The Polarized Light Microscope: How to Use the Polarized Light Microscope in Chemistry

The light microscope has been an especially useful tool in the life and physical sciences, and it has revolutionized the way we think about the world we live in. Light microscopy has also long since changed and evolved, and it has long since introduced innovations that make it useful for an even wider number of researchers. One such example is the polarized light microscope, which geologists and chemists use in order to study different materials. In fact, one of the basic lessons learned by beginning researchers is how to use the polarized light microscope in chemistry.

As the name implies, the polarized light microscope makes use of polarized light. In order to understand how light is polarized, and how it can make for good microscopy, one has to regard light as a series of waves traveling in a medium, with light traveling along the plane of vision, as well as perpendicular to it.

The Polarized Light Microscope Makes Use of Polarizing Filters

The two main filters in a polarizing light microscope are the analyzer and the polarizer. The analyzer is aligned vertically, and is located above the objective lenses. The analyzer can usually be rotated on some polarized light microscope models, and it can be pushed out of the path of light depending on the needs of the microscope user. On the other hand, the polarizer is positioned horizontally, and is located beneath the specimen. Like the analyzer, the polarizer can be rotated.

When both the analyzer filter and polarizer filter are positioned in the path of light, they stand at right angles to each other, so that all light that passes through them is scattered; in this case, the user’s field of view will be dark. When these two components are adjusted, however, the light passing through the filters will come in through different angles, and the polarized light microscope user will therefore see different angles of the specimen that he or she is observing.

There are also other components that are important in the polarized light microscope. The polarized light microscope will have a specimen stage that can be rotated so that the user will see different sides of the specimen. The objectives of the polarized light microscope are also special: they should be strain free, or free from stresses during assembly. Mistakes in alignment can result in optical effects that will produce varying results when polarized light is used. As with any other microscope, the polarized light microscope also has its own eyepiece objectives.

In addition to these common microscope pieces, the polarized light microscope also has slots to allow researchers to put in plates that can enhance or retard the light coming in through the filters.

The Polarized Light Microscope is Commonly Used in the Physical Sciences

Geologists and electrical engineers commonly use the polarized light microscope in order to observe crystals, stones, soils, and other minerals. However, chemists also use the polarized light microscope for their experiments. For instance, chemical engineers need to understand the properties of certain minerals before using these minerals in their experiments. Certain crystalline configurations of atoms can spell the fracture of a crystal under stress, or the susceptibility of a mineral to acid or alkaline degradation.

Composite materials such as ceramics or cement can also be examined under the polarized light microscope, and chemists need such a tool in order to asses the integrity of these materials, and whether or not they will survive chemical treatment. Industrial chemists also use the polarized light microscope in order to study fibers and fabrics, and to assess fiber strength, which is important when designing safety materials.

Large molecules such as starches can also be examined under the polarized light microscope. In fact, wood granules can best be examined using such a tool, as a polarized light microscope will not require thin sections of wood – almost an impossibility, especially since many scientists work out in the field. Moreover, chemists use polarized light microscopy in order to perform certain tasks, such as detecting the presence of dangerous forms of asbestos, which can lead to various cancers if inhaled in large quantities; and distinguishing between synthetic and natural fabrics, which is important in clothing design.

Because many scientists know how to use the polarized light microscope in chemistry, it is imperative that such knowledge be developed and passed on to more generations of researchers. With the help of the polarized light microscope, chemists can understand materials better, investigate the reaction of such materials to stress or strain, and ultimately give the world better materials for better buildings, fabrics, and even food.