scholarly journals Effect of the Addition of Essential Oils and Functional Extracts of Clove on Physicochemical Properties of Chitosan-Based Films

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Paola Reyes-Chaparro ◽  
Nestor Gutierrez-Mendez ◽  
Erika Salas-Muñoz ◽  
Juan Guillermo Ayala-Soto ◽  
David Chavez-Flores ◽  
...  
Keyword(s):  
Essential Oils ◽  
Water Vapour ◽  
Chitosan Film ◽  
Barrier Properties ◽  
Vapour Permeability ◽  
Force Microscopy ◽  
Atomic Force ◽  
Control Film ◽  
Chitosan Films ◽  
Positive Effect

Mechanical and barrier properties of chitosan films prepared with essential oils of clove and functional extract were studied. The films made with functional extracts (esters E6and E7) presented the significant increment of extensibility compared with the untreated chitosan films. In the case of punction test, the films made with the esters E6and E7resisted more the applied strength before tearing up compared with the chitosan control film (without any treatment). Thermogravimetric analysis values were determined for the chitosan control film and chitosan film treated with clove essential oil obtaining 112.17°C and 176.73°C, respectively. Atomic force microscopy (AFM) was used to determine their morphology by analyzing their surfaces and phase arrangement; AFM was also used to observe the porosity in chitosan-based antimicrobial films and the chitosan films incorporating functional extracts. The water vapour permeability (WVP) data showed that incorporating the functional extract to the formulation of films has a positive effect on water vapour barrier properties. In general, the incorporation of essential oils and functional extract of clove at 20% in chitosan films caused microstructural changes that were dependent on the different affinity of components.

Surface evaluation of whey protein films by atomic force microscopy and water vapour permeability analysis

2004 ◽  
Vol 17 (5) ◽  
pp. 267-273 ◽  
Author(s):  
Paulo Sérgio de Paula Herrmann ◽  
Cristiana M. Pedroso Yoshida ◽  
Aloísio José Antunes ◽  
Jorge A. Marcondes
Keyword(s):  
Atomic Force Microscopy ◽  
Whey Protein ◽  
Water Vapour ◽  
Water Vapour Permeability ◽  
Protein Films ◽  
Vapour Permeability ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Design of Chitosan and Alginate Emulsion-Based Formulations for the Production of Monolayer Crosslinked Edible Films and Coatings

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1654
Author(s):  
Tiago M. Vieira ◽  
Margarida Moldão-Martins ◽  
Vítor D. Alves
Keyword(s):  
Sodium Alginate ◽  
Water Vapour ◽  
Chitosan Film ◽  
Tensile Tests ◽  
Edible Films ◽  
Vapour Permeability ◽  
Hydrophobic Barrier ◽  
Colour Parameters ◽  
Chitosan Films ◽  
Crosslinking Agents

This study aimed to develop edible monolayer emulsion-based barriers with polysaccharides as film-forming components (chitosan and sodium alginate), soy lecithin as a surfactant and olive oil as a hydrophobic barrier. Monolayer barriers in the form of films were prepared by casting filmogenic emulsions composed of 2% w/v chitosan (dissolved in lactic acid 1% v/v) or 1% w/v sodium alginate, with different lipid contents (25, 50 and 100% w/w biopolymer basis) and different surfactant concentrations (5, 10 and 25% w/w, lipid basis). Glycerol was used as a plasticizer (25 % w/w, biopolymer basis). After the emulsion drying process, the obtained stand-alone films were sprayed with a crosslinking solution, achieving an optimized crosslinker content of 3.2 mgCa2+/cm2 alginate film and 4 mg tripolyphosphate/cm2 chitosan film. The effect of oil and lecithin contents, as well the presence of crosslinking agents, on the film’s water vapour permeability (WVP), water vapour sorption capacity, mechanical properties and colour parameters, was evaluated. The results have shown that the lowest WVP values were obtained with formulations containing 25% lipid and 25% surfactant for chitosan films, and 100% lipid and 25% surfactant for alginate films. The application of the crosslinking agents decreased even further the WVP, especially for chitosan films (by 30%). Crosslinking also increased films’ resistance to deformation under tensile tests. Overall, the films developed present a good potential as polysaccharide-based barriers with increased resistance to water, which envisages the use of the designed formulations to produce either edible/biodegradable films or edible coatings.

scholarly journals Atomic Force Microscopy Study of the Surface of Films of Chitosan and Its Salts with Organic Acids

2020 ◽  
Vol 20 (4) ◽  
pp. 387-394
Author(s):  
Darya A. Rudenko ◽  
◽  
Daniil N. Bratashov ◽  
Anna B. Shipovskaya ◽  
◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Morphological Characteristics ◽  
Chitosan Film ◽  
Microscopy Study ◽  
Chemical Form ◽  
Root Mean Square Roughness ◽  
Total Charge ◽  
Force Microscopy ◽  
Atomic Force ◽  
Chitosan Films

The results of the study of the morphology and surface topography of chitosan films of the salt (S-) and basic (B-) chemical form by atomic force microscopy are presented. The films were cast from polymer solutions in acetic, lactic, citric and succinic acid. NaOH and triethanolamine were used for the salt → chitosan base reaction. Surface tomograms were obtained; the main morphological characteristics and roughness parameters of the film samples were estimated. It was found that the morphology, the degree of order, root-mean-square roughness and the height of the surface roughness were determined by the polymer chemical form, the nature of the acid used and the reagent of the polymer-like conversion reaction. The surface of the S-form chitosan films is characterized by fibrillar structural ordering (also dendritic for chitosan succinate), and that of the B-form is globular. The smallest size of surface supramolecular elements was observed for the S-form chitosan films, while the greatest roughness was for the B-form ones. Changing the reagent of the chitosan S → B reaction did not affect the morphological characteristics of the films; however, it affected the microrelief roughness. A more uniform basic chitosan film is formed in an organic base environment. It was suggested that the formation of fibrillar supramolecular structures was due to the unfolding and straightening of macrochains because of the repulsion of the same charged monomer units, while the globular ones were formed due to the folding and densification of macrocoils after neutralizing the total charge of the macrochain.

scholarly journals Back to Nature: Combating Candida albicans Biofilm, Phospholipase and Hemolysin Using Plant Essential Oils

Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 81
Author(s):  
Ahmed M. El-Baz ◽  
Rasha A. Mosbah ◽  
Reham M. Goda ◽  
Basem Mansour ◽  
Taranum Sultana ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Essential Oils ◽  
Docking Study ◽  
New Drugs ◽  
Molecular Docking Study ◽  
Plant Essential Oils ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Analysis ◽  
Phenotypic Methods

Candida albicans is the causative agent of fatal systemic candidiasis. Due to limitations of antifungals, new drugs are needed. The anti-virulence effect of plant essential oils (EOs) was evaluated against clinical C. albicans isolates including cinnamon, clove, jasmine and rosemary oils. Biofilm, phospholipase and hemolysin were assessed phenotypically. EOs were evaluated for their anti-virulence activity using phenotypic methods as well as scanning electron microscopy (SEM) and atomic force microscopy (AFM). Among the C. albicans isolates, biofilm, phospholipase and hemolysins were detected in 40.4, 86.5 and 78.8% of isolates, respectively. Jasmine oil showed the highest anti-biofilm activity followed by cinnamon, clove and rosemary oils. SEM and AFM analysis showed reduced adherence and roughness in the presence of EOs. For phospholipase, rosemary oil was the most inhibitory, followed by jasmine, cinnamon and clove oils, and for hemolysins, cinnamon had the highest inhibition followed by jasmine, rosemary and clove oils. A molecular docking study revealed major EO constituents as promising inhibitors of the Als3 adhesive protein, with the highest binding for eugenol, followed by 1,8-cineole, 2-phenylthiolane and cinnamaldehyde. In conclusion, EOs have a promising inhibitory impact on Candida biofilm, phospholipase and hemolysin production, hence EOs could be used as potential antifungals that impact virulence factors.

scholarly journals Preparation And Properties Of Bionanocomposite Films Reinforced With Nanocellulose Isolated From Moroccan Alfa Fibres

2015 ◽  
Vol 15 (3) ◽  
pp. 164-172 ◽  
Author(s):  
Benyoussif Youssef ◽  
Aboulhrouz Soumia ◽  
El Achaby Mounir ◽  
Cherkaoui Omar ◽  
Lallam Abdelaziz ◽  
...  
Keyword(s):  
Carboxymethyl Cellulose ◽  
Food Packaging ◽  
Fourier Transforms ◽  
Tensile Modulus ◽  
Tensile Tests ◽  
X Ray Diffraction ◽  
Vapour Permeability ◽  
Force Microscopy ◽  
Atomic Force ◽  
Bionanocomposite Films

AbstractNanocellulose (NC) were extracted from the Moroccan Alfa plant (Stipa tenacissima L.) and characterised. These Alfa cellulosic nanoparticles were used as reinforcing phase to prepare bionanocomposite films using carboxymethyl cellulose as matrix. These films were obtained by the casting/evaporation method. The crystallinity of NC was analysed by X-ray diffraction, the dimension of NC by atomic force microscopy, molecular interactions due to incorporation of NC in carboxymethyl cellulose (CMC) matrix were supported by Fourier transforms infrared (FTIR) spectroscopy. The properties of the ensuing bionanocomposite films were investigated using tensile tests, water vapour permeability (WVP) study and thermogravimetric analysis. With the progress of purification treatment of cellulose, the crystallinity is improved compared to the untreated fibres; this can be explained by the disappearance of the amorphous areas in cellulose chain of the plant. Consequently, the tensile modulus and tensile strength of CMC film increased by 60 and 47%, respectively, in the bionanocomposite films with 10 wt% of NC, and decrease by 8.6% for WVP with the same content of NC. The NC obtained from the Moroccan Alfa fibres can be used as a reinforcing agent for the preparation of bionanocomposites, and they have a high potential for the development of completely biodegradable food packaging materials.

scholarly journals Poly(furfuryl alcohol)-Polycaprolactone Blends

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1069 ◽  
Author(s):  
Gabriele Nanni ◽  
José A. Heredia-Guerrero ◽  
Uttam C. Paul ◽  
Silvia Dante ◽  
Gianvito Caputo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Furfuryl Alcohol ◽  
Barrier Properties ◽  
Tensile Tests ◽  
Attenuated Total Reflection ◽  
Toxicity Tests ◽  
Scanning Calorimetry ◽  
Blend Films ◽  
Force Microscopy ◽  
Atomic Force

Poly(furfuryl alcohol) (PFA) is a bioresin synthesized from furfuryl alcohol (FA) that is derived from renewable saccharide-rich biomass. In this study, we compounded this bioresin with polycaprolactone (PCL) for the first time, introducing new functional polymer blends. Although PCL is biodegradable, its production relies on petroleum precursors such as cyclohexanone oils. With the method proposed herein, this dependence on petroleum-derived precursors/monomers is reduced by using PFA without significantly modifying some important properties of the PCL. Polymer blend films were produced by simple solvent casting. The blends were characterized in terms of surface topography by atomic force microscopy (AFM), chemical interactions between PCL and PFA by attenuated total reflection-Fourier transform infrared (ATR-FTIR), crystallinity by XRD, thermal properties by differential scanning calorimetry (DSC), and mechanical properties by tensile tests and biocompatibility by direct and indirect toxicity tests. PFA was found to improve the gas barrier properties of PCL without compromising its mechanical properties, and it demonstrated sustained antioxidant effect with excellent biocompatibility. Our results indicate that these new blends can be potentially used in diverse applications ranging from food packing to biomedical devices.

scholarly journals The Role of Birch Tar in Changing the Physicochemical and Biocidal Properties of Polylactide-Based Films

2021 ◽  
Vol 23 (1) ◽  
pp. 268
Author(s):  
Agnieszka Richert ◽  
Ewa Olewnik-Kruszkowska ◽  
Grażyna B. Dąbrowska ◽  
Henryk P. Dąbrowski
Keyword(s):  
Polymer Films ◽  
Plant Pathogens ◽  
Vapour Permeability ◽  
Elongation At Break ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Analysis ◽  
Physicochemical And Structural Properties ◽  
Reduced Water

The objective of this study was to produce bactericidal polymer films containing birch tar (BT). The produced polymer films contain PLA, plasticiser PEG (5% wt.) and birch tar (1, 5 and 10% wt.). Compared to plasticised PLA, films with BT were characterised by reduced elongation at break and reduced water vapour permeability, which was the lowest in the case of film with 10% wt. BT content. Changes in the morphology of the produced materials were observed by performing scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis; the addition of BT caused the surface of the film to be non-uniform and to contain recesses. FTIR analysis of plasticised PLA/BT films showed that the addition of birch tar did not change the crystallinity of the obtained materials. According to ISO 22196: 2011, the PLA film with 10% wt. BT content showed the highest antibacterial effect against the plant pathogens A. tumefaciens, X. campestris, P. brassicacearum, P. corrugata, P. syringae. It was found that the introduction of birch tar to plasticised PLA leads to a material with biocidal effect and favourable physicochemical and structural properties, which classifies this material for agricultural and horticultural applications.

scholarly journals Application of acrylic-based coatings for concrete protection

2018 ◽  
Vol 163 ◽  
pp. 05011
Author(s):  
Aleksander Kozak
Keyword(s):  
Carbon Dioxide ◽  
Water Vapour ◽  
Barrier Properties ◽  
Test Results ◽  
Coating Technology ◽  
Vapour Permeability ◽  
Coating Performance ◽  
Artificial Weathering ◽  
Current Trends ◽  
Acrylic Coatings

The paper presents a description of acrylic-based polymers used in civil engineering for concrete protection. Some information on chemistry and properties of the acrylic coatings is included together with current trends in coating technology. Moreover, the paper shows test results, that is barrier properties and SEM observations of a commercial elastic acrylic-based polymer subject to artificial weathering for 1000h. The studies showed that the weathering did not change carbon dioxide permeability of the tested coating and its influence on water vapour permeability of the material was also very small. The test results show that an assessment of coating performance based only on barrier properties is not enough.

Mechanical and Barriers Properties of Chitosan Films with Hydrophilic and Hydrophobic Phytotherapics

2014 ◽  
Vol 805 ◽  
pp. 71-76
Author(s):  
Amanda Luiza Basílio Belisário ◽  
Lívia de Siqueira Estevam ◽  
Henrique Selli Debone ◽  
Cristiana Maria Pedroso Yoshida ◽  
Patrícia Santos Lopes ◽  
...  
Keyword(s):  
Water Vapor ◽  
Chitosan Film ◽  
Barrier Properties ◽  
Biological Properties ◽  
Bioactive Substances ◽  
Lower Ability ◽  
Evaporation Technique ◽  
Chitosan Films ◽  
Positive Controls

Chitosan films have been used as dressings for healing burns. The physical and biological properties of these films can be modified by the addition of bioactive substances such as phytotherapics. This work used the casting - solvent evaporation technique for the preparation of chitosan film containing hydrophilic or hydrophobic phytotherapic. The barrier properties, mechanicals properties and microbial penetration were evaluated. The results showed that the films containing the hydrophobic herbal showed lower ability to move fluid and permeability to water vapor compared to the film containing the hydrophilic herbal. For the determination of microbial permeation, film were previously sterilized and were fixed in the mouth of glass vials containing sterile nutrient broth and left on the lab bench for a period of 10 days. Negative and positive controls were also conducted. The chitosan films do not allow the microbial penetration.

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