Color Durability Research Articles

Green technology for durable finishing of viscose fibers via self-formation of AuNPs

Sensitivity of dyes' colors to the surrounding environment causes lower durability and stability of color, which reflects the importance of durable finishing treatment. Current technique offered antimicrobial/durable finishing of viscose fibers through direct formation of AuNPs inside fibers macromolecules without using any external agents. By using the reducing properties of cellulose in viscose, Au+3 was reduced to AuNPs and CHO/OH of cellulose subsequently were oxidized to COOH. For comparison, two different media were used; aqueous and alkaline. Increasing the reactivity and accessibility of cellulose macromolecules in alkali leaded to enlargement of the reduction process and more incorporation of AuNPs. Size of AuNPs inside fiber was recorded to be in range of 22–112nm and 14–100nm, in case of using aqueous and alkaline medium, respectively. Structure and properties of fibers were not changed by treatment according to XRD and ATR-FTIR data. The treated fibers were acquired durable violet color by the action of LSPR for AuNPs and darker color obtained using higher Au+3 concentration. The treated fibers exhibited good inhibition against different pathogenic microbes including bacteria and fungi. One-pot, quite simple, inexpensive, green and industrial viable are the significant advantages of the current technique for viscose finishing (pigmentation and antimicrobial action).

Discovery of novel inorganic Mn5+-doped sky-blue pigments based on Ca6BaP4O17: Crystal structure, optical and color properties, and color durability

Novel inorganic sky-blue pigments, Ca6Ba(P1-xMnx)4O17 (0 ≤ x ≤ 0.13) were synthesized in a single phase form by a conventional solid-state reaction method and their color properties were investigated in the detail. The pigments exhibited strong optical absorption in the UV and the yellow-red light regions due to the CT transition in MnO4 tetrahedra and the DMSO-d6 transitions of Mn5+, which is the origin of the sky-blue color. The optimization of the composition resulted in the attainment of the highest sky-blue hue for the Ca6Ba(P0.99Mn0.01)4O17, where the L*, a*, b*, C, and H° values are 75.47, −11.67, −10.29, 15.6, and 221.4°, respectively. These pigments showed a low chemical stability of color for acid/alkali solution, whereas the pigments showed an excellent color durability for heat and light. Although they are required to improve the chemical stability of color, the present pigment could be an attractive candidate as a novel environment friendly inorganic sky-blue pigment.

Optimization of Dyeing Time of Eco-friendly Cotton Coloration Using Banana (Musa Sapientum) Floral Stem Sap

This study attempts to disclose the optimum dyeing time for exploiting banana agricultural bio-resource waste for sustainable dyeing of cotton fabric. 100% cotton knitted single jersey commercially scoured-bleached fabric used for this experiment having areal density 175 grams per square meter. Natural dye retrieved from banana floral stem by roller squeezer machine. Selected samples were dyed at 100℃ for 20, 30, 40, 50, 60 and 70 minutes respectively. Effect of time variation were calculated using CIE L*a*b* color space in terms of colorimetric properties of colored fabric viz. color co-ordinates, color strength (K/S), brightness index (BI), degree of color levelness. Color fastness to wash, water, perspiration, rubbing and light were valued for estimating the color durability. Except light fastness property all tested color fastness properties were 3-5 i.e. very good to excellent. For all evaluated parameters samples dyed for 60 minutes exhibited best result. This reports forecast a sustainable technology for effective utilization banana floral stem sap bio-resource waste for coloration of cotton fabric.

Full-Color Subwavelength Printing with Gap-Plasmonic Optical Antennas.

Metallic nanostructures can be designed to effectively reflect different colors at deep-subwavelength scales. Such color manipulation is attractive for applications such as subwavelength color printing; however, challenges remain in creating saturated colors with a general and intuitive design rule. Here, we propose a simple design approach based on all-aluminum gap-plasmonic nanoantennas, which is capable of designing colors using knowledge of the optical properties of the individual antennas. We demonstrate that the individual-antenna properties that feature strong light absorption at two distinct frequencies can be encoded into a single subwavelength-pixel, enabling the creation of saturated colors, as well as a dark color in reflection, at the optical diffraction limit. The suitability of the designed color pixels for subwavelength printing applications is demonstrated by showing microscopic letters in color, the incident polarization and angle insensitivity, and color durability. Coupled with the low cost and long-term stability of aluminum, the proposed design strategy could be useful in creating microscale images for security purposes, high-density optical data storage, and nanoscale optical elements.

Robust anodic colouring of titanium: Effect of electrolyte and colour durability

An ever growing number of studies involve the production of thin metal oxide films for various purposes, from surface hardening to sensing, to the production of self-cleaning surfaces. Among metallic oxides, titanium dioxide is by far the most investigated: it can be produced by anodic oxidation of titanium in a large variety of electrolytes, either acid, alkaline, or neutral, and within certain limits oxide thickness is linearly proportional to the cell voltage applied. Common industrial plants for titanium anodising use acid electrolytes, which may pose safety issues as well as plant corrosion issues. This article proposes a screening of most common, plus some uncommon, electrolytic solutions used in the anodising of titanium, in order to identify suitable alternatives to acids in the range of neutral electrolytes. Oxides produced in optimal conditions are fully characterised, and treatment robustness is investigated, in order to understand the feasibility of technological transfer. A selection of anodising electrolytes and conditions is finally proposed for applications in architectural and jewellery applications, together with a method for colour restoration in case of wear or mechanical damaging.

Development of a test method to determine the colour durability of coloured bituminous mixtures

Coloured asphalt pavements are increasingly used in large public spaces and also at hazardous junctions. In the former application, the role of the coloured pavement is often to give the area a particular aesthetic character or to integrate it well with its surroundings; in the latter, its major role is to improve the safety of users by improving visibility and road legibility. Once coloured asphalt mixtures have been laid, their colour tends to alter irreversibly (paling, pastellisation, etc.) due to climatic agents. Colour durability, therefore, appears to be very important. In this respect, it has been proved necessary, on the one hand, to identify the climatic agent, the composition, and the components of coloured bituminous mixtures actually having a substantial impact on colour development (using a natural weathering method) and, on the other, to develop an accelerated weathering methodology for a faster evaluation of colour durability. This paper will present results and findings from both natural and accelerated weathering methods developed at the Belgian Road Research Centre.

Evaluation of the color durability of acrylic resin veneer materials after immersion in common beverages at different time intervals: A spectrophotometric study.

Proper function, esthetics, and cost are the prime factors to be considered while selecting bridge veneering materials. The purpose of the study is to evaluate color durability of acrylic veneer materials after immersion in common beverages at different time intervals. Spectrophotometer was used for taking color measurements based on the transmission of light through the specimens made of the selected materials which were Tooth moulding powder (DPI) and Acrylux (Ruthinium). Thirty specimens of standardized dimensions were prepared from each material. The specimens were divided into three groups of 10 each. One group of each material was immersed in tea (TajMahal) and another group of each material in cola (Pepsi) as the staining solutions. The remaining group of 10 from each material served as control and was stored in distilled water. Color measurements were obtained pre-immersion, and after 1, 15, and 30 days of immersion. Tooth moulding powder displayed better color durability than Acrylux over the 1 month immersion period in both staining solutions. Tea resulted in more discoloration compared to cola (Pepsi). The difference in the color durability of Acrylux and Tooth moulding powder may be attributed to the differences in the composition of tested resin veneering materials, i.e. their polar properties, which contribute to the absorption of staining solution, and the different brands and the strengths of the solutions.

Integration of the Local Wisdom of Natural-Dyed Mud-Treated Silk in Thailand for Creative Economy

The present research compared minerals contained in mud from different sites. These were analyzed by atomic absorption spectroscopy: AAS. It found the highest quantity is iron, zinc in second, lead in third, copper in fourth. The study results show that silk threads with and without mud treatment were not so different in color durability towards light, color durability towards scrubbing, and color durability towards washing. We also found that crease recovery capacity of mud-treated silk cloth was better than that of silk cloth without mud treatment. Hence, the mud treated silk is more suitable for the development of Thai garment.

Fire resistance of “high-tech plastics”

The mechanical properties, thermal insulation, durability and the production technology make Fibre Reinforced Polyester Composites an interesting material to use as a facade cladding system or as unitized sandwich panels. Before the FRPC material became readily available for large facades, technical aspects had to be investigated and solutions had to be found for fire resistance/reaction to fire, aesthetic properties such as colour fastness, durability and strength calculations.This paper concentrates on the development of a composite material, especially in the form of sandwich panels as a unitized facade system, to meet certain requirements of “Fire resistance” and “Reaction to fire” according to the relevant European standards.

Physical and Sensory Properties of Electrohydrodynamic (EHD) Dried Scallop Muscle

Electrohydrodynamic (EHD) drying was tested as an improved dehydration method for scallop muscle. The scallop muscle was dried in an EHD drying system at 15°C, in an oven at 60°C, and in ambient air at 15°C. The energy consumption of EHD and oven drying, as well as the shrinkage rate, water absorption, solid loss, and sensory properties such as color and anti-crushing durability of the dried scallop muscle were measured. Results showed that the drying rate of scallop muscle significantly improved using the EHD drying system. Under a 45 kV voltage, the drying rate of EHD is 7 times higher compared with that of air drying in the 1st h. Compared with oven drying, EHD drying was more efficient in terms of energy saving. Furthermore, EHD drying cost only 28.67% of the electric energy required for oven drying. The dried scallop muscle by EHD had better sensory qualities and higher anti-crushing durability. EHD drying is very advantageous and can be used as a substitute to the traditional drying method.

Synthesis and photochromic response of a new precisely functionalized chitosan with “clicked” spiropyran

A new light responsive polysaccharide based on a precisely defined N-phthaloyl chitosan with a covalent bound photochromic spiropyran moiety in C-6 was synthesized through Cu(I) catalyzed azide–alkyne [3 + 2] dipolar cycloaddition between 6-azido-6-deoxy, N-phthaloyl chitosan and a new spiropyran derivative containing an alkynyl group (SPCC). The reaction product was characterized by NMR and FT-IR spectroscopies for confirming the molecular structure. The UV–vis spectroscopy analyses of films prepared by solution casting on glass from DMF solutions of the functionalized polysaccharide, before and after exposure to an UV lamp (in the 280–350 nm spectral range) or sunlight, showed very slow thermal decay of the photo-induced colored form which was substantially maintained after few months at room temperature. On the contrary, fast color fading was observed for SPCC in ethanol or diethyl ether solution where the color disappeared completely in few minutes at the same temperature. Intermediate color durability was found in diethyl ether suspensions, which indicated the solid polysaccharide phase as responsible of the observed color durability. Considering that the absorption spectra of the polymers are similar under the different conditions examined, the observed effect in the solid state is discussed with reference to the chromophore environment providing molecular and supramolecular hindrance by steric effect and weak binding.

Effect of Starch Sources on Properties of Extrudates Containing DDGS

Various levels of DDGS (20, 40, and 60% wb) were blended with starch sources (cassava, corn, and potato), and other ingredients to produce an iso-nitrogenous feed (28% protein) at varied moisture contents (15, 20, and 25% wb). The feed blends were extruded in a single-screw extruder at a preset screw speed of 130 rpm (13.6 rad/s) with three temperatures profiles 90–100–100°C, 90–120–120°C, and 90–140–140°C. The effect of these variables on processing conditions (extruder torque and die pressure) and other extrudate properties (expansion ratio (ER), unit density (UD), color (L*, a*, and b*), sinking velocity (SV), water absorption, water solubility, and pellet durability indices (PDI)) were analyzed. For all the three starch extrudates, changing the levels of DDGS, feed moisture content, and extruder barrel temperature had a significant effect on SV, PDI, a*, and b* values at α = 0.05.

Indigo@Silicalite: a New Organic−Inorganic Hybrid Pigment

In the search for stable and enduring organic colors, we have combined indigo, a historical and industrially important chromophore, with silicalite, the MFI zeolite. The resulting pigment presents high color durability against most external agents (e.g., light, temperature). This stability and its physical properties are explained by the association of indigo with an inert mineral, which is also influenced by formation conditions such as the initial indigo concentration and the thermal treatment. The formation of the indigo@silicalite hybrid, particularly diffusion of the organic molecule, is monitored by optical spectroscopies, thermogravimetric measurements, and X-ray diffraction. Color stability is attested when indigo enters the pores of the zeolitic host, thus forming a new pigment with characteristics similar to those of Maya Blue. This opens the way to the low-cost engineering of metal-free, nonhazardous pigment powders based on indigoid and other dyes.

The Color Durability of "Chocolate Pearls" by Ballerina Pearl Co.

The Color Durability of "Chocolate Pearls" by Ballerina Pearl Co.

Hair color changes caused by dyeing and thermal treatments

The aim of this study was to show the effect of heat exposure, dyeing, and shampooing on hair color as measured by diffuse reflectance spectrophotometry. Successive dyeing of virgin hair with six permanent commercial formulations showed that color saturation was obtained after the first dyeing cycle. An unexpectedly high difference in hair color saturation, measured as DE* values, was obtained for virgin hair samples that differed only in cleansing history. After six sequential washings of the dyed hair samples, no difference was observed in color durability, indicating that the adhesion strength is similar to long-lasting and tone-up dyeing formulations. Exposure to a hot plate at 172 degrees C showed a significant darkening of the virgin hair samples after 2 min. On the other hand, virgin hair samples exposed to the gentler heat of a hand dryer (approximately 60 degrees C) showed partial disappearance of the hair medulla after 60 min. However, values of total color difference were near the error limit.

The effect of accelerated aging on color stability of denture liners.

The objective of the present study was to determine the color changes resulting from the aging process in two cold and three hot curing soft liners and two hard liners. Seven samples were fabricated for each material. The initial color measurements were made with a UV-Visible Recording Spectrophotometer. The samples were then placed in an accelerated aging chamber to simulate the aging process. The color of the samples was then measured again with a colorimeter, and the color changes (delta E) were calculated. The critical mark of color change (delta E) has been quantified by the NBS. It was concluded that cold curing soft liners were not color-stable, and that hot curing soft liners and hard liners had similar color durability. These results suggest that colorants used in cold curing soft liners must be reinforced.

Anthocyanins as natural food colours—selected aspects

The anthocyanins have a long history as part of the human diet, these and other flavonoids, are receiving renewed attention for their positive health attributes. The principal commercially available anthocyanin food colorants, grape, elderberry, red cabbage and roselle are considered and others mentioned. Factors affecting the usage of extracts, in terms of colour hue and stability are discussed. Chemical aspects of anthocyanin colour are summarised briefly and the advantages of acylation for colour durability noted as a promising area for future development. Special emphasis is placed on quantitative information where applicable.

染色堅牢度向上の問題について

染色堅牢度向上の問題について