Colloidal assembly in droplets: structures and optical properties

Abstract

Colloidal assembly in emulsion drops provides fundamental tools for studying optimum particle arrangement under spherical confinement and practical means for producing photonic microparticles. Recent progresses have found that energetically-favored cluster...

Disorder explains dual‐band reflection spectrum in spherical colloidal photonic supraparticle assemblies

“…The quality of the particular surface cannot be decided on an individual basis, yet is this finding indicated by the cross sectional SEM-FIB analysis for our DSA-fabricated SCAs in analogy to the results by Vogel et al on WSA-fabricated SCAs [10] and Park et al on various colloidal assembly structures generated within droplets. [13] Our results indicate clearly that the obtained reflection spectra are qualitatively reproducible for different sizes of evaporation-assisted SCAs having undergone inket-based deposition as a common deposition technique.…”

“…During the last decade, bottom-up nanofabrication techniques based on self-assembly of nano-and microscopic constituents from colloidal dielectric nanoparticles to micro-and mesoscopic hierarchical large-area patterns and three-dimensional superstructures have become an interesting field of research both in fundamental and technical sciences. [4][5][6][7][8][9][10][11][12][13] Application examples comprise PC microarrays [14][15][16][17][18] aiming for, most visionary early on, all-optical computers [19] or, more practical, for attenuators, waveguides [20] and interconnects for narrow-band optical signals, [21] as tools for optical barcoding, [7] as security elements, [22] as lightconfining elements in photovoltaic cells, [23,24] or as components for refractive-index tuning. [25] Recent developments are devoted to thermally or environmentally responding displays, [26,27] pH sensors [28] and chemical sensors for reaction kinetics.…”

“…[25] Recent developments are devoted to thermally or environmentally responding displays, [26,27] pH sensors [28] and chemical sensors for reaction kinetics. [29] Wide-spread optical phenomena in nature are structural colors from bulk materials, [10,11] areal PC micropatterns [7,[30][31][32] and smallsize [8,13] down to magic-number [12] colloidal clusters. In structural colors, the origin of the color impression is mostly nanostructured bulk material rather than colloidal material.…”

Bottom-up synthesis of meta-atoms as building blocks in self-assembled metamaterials: recent advances and perspectives

“…Emulsion-Based Assembly Surfactant stabilized droplets of colloidal suspensions evaporated in situ to produce clusters. [28,[39][40][41][42] Facile.…”

Photonic Microbeads Templated by Oil‐in‐Oil Emulsion Droplets for High Saturation of Structural Colors

“…[5,[16][17][18][19][20] For example, colloidal particles are confined in emulsion droplets and enriched to form a close-packed array in a supraball by depleting the suspension medium through evaporation. [21][22][23][24] The supraballs contain either an onion-like arrangement, icosahedral structure, or single-crystalline structure depending on the rate of enrichment and relative size of supraballs to the particles, [25][26][27][28][29][30] which show pronounced structural colors. The color saturation has been enhanced by employing lightabsorbing additives.…”