ParaMagnetic Microspheres

Paramagnetic microspheres have the ability to increase in magnetization with an applied magnetic field and loose their magnetism when the field is removed. Neither hysteresis nor residual magnetization is observed and that provides the end use two very practical advantages:

• When the filed is removed, the microspheres demagnetize and re-disperse easily. This property allows efficient washing steps, low background and good reproducibility.
• The behavior of the microspheres is always the same whatever the magnetization cycles may be. Such behavior is a key point for automated instrument.

106-125um Magnetic Microspheres

Recently black paramagnetic microspheres have been produced in larger sizes of 10 micron to 1mm (1000um) and in dry form enabling scientists to leverage the benefits of paramagnetic particles in new applications. These highly spherical polyethylene microspheres offer the flow-ability of standard microspheres, with the ability to be separated from other materials for re-use and cleanup.

One use of paramagnetic microspheres as large as 1mm in diameter to simulate salmon eggs, Scientists are able to place them in a natural habitat, observe how they move with the water currents and then use their magnetic properties to clean them up.

SuperParamagnetic microspheres, sometimes just called magnetic microspheres or paramagnetic microspheres have become widely used in the life sciences industry (<10um diameters) for applications such as:

• Solid Phase Immunoassays
• Bacteria Detection
• High Throughput screening
• Rapid Tests
• Cell Sorting
• Biosensors
• Nucleic Acids Technology
• Microfluidics¹

Super paramagnetic microspheres used in the life science industry are supplied in solution form.

1. Merck Estapor Super Paramagnetic Microspheres Brochure

Solid Red Polyethylene Microspheres Announced

Santa Barbara, CA -  May 28, 2010 - Cospheric LLC is now offering a product line of solid red polyethylene microspheres in particle size ranges from 10um to 1000um (1mm).

Offering a bright red color.  These microspheres can be used as additives in personal care products, or in fluid flow visualization experiments.  Samples are in stock and ready to ship to customers for R&D use of product evaluation.  These high quality microspheres are specified to be greater than 90% spherical, and greater than 90% in the specified size range.

Sample Density is 0.98g/cc (Custom densities are available)

Spherical Particle sizes include:

10-27um, 27-32um (30 micron), 32-38um (35 micron), 38-45um (40 micron), 45-53um (50 micron), 53-63um (60 micron), 63-75um (70 micron), 75-90um (80 micron), 90-106um (0.1mm), 106-125um, 125-150um, 150-180um, 180-212um (0.2mm), 212-250um (0.25mm), 250-300um (0.3mm), 300-355um (0.35mm), 355-400um (0.4mm), 400-500um (0.5mm), 500-600um (0.6mm), 600-710um (0.7mm), 710-850um (0.8mm), 850-1000um (0.9mm).

Solid Polyethylene Microspheres for Effects in Color Cosmetics

A recent article in Cosmetics & Toiletries magazine describes the use Solid Polyethylene Mirospheres for Effects in Color Cosmetics.

Flesh Tone Microspheres - Color Matched to Skin Sample

Micropsheres have been used in cosmetics for some time, primarily as fillers and exfoliators. Most recently scientists started to utilize light reflecting properties of microspheres for creating unique optical effects, such as optical blurring and wrinkle filling.  Due to light scattering effects of the spherical surface, formulating with appropriate microspheres can minimize the appearance of fine lines and uneven skin tone, due to optically reducing contrast on the skin.

The spherical shape and smooth surface of microspheres creates a low friction ball-bearing effect that gives formulations an elegant, silky feel. This ball-bearing effect promotes better blending on the skin and a more natural finish due to the enhanced slip, glide and omnidirectional spreadability, imparting a cream to powder texture. Outstanding roundness also provides lubrication during application, which enhances the tactile experience of a cosmetic product. Continue reading “Solid Polyethylene Microspheres for Effects in Color Cosmetics” »

Porous Ceramics: Application for Polyethylene Microspheres

Background:

Usually porous ceramics are made from aluminum oxide, silicon carbide or Zirconia.  Most porous ceramics have a natural ability to fill pores by capillary action. This makes porous ceramics water accepting, thus they also are referred to as hydrophilic material. This means the pores and channels of a ceramic have a highly charged pore surface that attracts and bonds the polar molecules of water and other polar fluids. The net effect is called “wicking” — the ability to pull fluids into the material and transport that fluid by capillary forces.  The pore size directly affects the ceramic’s air entry or bubbling pressure and hydraulic conductivity. The effective pore size is determined by the minimum orifice within a channel or pore.¹

Some porous ceramic have 40-50% open porosity with a tortuous pore structure and is available in pore sizes ranging from 0.25 to 90 microns. Monolithic, single grade, aluminum oxide porous ceramic is available in 6, 15, 30, 50, 60 and 90 micron pore sizes. In addition, some ceramic membranes can use a medium pore substrate with a thin coating of fine porous ceramic membrane in 0.25, 1, 3 and 6 micron pore sizes.^{2 Continue reading “Porous Ceramics: Application for Polyethylene Microspheres” »}