Terms and words used frequently in the Sol-Gel area.
Their literal definitions
were taken from
Press Dictionary of Science and Technology and they are
published as they appear.
(with the permission
of Academic Press)
The dispersion of a gas
in a solid or liquid medium, such as foam; the reverse of an aerosol,
where the medium is a gas and the dispersed material is particles of a
solid or liquid.
A solution made with a mixture of a colloid and an alcohol.
A colloidal gel made with alcosol.
Surface treatment with dielectric material to reduce the reflection of
electromagnetic radiation while increasing light transmission.
A method of
removing water from a liquid at temperatures lower than 100°C; a second
liquid that forms an azeotropic mixture with water is added to the
behavior of fluids acting with surface tension on interfaces or
The evaporation of moisture from the surface of a porous mass and the
subsequent capillary movement of moisture from the interior of the mass
to its surface; eventually the amount of moisture on the surface and
interior of the mass stabilizes.
1. Of or relating to products, such as pottery, porcelain,
or tile, that are made from nonmetallic mineral 2. an object made of
such a material. an object made of such a material.
1. The process of applying a layer of ceramic material,
such as alumina, onto a metallic product in order to protect against
extremely high temperatures. 2. the material thus applied.
critical point drying
A procedure used in preparing a specimen for electron microscopic
examination, in which damage to the specimen during its drying step is
minimized by avoiding exposure to a liquid-gas boundary.
Arts. 1. any mineral substance used to cover the
surface of a printing paper, such as blanc fixe or china clay. 2. the application of such a
substance to a sheet of paper. 3. the application of a varnish or
photosensitive solution to a printing plate.
Science. a material that forms a continuous layer over a surface, or
the film formed by such a material.
Physical Chemistry. 1.
A substance consisting of very tiny particles that are usually between 1
nanometer and 1000 nanometers in diameter and that are suspended in a
continuous medium, such as a liquid, a solid, or a gaseous substance. 2.
the translucent, pale yellow, gelatinous substance resulting from
Chemistry. Any of the individual particles of a colloid.
A colloid of fine particles of silica that are negatively charged by a
small addition of alkali, forming a high-concentration solution that is
used to make molded ceramics or to treat textiles.
A condition of clouds in which the particles tend to aggregate into
masses large enough to precipitate.
Chemistry. A mixture of two substances, one of which (the colloid)
is uniformly distributed throughout the other (the dispersion medium);
either substance may be gaseous, liquid, or solid.
A process of scattering or separating; specific uses include:
Chemistry. a two-phase system consisting of finely divided particles
(the disperse phase) distributed throughout a bulk substance (the
continuous phase); for example, fog is a dispersion of liquid particles
in a gas; paint is a dispersion of solid particles in a liquid.
Physics. the separation
of a complex wave containing several frequencies into its individual
component waves by virtue of different wave speeds.
the slowing down of a radio signal's propagation velocity as it passes
through an ionized gas or plasma in the interstellar medium; short
frequencies are the least affected and long ones the most affected.
the scattering of microwave radiation by an obstruction.
the characteristic and specific manner in which a monopaque mineral will
refract white light.
1. The removal of most of the water from a substance
(usually 92-95%), often through heat exposure. 2.
the removal of solvents other than water from a substance.
A substance having an affinity for water, used to dry fluid substances;
Engineering. The quick evaporation of liquid from a granular or
porous solid by a rapid reduction in pressure or an updraft of warm air.
Engineering. A process in which food or tissue is preserved, by drying it in a frozen
state under high vacuum conditions; used in preparing medicines and
laboratory specimens and in some forms of food preservation.
1. A colloidal suspension of a liquid in a solid, forming a
jellylike material in a more solid form than a sol. 2. to form a
Chemistry. The stage at which a liquid begins to take on the
semisolid characteristics of a gel.
A predominantly crystalline product created by the controlled
crystallization of glass; characterized by high thermal shock resistance
and low thermal expansion.
Something that is heterogeneous; a composite.
1. an offspring of two genetically different parents, or
even different species. 2. see HETEROZYGOTE.
an igneous rock formed by the assimilation of wall rock into a magma or
by the mixing of two magmas. 2.
of or relating to a rock so formed. Thus, hybrid rock. of or
relating to a rock so formed.
Having an affinity for water; attracting, dissolving in, or absorbing
Relating to or being a hydrophobe; repelling water.
not tolerant of water or a wet environment.
of or relating to rabies.
Psychology. of or relating
A colloidal dispersion in water; a sol whose dispersion medium is water.
Science. A water-based gel; a gel whose liquid constituent is water.
A gel that contains ionic groups attached to the colloid structure,
preventing the groups from diffusing out into a surrounding medium.
Science. The progressive fusion of a ceramic material during the
firing process; as it proceeds the proportion of glassy bond increases
and the porosity of the fired product decreases.
monodisperse colloidal system
A colloidal system having particles of the same size, interaction, and
In powder metallurgy, a preliminary sintering operation performed at a
temperature lower than the final sintering temperature.
Science. A process in which a compacted powder is heated to a
temperature where sintering takes place simultaneously with a chemical
reaction; for example silicon powder heated in the presence of nitrogen
to produce silicon nitride.
Chemistry. A colloidal, highly absorbent form of silicon dioxide;
widely used as a dehumidifying and dehydrating agent and in many
Science. The process in which fine particles of a material become
chemically bonded at a temperature that is sufficient for atomic
Science. A coating produced by the sol-gel process of glassmaking,
in which glass is formed at low temperatures from suitable compounds by
chemical polymerization in a liquid phase; a gel is formed from which
glass may be derived by the successive elimination of interstitial
liquid and the collapse of the resulting solid residue by sintering.
Science. A ceramic processing used to create a uniform die fill for
automated pressing; the slurry is fed into the spray drier, where
circulating hot air evaporates the water; the resulting powder is
collected for further processing.
A condition in which a substance experiences a change in its pressure,
temperature, or volume that would normally carry the system through its
critical point although no phase change is observed.
of, relating to, having, or operating with a multiplication factor
greater than one.
Mechanics. The stretching force required to form a liquid film;
equal to the surface energy of the liquid per unit length of the film at
equilibrium; the force tends to minimize the area of a surface.
Any of several thin layers (generally less than 1m
each) of insulating, conducting, or semiconductor material that are
deposited successively on a supporting substrate in precise patterns to
collectively form all or part of an integrated circuit; the deposition
can be performed by mechanical, chemical, or high-vacuum evaporation
The removal of liquid from a solid material while in a vacuum system, to
lower the temperature at which evaporation takes place and thus prevent
heat damage to the material.
A gel from which all volatile liquid has been removed.