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Detergency
Two important applications of detergency are:
- Cleaning of fabrics
- Cleaning of wafers
These applications rest on the concept of interfacial tension. Addition of surfactant molecules helps in altering the interfacial tension between two surfaces. The surfactant molecules minimize the total energy of a system by favorably changing their orientation .For example, air-water interfacial tension can be reduced to 10 dynes/cm from a value of 72 dynes/cm by use of suitable surfactants.
Scope of the field
Colloid and interface science is an interdisciplinary and a multidisciplinary science. For example, consider MEMS and NEMS. Micro-Electro-Mechanical Systems (MEMS) is the integration of mechanical elements, sensors, actuators, and electronics on a common silicon substrate through micro-fabrication technology. These micromechanical components are fabricated using compatible "micromachining" processes that selectively etch away parts of the silicon wafer or add new structural layers to form the mechanical and electromechanical devices. This way of fabrication is also known as the top-down approach.
Nano-Electro-Mechanical Systems (NEMS) means machines, sensors, computers and electronics that are on the nano-scale. Here, a top-down approach can not be followed. Instead a bottom-up approach is used. In a bottom-up approach, one starts from the basic building units, molecules, and make larger objects by arranging those units in an order. Today, great importance is being attached to this approach to science, and in coming years it is expected to have a tremendous impact on our society
Within the domain of chemical engineering, colloids have been found to be of great use in applications in many areas like catalysis, chromatography and tertiary oil recovery.
Colloids are also equally important in other fields like nano-biology. For example, scientists have been working on targeted drug delivery where they intend to use the specificity of nano-molecules in treating diseases like cancer.
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