Structural Color Tuning: Mixing Melanin-Like Particles with Different Diameters to Create Neutral Colors

Kawamura, Ayaka; Kohri, Michinari; Yoshioka, Shinya; Taniguchi, Tadatsugu; Kishikawa, Keiki

doi:10.1021/acs.langmuir.7b00707

Cited by 77 publications

(61 citation statements)

References 58 publications

(74 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our results do suggest that, depending on the intensity of the oxidative reaction, chemically-distinct, dark-or light-colored MN-like pigments could be generated depending on the type of precursor that is present. Such physically and chemically distinct MN materials could find different applications 7,16,[43][44][45][46] or possess different cell-biological properties [47][48][49][50][51][52] In addition, our results suggest that the absence of a dark color does not necessarily mean the absence of MN-like materials which may have implications for the evaluation of histological or fossil specimens. [53][54] …”

Section: 323uv-vis Spectroscopy and Fluorescence Emissionmentioning

confidence: 89%

Dark- or Light-Colored Melanins: Generating Pigments Using Fe2+ and H2O2

Vercruysse

Russell²,

Knight³

et al. 2017

Preprint

View full text Add to dashboard Cite

We have studied the formation of melanin-like pigments from catechol or pyrogallol and a wide range of other phenolic compounds using Fe 2+ and H 2 O 2 . Combining UV_Vis spectroscopic measurements and size-exclusion chromatography analyses we evaluated the impact of the intensity of the oxidation reaction by varying the concentration of H 2 O 2 present in the reaction mixtures. All compounds tested, except tyrosine, reacted readily leading to mixtures that were black, brown or yellow-orange in color. For many compounds tested, the use of increasing concentrations of H 2 O 2 resulted in either precipitation of the pigment or the formation of a soluble, lighter-colored pigment. With catechol or pyrogallol as model compounds, and using different concentrations of H 2 O 2 , several materials were synthesized, purified and dried. The physic-chemical properties of these materials were compared to the properties of melanin-like pigments synthesized from the same precursors using air-oxidation in an alkaline environment. For both precursors, a distinct chemical change, as judged from FT-IR spectroscopy, was introduced in the melanin structures when using H 2 O 2 as the oxidizing agent and the relative intensity of this distinct signal strengthened with increasing concentration of H 2 O 2 used in the reaction. In general, our results suggest that depending on the precursor molecule and the intensity of the oxidizing reaction conditions involved, light-or dark-colored melanin-like pigments can be generated. This may be an important factor when evaluating the visible outlook of histological or archeological specimens: the presence of a lighter color or the absence of a dark color may not necessarily mean the absence of melanin-like biomolecules.

show abstract

Section: 323uv-vis Spectroscopy and Fluorescence Emissionmentioning

confidence: 89%

Dark- or Light-Colored Melanins: Generating Pigments Using Fe2+ and H2O2

Vercruysse

Russell²,

Knight³

et al. 2017

Preprint

View full text Add to dashboard Cite

show abstract

“…Instead of mixing absorbing dyes with particles, as is done in other techniques, we synthesize monodisperse hollow nanospheres with a carbon–silica shell using a method that distributes the absorbing carbon uniformly in the shell. Others have made core–shell particles with absorbing shells, but the colors in these studies do not come from Mie resonances …”

mentioning

confidence: 99%

Solution‐Processable Photonic Inks of Mie‐Resonant Hollow Carbon–Silica Nanospheres

Kim

Hwang

Lee

et al. 2019

Small

View full text Add to dashboard Cite

Whereas ordinary color comes from selective absorption by pigments or dyes, [1,2] structural color comes from coherent scattering from nanostructures. [3,4] However, ordered nanostructures lead to structural color that depends strongly on the viewing angle, which limits its practical applications. By contrast, materials with short-range order, such as colloidal glasses [5][6][7][8] or blue bird feathers, [9][10][11][12][13] show structural color that is independent of angle. While these materials could in principle be used in applications that require structural color that is indistinguishable from pigment, they also tend to diffuse or multiply scatter light, leading to colors that are not saturated. The multiple scattering can be suppressed by dyes such as carbon black.An alternative approach is to rely on the wavelengthdependent scattering of the particles themselves. Cho et al. [14] Hollow carbon-silica nanospheres that exhibit angle-independent structural color with high saturation and minimal absorption are made. Through scattering calculations, it is shown that the structural color arises from Mie resonances that are tuned precisely by varying the thickness of the shells. Since the color does not depend on the spatial arrangement of the particles, the coloration is angle independent and vibrant in powders and liquid suspensions. These properties make hollow carbon-silica nanospheres ideal for applications, and their potential in making flexible, angle-independent films and 3D printed films is explored. Photonic Inks

show abstract

“…[20] Consolidation of two different sizes of colloidal particles also leads to the formation of the amorphous array. [21][22][23] Although colloidal glasses show reduced iridescence, multiple scattering usually overwhelms the structural resonance, leading to undesired milky white appearance. To reduce the multiple scattering, absorptive additives such as carbon black nanoparticles, graphene nanosheets, magnetite nanoparticles, cuttlefish inks, and polydopamine nanoparticles have been incorporated, making the structural color relatively pronounced.…”

Section: Structural Colorationmentioning

confidence: 99%

“…This is because silica particles are repulsive and size contrast of ΔD/D avg is as small as 0.13, where ΔD and D avg are size differences between large and small particles and average size, respectively, the binary colloids with ΔD/D avg as small as 0.07 form amorphous array with a short-range order when consolidated by solvent evaporation, indicating that repulsive potential and nonclose-packed array are critical to maintain a long-range order. [23] With this set of silica particles, we are able to control the Δλ/λ max in the range of 0.025-0.055 and reflectivity in the range of 70-30% by adjusting f although these two are coupled by RΔλ/λ max ≈ 1.75. The value of λ max can be set to any value by properly selecting two different sizes of silica particles using the linear relation of Equation (2), while maintaining the size contrast of ΔD/D avg = 0.13.…”

Section: Influence Of Mixing Ratio On Colloidal Arrangement and Opticmentioning

confidence: 99%

“…Alternatively, the particles are destabilized to form random aggregates . Consolidation of two different sizes of colloidal particles also leads to the formation of the amorphous array . Although colloidal glasses show reduced iridescence, multiple scattering usually overwhelms the structural resonance, leading to undesired milky white appearance.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Structural Coloration with Nonclose‐Packed Array of Bidisperse Colloidal Particles

Lee

Kim

Choi

et al. 2019

Small

View full text Add to dashboard Cite

Colloidal crystals and glasses have their own photonic effects. Colloidal crystals show high reflectivity at narrowband, whereas colloidal glasses show low reflectivity at broadband. To compromise the opposite optical properties, a simple means is suggested to control the colloidal arrangement between crystal and glass by employing two different sizes of silica particles with repulsive interparticle potential. Monodisperse silica particles with repulsive potential spontaneously form crystalline structure at volume fraction far below 0.74. When two different sizes of silica particles coexist, the arrangement of silica particles is significantly influenced by two parameters: size contrast and mixing ratio. When the size contrast is small, a long‐range order is partially conserved in the entire mixing ratio, resulting in a pronounced reflectance peak and brilliant structural color. When the size contrast is large, the long‐range order is rapidly reduced along with mixing ratio. Nevertheless, a short‐range order survives, which causes low reflectivity at a broad wavelength, developing faint structural colors. These findings offer an insight into controlling the colloidal arrangements and provide a simple way to tune the optical property of colloidal arrays for structural coloration.

show abstract

Structural Color Tuning: Mixing Melanin-Like Particles with Different Diameters to Create Neutral Colors

Cited by 77 publications

References 58 publications

Dark- or Light-Colored Melanins: Generating Pigments Using Fe2+ and H2O2

Dark- or Light-Colored Melanins: Generating Pigments Using Fe2+ and H2O2

Solution‐Processable Photonic Inks of Mie‐Resonant Hollow Carbon–Silica Nanospheres

Structural Coloration with Nonclose‐Packed Array of Bidisperse Colloidal Particles

Contact Info

Product

Resources

About