光子晶体结构色纺织材料的制备及应用研究进展

为解决当前纺织印染行业大量使用高污染、高能耗且易褪色的传统化学染料和颜料的问题,针对结构生色材料所具有的不含着色剂、颜色鲜艳、不易褪色等特点,本文综述了近年来光子晶体结构色纺织材料的制备及应用研究进展。介绍了光子晶体结构及其结构生色机理,阐述了结构色纺织材料常用的制备方法,着重归纳了光子晶体结构色在纤维、纱线、织物及颜料等方面的应用,并分析了其在应用过程中存在的问题。分析表明,光子晶体结构色纺织材料已经可以达到大面积快速制备,且在织物上构筑结构色较为方便且研究较多,在纱线上构筑结构色的研究较少,在纤维上构筑结构色容易赋予其功能性且相关研究逐渐增多。最后总结了光子晶体结构色应用于纺织领域所存在的问题,并对该研究方向进行了展望。     

Examples of interference and the color pigment mixtures green with red and red with green

In industrial paint formulations, interference pigments are usually mixed with color pigments. Transparent interference pigments mix together according to the laws of additive mixing and color pigments to the laws of subtractive mixing. The behavior of both types differs depending on whether similar colors such as pearl green and green or contrasting colors such as pearl green and red are mixed. In this article examples of these differences for color measurement are discussed, along with showing the resulting charts. © 2001 Wiley Periodicals, Inc. Col Res Appl, 27, 276–281, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10063     

Dancheong colors used for Korean cultural heritage architecture restoration

Dancheong is Korean traditional decorative coloring on special wooden buildings, and it has been preserved by Danjeongjang as a national intangible cultural heritage—a craftman with a special skill to paint dancheong. All dancheong in the national heritage have been managed by the Cultural Heritage Administration following the standard procedure. However, there is no available information about final colors. In this study, a total of six different dancheong color paletts were prepared by six different apprentices of the living national treasures. In total, there were 20 different colors and 12 colors were shown in all six palettes. The color measurement result showed that well trained dancheong painter can reproduce the same colors repeatedly with fairly high precision with 1.8 on average except two colors—Ju‐hong and Yang‐cheong—showing high chroma differences, but with very similar lightness and hue angle indicating that hue of dancheong colors is the most important factor to judge the correctness of the color preproduction. The dancheong colors show large variations depending on the painters but the painters trained by the same teacher have the similar color palettes. Further in‐depth dancheong color investigation is needed to fully understand the contemporary dancheong colors.     

Digitally reconstructing Van Gogh's Field with Irises near Arles part 3: Determining the original colors

In earlier articles, we determined the spatial distributions and concentrations of all pigments used by Van Gogh in his painting Field with Irises near Arles. The colors of some pigments are expected to have changed over time, especially those of chrome yellow, cochineal, and eosin lake. For all pigments in this painting, we made physical paint reconstructions by following historical sources on raw materials and production processes, and we determined their optical properties. We combined this with pigment concentration maps to reconstruct the original colors of the painting digitally. When substituting the reconstruction paints into the calculations, we found that technical‐scientific data was not sufficient to resolve several issues. In those cases, discussions within the broad interdisciplinary team allowed us to make informed decisions. These issues refer to the representation of the sky area, and the original contributions of the red lake pigments to local colors. The digitally reconstructed colors of the painting show that due to discoloring of red lake pigments, the irises in the field have changed from a warm purple to purplish blue, and many pink spots in the field have turned to white. The range of yellows in the field has decreased and partly turned to dark brown. The digital reconstruction gives a better understanding of the color scheme used by Van Gogh when compared to remarks the artist made in letters when describing this painting. Also, the original color composition is seen to be aligned with color theories on which Van Gogh based his work.     

Digitally reconstructing Van Gogh's Field with Irises near Arles. Part 2: Pigment concentration maps

Colors in many paintings of great art historical value have changed over time, due to the combined effects of natural ageing, accumulated surface grime, and materials added during later conservation treatments. The physical restoration of the colors in such paintings is not possible. This article describes one part of work done to digitally restore the colors of Van Gogh's painting Field with Irises near Arles, dating from May 1888. We have used multispectral reflectance data to estimate absorption K and backscattering S parameters of Kubelka‐Munk 2‐constant theory. This was done for all 13 pigments known to have been used by Van Gogh in this painting, and based on this the concentration maps for each of these pigments were calculated. We validated the calculated concentration maps in several ways. For some pigments, we were able to predict spots on the painting where the pigment is expected to occur in unmixed form based on visual examination. For several other pigments, the concentration maps could be shown to agree with XRF data. Finally, for some other pigments the concentration maps were supported by additional evidence from microscopic examinations, remarks in Van Gogh's letters and from early color reproductions. For the 1.7 million pixels for which multispectral data is available, the average color difference between the calculated and measured spectral reflectance curves is CIEDE2000 = 1.05. This further confirms that the Kubelka‐Munk calculations are well suited to describe the variety of spectral reflectance on the painting.     

Perceived density,a further attribute of color,revealed by the colors favored in Japan

Colors can be characterized by three main attributes: hue, value, and saturation. But colors also exhibit other phenomenological qualities. In this study, we identify one such secondary attribute of color: perceived density. We discuss the prevalence of dense colors in Japan starting from the “48 Teas and 100 Mice” colors of the Edo period, and develop the concept of perceived density through this aspect of Japanese color preference. When vivid colors were forbidden to commoners during the Edo period, subtle variations of brownish and grayish colors were created. These colors with base tones were not salient, yet they looked dense. Muted colors with paradoxical richness are still common in Japan today. Japanese commodity design often uses muddy colors with white or gray undertones, and deep colors with black undertones. Together they form distinct groupings of relatively dense color. The perceived density of color corresponds to how dense and filled, or thin and airy a color appears. Colors of higher perceived density appear to be more packed and to have mass. Perceived density of color is unusual in that it does not have a monotonic relationship with one of the primary perceptual attributes. High apparent density is observed in a central region of an equi‐hue plane where value or saturation are at intermediate values. We consider two possible explanations of how high values of density can coincide with middling values of value and saturation: characteristics of the spectral reflectance curves, or the complexity of the neural signals that underlie the emergent property.     

锆基陶瓷色料的制备及其性能

本文论述了锆基陶瓷色料的制备工艺过程,矿化剂的作用机理以及着色离子在ZrSiO4晶体结构中的价态、取位,为获得性能稳定、呈色效果好的锆基陶瓷色料提供理论指导。     

Evaluation of the ASTM D7869-13 test method to predict the gloss and color retention of premium architectural finishes-I

A recently developed xenon arc-based accelerated weathering cycle, ASTM D7869-13, has been validated for automotive and aerospace coatings, but its ability to predict the gloss and color retention of premium architectural finishes has not yet been evaluated. We review new weathering data comparing the performance of poly(vinylidene fluoride) (PVDF) architectural finishes in south Florida exposure as well as several accelerated exposure methods including ASTM D7869-13. ASTM D7869 accurately reproduced Florida rank order gloss and color retention trends for coatings made with PVDF-acrylic blends and inorganic pigments, as well as the gloss and color changes seen in Florida for 70% PVDF masstone coatings made with a number of single organic pigments. However, the D7869 cycle has difficulty predicting the rank order of rutile TiO₂ grades for the gloss retention of PVDF coatings in Florida, as well as the magnitude and direction of color fade from organic pigment degradation in organic pigment/inorganic pigment blends. One open question that remains is whether the ASTM D7869 cycle might have some utility for industry standard or specification purposes, if the test is limited to specific reference colors or more ideally to specific reference pigments.     

New effect pigments from grey to black

This paper shows different possibilities of manufacturing silver-grey mica pigments. One example, the mica-ilmenite pigments Iriodin® 9602 WR II and Iriodin® 9612 WR II, are discussed in detail concerning the production process and their chemical and physical characteristics. The colorimetric data of the new mica pigments are discussed and the first weathering data presented. The results show that these pigments give the color chemist a new styling tool for the grey and silver-grey color range. Through the addition of transparent organic pigments brillant and deep metallic-like colors can be achieved. A second type of mica pigment, black magnetite on mica, is presented in its basic chemical structure and its potential use for the color chemist.     

Biosynthetic and Functional Color–Scent Associations in Flowers of Papaver nudicaule and Their Impact on Pollinators

Despite increasing evidence for biosynthetic connections between flower pigments and volatile compounds, examples of such relationships in polymorphic plant species remains limited. Herein, color–scent associations in flowers from Papaver nudicaule (Papaveraceae) have been investigated. The spectral reflectance and scent composition of flowers of four color cultivars was determined. We found that pigments and volatiles occur in specific combinations in flowers of P. nudicaule. The presence of indole in the bouquets is strongly associated with the occurrence of yellow pigments called nudicaulins, for which indole is one of the final biosynthetic precursors. Whereas yellow flowers emit an excess of indole, orange flowers consume it during nudicaulin production and lack the substance in their bouquet. By using the honeybee, Apis mellifera, evaluations were made on how color and scent affect the discrimination of these flowers by pollinators. Honeybees were able to discriminate artificial odor mixtures resembling those of the natural flower odors. Bees trained with stimuli combining colors and odors showed an improved discrimination performance. The results indicate that the indole moiety of nudicaulins and emitted indole might be products of the same biochemical pathway. We propose that conserved pathways account for the evolution of color–scent associations in P. nudicaule and that these associations positively affect flower constancy of pollinators.     

Global color impressions of multicolored textured patterns with equal unique hue elements

A global color impression from a multicolored textured pattern can be identified. It is not clear, however, how such a single color impression can be determined from the elemental colors of the multicolored textured pattern. To investigate this question, two hypotheses were evaluated. The first hypothesis is that a single color impression is determined by the colorimetric average of the elemental colors in the textured pattern (colorimetric average hypothesis). The second hypothesis is that the impression is influenced by the color appearances of the elemental colors in the textured pattern (color appearance hypothesis). Using an asymmetrical color matching method, the authors obtained single color impressions for random‐dot textured patterns consisting of two colors with the same unique hue and brightness but each with a different saturation. Our results showed that the matched colors were not located on the line connecting the two elemental colors of the pattern, but rather were on the curved unique hue loci line. Furthermore, the chromaticities of the matches shifted toward a higher saturation than the colorimetric averages. These results support the color appearance hypothesis and suggest that a single color impression from a multicolored textured pattern is determined by a mechanism that integrates the color appearances, i.e., hue, saturation, and brightness (or lightness), of the elemental colors in the pattern. In addition, it seems that the integration of the color appearances is not a simple process, because the apparent saturation of the color impression was higher than that of the colorimetric average and the average of the chromaticities of the colors in the pattern. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 267–277, 2007     

粉末涂料用有机颜料概述

粉末涂料用有机颜料属于高性能有机颜料,是作为无机颜料的一种补充,补齐了无机颜料在颜色鲜艳度、色相齐全方面的缺陷。有机颜料的许多应用性能不仅决定于化学结构,粒径大小与分布、颗粒表面极性、晶体类型与结晶度、表面改性对有机颜料也有很大的影响。本文从有机颜料物理形态、晶型、化学结构特性等方面阐述有机颜料的性能,同时介绍了粉末涂料对有机颜料的性能要求和一些粉末涂料中常用的有机颜料,以及这些颜料的特性。总结了有机颜料在粉末涂料中使用容易出现的问题,了解其产生的原因和机理,帮助从业者在众多的颜料色号中选择合适的高性能有机颜料。     

Functional colored ceramic coatings obtained by thermal spray for decorative applications

Many inorganic pigments consist of a ceramic matrix doped with transition metal cations, which act as chromophore agents in the ceramic material and provide intense colors. Cassiterite and malayaite are the pigments most commonly used to replace pigments that contain cadmium in the ceramic industry, and are normally deposited using techniques such as CVD, sputtering, sol–gel and spray-pyrolysis. The aim of this study was to produce and characterize SnO₂-based coatings for decorative applications employing a cost-effective technology (APS). The effects of spraying conditions on the crystallinity and microstructure of the coatings were studied. Tests revealed interesting results in terms of the structural features of the coatings, whose optical properties changed. The intrinsic color of the coatings was controlled and compared by reflectivity measurements in the CIELab space, and a change from red-pink to dark-gray was observed for the sample with the highest amount of amorphous cassiterite. The key factor seems to be the percentage of crystalline malayaite, which correlated with the redness value of the color space.     

A systematic approach of predicting color preference on the basis of gray relational grade

During the color design process, it is critical to create diversified color schemes for various consumer groups. It is also important to allow members in a design team to brainstorm for creative ideas. A theory of inspecting natural color elements was proposed in this study based on the CIE 1976 (L*,a*,b*) (CIE 1976) color space and the fuzzy c‐means clustering method. A calculation model was built to determine people's preference for colors based on a serialized system. To determine which factors affect the prediction of consumers' preference for a series of products, a gray relational color preference system was used in combination with gray relational grade so that a designer can obtain reasonable prediction results. The proposed system recommends not only the optimal colors for a product but also the optimal color scheme for a series of products.     

Visual and instrumental assessments of color differences in automotive coatings

The interest in gonioapparent pigments (metallic, pearlescent, interference, or diffractive) has increased in the last few years, especially for applications in the automotive industry. To assure a proper characterization of colors with gonioapparent pigments, commercial devices have appeared to characterize the color in different geometries, which are called multiangle spectrophotometers. As the gonioapparent pigments and multiangle instruments are relatively new, no studies exist regarding the instrumental‐based procedure followed in the industry, and if the results provided are in agreement with the observer perception. Consequently, the main objective of this study was to examine the correlation of the instrumental color differences with visual assessments. The instrumental color difference was calculated with the color difference formula AUDI2000 (specific for this sector) between the pairs of similar samples of three types of coated panels (solid, metallic, and pearlescent). The values measured by a telespectroradiometer in a directional lighting booth and the colorimetric values obtained by means of a multiangle spectrophotometer BYK‐mac were considered for this purpose. Additionally, a visual experiment was conducted to quantify the color difference by using the gray‐scale method. The results revealed that an acceptable instrumental correlation existed despite the visual and the instrumental correlation being worse. In particular, it was checked that observers accepted a larger number of color pairs, that is, the visual color difference was smaller than the tolerance demanded by the industry (derived from AUDI2000). © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 384–391, 2016     

高工程化颜料的基本概念与工程化问题

传统的颜料颗粒粒径分布较宽,大多数颗粒的尺度一般在5～50μm之间。经过研磨加工的颜料制备物（俗称颜料色浆）其粒径分布要窄得多,大多数颗粒的尺度一般在0．5～5μm之间,高工程化颜料的颗粒粒径分布更窄,在0．1～0．15μm之间。高工程化颜料的饱和值和透明性都接近它的最佳状态,因此可以用于液晶显示屏等高技术领域,但加工到这么小的尺度是有困难的。该文从粒径分布和加工方式以及应用领域诸方面讨论了高工程化颜料与颜料色浆的区别。同时结合理论分析,指出了制造高工程化颜料的技术瓶颈。     

Chromatic adaptation transform by spectral reconstruction

A color appearance model (CAM) is an advanced colorimetric tool used to predict color appearance under a wide variety of viewing conditions. A chromatic adaptation transform (CAT) is an integral part of a CAM. Its role is to predict “corresponding colors,” that is, a pair of colors that have the same color appearance when viewed under different illuminants, after partial or full adaptation to each illuminant. Modern CATs can sometimes generate colors with negative tristimulus values. For some imaging applications, it is important to maintain positive tristimulus values when applying a CAT. This article proposes a new CAT that does not operate on the standard von Kries model of adaptation. Instead, it uses a spectral reconstruction technique as an intermediate stage in the process, while still requiring only tristimulus values as inputs. It is demonstrated that the proposed CAT will not generate colors outside the spectral locus or colors with negative tristimulus values. The proposed CAT does not use established empirical corresponding‐colors data sets to optimize performance, as most modern CATs do, yet it performs as well as or better than the most recent CATs when tested against the data sets of corresponding colors.     

Color harmony: What is it?

Color atlases, such as those based on the theories of Ostwald and Munsell, are useful because they simplify finding the color one has in mind for a specific use, not because the colors in the scales have a harmonious relation that can be used without further consideration. The author believes it is the orderly sequence that gives this impression. Other limitations of the atlases are discussed. Selecting harmonious colors is a creative process that considers the design, and fashions and mores of the times, and the changing character of the arts. Looking at color usage everywhere seems the best way to learn and understand color harmony.