Chitosan Composite Films Research Articles

Synergistic Effects of Nanocomposite Films Containing Essential Oil Nanoemulsions in Combination with Ionizing Radiation for Control of Rice Weevil Sitophilus oryzae in Stored Grains.

The fumigant toxicity of eight individual essential oils (EOs; basil, cinnamon, eucalyptus, mandarin, oregano, peppermint, tea tree, and thyme) and one binary combination (thyme and oregano) for control of the rice weevil, Sitophilus oryzae, were investigated. In bioassays, all individual and combined EOs were toxic to the rice weevil. Eucalyptus EO exhibited the highest toxicity among the individual EO treatments, causing 100% mortality at a minimum concentration of 0.8 µL/mL after 24 hr of exposure. The combination treatment of oregano and thyme EO displayed higher fumigant activity than the individual oregano or thyme treatments. A stable oil-in-water nanoemulsion was evaluated using high-pressure homogenization (microfluidization [MF]) and varying the pressure and number of cycles. The droplet size of the emulsions was found to decrease from 217 to 71 nm and encapsulation efficiency increased from 37% to 84% with increasing MF pressure and number of cycles. The optimum conditions for preparing the mixture of oregano and thyme EO nanoemulsions were evaluated to be homogenization pressure of 103 MPa and three cycles. Incorporating an oregano:thyme nanoemulsion (0.75%) into cellulose nanocrystal (CNC) containing chitosan (CH/CNC), methyl cellulose (MC/CNC), and polylactic acid (PLA/CNC) composite films resulted in extended diffusion matrices causing 32% to 51% rice weevil mortality after 14 days exposure. Irradiation at 200 Gray alone caused 79% mortality and increased to 100% when combined with the bioactive chitosan film containing the oregano:thyme nanoemulsion. PRACTICAL APPLICATION: A binary combination of oregano:thyme has potential as a biopesticide against stored product pests. The encapsulation of EO nanoemulsions into biopolymeric support could be used for bioactive packaging to prevent food spoilage and extend shelf life. Combining bioactive films with irradiation can provide complete control of rice weevil in packaged rice. The system developed in this research may also be extended to explore other food-packaging films with various food models to control different types of stored pests.

Effects of amylose content on starch-chitosan composite film and its application as a wound dressing

This study analyzed the amylose content of starches and used them to prepare starch–chitosan composite films to assess their potential as wound dressings. Amylose content was 35.3% in potato starch, 30.5% in corn starch, and 9.7% in glutinous rice starch. The glutinous rice starch–chitosan composite (GC) film, which had a lower amylose content, had a coarser surface and exhibited a higher swelling rate, tensile strength, and elongation at break. In in vitro experiments by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay indicated that GC film had greater biocompatibility with mouse fibroblast L929 cells and human keratinocyte HaCaT cells. The results of the enzyme-linked immunosorbent assay indicated that GC film was more capable of alleviating inflammation than other films by preventing RAW264.7 macrophage from secreting cytokines (TNF-α and IL-6). Additionally, it possessed an excellent coagulation rate. Briefly, the GC film with a lower amylose content is a suitable material for wound dressing.

Capsicum-extract blended chitosan composite films and studying their antibacterial properties

Capsicum extract at different concentrations (0.5–3.0 ml) was blended with a chitosan polymer to obtain the composite films. It was compared with the pristine film to examine their antioxidant, mechanical, barrier, biodegradability, stability and antimicrobial properties. The morphology of the films was studied using a scanning electron microscope. From the obtained results, it was observed that the antioxidant, mechanical, biodegradability, stability and antimicrobial properties were enhanced when compared to the other films. The barrier properties of the composite films showed a decrease in activity when compared to the pure chitosan film. It may be due to the incorporation of a capsicum extract agent into the chitosan polymer matrix which plays a vital role in enhancing the overall properties.

Graphene oxide–polyoctahedral silsesquioxane–chitosan composite films with improved mechanical and water‐vapor‐transport properties

ABSTRACTGraphene oxide (GO) and ball‐milled maleamic acid–isobutyl polyoctahedral silsesquioxanes (MAIPSs) were incorporated simultaneously into chitosan (CS) via solution blending to evaluate their combined effects on the structures and properties of composite films. GO and MAIPS aggregates were homogeneously dispersed in CS and affected the crystallinities of the composite films. The binary addition of GO and MAIPS resulted in synergistic enhancements of the tensile strength and elongation at break of the composite films. Composite films containing 3% w/w MAIPS and 0.25% w/w GO (CS–GO–MAIPS‐3) exhibited the highest strength and modulus, which were 48 and 42.2% higher, respectively, than the values of the CS film. The water‐vapor‐sorption isotherms revealed that monolayer sorption sites decreased with the addition of GO or/and MAIPS, but the dissolution process was not significantly influenced. The water‐vapor permeability reached its lowest value for the CS–GO–MAIPS‐3 film because of hindered diffusion with the presence of impermeable nanoparticles. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47748.

Synthesis and Characterization of Acetic Acid-Doped Polyaniline and Polyaniline⁻Chitosan Composite.

Polyaniline–chitosan (PAni–Cs) composite films were synthesized using a solution casting method with varying PAni concentrations. Polyaniline powders used in the composite synthesis were polymerized using acetic acid as the dopant media. Raman spectroscopy revealed that the PAni powders synthesized using hydrochloric acid and acetic acid did not exhibit significant difference to the chemical features of PAni, implying that PAni was formed in varying concentrations of the dopant media. The presence of agglomerated particles on the surface of the Cs composite, which may have been due to the presence of PAni powders, was observed with scanning electron microscope–energy dispersive X-ray spectroscopy (SEM–EDX). Ultraviolet–visible (UV–Vis) spectroscopy further showed the interaction of PAni with Cs where the Cs characteristic peak shifted to a higher wavelength. Cell viability assay also revealed that the synthesized PAni–Cs composites were nontoxic and may be utilized for future biomedical applications.

Double Cross-Linked Chitosan Composite Films Developed with Oxidized Tannic Acid and Ferric Ions Exhibit High Strength and Excellent Water Resistance.

There is tremendous scientific interest in developing biodegradable films through facile and versatile strategies. Although extensive studies on the preparation of chitosan films have been conducted, the reported results commonly present low mechanical strength and weak water resistance. In the present study, high strength and significantly water resistance single-cross-linked chitosan-oxidized tannic acid (SC-CS/OTA) composite films and double cross-linked chitosan/oxidized tannic acid/FeIII (DC-CS/OTA/FeIII) composite films were created through a Schiff base reaction and metal coordination. As a result, the optimal tensile strength of SC-CS/OTA composite films and DC-CS/OTA/FeIII composite films was 35.92 and 209 MPa, respectively. Notably, when compared with other chitosan-based films, the tensile strength of DC-CS/OTA/FeIII composite films was approximately three times stronger. Moreover, the water vapor permeability (WVP) values of the films with FeIII(0.66 ± 0.03 × 10-10 g/m·h·Pa) was lower than that of films without FeIII (1.33 ± 0.01 × 10-10 g/m·h·Pa). More importantly, WVP values of the DC-CS/OTA/FeIII composite films were 3-4 orders of magnitude lower than those of chitosan films previously reported. The SC-CS/OTA composite films (96.69%) and DC-CS/OTA/FeIII composite films (99.06%) also presented high DPPH radical scavenging activity. Furthermore, SC-CS/OTA and DC-CS/OTA/FeIII hydrogels were also prepared. This work can be widely applied in the food, biomedical science, and wastewater treatment fields.

Preparation of chitosan composite film using activated carbon from oil palm empty fruit bunch for Cd2+ removal from water

Preparation of chitosan composite film using activated carbon had been successfully conducted. Activated carbon was produced by pyrolysis process of oil palm empty fruit bunch. The chitosan composite films were prepared by varying activated carbon content. The obtained chitosan composite films were charactherized by tensile test, Fourier Transform Infrared (FTIR), X-Ray Diffraction (XRD) and Scanning Electon Microscope (SEM). Tensile test results showed content of activated carbon influenced the tensile strength of chitosan film. Adsorption study was conducted with various contact time, pH and initial concentration of Cd2+. Langmuir and Freundlich isotherm models were used to describe the mechanism of Cd2+ adsorption by chitosan composite film. The maximum adsorption capacity based on Langmuir isoterm model (Q) was 333.33 mg/g. Regeneration study showed the chitosan composite film exhibited higher performance than pure chitosan film.

Preparation of chitosan composite film using activated carbon from oil palm empty fruit bunch for Cd2+ removal from water

Preparation of chitosan composite film using activated carbon had been successfully conducted. Activated carbon was produced by pyrolysis process of oil palm empty fruit bunch. The chitosan composite films were prepared by varying activated carbon content. The obtained chitosan composite films were charactherized by tensile test, Fourier Transform Infrared (FTIR), X-Ray Diffraction (XRD) and Scanning Electon Microscope (SEM). Tensile test results showed content of activated carbon influenced the tensile strength of chitosan film. Adsorption study was conducted with various contact time, pH and initial concentration of Cd2+. Langmuir and Freundlich isotherm models were used to describe the mechanism of Cd2+ adsorption by chitosan composite film. The maximum adsorption capacity based on Langmuir isoterm model (Q) was 333.33 mg/g. Regeneration study showed the chitosan composite film exhibited higher performance than pure chitosan film.

Cellulose⁻Chitosan Antibacterial Composite Films Prepared from LiBr Solution.

Cellulose and chitosan solutions were prepared in 60% LiBr and mixed with a different weight ratio. The washing and drying of the prepared cellulose–chitosan composite films were performed under identical conditions. The color of the liquefied mixtures and films was initially transparent but changed from colorless to brownish yellow depending on the ratio of chitosan in the solution. The cross section observed in the SEM results indicated that the film developed with a higher ratio of chitosan was more robust and possessed greater antibacterial properties. FT-IR analysis of the films showed that hydrogen bonds between cellulose and chitosan in composite films were successfully achieved and retained excellent mechanical properties. The proper ratio of chitosan in the cellulose solution can increase the tensile strength and improve the elongation of the films; however, the E-modulus property was consistently reduced. The antibacterial activity and mechanical properties of the films were greatly improved as the amount of chitosan in the film increased.

Solvent strength and biopolymer blending effects on physicochemical properties of zein-chitosan-polyvinyl alcohol composite films

The aim of this research was to optimise and develop edible films made from zein (ZN), chitosan (CS), poly(vinyl alcohol) (PVOH) and poly(ethylene glycol) (PEG400) using Box Behnken Design (BBD). Four factors viz. ZN:CS ratio (w/w) (1:3, 1:1, 3:1), PVOH wt.% (in dry film) (0, 0.25, and 0.5), PEG400 wt% (0.13, 0.21, 0.31) and ethanol (40–80% v/v in water), were investigated. The effects on tensile strength (TS), Young's modulus of elasticity (EM), elongation at break (%EAB), water vapour permeability (WVP), solubility in water (Ws), and optical properties were evaluated. The films were further characterised using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), x-ray diffraction (XRD) and swelling behaviour. SEM micrographs showed that high levels of ZN and PEG400 resulted in rough surfaces with major film defects, but these were minimised at high levels of CS or PVOH. XRD analysis indicated potential interactions through hydrogen bonding between the polar groups of ZN and hydroxyl moieties of PVOH and CS. Stress-strain curves showed that ZN and CS composite films possessed high TS but were brittle. Incorporation of PVOH increased the ductility of the composite films. Optimum films were obtained using ZN/CS/PVOH/PEG400 ratio of 0.35/0.29/0.13/0.23 (wt.%) and 60% ethanol, giving dry state properties of TS, EM, and EAB as 24.21 MPa, 356.62 MPa and 84.23%. respectively. This study demonstrated the influence of critical interactions between solvent features (polarity) and interfacial properties of ZN, CS, PVOH and PEG400. The observed crosslinking behaviour suggested the effectiveness of blending technique in improving the compatibility of biopolymers and overall functionality of edible films.

Development of antibacterial ε-polylysine/chitosan hybrid films and the effect on citrus

In this study, the ε-polylysine (PL)/chitosan (CS) composite films with the PL concentration of 0%, 1%, 3%, 5% and 7% were prepared via casting method. The Fourier transform infrared (FTIR), scanning electron microscope (SEM), mechanical and antibacterial properties of PL/CS composite films, as well as the effect of PL/CS coatings on citrus were observed. FTIR spectra suggested that there was no strong hydrogen bond between CS and PL. SEM images indicated that the film surface was smooth and the addition of PL to chitosan lead to more holes. The tensile strength was deceasing and the elongation at break of the films was elevating with the increase of PL content. The antibacterial activity against Staphylococcus aureus and Escherichia coli of PL/CS composite films was enhanced with increasing of PL content. Furthermore, it was found that the PL/CS coatings inhibited efficiently the decline of total soluble solids (TSS), ascorbic acid content and reduced the disease incidence of citrus, compared with the control. Also the disease incidence of citrus was decreasing with the increase of PL content. However, the weight loss did not show significant differences between the coated citrus and control during the whole storage period.

Accelerated skin wound healing by soy protein isolate–modified hydroxypropyl chitosan composite films

In this study, a series of hydroxypropyl chitosan (HPCS)/soy protein isolate (SPI) composite films (HCSFs) with different SPI contents were developed via crosslinking, solution casting, and evaporation process. Effects of the SPI content on the structure and physical properties of the HCSFs were characterized by Fourier transform infrared spectroscopy, X-ray diffraction patterns, scanning electron microscopy, swelling kinetics analysis, and mechanical testing. The HCSFs exhibited a lower swelling ratio with an increase in the SPI content. The tensile strength was in a tunable range from 7.88 ± 3.08 to 40.44 ± 2.31 MPa by adjusting the SPI content. Cytocompatibility and hemocompatibility of the HCSFs were evaluated by a series of in vitro assays, including MTT assay, live/dead assay, cell morphology observation, hemolysis ratio testing, and plasma recalcification time measurement. Results showed that the HCSFs support L929 cells attachment and proliferation without obvious hemolysis, indicating good cytocompatibility and hemocompatibility. The potential of resultant HCSFs as the wound dressings was investigated using a full-thickness skin wound model in rats. Results exhibited that the HCSFs with 50% SPI content had the fastest healing speed and the best skin regeneration efficiency and may be a potential candidate as the wound dressing.

Construction of novel cellulose/chitosan composite hydrogels and films and their applications

In the present study, novel cellulose and chitosan composite hydrogels and films were constructed by directly dissolving cellulose and chitosan in alkali/urea aqueous solutions followed by a facile blending method and a mild coagulation process in an ethyl acetate gaseous phase. The structure and properties of the cellulose/chitosan composite materials were characterized by Field emission scanning electron microscopy, FTIR, wide angle X-ray diffraction, mechanical test and antibacterial experiment etc. The results indicated that there is strong hydrogen bonding interaction between cellulose and chitosan. The composite hydrogels exhibited homogeneous porous structure and the resultant films exhibited relative high light transmittance, indicating good miscibility between cellulose and chitosan due to their structure similarity. The mechanical strength increased with the cellulose content for the composite films, while the equilibrium swelling ratio, antibacterial activity and biocompatibility increased with the chitosan content. Facial mask shaped composite hydrogels with heavy metal ion adsorbability could be prepared facilely by using glass molds. Thus, the composite materials showed potential applications in the facial mask, antimicrobial packaging and water treatment fields.

Chitosan composite films: physicochemical characterization and their use as coating in papaya Maradol stored at room temperature

The main objectives of this study were; first formulate and evaluate some properties of chitosan composite films enriched with essential oils of cinnamon, thyme, clove, and lime alone or in combination; and second select the most appropriate formulation and evaluate their effect on physiological properties and fungal incidence of papaya Maradol stored at environmental tropical conditions. Breaking strength, thickness, color, moisture, water vapor permeability, solubility and water sorption of films were measured. Furthermore, in vitro activity was evaluated against Colletotrichum gloeosporioides Penz. Using multivariate analysis and based on the most desirable characteristics (low water sorption values, water vapor permeability, solubility, and greater inhibition of C. gloeosporioides), three formulations of films were used lately for coated fruit of papaya Maradol and stored at 28 ± 2 °C and 85 % RH. Two control treatments were included: one uncoated and other treated with Mancozeb® fungicide. At six days of storage, the fruit of both control treatments showed evident signs of ripening; contrary to the treatments wherein fruit were coated, and had low respiration, other attributes as firmness, little change in the external color of the fruit were manifested. Similarly, the use of composite films reduced the fungus C. gloeosporioides by 30-50 %. The use of film enriched with essential oil of 1 % cinnamon- 1 % thyme improved the characteristics of fruit quality, increased shelf life and reduced by 50 % the incidence of fungus in papaya Maradol stored under humid tropic environmental conditions. This coating can be an alternative to potentially reduce the need for cold storage during postharvest handling.

Diatomite as a novel composite ingredient for chitosan film with enhanced physicochemical properties

Practical applications of biopolymers in different industries are gaining considerable increase day by day. But still, these biopolymers lack important properties in order to meet the industrial demands. In the same regard, in the current study, chitosan composite films are produced by incorporating diatomite soil at two different concentrations. In order to obtain a homogeneous film, glutaraldehyde was supplemented to chitosan solution as a cross-linker. Compositing diatomaceous earth to chitosan film resulted in improvement of various important physicochemical properties compared to control such as; enhanced film wettability, increase elongation at break and improved thermal stability (264–277°C). The microstructure of the film was observed to haveconsisted of homogeneously distributed blister-shaped structures arised due to the incorporation of diatomite. The incorporation of diatomite did not influence the overall antioxidant activity of the composite films, which can be ascribe to the difficulty radicals formation. Chitosan film incorporated with increasing fraction of diatomite revealed a notable enhancement in the antimicrobial activity. Additionally with the present study, for the first time possible interactions between chitosan/diatomite were determined via quantum chemical calculations. Current study will be helpful in giving a new biotechnological perspective to diatom in terms of its successful application in hydrophobic composite film production.

Strong and stiff Ag nanowire-chitosan composite films reinforced by Ag–S covalent bonds

High-performance composites containing various kinds of nanofibers as reinforcing building blocks have recently received considerable attention, owing to their superior mechanical properties. One of the effective strategies to reinforce these composites involves strengthening interfacial interactions via covalent bonds. However, in contrast to nanosheets, covalent bonds have been rarely used in nanofiber-reinforced composites. Herein, we report the macroscale fabrication of a series of Ag nanowire (NW)-thiolated chitosan (TCS) composite films via spray induced self-assembly. The obtained films were significantly strengthened by Ag–S covalent bonds formed between the Ag NWs and the thiol groups of TCS. The tensile strength of the optimized Ag NW-TCS film was up to 3.9 and 1.5 times higher compared with that of pure TCS and Ag NW-chitosan (CS) films, respectively.

Preparation of chitosan composite film reinforced with cellulose isolated from oil palm empty fruit bunch and application in cadmium ions removal from aqueous solutions

Chitosan composite films reinforced with cellulose isolated from oil palm empty fruit bunch had been successfully prepared and applied in cadmium ions removal from aqueous solutions. Cellulose particles were isolated by hydrolyzing oil palm empty fruit bunch with hydrochloric acid. Several compositions were prepared by varying the chitosan/cellulose ratio of composites. The structure and the properties of composites were investigated by Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD) and mechanical performance measurement. FTIR spectra confirmed that cellulose particles were incorporated into the chitosan matrix. Tensile test results showed that the contents of chitosan and cellulose influenced the mechanical properties of composites. The composite with 10wt% cellulose particles had the highest tensile strength. The X-ray diffraction patterns indicate the crystallinity index of composites decreased with addition of cellulose particles. This low crystallinity is important for metal ions removal in water treatment. Application of composite for cadmium removal from aqueous solutions was done by various solution pH, contact time and concentrations. The adsorption isotherm of Cd ions onto the composite was well fitted to Langmuir equation. Furthermore, the adsorbent still exhibited good adsorption performance after regeneration.

Electrochemical synthesis of poly(pyrrole-co-o-anisidine)/chitosan composite films

In this study, poly(pyrrole-co-o-anisidine)/chitosan composite films were electrochemically synthesized in various monomers feed ratio (pyrrole: o-anisidine; 9:1, 7:3, 1:1, 3:7 and 1:9) of pyrrole and o-anisidine on the platinum electrode. Electrochemical synthesis of the composite films was carried out via cyclic voltammetry technique. They were characterized by FT-IR, cyclic voltammetry, SEM micrographs, digital images, TGA and DSC techniques. The SEM results indicated that the particle size of the composite decreased with increasing o-anisidine ratio and the films became more likely to be smooth morphology. The TGA results proved that the film of the composite with 1:1 ratio showed highest final degradation temperature and lowest weight loss (83%) compared to copolymer and 9:1 1:9 composite films. The 1:1 composite film had higher thermal stability than copolymer and the other composite films (9:1 1:9). Meanwhile, electrochemical studies exhibited that the 1/9 composite film had good electrochemical stability as well.

Surface characteristics of the 316L stainless steel modified by ethylene vinyl acetate/chitosan composite films

This study investigated the surface characteristics and anticoagulant properties of 316L stainless steel coated with ethylene vinyl acetate (EVA)/chitosan (CS) composite films, using various EVA/CS ratios, for biomedical applications. The Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) results showed that in the EVA/CS composite films, the signal of the –CH3 hydrophobic functional group became more significant when the EVA powder content increased. The results of the bicinchoninic acid (BCA) protein assay showed that EVA/CS composite films with EVA/CS content ratios lower than 5 possessed lower adsorption concentrations of bovine serum albumin than chitosan films, suggesting that the anticoagulant properties of 316L stainless steel could be improved after its surface modification with EVA/CS composite films. However, when the EVA/CS content ratio was higher than 8, the anticoagulant properties of the EVA/CS composite films deteriorated significantly because its surface morphology became rougher with abundant protuberances. Therefore, EVA/CS composite films with appropriate EVA/CS content ratios are good candidate materials for biomedical applications because they possess advantages such as hydrophobic properties, smooth surface morphologies, and a low capacity for protein adsorption.

Characterization of whey protein-carboxymethylated chitosan composite films with and without transglutaminase treatment

Edible composite packaging has the advantage of complementary functional properties over its each bio-components. However, reports on whey protein concentrates (WPC)-carboxymethylated chitosan (CMC) composite films have not yet been released. To investigate the preparation of WPC-CMC composite films and its functional properties, four types of WPC-CMC composite films were prepared with and without Transglutaminase (TGase) treatment by mixing WPC aqueous solutions (10%, w/v) with CMC aqueous solutions (3%, w/v) at WPC to CMC volume ratios of (100:0), (75:25), (50:50), and (25:75). SDS-PAGE confirmed that TGase catalyzed crosslinking of whey protein. Results revealed that CMC incorporation conferred a smooth and even surface microstructure on the films and markedly improved the transparency, water barrier properties, mechanical properties and solubility of the composite film. Furthermore, TGase resulted in an improvement in the water vapor barrier properties and mechanical properties of WPC-CMC (75:25 and 50:50, v/v) composite films, and there was no impairment of thermal stability of composite films. Therefore, TGase successfully facilitated the formation of WPC-CMC composite films with some improved functional properties. This offers potential applications as an alternative approach to the preparation of edible packaging films.