Clays: A family of finely crystalline
materials, composed primarily of silicates, with layered crystal
structures. Clays may be refined from geological materials or may be
Crystal grain boundary: Crystalline
materials are composed of atoms arranged in an orderly way, in precise
relationships to one another. A grain boundary is a narrow region of
transition for one ordered area to another of different crystallographic
orientation - an interface between one crystal grain and another.
Feature size: Refers to the particle
size or crystalline grain size.
Ion exchange: A chemical reaction
involving the exchange of hydrated ions in a solid for similarly charged
but different element ions in solution.
Nanomaterials: Nanoscale materials;
materials with structural features (particle size or grain size, for
example) of at least one dimension in the range 1-100 nm.
Nanometer: One-billionth of a meter
Nanotechnology: Processes, systems,
and materials that involve at least one dimension in the nano (sub-micron)
range. The term has been used in various ways by different authors.
Photoluminescence: Emission of light
from a molecule or atom that has absorbed electromagnetic energy.
Examples include fluorescence and phosphorescence.
Polyimide: A family of polymers
involving carbon and nitrogen bonds, known for good thermal stability.
Polymeric materials: Materials
composed of large molecules, generally based on carbon, that have been
formed from the chemical bonding of smaller units (monomers). Commonly
known as plastics.
Polymerization: A chemical reaction
resulting in the bonding together of small molecular units (monomers) to
form a much larger molecule (polymer). There are many different routes, or
reaction mechanisms, for polymerization.