Colour Stability of Natural Adhesives – Light Ageing of Adhesive Films and Colour Changes of Pigment Layers after Aerosol Application

2016 ◽  
Vol 37 (2) ◽  
Author(s):  
Andrea Pataki-Hundt ◽  
Eva Hummert
Keyword(s):  
Surface Structure ◽  
Light Exposure ◽  
Colour Stability ◽  
Pigment Layer ◽  
Aerosol Generator ◽  
Colour Changes

AbstractTwo aspects of consolidation of powdery paint layers are discussed in this paper: First, the colour stability of different consolidation media including cellulose and protein based materials was evaluated. Film sheet samples of the adhesives were exposed to a Xenontester for 276 hours to reach Blue Wool Standard 7. Light exposure caused loss of colour rather than yellowing in most adhesives which correlates to microfading tests. Secondly, colour changes of the pigment layer during application of consolidation media with an aerosol generator were examined. Any shift of colour results in a change of surface structure rather than a detectable shift seen in the ΔE*

Influence of visible-light exposure on colour stability of current dual-curable luting composites

2002 ◽  
Vol 29 (4) ◽  
pp. 387-393 ◽  
Author(s):  
Y. Koishi ◽  
N. Tanoue ◽  
M. Atsuta ◽  
H. Matsumura
Keyword(s):  
Visible Light ◽  
Light Exposure ◽  
Colour Stability

scholarly journals Photostabilization of rubberwood using cerium oxide nanoparticles. Part 1: Characterization and colour changes

Les/Wood ◽  
2020 ◽  
Vol 69 (1) ◽  
pp. 57-70
Author(s):  
Kavyashree Srinivasa ◽  
Krishna Kumar Pandey ◽  
Marko Petrič
Keyword(s):  
Cerium Oxide ◽  
Uv Light ◽  
Light Exposure ◽  
Visible Region ◽  
Accelerated Weathering ◽  
Uva Light ◽  
Nanoparticles Concentration ◽  
Colour Changes ◽  
Good Transparency ◽  
Harmful Radiation

Light induced darkening and deterioration of wood used outdoors is undesirable. Photoprotection of wood could be achieved by using additives that reflect or absorb harmful radiation responsible for degradation. Nano metal oxides have strong absorption in the UV range of solar radiation and good transparency in the visible region. They offer unique benefits in protecting coatings and coated substrates from being degraded by UV radiation. However, to exploit the properties of nanoparticles, homogenous dispersion without agglomeration is necessary. In the present work, the photostabilization of rubberwood surfaces coated with cerium oxide (CeO2) was studied. The nanoparticles were surface functionalized with an organic alkoxy silane (3-glycidyloxypropyltrimethoxy silane) to improve the homogenous distribution in coatings, and the modified nanoparticles were dispersed in isopropanol and polyurethane (PU) coating. Rubberwood surfaces coated with dispersed nanoparticles (concentration 0.5 % to 6 % w/v) were exposed to a fluorescent UVA light source (λ=340 nm) at 60 °C in an accelerated weathering tester for 500 h and 1000 h. Colour changes due to UV light exposure were monitored using a spectrocolourimeter. Dispersion of CeO2 nanoparticles in PU coatings (concentration >2 %) restricted the photoyellowing of wood polymers.

Effect of multiple vacuum packs on colour development and stability in beef steaks

2014 ◽  
Vol 94 (1) ◽  
pp. 63-69 ◽  
Author(s):  
C. Avilés ◽  
M. Juárez ◽  
I. L. Larsen ◽  
A. Rodas-González ◽  
J. L. Aalhus
Keyword(s):  
Atmospheric Oxygen ◽  
Vacuum Packaging ◽  
Colour Stability ◽  
Longissimus Dorsi Muscle ◽  
Dorsi Muscle ◽  
Beef Steaks ◽  
Colour Changes ◽  
Retail Display ◽  
Colour Development ◽  
Over Time

Avilés, C., Juárez, M., Larsen, I. L., Rodas-González, A. and Aalhus, J. L. 2014. Effect of multiple vacuum packs on colour development and stability in beef steaks. Can. J. Anim. Sci. 94: 63–69. The aim of this study was to compare the colour stability of steaks from longissimus dorsi muscle previously submitted to four treatments of vacuum packaging and aged for 15 d. Muscle portions were either vacuum packed and aged for 15 d (NRP), or repacked after 2 h (RP2h), 8 d (RP8d) and after 2 h and 8 d (RP2h+8d). Purge loss values from RP8d and RP2h+8d treatments were higher (P=0.019) than those from NRP and drip loss was higher (P=0.001) for RP2h and RP8d. Colour changes during a 30-min period of exposure to atmospheric oxygen immediately after opening the packages were similar for repackaged-aged steaks and NRP steaks (P>0.05). Nevertheless, colour stability during subsequent retail display under atmospheric air conditions was affected by the packaging treatment. The decrease in chroma values (P=0.043) and the increase in hue (P=0.011) between day 3 and day 6 was minimum for RP2h+8d, compared with NRP, RP2h and RP8d. Also, the proportion of pigment in the myoglobin form in these three treatments dramatically increased from day 3 to day 6, while no effect was observed for RP2h+8d (P=0.005). Similarly, the decrease over time in the proportion of pigment in the oxymyoglobin form in meat from the RP2h+8d treatment was much lower (P=0.002) than for the other three packaging treatments. Changes in colour stability associated with multiple vacuum packagings may confound results in experimental designs. Thus, if beef colour is to be evaluated, repeated vacuum packaging should be limited.

Luminous Exposures and Light-Fastness Survey in Daylit Historical Museum Galleries under Tropical Sky Conditions

2012 ◽  
Vol 488-489 ◽  
pp. 1547-1552 ◽  
Author(s):  
Noraini Ahmad ◽  
Sabarinah Sh Ahmad ◽  
Anuar Talib
Keyword(s):  
Light Exposure ◽  
Light Fastness ◽  
Preventive Conservation ◽  
Light Levels ◽  
Data Loggers ◽  
Architectural Features ◽  
Colour Changes ◽  
Sky Conditions ◽  
The Impact ◽  
Exposure Measurements

This paper highlights the results of light levels and light-fastness study conducted in four daylit historical museum galleries in Malaysia. These museums architectural features allow sun radiation into the building, causing light exposure damage to artifacts. This study aims to evaluate the luminous exposures and light-fastness as an initial preventive conservation measure in daylit historical museum galleries under the tropical sky conditions. Light sensors with data-loggers and Light-fastness dosimeters were installed throughout the museums to take cumulative light exposure measurements during museum opening hours. Both instrumentations were tested in the field during different campaigns exposures. After exposures between 90 and 100 days, these dosimeters showed photo-induced colour changes which translated exposures into equivalent luminous exposure and estimated annual exposures (Lux hours) which were used to validate the measured values of illuminance data. Simulated light dosimeters and measured illuminance data show good correlation. Thus, equivalent light dosimeter makes sense to assess the impact of light distributions.

Colour stability of 3D-printed resin orthodontic brackets

2021 ◽  
pp. 146531252110010
Author(s):  
Allison S Haynie ◽  
Jeryl D English ◽  
Rade D Paravina ◽  
Audrey Moon ◽  
James Hanigan ◽  
...  
Keyword(s):  
Accelerated Aging ◽  
Orthodontic Brackets ◽  
Colour Stability ◽  
Water Control ◽  
3D Print ◽  
Difference Formula ◽  
Before And After ◽  
Colour Changes ◽  
3D Printed

Objective: To evaluate the colour stability of polymeric resins that could be used to 3D-print orthodontic brackets. Design: In vitro, laboratory study Materials and Methods: Disc-shaped specimens were fabricated via 3D printing using three resins: Dental LT; Dental SG; and Clear. Five conditions were evaluated for each resin (n = 10 per treatment per resin) to assess its corresponding effect on colour and translucency: immersion in (1) red wine, (2) coffee, (3) tea and (4) distilled water (control), and (5) exposure to accelerated aging. Colour and translucency measurements were made before and after exposure using a spectrophotometer. Mean colour differences (ΔE00) and changes in translucency parameter (ΔTP00) were calculated for each sample using the CIEDE2000 colour difference formula. Results: Statistically significant effects of the resin material, the treatment condition and interactions effects of material and condition were observed for ΔE00 and ΔTP00 ( P < 0.001). The most pronounced changes in colour (ΔE00) were a result of the staining effects of wine on all three resins, ranging from 14.5 ± 0.6 to 20.8 ± 1.2. Dental LT, Dental SG and Clear resins all showed changes in colour when exposed to certain staining agents. Dental SG and Clear resins exhibited changes in colour with aging, while the colour of Dental LT resin remained stable with aging. Conclusions: The colour changes of the resins investigated does not support their use in 3D-printed aesthetic bracket applications.

scholarly journals Influence of Different Drinks on the Colour Stability of Dental Resin Composites

2009 ◽  
Vol 03 (01) ◽  
pp. 50-56 ◽  
Author(s):  
Fulya Toksoy Topcu ◽  
Gunes Sahinkesen ◽  
Kivanc Yamanel ◽  
Ugur Erdemir ◽  
Elif Aybala Oktay ◽  
...  
Keyword(s):  
Red Wine ◽  
Artificial Saliva ◽  
Colour Change ◽  
Resin Composites ◽  
Colour Stability ◽  
Dental Resin ◽  
Dental Resin Composites ◽  
Colour Measurements ◽  
Restorative Materials ◽  
Colour Changes

ABSTRACTObjectives: The objective of this study was to evaluate the discolouration effects of artificial saliva, granule lemon juice, coffee (without sugar), coca cola, sour cherry juice, fresh carrot juice and red wine on resin-based composite materials that are commonly used in restorative dentistry.Methods: Colour of four brands of resin composites (Filtek Z 250 (3M Espe), Filtek Supreme (3M Espe), Quadrant (Cavex), Charisma (Heraeus-Kulzer)) of A2 shade was measured after one day of immersion in eight different solutions. Colour measurements were obtained by using a XL-20 Trismus Colourimeter and colour differences (�E) were estimated. For statistical evaluation, analysis of variance (ANOVA), Dunnett and Tukey tests were used at a significance level of 0.05.Results: For the four restorative materials tested, the lowest ΔE values were observed in the artificial saliva, while ΔE values were the highest in red wine group. When comparing the four different restorative materials, Filtek Supreme exhibited the least colour changes whereas Filtek Z250 was the least colour-stable.Conclusions: Dental resin composites and drinking solutions were significant factors that may affect the colour stability. After immersion for one day, all materials showed visible colour changes. The red wine solution exhibited more staining than others in three groups. Filtek Supreme showed significantly the least colour change due to its nano particle sizes. (Eur J Dent 2009;3:50-56)

scholarly journals Colour Stability of Veneering Composites after Accelerated Aging

2010 ◽  
Vol 04 (02) ◽  
pp. 137-142 ◽  
Author(s):  
Triantafillos Papadopoulos ◽  
Aspasia Sarafianou ◽  
Andreas Hatzikyriakos
Keyword(s):  
Colour Change ◽  
Accelerated Aging ◽  
Blue Shift ◽  
Colour Stability ◽  
Before And After ◽  
Indirect Composites ◽  
Colour Changes ◽  
Indirect Composite ◽  
The Mean ◽  
One Way Anova

Objectives: To investigate the colour stability of four indirect composite restorative materials after accelerated aging.Methods: Four indirect composites (Gradia, Signum+, HFO and Adoro) were used. For each material, six specimens were prepared and subjected to accelerated aging (Suntest CPS+, Atlas, Chicago, IL, USA) according to ISO 7491. A Dr. Lange Microcolor Data Station colorimeter (Braive Instruments, Liege, Belgium) was used to measure specimen colour before and after aging. Measurements were performed according to the CIE L*a*b* system, and the mean L*, a* and b* values for each material were calculated. The equation ΔΕ = [(ΔL*)2 + (Δa*)2 + (Δb*)2]1/2 was used to measure the total colour change (ΔΕ), where ΔL*, Δa* and Δb* are the differences in the respective values before and after aging. One-way ANOVA were used to determine statistically significant differences in ΔL*, Δa*, Δb* and ΔΕ.Results: No statistically significant differences were found in ΔL*, Δa*, Δb* and ΔΕ among the materials tested (PΔL*=.063; PΔa*=.521; PΔb*=.984 and PΔE=.408). After aging, Gradia specimens showed an increase in lightness (ΔL*=0.36) and a green-yellow shift (Δa*=-1.18, Δb*=0.6), while Signum+ specimens exhibited an increase in lightness (ΔL*=0.5) and a green-blue shift (Δa*=-0.9, Δb*=- 0.45). HFO specimens exhibited an increase in lightness (ΔL*=0.75) and a green-yellow shift (Δa*=- 1.3, Δb*=0.06), and Adoro specimens exhibited an increase in lightness (ΔL*=2.07) and a green-yellow shift (Δa*=-1.3, Δb*=0.68).Conclusions: Colour changes were found to be within accepted values of perceptibility and clinical acceptance after accelerated aging, and no statistically significant differences were found in ΔL*, Δa*, Δb* and ΔΕ among the materials tested. (Eur J Dent 2010;4:137-142)

scholarly journals The Influence of Topical Fluoride Application on Colour Stability of Aesthetic Fluoride-Releasing Restorative Materials

2014 ◽  
Vol 18 (1) ◽  
pp. 24-28
Author(s):  
E. Kalampalikis ◽  
E.A. Koulaouzidou ◽  
E. Koliniotou-Κοumpia ◽  
M. Helvatjoglu- Antoniades
Keyword(s):  
Colour Properties ◽  
Restorative Material ◽  
Colour Stability ◽  
B Method ◽  
Restorative Materials ◽  
Colour Changes ◽  
Clinically Significant ◽  
Topical Fluoride ◽  
Topical Fluorides

AbstractFluoride-releasing restorative materials are often combined with topical fluoride application products in order to enhance fluoride effects. The purpose of this study was to determine the colour stability of 3 aesthetic fluoride-releasing restorative materials after application of 2 topical fluoride products. 15 disc shaped specimens were prepared for each restorative material and were divided into 3 groups. Topical fluorides were applied onto the specimens according to the manufacturer’s instructions. The procedure of fluoride application was repeated twice. Colour properties of all specimens were evaluated at baseline and 48 hours after topical fluoride application. Colour analysis was performed using the spectrophotometer and CIE L*a*b* method. 3 consecutive readings were recorded for each specimen and L*, a*, b* parameters and a mean number of readings were calculated.According to the results, topical fluoride application products caused changes of colour properties in the examined materials, but these changes were clinically acceptable with the ΔΕ* value being below 3.3. In general, it can be concluded that fluoride application products can be safely used on the restorative materials without causing clinically significant colour changes.

scholarly journals The relationship between colour and pH in cold-stored quail breast muscle / Zależność między barwą a pH w mięśniach piersiowych przepiórek przechowywanych w warunkach chłodniczych

2013 ◽  
Vol 13 (2) ◽  
pp. 401-413 ◽  
Author(s):  
Tadeusz Karamucki ◽  
Józefa Gardzielewska ◽  
Małgorzata Jakubowska ◽  
Kinga Rybak ◽  
Justyna Garczewska
Keyword(s):  
Sensory Evaluation ◽  
Breast Muscle ◽  
Colour Stability ◽  
Muscle Ph ◽  
Old Japanese ◽  
Colour Parameters ◽  
Colour Changes ◽  
Hue Angle ◽  
Ph Range ◽  
High Degree

Abstract The purpose of this study was to analyse the colour of the breast muscles of Japanese Pharaoh quail on the first day after slaughter and again after further six days of cold storage, in relation to their muscle pH. The material for the study consisted of 40 breast muscles taken from the carcasses of six-week-old Japanese Pharaoh quail. Based on pH results, the muscles were divided into three groups: I (pH = 5.51-5.70), II (pH = 5.71-5.90) and III (pH = 5.91-6.10). After this the muscles were stored for a further 6 days at 4°C. It was found that the pH of freshly dissected quail breast muscle is a good indicator of the colour stability of muscles cold-stored at 4°C for six days. The lowest degree of colour stability was observed in the pH range 5.51-5.70. In the sensory evaluation muscles displaying this degree of colour instability were considered unacceptable or barely acceptable. In contrast, muscles in the pH ranges 5.71-5.90 and 5.91-6.10 displayed a high degree of colour stability and were considered acceptable in the sensory evaluation. The colour changes that occurred during storage of the muscles were due to changes in the values of all of the colour parameters (L*, a*, b*, C* and hº); however, the greatest changes were found in the case of redness (a*) and the hue angle (hº). The changes were caused both by alterations in the amount of pigment reached by light, and by changes in the relative amounts of the chemical forms of myoglobin.

Sign in / Sign up

Export Citation Format

Share Document