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In polymer chemistry, emulsion polymerization is a type of radical polymerization that usually starts with an emulsion incorporating water, monomers, and surfactants.The most common type of emulsion polymerization is an oil-in-water emulsion, in which droplets of monomer (the oil) are emulsified (with surfactants) in a continuous phase of water.
The kinetics of microemulsion polymerization has much in common with emulsion polymerization kinetics, the most characteristic feature of which is the compartmentalization, where the radicals growing inside the particles are separated from each other, thus suppressing termination to a high extent and, as a consequence, providing high rates of ...
The term "emulsion" is also used to refer to the photo-sensitive side of photographic film. Such a photographic emulsion consists of silver halide colloidal particles dispersed in a gelatin matrix. Nuclear emulsions are similar to photographic emulsions, except that they are used in particle physics to detect high-energy elementary particles.
In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. [1] [2] [3] There are many forms of polymerization [4] and different systems exist to categorize them. IUPAC definition for ...
Mini-emulsion: emulsion in which the particles of the dispersed phase have diameters in the range from approximately 50 nm to 1 μm. Note 1 : Mini-emulsions are usually stabilized against diffusion degradation (Ostwald ripening (ref. [ 6 ] )) by a compound insoluble in the continuous phase .
This type of emulsion is thermodynamically unstable, but can be stabilized for a period of time with applications of kinetic energy. [1] Surfactants (as the main emulsifiers ) are used to reduce the interfacial tension between the two phases, and induce macroemulsion stability for a useful amount of time.
All polymerization occurs in the continuous phase, rather than on both sides of the interface between the continuous phase and the core material. In situ polymerization of such formaldehyde systems usually involves the emulsification of an oil-phase in water. Then, water-soluble urea/melamine formaldehyde resin monomers are added, which are ...
Thus, emulsion stability depends greatly on the polyelectrolyte film thickness. [13] The polyelectrolyte film thickness is dependent upon its ionic strength. [13] charged species on polyelectrolyte chains repel each other, causing the chains to stretch out. As the salt concentration increases, ionic strength increases, and the ions will shield ...