Colloidal crystal
[1] A natural example of this phenomenon can be found in the gem opal, where spheres of silica assume a close-packed locally periodic structure under moderate compression.
[2][3] Bulk properties of a colloidal crystal depend on composition, particle size, packing arrangement, and degree of regularity.
A good natural example of this phenomenon can be found in precious opal, where brilliant regions of pure spectral color result from close-packed domains of colloidal spheres of amorphous silicon dioxide, SiO2 (see above illustration).
Using X-ray diffraction methods, it was subsequently determined that when concentrated by centrifuging from dilute water suspensions, these virus particles often organized themselves into highly ordered arrays.
The use of a large number of the same proteins to build a protective shell is consistent with the limited length of RNA or DNA content.
[11][12] It has been known for many years that, due to repulsive Coulombic interactions, electrically charged macromolecules in an aqueous environment can exhibit long-range crystal-like correlations with interparticle separation distances often being considerably greater than the individual particle diameter.
In all of the cases in nature, the same iridescence is caused by the diffraction and constructive interference of visible lightwaves which falls under Bragg’s law.
The science of photonics includes the emission, transmission, amplification, detection, modulation, and switching of lightwaves over a broad range of frequencies and wavelengths.
Photonic devices include electro-optic components such as lasers (Light Amplification by Stimulated Emission of Radiation) and optical fiber.
Applications include telecommunications, information processing, illumination, spectroscopy, holography, medicine (surgery, vision correction, endoscopy), military (guided missile) technology, agriculture and robotics.
This includes an emerging class of mechanically superior biomaterials based on microstructure features and designs found in nature.
[22] Periodic ordered lattices behave as linear viscoelastic solids when subjected to small amplitude mechanical deformations.
However, hard-sphere single crystals (size 3 mm) have been obtained from a sample in a concentration regime that would remain in the liquid state in the absence of a temperature gradient.
Small-angle laser light scattering has provided information about spatial density fluctuations or the shape of growing crystal grains.
Experiments performed in microgravity on the Space Shuttle Columbia suggest that the typical face-centered cubic structure may be induced by gravitational stresses.
[16] All of the experiments have led to at least one common conclusion: colloidal crystals may indeed mimic their atomic counterparts on appropriate scales of length (spatial) and time (temporal).
Defects have been reported to flash by in the blink of an eye in thin films of colloidal crystals under oil using a simple optical microscope.
The low aspect ratio, such as bulge, eye-ball, and snowman-like non-spherical colloids, which spontaneously self-assembled to photonic crystal array with high uniformity.
[41][42][43][44][40] The observed lattice and particle orientations experimentally confirmed a body of theoretical work on the condensed phases of non-spherical objects.
Residual hollow honeycomb structures provide a relative index of refraction (ratio of matrix to air) sufficient for selective filters.
Self-assembly is the most common term in use in the modern scientific community to describe the spontaneous aggregation of particles (atoms, molecules, colloids, micelles, etc.)
