Color variation

Structures of different conjugated polymers including various thiophenes (3,4,8,9,10,11) and pyrroles 12,5,6,7) that show color variation. (From A. A. Argun. R Aubert, B. Thompson, I. Schwendeman, C. L. Gaupp, J. Hwang. N. J. Pinto. D. B. Tanner, A. G. MacDiarmid, J. R. Reynolds "Multielectrochromism in Polymers Structures and Devices" Chem. Mater. 2004, 1B, 4401-4412). 

Color Variations in Certain Dehydrated Foods with Variation of Particle Size... 

McCapra et al. (1994) and McCapra (1997) suggested that the color variation could be caused by the conformational difference of the oxyluciferin molecule, when the plane of thiazolinone is rotated at various angles against the plane of benzothiazole on the axis of the 2-2 bond the red light would be emitted at 90° angle, reflecting its minimum structural energy. 

Goto, T., Structure, stability and color variation of natural anthocyanins, Fortsch. Chem. Org. Natur., 52, 113, 1987. 

Certain varieties of hydrangeas are extremely popular for their ability to vary in color from blue to pink with growing conditions (see color Fig. 9.4.1). Research has determined that the actual mechanism for color variation is determined by the concentration of aluminum compounds in the flowersJ J In the presence of aluminum, blue flowers result in the absence of aluminum compounds, pink flowers predominate. 

Figure 10.1 The same specimen imaged by three different commercial imaging systems. Note the significant color variations in each image, as well as the shading of the background. There are also visible differences in resolution between the systems, even though total magnification is the same in all images. See color insert.

A. Dodabalapur, L.J. Rothberg, and T.M. Miller, Color variation with electroluminescent organic semiconductors in multimode resonant cavities, Appl. Phys. Lett., 65 2308-2310 (1994). 

Fig. 16.3 A carbon nanoparticle with surface defects (left), and emission color variations in carbon dots depending on size and type of defects. Adapted from Cao et at. [53] and Sun et at. [54] with kind permission from American Chemical Society (2006 and 2013).

Fig. 10. Defeclivity observed by the digital image comparison method (a) wafer map showing color variation problem after CMP, and (b) the same wafer using a modified computer algorithm.

Figure 5-30 The dependence of color variation from white pumice to pink or dark pink pumice on temperature and heating time. The equation for the line separating white and pink pumice is Time (s)=exp(64.10 0.05487), and the equation for the line separat-...

Quartzite. Quartzite is a very compact, exceptionally hard and tough meta-morphic rock derived from sandstone. It consists mainly of rather large crystals of quartz (composed of silicon dioxide) naturally cemented by secondary quartz. Most varieties of quartzite contain over 90% quartz, and in some cases the quartz content exceeds 95% of the total weight of the stone. The color of most quartzite is white or light yellow, but if it contains iron oxide impurities it is red, while other metal oxide impurities may cause the rock to display patchy color variations. Quartzite is very hard, which makes it difficult to quarry. Nevertheless, because of its strength and resistance to weathering, it has occasionally been used for construchon, sculphng statuary, and ornamentation. 

Goto, T. and Kondo, T., Structure and molecular stacking of anthocyanins. Flower color variation. Angew. Chem. Int. Ed. Engl. 30, 17, 1991. 

One of the best-established functions of anthocyanins is in the production of flower color and the provision of colors attractive to plant pollinators. Considerable effort has been made to give explanations for the color variations expressed by anthocyanins in plants. Various factors including concentration and nature of the anthocyanidin, anthocyanidin equilibrium forms, the extent of anthocyanin glycosidation and acylation, the nature and concentration of copigmentation, metal complexes, intra- and intermolecular association mechanisms, and influence of external factors like pH, salts, etc. have been found to have impact on anthocyanin colors. ... 

Kondo, T. et al.. Cause of flower color variation of hydrangea, Hydrangea macrophylla, Tennen Yuki Kagobutsu Toronkai Koen Yoshishu, 41, 265, 1999. 

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