Microparticles
Encyclopedia
Microparticles are particles between 0.1 and 100 
m in size. Commercially available microparticles are available a wide variety of materials, including those made of ceramics, glass
, polymers, and metals. One encounters microparticles everyday in nature with items such as pollen
, sand, and dust. Many Microparticles can be found in your kitchen as well with items such as: flour, and powdered sugar.
Microparticles have a much larger surface-to-volume ratio than at the macroscale, and thus their behavior can be quite different. For example, metal microparticles can be explosive in air.
Microsphere
are spherical microparticles, and are used where consistent and predictable particle surface area is important.
In biological systems, microparticles are small membrane bound vesicles circulating in the blood derived from cells that are in contact with the bloodstram such as platelets and endothelial cells. (see Endothelial microparticle
). Because they retain the signature membrane protein composition of the parent cell, microparticles carry useful information and can be detected and characterized by Flow cytometry
.
m complements the size definition of nanoparticles, there are other ways to define the size.
Mathematical: as the term "micro" refers to
, the range for micro would then be 
to 
, or roughly 31.6 nm to 31.6 micrometers. However, general acceptance considers particles smaller than 100 nm nanoparticles.
Rounding: rules of rounding in mathematics provide an alternative for the definition. Anything larger than 0.5
m and anything smaller than 0.5 mm is considered microparticles.
Convenient/popular: Very often particles with dimensions more than 100 nm are still called nanoparticles. The upper range may be between 300 to 700 nm, so this would give a size definition for microparticles of 0.3 to 300
m or 0.7 to 700 micrometers.
article.
m in size. Commercially available microparticles are available a wide variety of materials, including those made of ceramics, glassGlass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
, polymers, and metals. One encounters microparticles everyday in nature with items such as pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
, sand, and dust. Many Microparticles can be found in your kitchen as well with items such as: flour, and powdered sugar.
Microparticles have a much larger surface-to-volume ratio than at the macroscale, and thus their behavior can be quite different. For example, metal microparticles can be explosive in air.
Microsphere
Microsphere
Microsphere are small spherical particles, with diameters in the micrometer range . Microspheres are sometimes referred to as microparticles....
are spherical microparticles, and are used where consistent and predictable particle surface area is important.
In biological systems, microparticles are small membrane bound vesicles circulating in the blood derived from cells that are in contact with the bloodstram such as platelets and endothelial cells. (see Endothelial microparticle
Endothelial microparticle
Endothelial microparticles are small vesicles that are released from endothelial cells and can be found circulating in the blood. The microparticle consists of a plasma membrane surrounding a small amount of cytosol...
). Because they retain the signature membrane protein composition of the parent cell, microparticles carry useful information and can be detected and characterized by Flow cytometry
Flow cytometry
Flow cytometry is a technique for counting and examining microscopic particles, such as cells and chromosomes, by suspending them in a stream of fluid and passing them by an electronic detection apparatus. It allows simultaneous multiparametric analysis of the physical and/or chemical...
.
Alternative definitions for size
Although the generally accepted definition of 0.1 to 100m complements the size definition of nanoparticles, there are other ways to define the size.Mathematical: as the term "micro" refers to
, the range for micro would then be to , or roughly 31.6 nm to 31.6 micrometers. However, general acceptance considers particles smaller than 100 nm nanoparticles.Rounding: rules of rounding in mathematics provide an alternative for the definition. Anything larger than 0.5
m and anything smaller than 0.5 mm is considered microparticles.Convenient/popular: Very often particles with dimensions more than 100 nm are still called nanoparticles. The upper range may be between 300 to 700 nm, so this would give a size definition for microparticles of 0.3 to 300
m or 0.7 to 700 micrometers.Applications
Most people are familiar with home pregnancy test - a color appears if the test is positive. These tests make use of gold micro particles. Many applications are also listed in the MicrosphereMicrosphere
Microsphere are small spherical particles, with diameters in the micrometer range . Microspheres are sometimes referred to as microparticles....
article.