• The Korean Journal of Food And Nutrition
• /
• v.32 no.1
• /
• pp.41-49
• /
• 2019

Carotene, xanthophyll, carotenoid anthocyan, phycopyrine, chlorophyll, and monascus pigments are used as natural coloring agents since they are more stable to human body than synthetic coloring agents. Among them, monascus pigments are a natural red pigment produced by the Monascus purpureus. For the development of edible paint using natural pigment, Monascus purpureus strain was cultured at a temperature of $35^{\circ}C$ for 15 days on a PDYA plate and liquid medium to produce a red pigment. In addition, a large amount of the red pigment was extracted from Hongkuk Koji in parallel with water extraction and ultrasonic wave extraction. At this time, the yield of ultrasonic extract was 2~4 times higher. Thus, Monascus purpureus strains, etc. were prepared by freeze-drying powder. In conclusion, natural paints made with red pigments have enabled the development of been edible paints that can be used as eco-friendly materials with good viscosity, enhanced spread ability and coloration.

• Journal of the Korean Wood Science and Technology
• /
• v.49 no.5
• /
• pp.471-481
• /
• 2021

This study investigated the hygroscopicity and UV deterioration characteristics of 3 domestic and 4 imported woods using natural oil, stain, and varnish paints. In terms of hygroscopicity, it was found that the hygroscopicity of the painted wood was lower than that of the unpainted wood, and that as the number of coatings increased, the hygroscopicity decreased. In terms of anti-absorption, oil-based chemical paints showed higher resistance than water-based paints, and natural oils showed results comparable to oil-based paints. As for the UV deterioration, the amount of color change of the painted wood was lower than that of the unpainted wood, and there was no significant difference according to the number of times of painting. The amount of color change was found to be low in oil-based paints and hardwoods. Through this study, we confirmed effective moisture blocking and small color changes during painting using paints, and it is believed that wood can be protected from internal and external defects through selective and efficient painting based on data for excellent painting performance.

• Journal of Applied Reliability
• /
• v.1 no.2
• /
• pp.79-93
• /
• 2001

Recently, new aspects of paints such as a beautiful appearance, use of environmentally friendly paints, etc., in addition to the superior performance of paints have been requested for industrial paints including the paints for heavy construction equipment and others. Particularly, the quality of appearance of coating affects the sales of heavy construction equipment. And the necessity for the paints to have a superior weather-proof property without changing the luster or color even after long-time exposure to the open air is emphasized. The change in the surface color and luster of the paint due to the natural environment progresses very slowly, and it takes a long time to verify material properties when developing new paints. In order to improve such methods, weathering tests are performed in many laboratories as a test for accelerating aging of coating, and the lifetime of the products is estimated through evaluation of the weathering (environment-proof) quality of paints. However, not a great deal of research activity has been conducted up to the present time since the interrelationship between the actual results of testing and field data is different for each paint and it takes a long time to study relevant materials. Therefore, introduced in the present study is the estimation of the change in the quality of appearance of coating in the field through the accelerated aging test among the cases of improvement of the quality of appearance of the urethane paint for heavy construction equipment.

• Journal of Conservation Science
• /
• v.30 no.2
• /
• pp.219-234
• /
• 2014

Fabrics, natural dyed fabrics, papers, natural dyed papers and paints were examined effects of colors and mechanical properties for materials of museum collections under anoxic treatment. Anoxic conditions using nitrogen and argon were oxygen concentration 0.01%, temperature($20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$), 50% RH and exposure time 30 days. Examined fabrics were raw silk fabric, UV irradiated raw silk fabric, degummed silk fabric, UV irradiated degummed silk fabric, cotton fabric, and UV irradiated cotton fabric. Natural dyed silk and cotton fabrics were dyed with fresh indigo, indigo, safflower, gromwell, madder sappanwood, amur cork tree, turmeric, gardenia, barberry root, pagoda tree flower, cochineal, lac, alnus japonica, gallnut, chestnut shell, and combination(indigo and safflower, indigo and amur cork tree, indigo and pagoda tree flower, indigo and sappanwood). Papers were Korean papers(mulberry paper, mulberry(70%) and rice straw(30%) mixed paper), Japanese paper(gampi paper), cotton paper, refined linen paper, cotton, linen & manila mixed fibre furnish, copy paper, news print, and alum sized mulberry paper. Natural dyed papers were dyed with indigo, sappanwood, madder, safflower, gardenia, amur cork tree, and pagoda tree flower. Paints were painted on alum-sized papers and silk fabrics using glue and pigments(azurite, malachite, cinnabar, vermilion, orpiment, gamboge, red lead, haematite, iron oxide red, indigo(lake), lac, cochineal, safflower, madder root lake, celadonite, smalt, ultramarine blue, lapis lazuli, prussian blue, kaolin, lead white, oyster-shell white, and clam-shell white). The color differences(${\Delta}E^*$) of all examined materials were below 1.5 or lowered than control samples after anoxic treatment. The variations of tenacity of yarns of fabrics and natural dyed fabrics after anoxic treatment were within that of standard silk and cotton fabrics. Gases(nitrogen and argon) and temperatures of anoxic treatment did not also affected color differences and variations of tenacity of materials.

• Journal of Adhesion and Interface
• /
• v.24 no.3
• /
• pp.95-99
• /
• 2023

In this study, LiDAR-detectable black materials are synthesized by coating and reduction of titanium dioxide onto plate-type natural mica, which evaluated practical LiDAR verification. In detail, black TiO₂@Mica materials are fabricated by utilizing a sol-gel reaction to coat titanium dioxide onto natural mica, followed by reduction using sodium tetrahydridoborate. Subsequently, Black TiO₂@Mica materials are dispersed in hydrophilic transparent varnish and sprayed onto the glass substrate to assess applicability as paints. As a result, Black TiO₂@Mica-based paints exhibit true blackness (L^*=12.1) and a higher NIR reflectance (30.2 R%). In addition, it was confirmed that as-synthesized Black TiO₂@Mica materials are successfully recognized by a LiDAR sensor. This phenomenon is attributed to Fresnel's reflection law, in which light reflection occurs at the interface between natural mica and titanium dioxide with different refractive indices. In this regard, the findings of the study are expected to contribute to the potential utilization of LiDAR-detectable materials in various fields such as autonomous vehicles, robotics, and drones.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2002.10a
• /
• pp.521-526
• /
• 2002

In this paper, we described about the characteristic evaluation of environment-friendly ceramic paint with calcium-silicate mineral as a main binder. Particularly, we performed discharge of the environmental poisoning materials(e.g. VOCs, heavy metal, etc.), and properties of paint slurry and coating film of the ceramic paint. In the comparison of the ceramic paint with natural paint and mineral paint which were known as our environment-friendly paints, ceramic paint had good characteristics in the environmental safety and properies of wet slurry and dried coating film.

• Carbon letters
• /
• v.17 no.1
• /
• pp.11-17
• /
• 2016

Recently, with continuous developments in the field of materials science, graphene oxide (GO) has emerged as a promising material with excellent electrical, thermal, mechanical, and optical properties, which play important roles in most fields. Researchers have achieved considerable progress with graphene. Chitosan (CS) is a natural polymer that has been studied intensively owing to its specific formation, high chemical resistance, and excellent physical properties. These outstanding properties have led to its universal use in applications such as textile fabrics, tissue engineering, medicine and health, coatings, and paints. By combining the advantages of GO and CS, different types of promising materials can be obtained. This review discusses the preparation of GO-CS fibers, hydrogel and aerogel, and the applications of GO-CS nanocomposites. In addition, directions for future research on graphene material composites are discussed.

• Applied Chemistry for Engineering
• /
• v.28 no.5
• /
• pp.501-505
• /
• 2017

Due to the rapid urbanization and increased population, there is an increase in airtight nature of buildings which causes serious indoor air pollution. Among several indoor air pollutants, volatile organic compounds (VOCs) emitted from paint are of major concern. Therefore, there is an urge for the development of environmental friendly paint products. In this wok, a natural wall paint (NWP) was prepared by utilizing a natural clay material "sericite" as a main component. A small chamber test was carried out to identify the toxic substances release from NWP and the results were compared with two eco-friendly commercial paints. The total VOCs were detected in trace level inside the test chamber and their concentrations were below the recommended indoor air quality standards. Toluene was not detected for NWP, whereas formaldehyde was observed in trace level. The toxicity index results were compared with two commercial paints and found that NWP exhibited less harmful gas emission. Based on certification rating of building materials, NWP can be classified as the first grade of building materials. Due to the above advantages, the use of sericite as a major component in NWP will be a useful technique to maintain the indoor air quality.

• Journal of Korean Society for Atmospheric Environment
• /
• v.21 no.2
• /
• pp.191-204
• /
• 2005

Building and furnishing materials and consumer product are important sources of volatile organic compounds(VOCs) and other aldehydes in the indoor environment. Some available evidence indicates that VOCs can cause adverse health effects to the building occupants and contribute to some of the symptoms of what we call, 'Sick House Syndrome' in Korea. The aims of this study were to evaluate the efficiency of emission system and to investigate comparison of the emission characteristics of different building materials such as wall-papers, paints, and adhesives. The emission of VOCs from building materials were determined in the small chambers defining the temperature, relative humidity, and ventilation rate in this study. VOCs were sampled for 20 minutes using Tenax-TA tubes and analysed by GC-MS with thermal desorption. The stability of conditions for temperature and relative humidity in this small chamber system showed that the fluctuation of temperature was between 25.4$\pm$0.3$^{\circ}C$ and that of relative humidity was 50.2$\pm$0.6$\%$ under the airflow rate of 167 mL/min. The emission tests from building materials resulted in TVOC emission rates of 0.011 $\~$ 3.108 mg/m$^{2}$h after 7 days. The general wall-papers emitted toluene abundantly and the natural wall-papers mainly emitted n-butanol and a minor amount of alkanes compound such as n -tetradecane. The remainder consisted of toluene, m,p -xylene, and styrene. The paints mainly emitted toluene and the adhesives mainly emitted chloroform as well as toluene. As a result, this study is expected to suggest meaningful data for future studies in exposure control through selecting healthy building materials and for the establishment of guidelines for various building materials in Korea.

• Korean Journal of Environmental Biology
• /
• v.21 no.3
• /
• pp.303-307
• /
• 2003

Tributyltin (TBT) used world-wide in antifouling paints toy ships is a wide-spread environmental pollutant. At low doses, antiproliferative modes of action have been shown to be involved, whereas at higher doses apoptosis seems to be the mechanism of toxicity in reproductive organs by TBT. In this study, we investigated that the mechanisms underlying apoptosis induced by TBT in R2C cell. Effects of TBT on intracellular $Ca^{2+}$ level and reactive oxygen species (ROS) were investigated in R2C cells by fluorescence detector. TBT significantly induced intracellular $Ca^{2+}$ level in a time-dependent manner. The rise in intracellular $Ca^{2+}$ level was followed by a time-dependent generation of reactive oxygen species (ROS) at the cytosol level. Simultaneously, TBT induced the release of cytochrome c from the mitochondrial membrane into the cytosol. Furthermore, ROS production and the release of cytochrome c were reduced by BAPTA, an intracellular $Ca^{2+}$ chelator, indicating the important role of $Ca^{2+}$ in R2C during these early intracellular events. In addition, Z-DEVD FMB, a caspase -3 inhibitor, decreased apoptosis by TBT. Taken together, the present results indicated that the apoptotic pathway by TBT might start with an increase in intracellular $Ca^{2+}$ level, continues with release of ROS and cytochrome c from mitochondria, activation of caspases, and finally results in DNA fragmentation.