scholarly journals Modification Effect of Cellulase on the Physicochemical Characteristic of Polysaccharides Edible Films

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Anna Zimoch-Korzycka ◽  
Jagoda Ambrozik-Haba ◽  
Dominika Kulig ◽  
Andrzej Jarmoluk
Keyword(s):  
Contact Angle ◽  
Hydroxypropyl Methylcellulose ◽  
Physicochemical Characteristic ◽  
Edible Films ◽  
Enzyme Treatment ◽  
Infrared Spectrometry ◽  
Vapour Permeability ◽  
Physicochemical Stability ◽  
Higher Temperature ◽  
Thermal Stability Of

This study was conducted to assess hydrolytic influence of cellulase (C) on the physicochemical stability of chitosan (CH)/hydroxypropyl methylcellulose (HPMC) films in time of storage (T). Initially, nine films were physically characterized by contact angle, water vapour permeability (WVP), water activity(aw), tensile test, dynamic mechanical thermal analysis (DMTA), and thermogravimetric analysis (TGA) and chemically by Fourier Transform Infrared Spectrometry (FTIR). The contact angle results varied from 53.67° to 78.33°. The presence of the enzyme and passing time reduced the WVP from8.46E-09to7.41E-09 g/s·m·Pa. The enzyme treatment improved elasticity but decreased tensile strength of films. After adding cellulaseTgwas shifted to a higher temperature. Thermal stability of the films decreased with addition of cellulase and after prolonging storage time. FTIR analysis proved that chemical changes in polysaccharides structure were caused by cellulase incorporation in films composition, which may be observed in appearance of 1656 cm−1band. Theawvalues did not change.

scholarly journals Chitosan and Cystatin/Lysozyme Preparation as Protective Edible Films Components

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Anna Zimoch-Korzycka ◽  
Antoine Rouilly ◽  
Łukasz Bobak ◽  
Andrzej Jarmoluk ◽  
Michał Korzycki
Keyword(s):  
Hydroxypropyl Methylcellulose ◽  
Chemical Properties ◽  
Inhibition Zone ◽  
Mechanical Analysis ◽  
Edible Films ◽  
Vapour Permeability ◽  
Candida Famata ◽  
Higher Temperature ◽  
Physical And Chemical ◽  
And Storage

This work characterizes biological, physical, and chemical properties of films formed from an aqueous solution of hydroxypropyl methylcellulose (HPMC), with different concentrations of chitosan (CH) and bioactive cystatin/lysozyme preparation (C/L). The properties of biocomposites were examined by Dynamic Mechanical Analysis (DMA), Fourier’s transfer infrared spectroscopy (FTIR), water vapour permeability (WVP), and tensile testing. Antimicrobial activity againstMicrococcus flavus,Bacillus cereus,Escherichia coli,Pseudomonas fluorescens, andCandida famatawas conducted. Films glass transition and storage modulus were dependent on the C/L and CH concentration. Modulus values decreased during the temperature scan and with higher reagents levels. An increase of CH and C/L concentrations in the films resulted in a decrease in tensile strength from 2.62 to 1.08 MPa. It suggests the hydrolyzing influence of C/L, also observed in smaller peak size ofαrelaxation. C/L addition caused shiftingTgto higher temperature. DMA and FTIR analysis proved that HPMC and CH are compatible polymers. Water resistance was improved with rising CH concentration from1.08E-09to7.71E−10 g/m∗s∗Pa. The highest inhibition zone inM. flavusandC. famatawas recorded at the highest concentration of CH and C/L.

scholarly journals Ecofriendly Preparation and Characterization of a Cassava Starch/Polybutylene Adipate Terephthalate Film

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 329
Author(s):  
Tan Yi ◽  
Minghui Qi ◽  
Qi Mo ◽  
Lijie Huang ◽  
Hanyu Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Contact Angle ◽  
Water Vapor ◽  
Composite Film ◽  
Water Absorption ◽  
Composite Films ◽  
Thermoplastic Starch ◽  
Light Transmittance ◽  
Infrared Spectrometry ◽  
Nano Zno

Composite films of polybutylene adipate terephthalate (PBAT) were prepared by adding thermoplastic starch (TPS) (TPS/PBAT) and nano-zinc oxide (nano-ZnO) (TPS/PBAT/nano-ZnO). The changes of surface morphology, thermal properties, crystal types and functional groups of starch during plasticization were analyzed by scanning electron microscopy, synchronous thermal analysis, X-ray diffraction, infrared spectrometry, mechanical property tests, and contact Angle and transmittance tests. The relationship between the addition of TPS and the tensile strength, transmittance, contact angle, water absorption, and water vapor barrier of the composite film, and the influence of nano-ZnO on the mechanical properties and contact angle of the 10% TPS/PBAT composite film. Experimental results show that, after plasticizing, the crystalline form of starch changed from A-type to V-type, the functional group changed and the lipophilicity increased; the increase of TPS content, the light transmittance and mechanical properties of the composite membrane decreased, while the water vapor transmittance and water absorption increased. The mechanical properties of the composite can be significantly improved by adding nano-ZnO at a lower concentration (optimum content is 1 wt%).

Effect of temperature on composite films made with activated carbon, graphite, or graphene oxide (GO) in a gelatin matrix

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 77-95
Author(s):  
Siqiao Yang ◽  
Haichao Li
Keyword(s):  
Contact Angle ◽  
Activated Carbon ◽  
Water Absorption ◽  
Composite Films ◽  
Effect Of Temperature ◽  
Gelatin Matrix ◽  
Vapour Permeability ◽  
Blending Method ◽  
The Matrix ◽  
Different Temperatures

Activated carbon, graphite, and GO/gelatin composite films were prepared by the blending method. The properties of composites were characterized by tensile strength (TS), elongation at break (EB), water vapour permeability (WVP), water-absorption ability, contact angle, scanning electron microscopy (SEM), and moisture at different temperatures. The properties of GO/gelatin composite films were better when each of three kinds of carbon materials were used as reinforcement phases and added into the matrix gelatin. The results showed that EB and TS of GO/gelatin composite films were both excellent. The moisture of GO/gelatin composite films was greater than the others. SEM micrographs showed that GO had better compatibility and dispersibility with gelatin than activated carbon and graphite. The water absorption of GO/gelatin composite films were low, at 15 °C and 25 °C, and the WVP was low at 35 °C. The WVP of GO/gelatin composite films was lower than the others at different temperatures. The contact angle of GO/gelatin composite films was larger than the others.

Systematic Characterization of Different Quaternary Ammonium Salts to be Used in Organoclays

2012 ◽  
Vol 727-728 ◽  
pp. 1552-1556
Author(s):  
Renata Barbosa ◽  
Dayanne Diniz Souza ◽  
Edcleide Maria Araújo ◽  
Tomás Jefférson Alves de Mélo
Keyword(s):  
Thermal Stability ◽  
Quaternary Ammonium ◽  
Chemical Structure ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Degradation Mechanisms ◽  
Scanning Calorimetry ◽  
Higher Temperature ◽  
Thermal Stability Of

Studies of degradation have verified that the decomposition of some quaternary ammonium salts can begin to be significant at the temperature of about 180 ° C and like most thermoplastics are processed at least around this temperature, the thermal stability of the salt in clay should always be considered. Some salts are more stable than others, being necessary to study the degradation mechanisms of each case. In this work, four quaternary ammonium salts were characterized by differential scanning calorimetry (DSC) and thermogravimetry (TG). The results of DSC and TG showed that the salts based chloride (Cl-) anion begin to degrade at similar temperatures, while the salt based bromide (Br-) anion degrades at higher temperature. Subsequently, a quaternary ammonium salt was chosen to be used in organoclays, depending on its chemical structure and its thermal behavior.

scholarly journals Effect of High Temperature on the Electrochemical and Optical Properties of Emeraldine Salt Doped with DBSA and Sulfuric Acid

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Salma Gul ◽  
Anwar-ul-Haq Ali Shah ◽  
Salma Bilal
Keyword(s):  
Thermal Stability ◽  
Cyclic Voltammetry ◽  
Sulfuric Acid ◽  
Effect Of Temperature ◽  
Visible Spectroscopy ◽  
Emeraldine Salt ◽  
Higher Temperature ◽  
Stability Effect ◽  
Thermal Stability Of ◽  
Comprehensive Study

A comprehensive study of thermally treated polyaniline in its emeraldine salt form is presented here. It offers an understanding of the thermal stability of the polymer. Emeraldine salt was prepared by a novel emulsion polymerization pathway using dodecylbenzene sulfonic acid and sulfuric acid together as dopants. The effect of temperature and heating rate on the degradation of this emeraldine salt was studied via thermogravimetric analysis. The thermally analyzed sample was collected at various temperatures, that is, 250, 490, 500, and 1000°C. The gradual changes in the structure of the emeraldine salt were followed through cyclic voltammetry, Fourier transform infrared spectroscopy, and ultraviolet-visible spectroscopy. Results demonstrate that emeraldine salt shows high thermal stability up to 500°C. This is much higher working temperature for the use of emeraldine salt in higher temperature applications. Further heat treatment seems to induce deprotonation in emeraldine salt. Cyclic voltammetry and ultraviolet-visible spectroscopy revealed that complete deprotonation takes place at 1000°C where it loses its electrical conductivity. It is interesting to note that after the elimination of the dopants, the basic backbone of emeraldine salt was not destroyed. The results reveal that the dopants employed have a stability effect on the skeleton of emeraldine salt.

Siliconic and Acrylic Resins Dispersed in Water as Protectives for Stone Surface

1992 ◽  
Vol 267 ◽  
Author(s):  
Guido Biscontin ◽  
P. Maravelaki ◽  
E. Zendri ◽  
A. Glisenti
Keyword(s):  
Contact Angle ◽  
Protective Effect ◽  
Water Absorption ◽  
Water Repellency ◽  
Point Of View ◽  
General Effect ◽  
Pore Filling ◽  
Complete Wetting ◽  
Vapour Permeability ◽  
Acrylic Resins

The aim of the present work is to compare the protective effect of solvent and water dispersed products on marble, Lecce and Istria stones. This choice is justified by the need of products effective also from the ecological and toxicological point of view. To obtain these informations two tests have been chosen: contact angle and water absorption. The contact angle may, in theory, be considered a measure of the water repellency, since complete wetting implies a contact angle of 0° and absolutely no wetting an angle of 180°. This does not apply to the water absorption by capillarity test because the absorption variation may be caused by either the water repellency action of the treatments or by the pore filling. However this test may give practical information about the general effect of the treatments. Moreover, the effect of treatments on permeability was investigated by vapour permeability test. Protective effect was studied after application of the products and at various stages of artificial weathering.

Thermal Stability of Soybean Protein Isolate-Based Oleic Acid/Stearic Acid Blend Edible Films

2013 ◽  
Vol 469 ◽  
pp. 171-174 ◽  
Author(s):  
Ning Zhang ◽  
Si Yao Sui ◽  
Zhe Wang ◽  
Zhong Su Ma
Keyword(s):  
Thermal Stability ◽  
Oleic Acid ◽  
Stearic Acid ◽  
Soybean Protein ◽  
Soy Protein Isolate ◽  
Edible Films ◽  
Protein Isolate ◽  
Soybean Protein Isolate ◽  
The Matrix ◽  
Thermal Stability Of

Edible films were prepared using soy protein isolate (4g/100g), oleic acid (0-2g/100g) and stearic acid (0-2g/100g). Effects of the type and ratio of fatty acids (oleic acid and stearic acid) on the thermal properties of soybean protein isolate-based films were investigated. The results indicated that the addition of oleic acid and stearic acid take a significant effect on the thermal stability of soybean protein isolate-based films, as may attribute to that oleic acid is an amphiphilic substance that interacts with both polar and hydrophobic sites on proteins, thus it could improve the functional properties of the films. Besides, the solid state and hydrophobic nature of stearic acid could help limit water diffusion in the matrix more efficiently when it is well-integrated in the matrix through the surfactant action of oleic acid.

The Synthesis and Characterization of the Graphene Oxide Covalent Modified Phenolic Resin Nanocomposites

2011 ◽  
Vol 327 ◽  
pp. 115-119 ◽  
Author(s):  
Duo Wang ◽  
Jie Gao ◽  
Wei Fang Xu ◽  
Feng Bao ◽  
Rui Ma ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Phenolic Resin ◽  
Synthesis And Characterization ◽  
Infrared Spectrometry ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Hummers Method ◽  
Modified Hummers Method ◽  
Thermal Stability Of

Graphene oxide (GO) was made by a modified Hummers method. Graphene oxide modified phenolic resin nanocomposites (GO/PF) were prepared by Steglich esterification, catalyzed by dicyclohexyl carbodiimide and 4-dimethylaminopyridine. The composites were characterized by Fourier transform infrared spectrometry, differential scanning calorimetry, X-ray powder diffraction, and scanning electron microscopy. The result revealed that the graphene oxide was absolutely exfoliated and covalent linked GO/PF composite was obtained. The thermal stability of PF is remarkably improved by modification with GO.

Study of Thermal Stability of Superhydrophobic Properties of Coatings Formed on Magnesium Alloy

2021 ◽  
Vol 324 ◽  
pp. 3-8
Author(s):  
Konstantine V. Nadaraia ◽  
Dmitry V. Mashtalyar ◽  
Sergey N. Suchkov ◽  
Vera V. Mostovaya ◽  
Igor M. Imshinetskiy ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Contact Angle ◽  
Magnesium Alloy ◽  
Contact Angle Hysteresis ◽  
Surface Layers ◽  
Properties Of Coatings ◽  
Composite Layers ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Thermal Stability Of

The thermal stability of the superhydrophobic properties of coatings obtained on a magnesium alloy by plasma electrolytic oxidation (PEO) followed by treatment with fluoropolymer was studied. It was established that formed surface layers have contact angle (CA) equal to 171° and contact angle hysteresis equal to 6° at 25 °C, which allows to characterize them as superhydrophobic. After 5 cycles of cooling-heating of composite layers, CA was 135°, indicating the durability of coatings. Additionally, obtained polymer-containing layers demonstrated low wettability at 0 °C (CA was 105°).

Sign in / Sign up

Export Citation Format

Share Document