• Journal of Powder Materials
• /
• v.20 no.3
• /
• pp.210-214
• /
• 2013

This manuscript reports on compared color evolution about phase transformation of ${\alpha}-FeOOH@SiO_2$ and ${\beta}-FeOOH@SiO_2$ pigments. Prepared ${\alpha}$-FeOOH and ${\beta}$-FeOOH were coated with silica for enhancing thermal properties and coloration of both samples. To study phase and color of ${\alpha}$-FeOOH and ${\beta}$-FeOOH, we prepared nano sized iron oxide hydroxide pigments which were coated with $SiO_2$ using tetraethylorthosilicate and cetyltrimethyl-ammonium bromide as a surface modifier. The silica-coated both samples were calcined at high temperatures (300, 700 and $1000^{\circ}C$) and characterized by scanning electron microscopy, CIE $L^*a^*b^*$ color parameter measurements, transmission electron microscopy and UV-vis spectroscopy. The yellow ${\alpha}$-FeOOH and ${\beta}$-FeOOH was transformed to ${\alpha}-Fe_2O_3$ with red, brown at 300, $700^{\circ}C$, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.55 no.6
• /
• pp.802-807
• /
• 2022

We investigated the physical properties and color values of surimi mixtures with added natural red pigments from laver Pyropia yezoensis. After adding the natural red pigment from seaweed extract to surimi, the hardness, gumminess, and chewiness of the surimi decreased compared to the negative controls. The L^* color value was lower for the surimi mixture than the negative controls, but the a^* and b^* color values were higher. After cold storage for 7 days, the unheated surimi mixture showed increased firmness, but decreased adhesiveness. Moreover, the gumminess and chewiness of the surimi mixture stored after heating were increased compared to the pre-storage values. These results indicate that seaweed extract pigments may be used as additives for surimi, to increase the color preference, with little effect on the physical properties.

• Journal of Conservation Science
• /
• v.36 no.5
• /
• pp.351-367
• /
• 2020

The pigments of three old and new celestial charts folding screens(『Celestial Chart(Folding Screen)』 and 『Old and New Celestial Charts, Eight-Panel Folding Screen』 of National Folk Museum of Korea and 『Koudou-Nanboku-Ryousouseizu』 of National Diet Library of Japan) were analyzed to estimate their dating. It was estimated that the 『Celestial Charts(Folding Screen)』 was painted using traditional pigments from the Joseon dynasty such as azurite, indigo lake, malachite, atacamite, vermilion, iron oxide, cochineal, gamboge, orpiment, lead white, talc and soot. The green and blue colors of the 『Old and New Celestial Charts, Eight-Panel Folding Screen』 and 『Koudou-Nanboku-Ryousouseizu』 were painted using artificial inorganic pigments such as emerald green and ultramarine blue. These pigments were imported from Europe post the mid-19th century. In the 『Old and New Celestial Chart, Eight-Panel Folding Screen』, only artificial inorganic pigments were used for green and blue colors. However in the 『Koudou-Nanboku-Ryousouseizu』, emerald green and atacamite in green color, and ultramarine blue and indigo lake in blue color were used together. Based on both the results of pigment analysis and the study of star charts and inscriptions, the 『Celestial Charts(Folding Screen)』 was painted post mid-18th century. The 『Koudou-Nanboku-Ryousouseizu』 and 『Old and New Celestial Charts, Eight-Panel Folding Screen』 were painted after green and blue artificial pigments were imported in the mid-19th century. The 『Koudou-Nanboku-Ryousouseizu』 in which both traditional and western artificial pigments were used, can be dated earlier than the 『Old and New Celestial Chart, Eight-Panel Folding Screen』.

• ALGAE
• /
• v.18 no.1
• /
• pp.83-88
• /
• 2003

• Journal of the Korean Ceramic Society
• /
• v.47 no.6
• /
• pp.608-612
• /
• 2010

Uvarovite Garnet is green pigment prepared by using $Cr_2O_3$, CaO and $SiO_2$ which are widely used in ceramic industry. The synthesis of above pigment was carried out by mixing $K_2Cr_2O_7$, $SiO_2$ and $CaCO_3$ as formulated and then firing at $1000{\sim}1200^{\circ}C$. To investigate the optimum synthesis condition of the Uvarovite Garnet. it was prepared by using CaO to replace $CaCO_3$, $CaF_2$ and $CaCl_2$. To get green brighter color, $Al^{3+}$ was substituted for $Cr^{3+}$. They were characterized by X-ray diffraction, UV-Vis spectroscopy, Raman spectroscopy and SEM analysis. When the pigments were applied to lime glazes (6 wt%), color parameters of Uvarovite Garnet showed the $L^*$=40.99, $a^*$=-16.23 and $b^*$=17.04.

• Journal of the Korean Ceramic Society
• /
• v.45 no.5
• /
• pp.268-275
• /
• 2008

In high temperature ceramic glazes, a stable range of pink-red colors producing $Cr_2O_3-SnO_2-CaO-SiO_2$ pigments are factored by Cassiterite and Malayaite relationship with $Cr_2O_3$. The experiment described the effect of $CrCl_3$ by adding $H_3BO_3$ as a mineralizer to increase the formation of Malayaite crystal, substituting $CrCl_3$ instead of $Cr_2O_3$ in pigment as a chromophore. Synthesized pigments were analyzed by XRD, FT-IR, Raman Spectroscop, UV and UV-vis. The result shows the differences in amount of crystal phases and oxidation state of Cr ion, which causes the color change. The melting point of $CrCl_3$ is lower than $Cr_2O_3$ which act as a mineralizer and makes the pigment synthesized in lower temperature at $1200^{\circ}C$. Holding 3 h firing at $900^{\circ}C$ where the synthesize forms shows better effect of Malayaite crystal phases and increasing engaged effect of $CrCl_3$ where the color pigmentation is more defined then in $Cr_2O_3$.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.47 no.5
• /
• pp.120-126
• /
• 2015

In this study, we used various dyes from natural pigments such as tumeric, goldthread, indigo, pagoda tree flower, sappanwood, and safflower to make the Hanji wallpaper with super eight colors of yellow, orange, green, turquoise, violet, red, blue, and magenta. As a result of measuring the lightfastness, magenta dyed with sappanwood showed the worst effect, but blue dyed with only indigo showed the best effect. In terms of the spot test by water, red wallpaper dyed with safflower showed the clear spot, but blue, turquoise, and green dyed with indigo resulted in a little spot. The orange, violet, and magenta dyed with goldthread and sappanwood showed antibacterial activity, and the turquoise, green, and blue also has a little antibacterial activity. However, yellow and red didn't show the some result as expected. In the experiment for efficiency of formaldehyde removal, all Hanji wallpapers dyed with natural pigments showed the significant removal effect of formaldehyde, especially turquoise and red were the highest.

• Korean Journal of Materials Research
• /
• v.24 no.1
• /
• pp.43-47
• /
• 2014

NiO-doped hibonite pigments were synthesized by the solid state method to get stabilized blue color pigment in both oxidation and reduction atmospheres. Optimum substitution condition with NiO for hibonite blue pigment was investigated. Experimental results were comparable to those of previous cobalt-minimization studies performed with other phosphate- or oxide-based cobalt-containing ceramic pigments (having olivine ($Co_2SiO_4$), spinel ($CoAl_2O_4$), or with co-doped willemite ($(Co,Zn)_2SiO_4$) structures). Composition was designed varying the NiO molar ratio increasing with $SnO_2$. The optimum substitution content is 0.93 mole NiO with 0.75mole $SnO_2$. The characteristics of the synthesized pigment were analyzed by XRD, Raman spectroscopy, SEM, and UV-vis. Synthesized pigment was applied to a lime-barium glaze with 10 wt% each and fired at an oxidation atmosphere of $1250^{\circ}C/1h$ and a reducing atmosphere $1240^{\circ}C/1h$. Blue color was obtained with $L^*a^*b^*$ values at 43.39, -6.78, -18.20 under a reducing atmosphere and 41.66, -6.36, -14.7 under and oxidation atmosphere, respectively.

• Journal of the Korean Ceramic Society
• /
• v.47 no.3
• /
• pp.249-255
• /
• 2010

To investigate optical properties of (V, Pr)-doped $ZrSiO_4$ green pigments, samples were prepared by the ceramic method using NaF and NaCl as mineralizers. They were characterized by X-ray diffraction, UV-Vis spectroscopy and Raman spectroscopy. The changes of color in the samples during heating and effect of mineralizers were studied in terms of valence of the vanadium and praseodymium in the zircon matrix. (V, Pr)-doped $ZrSiO_4$ pigments give rise to green coloration in $800^{\circ}C$. The oxidation state of V and Pr ions of pigments in the glazed samples were confirmed by UV-Vis absorption spectra. This absorption spectra showed three typical bands of trivalent Pr at the 445, 480~490, 592 nm due to f-f transitions and two broad bands of 302~380, 400~500 nm due to f-d transitions of tetravalent Pr. According to the increasing amounts of $Pr_6O_{11}$, the two broad bands showed decreasing intensity at 290, 640 nm due to d-d transitions of tetravalent V.

• Fashion & Textile Research Journal
• /
• v.11 no.2
• /
• pp.337-343
• /
• 2009

This study systematically investigated a method for extraction of safflower (Carthamus tinctorius Linnaeus) colorants by ultrasonic treatment. Compared to pigments productivity and cell wall structures of safflower after general and ultrasonic method, the ultrasonic method showed high extraction efficiency of safflower pigments due to destruction of safflower cell wall caused by high vibration energies. Microscopic analysis confirmed the hypothesis that the ultrasonic treatment of safflower caused its cell wall structure loosened and made efficient extraction of safflower pigments. And also, LC-MS/MS analysis revealed that productivities of the yellow and red safflower pigments by ultrasonic method were 21.9% and 14.6% higher, respectively, than those of pigments extracted by general method. The ultrasonic extracted yellow and red colorants could be used to dye not only natural fibers like cotton, silk and wool, but also synthetic fiber like nylon, and generally gave a better color tone than the general extracted colorants from safflower due to the affinities of red and yellow colorant on different fibers. As the yellow and red colorant were extracted by ultrasonic treatment in water, the K/S value on of 550/440nm of cotton and rayon was increased but in the case of silk and wool the change of this value was almost not detected. Finally, this technique might provide a solution to establish reproducibility and standardization for the extraction and dyeing methods on fabrics.