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Molecular Description of Heterophase Polymerization
Published in Hugo Hernandez, Klaus Tauer, Heterophase Polymerization, 2021
Particularly for emulsion polymerization, it is assumed that the continuous phase is water, with the monomer being only partially soluble in the aqueous phase. The term emulsion polymerization is due to the fact that the monomer is initially present in the form of an oil-in-water emulsion (or water-in-oil emulsion with a subsequent phase inversion).
Conjugated Polymers
Published in Narendra Pal Singh Chauhan, Functionalized Polymers, 2021
Emulsion polymerization is performed in a homogenous system (Yamak 2013). This outstanding method is used for preparation of conjugated polymers with desirable processability (Palaniappan and John 2008). A micelle-forming surfactant, a water-soluble initiator in a mixture, and a water-insoluble monomer are used (Kumar et al. 2015). Two types of emulsion polymerization are common: water in oil emulsion consisting of small drops of water in oil and oil in water emulsion consisting of small drops of oil in water. The procedure is conducted by addition of initiator, monomer and surfactant all together to the solvent to form micelles. Afterwards, the polymerization starts and well-dispersed colloids are obtained (Iqbal and Ahmad 2018, John et al. 2008).
Synthesis and Functionalization of Magnetic Particles
Published in Jeffrey N. Anker, O. Thompson Mefford, Biomedical Applications of Magnetic Particles, 2020
Erika C. Vreeland, Dale L. Huber
One method of functionalization that has been popular for many years is the formation of latex particles containing magnetic nanoparticles. Though latex particles are very commonly made of polystyrene, the term latex does not refer to a specific material, but to a material made by an emulsion polymerization. (The exception here is the term natural latex that refers to the polymerizable sap from rubber plants that contains emulsified rubber that is used to make a variety of consumer products and is also a well-known allergen.) An emulsion polymerization is one where a hydrophobic monomer and a hydrophobic initiator are dispersed in an aqueous matrix with the aid of surfactants. The emulsion is generally generated and maintained by constant, strong stirring, and the emulsion is heated (or occasionally exposed to UV light) to initiate the polymerization. Latex paints therefore contain water-borne hydrophobic polymers, latex films (e.g. gloves) are formed from these types of emulsions, and latex particles are formed by solidifying the droplets in an emulsion. Because the distribution of the sizes of droplets in an emulsion can be very small, latex spheres can be manufactured that are extraordinarily uniform and reproducible. For this reason, latex spheres have a long history of use as size calibration standards in, for example, electron microscopy.
Biodiesel-assisted fabrication of porous polystyrene nanostructures and their excellent adsorption capacity
Published in Journal of Dispersion Science and Technology, 2020
Bao Mei, Mingbo Sun, Xiaohui Gao, Qing Yang
Porous polymers are an emerging class of amorphous materials with high specific surface areas and well-defined porosities. They have been applied in biomedical devices, microelectronics, precursors, catalysis and membrane processes.[1] The templated method has been the major approach to prepare porous polymers in previous work.[2–6] Recently, Sebastjan etal. prepared a porous functionalized poly(glycidyl methacrylate) by means of high internal phase emulsions to remove the silver, lead and cadmium ions from the solutions.[4] Emulsion polymerization technology has been widely applied in the chemical industries to prepare adhesives, paints, additives and textiles due to its fast polymerization rate and the uniform morphology of its products.[7–9] Many groups have paid attention to the fabrication of polystyrene and its composite nanoparticles by emulsion polymerization.[10–14] However, the obtained nanoparticles having solely spherical morphology may affect their application performance and limit their wide application. Thus, we attempt to employ a facile emulsion polymerization method to fabricate porous polystyrene with the assistance of biodiesel.
Synthesis of monodisperse, re-dispersable polymer particles by one-step high solid emulsion polymerization in the presence of reactive surfactant
Published in Journal of Dispersion Science and Technology, 2019
Baijun Liu, Yang Bai, Chunfu Sun, Ming Chen, Zhichen Cao, Shuai Du, Lu Xu, Mingyao Zhang
Monodispersed polymer particles are of growing interest in both industry and academia due to their various applications in synthetic rubbers, paints, adhesives, diagnostic tests, and drug delivery systems.[1–3] In general, these polymer particles were usually prepared by emulsion polymerization. A traditional emulsion polymerization system contains monomer, water, surfactant, and initiator. Surfactant is considered as a very important role in determining particle formation and growth. The addition of surfactant can promote the particle nucleation and improve the stability of ultimate latex. However, the addition of surfactant also plays some adverse effects. For example, the surfactant molecules adsorbed on the particle surface can migrate to the film-air surface of the polymer film and affect gloss, also migrate through film and segregate (or concentrate) in pockets, decreasing water tolerance of the film.[4,5] This is attributed to the state of surfactant existence, in which the surfactant molecules only adsorbed on the particle surface, and was easily disturbed by environment, e.g. film formation etc.
Atom transfer radical polymerization initiated by activator generated by electron transfer in emulsion media: a review of recent advances and challenges from an engineering perspective
Published in Journal of Dispersion Science and Technology, 2023
Mohammed Awad, Ramdhane Dhib, Thomas Duever
Emulsion polymerization is a combination of the chemical kinetics mechanism with various colloidal phenomena that control the nucleation, growth and stabilization of polymer particles.[87] Although the nucleation period is quite short, the generation of particle nuclei during the early stages of polymerization plays a crucial role in determining the final latex particle size, particle size distribution and the quality of the latex product. The quality of the latex product is strongly determined by the choice of the recipe, the reactor configuration and the process conditions. The ability to control the emulsion polymerization process is essential to guarantee constant product properties.[89]
