Biliproteins

Biliproteins, covalently bonded complexes of proteins and bile pigments, serve as light-harvesting pigments in photosynthesis and light-sensory pigments of photosynthetic organisms. Recent developments in the biochemistry and biophysics of these pigments are reviewed and an attempt is made to describe their functions of light-harvesting and of information transduction on a molecular level

Common Medieval Pigments

This paper discusses the pigments used in medieval manuscripts. Specific types of pigments that are examined are earths, minerals, manufactured, and organics. It also focuses on both destructive and non-destructive methods for identifying medieval pigments

Superhydrophobic dyeing of orange fruit pigment on cotton knitted textile application

The pigment is the substance that changes the colour of light based on the result of selective colour absorption. Pigments are used for colouring paint, fabric, ink, food, cosmetic and other materials. The materials that chosen and developed by human for use as pigment must have special properties that make them ideal for make them colouring other materials. The pigment must be stable in solid form at ambient temperatures [1]. Pigments can be divided into two groups which is organic pigment and inorganic pigment. For inorganic pigments, the colour is comparatively less bright and these pigments are also seemed to be less rich than the organic pigments. Large amount of inorganic pigments are required to generate desired effects since these pigments have low tinting strength. The most important thing is inorganic pigment contains toxic substances that may be harm to our health and environment. The researchers are started to investigate and use organic pigment into textile application nowadays [2]

Utilization dyeing process of coffea pigment as superhydrophobic coating on fabric application

Synthetic pigments and dyes was frequently used for textile products in order to fulfill the customers demand because it is less expensive and high durability compared to natural pigments or dyes. Therefore, the contribution of synthetic dyes waste water is higher and it becomes one of cause of hazardous pollution to the environment. Factories that discharge this dye waste water are harmful toxic waste and high chemical usage which can give a bad effect to the human health [1]. An alternative way need to be considered in order to overcome the problems that comes from the synthetics dyes. The alternative way that were studied in this project as the solution to the problems stated was by using natural resources which is coffee as a colorant for pigmentation or dyeing in order to replace the harmful synthetic dyeing [2]. Robusta coffee or Coffea canephora is chosen as the pigments colorant because it has minimal environmental impacts compare to synthetic pigments. Natural pigments are not harmful to the environment, which makes it so captivating for consumers. Natural pigments are biodegradable and disposing them will not lead to pollution [3]. Furthermore, natural pigments are safe to use. It does not cause any harm or health problem when abstain. Pigment appearance is altered by selective absorption and by scattering of light [4]. Other than that, different composition of natural pigments can give a wide-range of colour by modifying the concentration percentage of pigments ingredients such as Robusta coffee which brew for pigments in order to provide a varied brown colour to textile fabrics. The superhydrophobic coating fabrics for textile application provide a durable water repellent which is useful for fabrics in order to protect them from water. In addition, the fabric also can be easily clean [5]

Optimal number of pigments in photosynthetic complexes

We study excitation energy transfer in a simple model of photosynthetic complex. The model, described by Lindblad equation, consists of pigments interacting via dipole-dipole interaction. Overlapping of pigments induces an on-site energy disorder, providing a mechanism for blocking the excitation transfer. Based on the average efficiency as well as robustness of random configurations of pigments, we calculate the optimal number of pigments that should be enclosed in a pigment-protein complex of a given size. The results suggest that a large fraction of pigment configurations are efficient as well as robust if the number of pigments is properly chosen. We compare optimal results of the model to the structure of pigment-protein complexes as found in nature, finding good agreement.Comment: 20 pages, 7 figures; v2.: new appendix, published versio

Investigation of dyeing based on pandanus amaryllifolius for superhydrophobic coating in cotton-polyester blended in textile application

Natural dyes are derived from natural resources. Colouring materials obtained from natural resources of plant, animal, mineral, and microbial origins were used for colouration of various textile materials. Use of natural dyes started fall after the invention of synthetic dyes in the second half of the nineteenth century. The synthetic dyes were rapidly industrialization of textile production resulted in almost complete replacement of natural dyes by synthetic dyes because their easy availability simple application process, better fastness properties and consistency of shades [1]. Recent environmental awareness has again revived interest in natural dyes mainly among environmentally conscious people. Natural pigments are considered eco-friendly as these are renewable and biodegradable which is skin friendly and provide healthier benefits to the wearer [2]. Pandanus amaryllifolius also called as pandan leaf is a tropical plant that under screw pine genus and it can be easily found all around in Malaysia. It is a genus monocotyledon plants with over 750 accepted species. Extraction of green pigments from pandanus amaryllifolius to produce an organic pigment for fabric dyeing can become an alternative of synthetic pigments. Organic pigments also can be classified as a biochrome substance which is produced by living organisms. These biological pigments include flower and plant pigments [3]

Correlation of structural and spectroscopic properties of a photosynthetic reaction center

Polarized spectra of absorption and light-induced absorbance changes are presented for the crystallized reaction centers of Rhodopseudomonas viridis. We find that a model based on extended dipole interaction between all six pigments is capable of interpreting detailed features such as the contributions from the individual pigments to the various absorption peaks. Even though the pigments are arranged in approximate C2 symmetry, the optical spectra together with the calculations reflect deviations from this symmetry, which may be important in understanding the electron pathway

Investigating Leaf Pigments

The purpose of this resource is to explore what pigments exist in leaves and their importance. Students will conduct an experiment using paper chromatography to separate pigments present in leaves. Educational levels: Middle school, High school