What is the function of capillary tube in glass?

Function of Capillary Tube in Glass

The capillary tube in glass plays a crucial role in various scientific and industrial applications due to its unique properties and the capillary action phenomenon. Capillary action, also known as capillarity, is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to, external forces like gravity. This phenomenon is primarily observed in thin tubes, such as glass capillary tubes, due to the interaction between the liquid's adhesive forces to the tube's surface and the cohesive forces within the liquid itself.

Key Functions and Applications

• Medical Applications: Glass capillary tubes are extensively used in medical laboratories for blood collection and handling. They are ideal for micro-hematocrit tests, where small amounts of blood are required for the analysis of its components.
• Scientific Research: In scientific experiments, capillary tubes are used to handle and measure very small volumes of liquids. Their precision and ability to work with minute quantities make them indispensable in chemistry and biology labs.
• Thermometers: Traditional mercury and alcohol thermometers utilize the capillary action in glass tubes to measure temperature. The expansion and contraction of the liquid inside the tube correspond to temperature changes, allowing for accurate readings.
• Chromatography: Capillary tubes are used in chromatography techniques, including gas chromatography (GC) and capillary electrophoresis, for the separation of substances within a mixture. The capillary action facilitates the movement of the mobile phase through the stationary phase, enabling the analysis.

Overall, the function of a capillary tube in glass is pivotal across various fields, leveraging the natural phenomenon of capillary action for precise liquid handling, measurement, and analysis in both scientific and medical contexts.