scholarly journals Development and Evaluation of the Chromatic Behavior of an Intelligent Packaging Material Based on Cellulose Acetate Incorporated with Polydiacetylene for an Efficient Packaging

Biosensors ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 59 ◽  
Author(s):  
Lina D. Ardila-Diaz ◽  
Taíla V. de Oliveira ◽  
Nilda de F. F. Soares
Keyword(s):  
Cellulose Acetate ◽  
Color Change ◽  
Uv Light ◽  
Research Field ◽  
Polymerization Time ◽  
Intelligent Packaging ◽  
Color Coordinates ◽  
Color Changes ◽  
Consumer Safety ◽  
Temperature Exposure

Global growth of the food industry and the demand for new products with natural characteristics, safe conditions and traceability have driven researches for the development of technologies such as intelligent packaging, capable to fulfil those needs. Polydiacetylene (PDA) is a synthetic material that has been highlighted in research field as a sensor substance, which can be used to produce intelligent packaging capable to detect chemical or biochemical changes in foods and in their environment due to PDA’s color transition from blue to red. This work focused on the development and optimization of an intelligent packaging constituted of a polymeric matrix of cellulose acetate-based incorporated with PDA as the substance sensor. Cellulose acetate films (3% wt.) were developed by a casting method, and the amounts of triethyl citrate plasticizer (TEC) (0–25% wt. of cellulose-acetate) and PDA (0–60 mg) were analyzed to optimize the conditions for the best color transitioning at this study range. The compound amounts incorporated into polymeric matrices were established according to Central Composite Designs (CCD). Three more design variables were analyzed, such as the polymerization time of PDA under UV light exposition (0–60 min), pH values (4–11) and temperature exposure on the film (0–100 °C), important factors on the behavior of PDA’s color changing. In this study, film thickness and film color coordinates were measured in order to study the homogeneity and the color transitioning of PDA films under different pH and temperature conditions, with the purpose of maximizing the color changes through the optimization of PDA and TEC concentrations into the cellulose acetate matrix and the polymerization degree trigged by UV light irradiation. The optimal film conditions were obtained by adding 50.48 g of PDA and 10% of TEC, polymerization time of 18 min under UV light, at 100 °C ± 2 °C of temperature exposure. The changes in pH alone did not statistically influence the color coordinates measured at the analyzed ratio; however, variations in pH associated with other factors had a significant effect on visual color changes, and observations were described. PDA films were optimized to maximize color change in order to obtain a cheap and simple technology to produce intelligent packaging capable to monitor food products along the distribution chain in real time, improving the food quality control and consumer safety.

scholarly journals Biobased intelligent packaging application

2020 ◽  
Author(s):  
Aslı Beyler Çiğil ◽  
Keyword(s):  
Cellulose Acetate ◽  
Intelligent Systems ◽  
Color Change ◽  
Consumer Preferences ◽  
Uv Spectroscopy ◽  
Contact Angles ◽  
Active Packaging ◽  
Cellulose Acetate Butyrate ◽  
Intelligent Packaging ◽  
Acetate Butyrate

Changes in consumer preferences in order to reach safe food have led to innovations in packaging technologies. Intelligent and active packaging is a constantly developed packaging technology that plans to offer safer and higher quality products. Active packaging refers to the inclusion of additives in the package in order to maintain and / or extend shelf life and product quality. Intelligent systems, on the other hand, are systems that monitor the status of packaged food during this entire period to provide information about the quality of the packaged during storage and transportation. The aim of this study is to produce a completely natural intelligent packaging material using rosehip extract and biopolymer, which is a substance that naturally changes color with pH. In this study, cellulose acetate butyrate biobased films containing different rates (1, 2.5, 5, 10 wt%) of rosehip extract were produced by solvent casting method. The chemical structure the rosehip containing biobased film and blank biobased film were characterized by ATR-FTIR. The transparency of prepared five different films were determined by UV spectroscopy. The color characteristic of blank and rosehip containing films measured with spectrophotometer. Surface energy of all films and contact angles were determined with goniometer. Biobased films were printed and printability parameters such as color, gloss, contact angle, surface tension were examined. It is concluded that blank biobased film is colorless, transparent and all biobased films have good printability. It was determined that the amount of rosehip extract increased the color change visibly. The biobased films obtained are pink in acidic medium and yellow-green in alkaline medium. The results prove that biobased film produced with rosehip extract and cellulose acetate butyrate can be used in intelligent packaging applications.

Photostabilizers performance on the surface analysis of green composites

2020 ◽  
Vol 29 (1) ◽  
pp. 57-64
Author(s):  
Hasret Ece Sönmez ◽  
Mehmet Safa Bodur ◽  
Alper Adrian Baysan ◽  
Mustafa Bakkal ◽  
Ersin Serhatli
Keyword(s):  
Surface Analysis ◽  
Color Change ◽  
Uv Light ◽  
Light Exposure ◽  
Accelerated Weathering ◽  
Reinforced Composites ◽  
Color Changes ◽  
Photodegradation Mechanism ◽  
Ldpe Composites

In this work, various stabilizers have been introduced to prevent or delay degradation due to ultraviolet (UV) light exposure to prolong the service life of cotton fiber-reinforced composites. The effect of various additives like hindered amine light stabilizer, UV absorber (UVA), and antioxidant as photostabilizers of CF/low-density polyethylene (CF/LDPE) composites was compared. We showed how they influence to delay or eliminate the photodegradation of CF/LDPE subjected accelerated weathering. Surface analysis was performed by Fourier transform infrared spectroscopy and color measurements. The results showed us the insight of the photodegradation mechanism of weathered CF/LDPE composites undergoing photooxidative reactions which causes a loss surface quality such as micro-cracking and color change. Among the stabilizers, UVA was found to be the most effective to delay some color changes in long term.

scholarly journals Effects of UV light irradiation on color changes in thermally modified rubber wood based on FTIR

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 5179-5197
Author(s):  
Xiaowen Li ◽  
Tongtong Li ◽  
Guanjun Li ◽  
Min Li ◽  
Quanji Lu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Color Change ◽  
Uv Light ◽  
Untreated Wood ◽  
Transformation Process ◽  
Carbonyl Groups ◽  
Chemical Changes ◽  
Color Changes ◽  
Rubber Wood ◽  
Treatment Conditions

To evaluate the effects of chemical changes during thermal modification on the resistance of wood against photodegradation, heat-treated specimens of rubber wood (Hevea brasiliensis) were exposed to ultraviolet light for 384 h. The color changes in the exposed wood surfaces were analyzed using a colorimeter; the chemical changes were monitored using Fourier-transform infrared spectroscopy (FTIR). The photoweathering performances of rubber wood treated at 155 °C for 2 h, 155 °C for 6 h, and 185 °C for 2 h were similar to that of untreated wood, as the lignin did not undergo profound chemical transformation under mild modification conditions. However, compared to untreated rubber wood, the photoaging performances of rubber wood treated at 185 °C for 6 h and 215 °C for 2 h were notably changed. The transformation process was confirmed by FTIR. A good linear relationship between color change and lignin degradation was observed after mild, but not severe, heat treatment. The concentration of carbonyl groups in the wood specimens generally increased during photoaging, although not all samples showed a good correlation between color change and the concentration of carbonyl groups. Only the photochromic performance of wood changed notably when lignin was extensively modified under severe heat-treatment conditions.

scholarly journals The Influence of Drying Temperature on Color Change of Hornbeam and Maple Wood Used as Surface and Inner Layers of Wood Composites

2021 ◽  
Vol 11 (22) ◽  
pp. 10673
Author(s):  
Ivan Klement ◽  
Peter Vilkovský ◽  
Tatiana Vilkovská ◽  
Kazimierz A. Orłowski ◽  
Jacek Barański ◽  
...  
Keyword(s):  
High Temperature ◽  
Color Change ◽  
Color Difference ◽  
Wood Composites ◽  
Drying Temperature ◽  
Color Coordinates ◽  
Color Changes ◽  
Hot Air ◽  
Two Phases ◽  
Total Color Difference

The thermal treatment of wood changes its structure due to the degradation of wood polymers (cellulose, hemicellulose and lignin), so the physical properties of wood are either improved or degraded. Color changes apply not only to natural wood, but also to such wood composites for which some amount of glue is used in their construction (e.g., plywood, blockboard or laminboard). This article is focused on the analysis of hornbeam and field maple wood color changes influenced by drying temperature. Two types of drying modes were used: hot-air mode where the temperature of the drying environment was 60 °C, and high-temperature mode with a drying temperature of 120 °C. The drying mode was divided into two phases depending on the moisture content of the wood. The compared woods had similar values of color coordinates at the beginning of drying. During hot-air drying, the largest changes in color coordinates occurred during the first 24 h. The total color difference between the color at the end and the beginning of drying was 7.3 for hornbeam and 11.1 for maple. The overall color difference between the compared woods was minimal. During high-temperature drying (120 °C), the color changes of the dried woods were more pronounced. In the case of maple wood, there was a very significant change in color and the value of ΔE* was twice as high as for hornbeam. The total color difference between the color at the end and at the beginning of drying was 8.7 for hornbeam and 18.9 for maple.

Reddening by UV Irradiation after Smoke-Heating in Sugi (Cryptomeria japonica D. Don) Black Heartwood

Holzforschung ◽  
2001 ◽  
Vol 55 (4) ◽  
pp. 347-354 ◽  
Author(s):  
Saori Maruyama ◽  
Futoshi Ishiguri ◽  
Minoru Andoh ◽  
Zensaku Abe ◽  
Shinso Yokota ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Uv Irradiation ◽  
Cryptomeria Japonica ◽  
Color Change ◽  
Ph Value ◽  
Uv Light ◽  
Japanese Cedar ◽  
Color Changes ◽  
Black Heartwood ◽  
Thermally Treated

Summary Sugi (Japanese cedar, Cryptomeria japonica D. Don) green logs with black heartwood were smoked, heated, and smoke-heated separately to improve the heartwood color. After each treatment, changes in heartwood color, pH, and extract amounts were examined. In addition, changes in heartwood color caused by UV irradiation were observed. Heating and smoke-heating of logs prevented the heartwood from discoloring to black, and the resulting color of thermally-treated heartwoods was yellow-white, whereas smoking alone allowed discoloration to black. The pH value decreased from the original 7.6 to 6.8 by smoking and to 6.5 by thermal treatment. The results obtained here suggest that a pH drop in heartwood by thermal treatment is involved in color changes of black heartwood. When thermally-treated black heartwood was exposed to UV light, redness and yellowness increased and brightness decreased. The resulting color tone was reddish brown. The color of non-thermally-treated woods, however, showed little change. Furthermore, acetone, ethanol, and methanol extracts of thermally-treated black heartwood showed an increase in redness by UV irradiation, but the residues showed little color change. The coloring substances relating to the reddening of heartwood could be extracted with these solvents, particularly with methanol. Reddening in black heartwood by a combination of smoke-heating and UV irradiation is considered to be due to a decrease in brightness and an increase in both redness and yellowness.

scholarly journals Investigation of the selective color-changing mechanism of Dynastes tityus beetle (Coleoptera: Scarabaeidae)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiyu Sun ◽  
Wei Wu ◽  
Limei Tian ◽  
Wei Li ◽  
Fang Zhang ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Color Change ◽  
Incidence Angle ◽  
Ion Beam ◽  
Three Dimensional ◽  
Water Infiltration ◽  
Photonic Materials ◽  
Local Color ◽  
Water Contact ◽  
Color Changes

AbstractNot only does the Dynastes tityus beetle display a reversible color change controlled by differences in humidity, but also, the elytron scale can change color from yellow-green to deep-brown in specified shapes. The results obtained by focused ion beam-scanning electron microscopy (FIB-SEM), show that the epicuticle (EPI) is a permeable layer, and the exocuticle (EXO) is a three-dimensional photonic crystal. To investigate the mechanism of the reversible color change, experiments were conducted to determine the water contact angle, surface chemical composition, and optical reflectance, and the reflective spectrum was simulated. The water on the surface began to permeate into the elytron via the surface elemental composition and channels in the EPI. A structural unit (SU) in the EXO allows local color changes in varied shapes. The reflectance of both yellow-green and deep-brown elytra increases as the incidence angle increases from 0° to 60°. The microstructure and changes in the refractive index are the main factors that influence the process of reversible color change. According to the simulation, the lower reflectance causing the color change to deep-brown results from water infiltration, which increases light absorption. Meanwhile, the waxy layer has no effect on the reflection of light. This study lays the foundation to manufacture engineered photonic materials that undergo controllable changes in iridescent color.

scholarly journals Deposition of Zinc Oxide Coatings on Wood Surfaces Using the Solution Precursor Plasma Spraying Process

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 183
Author(s):  
Ghiath Jnido ◽  
Gisela Ohms ◽  
Wolfgang Viöl
Keyword(s):  
Zinc Oxide ◽  
Ftir Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Color Change ◽  
Uv Light ◽  
Beech Wood ◽  
Nitrate Solution ◽  
Ftir Spectra ◽  
Solution Precursor ◽  
Wood Surfaces

In the present work, the solution precursor plasma spray (SPPS) process was used to deposit zinc oxide (ZnO) coatings on wood surfaces using zinc nitrate solution as precursor to improve the hydrophobicity and the color stability of European beech wood under exposure to ultraviolet (UV) light. The surface morphology and topography of the wood samples and the coatings were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The formation of ZnO was detected with the help of X-ray photoelectron spectroscopy (XPS) and by Fourier transform infrared (FTIR) spectroscopy. The FTIR spectra of the coated samples showed the typical Zn–O band at 445 cm−1. According to the XPS analysis, the coatings consist of two different Zn-containing species: ZnO and Zn(OH)2. Variation of the deposition parameters showed that the most significant parameters affecting the microstructure of the coating were the solution concentration, the deposition scan speed, and carrier gas flow rate. The wettability behaviors of the coated wood were evaluated by measuring the water contact angle (WCA). The coatings that completely covered the wood substrates showed hydrophobic behaviors. UV-protection of wood surfaces after an artificial UV light irradiation was evaluated by color measurements and FTIR spectroscopy. The ZnO-coated wood surfaces were more resistant to color change during UV radiation exposure. The total color change decreased up to 60%. Additionally, the FTIR spectra showed that the wood surfaces coated with ZnO had more stability. The carbonyl groups formation and C=C-bonds consumption were significantly lower.

scholarly journals Characterization of Food Packaging Films with Blackcurrant Fruit Waste as a Source of Antioxidant and Color Sensing Intelligent Material

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2569
Author(s):  
Mia Kurek ◽  
Nasreddine Benbettaieb ◽  
Mario Ščetar ◽  
Eliot Chaudy ◽  
Maja Repajić ◽  
...  
Keyword(s):  
Food Packaging ◽  
Water Solubility ◽  
Color Change ◽  
Chitosan Film ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Color Changes ◽  
Insoluble Particles ◽  
Polymer Stability ◽  
Food Packaging Films

Chitosan and pectin films were enriched with blackcurrant pomace powder (10 and 20% (w/w)), as bio-based material, to minimize food production losses and to increase the functional properties of produced films aimed at food coatings and wrappers. Water vapor permeability of active films increased up to 25%, moisture content for 27% in pectin-based ones, but water solubility was not significantly modified. Mechanical properties (tensile strength, elongation at break and Young’s modulus) were mainly decreased due to the residual insoluble particles present in blackcurrant waste. FTIR analysis showed no significant changes between the film samples. The degradation temperatures, determined by DSC, were reduced by 18 °C for chitosan-based samples and of 32 °C lower for the pectin-based samples with blackcurrant powder, indicating a disturbance in polymer stability. The antioxidant activity of active films was increased up to 30-fold. Lightness and redness of dry films significantly changed depending on the polymer type. Significant color changes, especially in chitosan film formulations, were observed after exposure to different pH buffers. This effect is further explored in formulations that were used as color change indicators for intelligent biopackaging.

scholarly journals Effect of Cellulose Nanocrystal Addition on the Physicochemical Properties of Hydroxypropyl Guar-Based Intelligent Films

Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 242
Author(s):  
Yahui Meng ◽  
Yunfeng Cao ◽  
Kaifeng Xiong ◽  
Li Ma ◽  
Wenyuan Zhu ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Composite Films ◽  
Food Preservation ◽  
Ph Sensing ◽  
Functional Material ◽  
Intelligent Packaging ◽  
Application Range ◽  
Color Changes ◽  
Hydroxypropyl Guar ◽  
Food Freshness

As an important functional material in food industry, intelligent packaging films can bring great convenience for consumers in the field of food preservation and freshness detection. Herein, we fabricated pH-sensing films employing hydroxypropyl guar (HPG), 1-butyl-3-methylimidazolium chloride (BmimCl), and anthocyanin (Anth). Besides, the effects of adding cellulose nanocrystals (CNC) into the composite films upon the films’ structures and physicochemical properties are elucidated. The addition of CNC promoted more compact film structures. Moreover, CNC dramatically improved several properties of the pH-sensing films, including the distinguishability of their color changes, sensitivity to pH, permeability to oxygen and water vapor, solvent resistance, durability, and low-temperature resistance. These results expand the application range of pH-sensing films containing CNC in the fields of food freshness detection and intelligent packaging.

Influence of Hydrogen Peroxide Bleaching Gels on Color, Opacity, and Fluorescence of Composite Resins

2012 ◽  
Vol 37 (5) ◽  
pp. 526-531 ◽  
Author(s):  
CRG Torres ◽  
CF Ribeiro ◽  
E Bresciani ◽  
AB Borges
Keyword(s):  
Hydrogen Peroxide ◽  
Composite Resin ◽  
Color Change ◽  
Composite Resins ◽  
Control Group ◽  
Peroxide Bleaching ◽  
Color Changes ◽  
Tukey Test ◽  
Bleaching Gels ◽  
Bleaching Treatment

SUMMARY The aim of the present study was to evaluate the effect of 20% and 35% hydrogen peroxide bleaching gels on the color, opacity, and fluorescence of composite resins. Seven composite resin brands were tested and 30 specimens, 3-mm in diameter and 2-mm thick, of each material were fabricated, for a total of 210 specimens. The specimens of each tested material were divided into three subgroups (n=10) according to the bleaching therapy tested: 20% hydrogen peroxide gel, 35% hydroxide peroxide gel, and the control group. The baseline color, opacity, and fluorescence were assessed by spectrophotometry. Four 30-minute bleaching gel applications, two hours in total, were performed. The control group did not receive bleaching treatment and was stored in deionized water. Final assessments were performed, and data were analyzed by two-way analysis of variance and Tukey tests (p<0.05). Color changes were significant for different tested bleaching therapies (p<0.0001), with the greatest color change observed for 35% hydrogen peroxide gel. No difference in opacity was detected for all analyzed parameters. Fluorescence changes were influenced by composite resin brand (p<0.0001) and bleaching therapy (p=0.0016) used. No significant differences in fluorescence between different bleaching gel concentrations were detected by Tukey test. The greatest fluorescence alteration was detected on the brand Z350. It was concluded that 35% hydrogen peroxide bleaching gel generated the greatest color change among all evaluated materials. No statistical opacity changes were detected for all tested variables, and significant fluorescence changes were dependent on the material and bleaching therapy, regardless of the gel concentration.

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