permeability, enhanced mechanical strength, lower moisture content, and water solubility. The FTIR spectra indicated the formation of imine bonds in the composite film network. The microstructure of composite films was affected by the cross-linking agent. The films cross-linked by G and C showed smooth and rough surfaces, respectively. C induced very small pores in the cross-section of the composite film. The composite films incorporated with ε-PLL revealed higher and steady-state in vitro antimicrobial properties against food spoilage bacteria. A higher release of ε-PLL and hence higher antibacterial activity was measured in the matrices cross-linked by C than those cross-linked by G. The results showed that the ε-PLL-fortified fish gelatin/chitosan composite films can be considered as a food-packaging material. G and C, as cross-linkers, can improve the structural and antimicrobial properties of this composite film.

The effect of nanocellulose on mechanical and physical properties of chitosan-based biocomposites

The effect of two types of nanocellulose on the mechanical properties of chitosan (CH) film was examined in terms of elongation, tensile strength, and dynamic-mechanical properties such as tan δ and storage modulus. Chitosan films were reinforced by cellulose nanocrystal (CNC) and cellulose nanofiber (CNF) with different ratios. CH/CNC and CH/CNF nanocomposite films containing 0–7 wt.% nanofibers were produced by solution casting. A comparison between CNC and CNF was made based on their nanostructures and interfacial bonding with the CH matrix. For both CNC and CNF, reinforcing effects in nanocomposite polymer films were presented. The results demonstrated that nanocomposite films can increase mechanical properties; 7 wt.% CNF and CNC had the most increasing effect on the mechanical properties, raising the tensile strength of the chitosan film by 104% and 52%, respectively. Moreover, the values of CH/CNC and CH/CNF films showed higher storage modulus compared to the pure chitosan film. CNF shows higher modulus and strength compared with CNC at the same amount of fiber because of CNFs’ percolation networks and their larger aspect ratio. Morphological studies revealed the dispersion of CNC and CNF is in the contiguous matrix of chitosan with a homogeneous distribution without agglomeration. The results also illustrated that CNC and CNF can improve the water resistance of chitosan films. The mechanical properties of composite films were acceptable to use as artificial skin and wound dressings.

Development and characterization of chitosan films carrying Artemisia campestris antioxidants for potential use as active food packaging materials

Active food packaging films based on chitosan and enriched with Artemisia campestris hydroalcoholic extract (ACHE), aqueous extract (ACAE) and essential oil (ACEO) were developed. The effects of incorporating A. campestris were investigated on the physical, mechanical, thermal and antioxidant characteristics of the films. The structural properties of the films were evaluated using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that adding ACHE and ACEO improved the water resistance of chitosan films. The FTIR spectroscopy analysis revealed covalent interaction and hydrogen bonding between chitosan and ACHE. The XRD and SEM analyses indicated that interactions occurred between the film matrix and A. campestris active compounds, which could be reflected by the physical and mechanical properties of composite films. Incorporating ACHE and ACAE in the chitosan matrix decreased the tensile strength. The film extensibility was reduced when ACHE and ACEO were added. All films exhibited great thermal stability as the degradation occurred above 300 °C. The addition of A. campestris active compounds, particularly extracts, to chitosan films notably increased the antioxidant and UV–Vis barrier properties. Chitosan films enriched with the A. campestris antioxidant compounds could be applied as food packaging alternatives.

Fabrication of pectin/agar blended functional film: Effect of reinforcement of melanin nanoparticles and grapefruit seed extract

Pectin/agar blended multifunctional composite films were prepared by reinforcing with melanin nanoparticles (MNP) and grapefruit seed extract (GSE). The physical properties of composite films made by mixing pectin and agar have been improved. The MNP and GSE were well dispersed in the pectin/agar blend film. The addition of MNP and GSE significantly increased the composite film's UV-blocking property, with some sacrificing transparency. The addition of MNP increased the mechanical strength of the agar/pectin film over GSE, but the addition of MNP and GSE together synergistically increased the film's strength. The film's thermal stability was not affected by the addition of MNP and GSE, but the water vapor barrier property was significantly increased. The water resistance and water swelling properties were increased considerably by the addition of MNP and GSE. The pectin/agar composite film showed intense antioxidant activity and excellent antibacterial activity against foodborne pathogens by adding MNP and GSE.

Effect of the Mixture of Polymers on the Rheological and Technological Properties of Composite Films of Acoupa Weakfish (Cynoscion acoupa) and Cassava Starch (Manihot esculenta C.)

Biopolymers, such as proteins and carbohydrates, can be used for the production of biofilms, as they are biodegradable, biocompatible, and capable of providing adequate technological characteristics for films. This study aimed to evaluate the influence of different concentrations of fish myofibrillar proteins and cassava starch on the rheological and technological properties of filmogenic solutions (FS) and films. FS were prepared with 1% protein (fish residue) (F1), 4% starch (F2), 0.5% protein + 2% starch (F3), 1% protein + 2% starch (F4), and 0.5% protein + 4% starch (F5) all with 30% glycerol. Rheological analyzes of apparent viscosity were performed on the filmogenic solutions and were evaluated the technological properties, thermogravimetric (TGA/DTG and DSC), x-ray diffraction, infrared spectroscopy (FTIR-ATR), microscopy (SEM), and spectroscopy (EDS) in elaborate films. The FS showed a non-Newtonian behavior (n ≠ 1), with dilating and pseudoplastic fluids for proteins and starch, respectively, both model Herschel-Bulkley. The color of the raw materials influenced the color of the films (p ≤ 0.05). Composite films (F3, F4, and F5) showed better barrier properties in the visible range (350–800 nm), with starch (F1) being the most transparent (p ≤ 0.05). F4 film showed the best technological properties: PVA, solubility and mechanics. The films with the highest percentage of protein, F1 and F4, presented higher (p ≤ 0.05) thermal resistance. In addition, starch favored the crystallinity of films (F3, F4, and F5), providing more orderly matrices. The FTIR and EDS analyzes of the films confirmed the successful interaction of proteins and starch. Therefore, the properties of the elaborated composite films indicate that the interaction between biopolymers is positive to produce packaging for different types of food.

Effect of chitosan/essential oils/silver nanoparticles composite films packaging and gamma irradiation on shelf life of strawberries

The present study illustrates the synthesis of silver nanoparticles (AgNPs) using tyrosine as a reducing agent and preparation of chitosan (CHI) based films by blending essential oils (EOs) and synthesized AgNPs. The prepared CHI-EOs-AgNPs composite films were used for the packaging of strawberries in the presence or absence of gamma irradiation. The composite films were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, color property, tensile properties, and water vapor permeability. The scanning electron microscopy result showed the smooth surface of the composite films, whereas Fourier transform infrared spectroscopy results exhibited a change in the structure of CHI after blending EOs and AgNPs. The flexibility of the composite films increased after the addition of EOs, but tensile strength increased after blending AgNPs. The water vapor barrier property of composite films has not changed upon blending EOs or AgNPs. The CHI-EOs-AgNPs composite films exhibited strong antimicrobial activity against Escherichia coli, Listeria monocytogenes, Salmonella Typhimurium, and Aspergillus niger. The effects of packaging and γ-irradiation on the shelf life and quality of packaged strawberries during storage were evaluated by the weight loss, firmness, decay (%), color, anthocyanin, and total phenol content. All composite films exhibited lower weight loss than control samples, and γ-irradiation reduce the firmness and decay during 12 d of storage.

Antimicrobial Active Bioplastics Using Triangular Silver Nanoplate Integrated Polycaprolactone and Polylactic Acid Films

An innovative antimicrobial technology for plastic surfaces is presented. We report the synthesis and scale-up of triangular silver nanoplates (TSNPs) and their integration into polycaprolactone (PCL) and polylactic acid (PLA) polymers through a solvent-casting technique. The TSNPs have a high geometric aspect ratio and strong local surface plasmon resonance (LSPR) response, which provides an effective tool for monitoring their integrity during processing and integration with the biodegradable plastics. An aqueous-based seed-mediated chemical method was used to synthesize the TSNPs, and characterisation was carried out using TEM and UV (Ultraviolet)-VIS (Visible) spectroscopy to measure LSPR profiles. The UV-VIS spectra of silver seeds and TSNPs exhibited characteristic peaks at 395 and 600 nm respectively. Synthesized TSNPs were coated with thiol-terminated polyethylene glycol (SH-PEG) and transferred into chloroform in order to effect compatibility with PCL and PLA. TSNP/PCL and TSNP/PLA composite films were prepared by solvent casting. The morphological structure, thermal, mechanical, and antimicrobial properties of the TSNP-incorporated composite films were evaluated. Results showed the TSNP-treated films had a rougher surface than the bare films. Insignificant changes in the thermal properties of TSNP-treated films compared to bare ones were also observed, which indicated the thermal stability of the composite films. The tensile strength and antimicrobial properties of the composite films were increased after TSNP incorporation. TSNP/PCL and TSNP/PLA films exhibited improved antimicrobial activity against Escherichia coli and Staphylococcus aureus with antimicrobial effect (AE) values ranging between 0.10 and 0.35. The obtained results and demonstrated TSNP production scalability validate the TSNP treated PCL and PLA films as a composite material with desirable antimicrobial effect for wide-ranging surface applications.

Dihydromyricetin incorporated active films based on konjac glucomannan and gellan gum

Active composite films were developed by incorporating different concentration of dihydromyricetin (DMY) into konjac glucomannan (KGM)/gellan gum (GG) matrix. Physicochemical, mechanical, released behaviour, antioxidant and antimicrobial properties of composite films were investigated. The results from the Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) indicated that DMY which well-dispersed in the KGM/GG matrix interacted with matrix through hydrogen bonds. The obtained films presented predominant thermostability, good water resistance property, excellent ultraviolet light barrier ability and sustained controlled release behaviour. In particular, the incorporation of DMY remarkably enhanced the antioxidant and antimicrobial activities of the films. Overall, the fabricated KGM/GG-DMY composite films have a promising application in the fields of food packaging.

Polyimide hollow glass microspheres composite films with low dielectric constant and excellent thermal performance

AbstractNowadays, polyimide (PI) with low dielectric constant is expected to be widely applied in microelectronics. For this reason, hollow glass microspheres (HGM) modified by silane coupling agent KH‐550 (K‐HGM), a series of HGM/PI and K‐HGM/PI composite films with excellent thermal performance, hydrophobic and low dielectric constant were fabricated by in situ polymerization. The effect of HGM/K‐HGM content on the properties of composite films was studied. The superior heat resistance of HGM can improve the thermal performance of composite films. Due to silane coupling agent KH‐550, K‐HGM exhibits a good interfacial compatibility with PI matrix and forms an interfacial adhesion region. With the HGM loading of 6%, comparing with pure PI films, the glass transition temperatures (Tg) of composite films were dramatically increased by 32.3°C. Especially, the low dielectric constant of 2.21 and dielectric loss of 0.0059 at 1 MHz were obtained for the PI/K‐HGM composite film with addition of 8 wt%. Thus, PI/K‐HGM composite films show more excellent performance. The current work provides a promising solution for fabrication of PI with low dielectric constant and superior thermal performance that may be applied in microelectronics industry.

Conception of active food packaging films based on crab chitosan and gelatin enriched with crustacean protein hydrolysates with improved functional and biological properties

This study aims to assess the effect of shrimp and crab protein hydrolysates (SPH and CPH) on structure, physicochemical, antioxidant and antimicrobial properties of composite films based on chitosan and fish gelatin. To this end, protein hydrolysates as bioactive additives were incorporated into edible films at different weight ratios 1.5, 3 and 6% (g/100 g polymer). SPH and CPH enriched films were colored and exhibited higher UV-barrier properties compared to the control chitosan-gelatin film. In addition, an improvement in the mechanical properties and thermal degradation temperatures was also observed with PHs incorporation. Furthermore, the hydrophobicity of the composite films was evaluated by determining the contact angle using different solvents (water, ethylene glycol and diiodomethane) during 120 s. With the PHs incorporation, a significant decrease, which was dependent on time and film composition, in the contact angle was found for the composite films. However, an increase in the surface wettability (especially polar component and surface tension) was observed for enriched films. Therefore, PHs addition increases the hydrophilicity of CS-gelatin based films. Interestingly, the composite films, evaluated by several in vitro assays, displayed higher antibacterial and antioxidant potential than control film. Consequently, composite films are promising alternative for active packaging to hinder food oxidation.

Incorporating MXene into Boron Nitride/Poly(Vinyl Alcohol) Composite Films to Enhance Thermal and Mechanical Properties.

Aggregated boron nitride (ABN) is advantageous for increasing the packing and thermal conductivity of the matrix in composite materials, but can deteriorate the mechanical properties by breaking during processing. In addition, there are few studies on the use of Ti3C2 MXene as thermally conductive fillers. Herein, the development of a novel composite film is described. It incorporates MXene and ABN into poly(vinyl alcohol) (PVA) to achieve a high thermal conductivity. Polysilazane (PSZ)-coated ABN formed a heat conduction path in the composite film, and MXene supported it to further improve the thermal conductivity. The prepared polymer composite film is shown to provide through-plane and in-plane thermal conductivities of 1.51 and 4.28 W/mK at total filler contents of 44 wt.%. The composite film is also shown to exhibit a tensile strength of 11.96 MPa, which is much greater than that without MXene. Thus, it demonstrates that incorporating MXene as a thermally conductive filler can enhance the thermal and mechanical properties of composite films.

Fabrication of anti-bacterial, hydrophobic and UV resistant galactomannan-zinc oxide nanocomposite films

The use of organic and inorganic materials to prepare membrane materials with functional performance has attracted much attention in recent years. In this paper, galactomannan (GM) is used as raw material and nano zinc oxide (nano-ZnO) is used as functional modifier to prepare GM based food packaging films. The properties influence for films of different nano-ZnO content were studied. The obtained nano-ZnO/GM composite films showed superior hydrophobicity and almost absorbing all UVA and UVB. The tensile strength of composite film was superior to plastic HDPE film, and the oxygen barrier properties of composite films were better than PVC plastic film. The composite films against E. coli and B. subtilis showed great antibacterial properties. The antibacterial effect was demonstrated by Shine-Muscat grapes after storage for 5 days. The final prepared GM based functional food packaging film provides a foundation for the potentials for futural plastic packaging alternatives.

Improvement the barrier and mechanical properties of whey protein isolate film using fructan obtained from Serish (Eremurus spectabilis) root as a novel polysaccharide

In this study, we investigated the effect of fructan obtained from Serish root (Eremurus spectabilis) as a new film-base material in order to improve the barrier and mechanical properties of whey protein isolate (WPI) film. The effects of fructan (0, 50, 60, 70% v/v) and glycerol (Gly) (40 and 50% v/v) ratios on the mechanical, chemical, thermal, surface wetting, water vapor permeability (WVP), and morphological properties of WPI film were investigated. According to scanning electron microscope (SEM), the substitution of fructan to WPI significantly modified the surface properties of composite films, which had fewer cracks and pores compared to WPI films. The substitution of fructan decreased the water vapor permeability (6.64 × 10–6-1.85 × 10–6 g / m.s.pa) and increased the tensile strength (6.91–16.25 Mpa) and Young's modulus (30.84–42.84 Mpa) of the WPI film. Increasing the fructan content improved the mechanical properties and reduced the water vapor permeability of composite films. Fourier transform infrared (FTIR) spectra confirmed the formation of hydrogen bonding interactions between WPI and fructan. Differential scanning calorimetry (DSC) analysis exhibited a slight increase in the enthalpy values (81.43–154.3 J/g) with increasing fructan ratio of composite films, so that the thermal stability of WPI film improved due to stablishing more hydrogen bonds which also evidenced by FTIR. These results suggest that WPI 30 / Fructan 70 (40% Gly) can be considered as the best ratio for preparation of the composite film.