Exploring the use of unprocessed waste chicken eggshells for UV-protective applications

Photodegradation causes a steady loss of the useful physical, mechanical and optical properties of materials, necessitating their replacement over time. Because UV (Ultraviolet) light is most harmful in this regard, many materials now contain UV-protective additives. However, these additives are not always effective and durable, can be expensive, and their natural extraction or synthetic production can be harmful to the environment. Here, we investigated the use of unprocessed chicken eggshells in providing UV protection to two commonly used synthetic polymers: polystyrene and nylon. We show that unprocessed chicken eggshells provide a durable and effective UV protection. Our data sets the stage for future research to find a practical way to use the large amounts of unprocessed chicken eggshell waste as novel, economically appealing and environmentally friendly UV-protective additives

The cuticle modulates ultraviolet reflectance of avian eggshells

ABSTRACT Avian eggshells are variedly coloured, yet only two pigments, biliverdin and protoporphyrin IX, are known to contribute to the dramatic diversity of their colours. By contrast, the contributions of structural or other chemical components of the eggshell are poorly understood. For example, unpigmented eggshells, which appear white to the human eye, vary in their ultraviolet (UV) reflectance, which may be detectable by birds. We investigated the proximate mechanisms for the variation in UV-reflectance of unpigmented bird eggshells using spectrophotometry, electron microscopy, chemical analyses, and experimental manipulations. We specifically tested how UV-reflectance is affected by the eggshell cuticle, the outermost layer of most avian eggshells. The chemical dissolution of the outer eggshell layers, including the cuticle, increased UV-reflectance for only eggshells that contained a cuticle. Our findings demonstrate that the outer eggshell layers, including the cuticle, absorb UV-light, probably because they contain higher levels of organic components and other chemicals, such as calcium phosphates, compared to the predominantly calcite-based eggshell matrix. These data highlight the need to examine factors other than the known pigments in studies of avian eggshell colour

Exploring the Use of Unprocessed Waste Chicken Eggshells for UV-Protective Applications

Photodegradation causes a steady loss of the useful physical, mechanical and optical properties of materials, necessitating their replacement over time. Because UV (Ultraviolet) light is most harmful in this regard, many materials now contain UV-protective additives. However, these additives are not always effective and durable, can be expensive, and their natural extraction or synthetic production can be harmful to the environment. Here, we investigated the use of unprocessed chicken eggshells in providing UV protection to two commonly used synthetic polymers: polystyrene and nylon. We show that unprocessed chicken eggshells provide a durable and effective UV protection. Our data sets the stage for future research to find a practical way to use the large amounts of unprocessed chicken eggshell waste as novel, economically appealing and environmentally friendly UV-protective additives

The cuticle modulates ultraviolet reflectance of avian eggshells

Avian eggshells are variedly coloured, yet only two pigments, biliverdin and protoporphyrin IX, are known to contribute to the dramatic diversity of their colours. By contrast, the contributions of structural or other chemical components of the eggshell are poorly understood. For example, unpigmented eggshells, which appear white to the human eye, vary in their ultraviolet (UV) reflectance, which may be detectable by birds. We investigated the proximate mechanisms for the variation in UV-reflectance of unpigmented bird eggshells using spectrophotometry, electron microscopy, chemical analyses, and experimental manipulations. We specifically tested how UV-reflectance is affected by the eggshell cuticle, the outermost layer of most avian eggshells. The chemical dissolution of the outer eggshell layers, including the cuticle, increased UV-reflectance for only eggshells that contained a cuticle. Our findings demonstrate that the outer eggshell layers, including the cuticle, absorb UV-light, probably because they contain higher levels of organic components and other chemicals, such as calcium phosphates, compared to the predominantly calcite-based eggshell matrix. These data highlight the need to examine factors other than the known pigments in studies of avian eggshell colour

A Nanostructural Basis for Gloss of Avian Eggshells

The role of pigments in generating the colour and maculation of birds\u27 eggs is well characterized, whereas the effects of the eggshell\u27s nanostructure on the visual appearance of eggs are little studied. Here, we examined the nanostructural basis of glossiness of tinamou eggs. Tinamou eggs are well known for their glossy appearance, but the underlying mechanism responsible for this optical effect is unclear. Using experimental manipulations in conjunction with angle-resolved spectrophotometry, scanning electron microscopy, atomic force microscopy and chemical analyses, we show that the glossy appearance of tinamou eggshells is produced by an extremely smooth cuticle, composed of calcium carbonate, calcium phosphate and, potentially, organic compounds such as proteins and pigments. Optical calculations corroborate surface smoothness as the main factor producing gloss. Furthermore, we reveal the presence of weak iridescence on eggs of the great tinamou (Tinamus major), an optical effect never previously documented for bird eggs. These data highlight the need for further exploration into the nanostructural mechanisms for the production of colour and other optical effects of avian eggshells

Data from: A nanostructural basis for gloss of avian eggshells

The role of pigments in generating the colour and maculation of birds' eggs is well characterized, whereas the effects of the eggshell's nanostructure on the visual appearance of eggs are little studied. Here, we examined the nanostructural basis of glossiness of tinamou eggs. Tinamou eggs are well known for their glossy appearance, but the underlying mechanism responsible for this optical effect is unclear. Using experimental manipulations in conjunction with angle-resolved spectrophotometry, scanning electron microscopy, atomic force microscopy and chemical analyses, we show that the glossy appearance of tinamou eggshells is produced by an extremely smooth cuticle, composed of calcium carbonate, calcium phosphate and, potentially, organic compounds such as proteins and pigments. Optical calculations corroborate surface smoothness as the main factor producing gloss. Furthermore, we reveal the presence of weak iridescence on eggs of the great tinamou (Tinamus major), an optical effect never previously documented for bird eggs. These data highlight the need for further exploration into the nanostructural mechanisms for the production of colour and other optical effects of avian eggshells

Contrast gloss

Data for Hunter's contrast gloss measurements collected using a spectrophotometer. Spreadsheet contains specular and diffuse reflectance measurements for four tinamou species and an Araucana chicken