Microscopy cold stage

The solid-liquid transition temperatures of ionic liquids can (ideally) be below ambient and as low as -100 °C. The most efficient method for measuring the transition temperatures is differential scanning calorimetry (DSC). Other methods that have been used include cold-stage polarizing microscopy, NMR, and X-ray scattering. 

In contrast transmission electron microscopy (TEM) can in skilled hands yield detailed quantitative data on pore structure, and can even provide valuable information on the wet state of resins by plunge freezing such samples and microtom-ing on a cold stage [105]. To obtain quantitative information it is necessary to use advanced image analysis methodology which is extremely powerful [106]. Unfortunately the approach is time consuming and costly and can rarely be applied routinely in morphology studies. 

There are two types of stages for dynamic microscopy (a) hot and cold stages and (b) tensile stages [1], Hot stages are most commonly used for the dynamic microscopy of polymers [1,43]. Thermal analysis in the OM is complementary to other thermal analysis methods, such as differential thermal analysis (DTA) [1], Direct observation of the structural changes of a polymer as a function of temperature can determine the nature of phase changes and thermal decomposition [1], It also measures the transformation temperatures. 

Microscopic analysis is the only method available for estimating ice crystal size in ice cream. Light microscopy, equipped with cold stage and image analysis, may be used for this purpose54. Low temperature scanning electron microscopy may also be used55. 

In the U.S. in 1957, McCrone presented a review of fusion methods, techniques, equipment, and applications (12). His definition of fusion methods included the methods and procedures useful in research and analysis, which involved heating a compound or mixture of compounds on a microscope slide (12). His text comprises five parts. Chapter I is an introduction discussing the scope and limitations of fusion microscopy, and Chapter II discusses the commercially available equipment at the time. Chapter III details the general techniques for hot stages, cold stages, and hot bars, characterization and identification of organic compounds, purity estimations,... 

There are some simple freezing methods that provide adequate preparation for some polymers. Cold stage microscopy of colloidal suspensions, microemulsions and liquids is possible by fast freezing and examination of the thin, frozen specimen in an EM. Talmon et ah [404] developed a rather interesting technique in which a thin sample is trapped between two polyimide films. The liquid layer is about 100 nm thick, while the films are about 40 nm thick. Film selection is quite important as the polyimide is more radia-... 

Sargent, J. A. The application of cold stage scanning electron microscopy to food research. Food Mi-crostructure 7, 123 (1988)... 

Figure 4.21. Transmission electron microscopy micrographs of latex particles are shown images taken in a microscope with a cold stage (A) and after both staining with PTA and using the cold stage (B). (From Shaffer [274] unpublished.)...

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