Interfacial polyaddition

Rosenbauer E-M, Landfester K, Musyanovych A (2009) Surface-active monomer as a stabilizer for polyurea nanocapsules synthesized via interfacial polyaddition in inverse miniemulsion. Langmuir 25(20) 12084-12091... 

Fig. 17 For mation of polymeric nanocapsules (a) by interfadal reaction in direct miniemulsion and (b) interfacial polyaddition in inverse miniemulsion...

Reports of interfacial radical copolymerization, anionic polymerization, and interfacial polyadditions can be found in the literature. Representatively for the formation of polymeric shells by interfacial reactions, the polyaddition in direct and inverse miniemulsions is shown in Fig. 17. 

The interfacial polyaddition of chitosan used as stabilizer with two biocompatible costabilizers, Jeffamine D2000 and Gluadin, and a linking diepoxide in presence of an inert oil results in thin but rather stable nanocapsules (see Fig. 19a). Since both water and oil soluble aminic costabilizers can be used, these experiments show the way to a great variety of capsules with different chemical structure [185]. 

Fluorescent dyes as markers can also be used to follow particle-cell interactions, via LSM and FACS measurements. Hence, polyure thane/urea capsules were created in inverse miniemulsion that could encapsulate a fluorescent dye with 90% efficiency [129]. In this case, carboxymethylation was carried out on the particle surface, followed by the physical adsorption of poly(2-aminoethylmethacrylate) or polyethylene imine polycations. As expected, the rate of uptake of capsules modified by the polycation was higher than for non-modified capsules. Rosenbauer et al. applied the same synthetic procedure, but in the presence of a surfactant that crosslinked the shell [130]. The commercially available surfactant containing several amine groups reacted with the diioscyanate monomer subsequently, the capsule shell wall was found to be less permeable than capsules synthesized with a non-crosslinkable surfactant. Baier el al. used the above-described synthesis to perform a polymerase chain reaction (PCR) in crosslinked starch nanocapsules [131]. The permeability of the shell was also evaluated using fluorescence spectroscopy. The combination of a cleavable polyurethane [132] with the interfacial polyaddition described above [126] afforded polymer shells that could be opened by ultraviolet (UV) irradiation, or by modifying the temperature or pH [133], In order to determine the release of encapsulated sulforhodamine dye, polyurethanes with... 

The formation of polyurethane nanoparticles from inverse nano-emulsions (W/O) has also been achieved. Interfacial polyaddition in inverse nano-emulsion is of special interest since this allows the encapsulation of hydrophilic active materials such as proteins or nucleic acids. Thus, taking advantage of the high reactivity of tolylene 2,4-diisocyanate with water molecules, polyurea lipid nanocapsules with aqueous cores obtained from W/O nano-emulsions and prepared by PIT method were designed. Polymer synthesis occurs by in situ interfacial polymerization after nano-emulsion formation. Volatile oils employed as the continuous phase were removed by evaporation and the nanocapsules were redispersed in water. These nanocapsules could be potentially used for encapsulation of both hydrophilic and lipophilic molecules simultaneously. 

Du YZ, Wang L, Dong Y, Yuan H, Hu FQ. Characteristics of pacUtaxel-loaded chitosan oU-gosacchatide nanoparticles and their preparation by interfacial polyaddition in 0/W miniemulsion system. Carbohydr Polym. 2010 79(4) 1034-9. 

A. Shulkin, and H.D.H. Stover, Polymer microcapsules by interfacial polyaddition between styrene-maleic anhydride copolymers and amines, /. Membrane ScL, 209,421-432,2002. 

Roux R, Sallet L, Alcouffe P, Chambert S, Sintes-Zydowicz N, Fleury E et al (2012) Facile and rapid access to glyconanocapsules by CuAAC interfacial polyaddition in miniemulsion conditions. ACS Macro Lett 1 1074—1078... 

---