Micelle core-crosslinked

Figure 6.4 The preparation of nanostructured materials in solution evolves from (a) the classic examples of suspension, dispersion, or emulsion polymerization, to the methods that include the covalent crosslinking of select domains within supramolecular polymer assemblies (b) core crosslinking of polymer micelles (c) shell crosslinking of polymer micelles (SCKs) (d) nanocages from core-eroded SCKs (e) shaved hollow nanospheres from outer shell/core-eroded vesicles.

Figure 6.5 Illustrations of nanoscale spherical assemblies resulting from block copolymer phase separation in solution are shown, along with the chemical compositions that have been employed to generate each of the nanostructures (a) core crosslinked polymer micelles (b) shell crosslinked polymer micelles (SCKs) with glassy cores (c) SCKs with fluid cores (d) SCKs with crystalline cores (e) nanocages, produced from removal of the core of SCKs (f) SCKs with the crosslinked shell shielded from solution by an additional layer of surface-attached linear polymer chains (g) crosslinked vesicles (h) shaved hollow nanospheres produced from cleavage of the internally and externally attached linear polymer chains from the structure of (g)...

Fig. 4 (a) Micelles formation in non-selective solvent and core-crosslinked nanoparticles, (b) Chemical structures of the implied copolymers. Reprinted from de Luzuriaga et al. [37]. Copyright 2010, with permission from Elsevier... 

Matsumoto K, Matsuoka H (2005) Synthesis of core-crosslinked carbosilane block copolymer micelles and their thermal transformation to silicon-based ceramics nanoparticles. J Polym Sci A Polym Chem 43(17) 3778-3787... 

Two types of poly(2-vinyl pyridine-b-styrene-b-2-vinyl pyridine) triblock copolymers were synthesised by anionic living polymerisation. These polymers formed monodispersed micelles in toluene or toluene/cyclohexane mixture. Poly(2-vinyl pyridine) sequences in the core part of the polymer micelles were crosslinked with 1,4-diiodobutane. After crosslinking, no macrogelation was observed. The morphology of the crosslinked products did not correspond with that of the original triblock copolymer. All products were polystyrene spheres and each of them had one poly(2-vinyl pyridine) core in its centre. It was therefore concluded that the poly(2-vinyl pyridine) core-PS shell type flower microgels were synthesised by crosslinking of the flower micelles in solution. 27 refs. 

Figure 4.13. Assembly of reverse PM in organic solvent (CH2CI2 (DCM)) and crosslinking of the micelle core.

The synthesis of shell crosslinked knedel (SCK) micelles has been reported. Various applications, in areas as diverse as solubilisation, catalysis, fillers, coatings and delivery, have been proposed for these nanoparticles. However, in all studies the micelle cores are based on PS or polyisoprene and are therefore permanently hydrophobic. The synthesis of two new classes of SCK micelles with hydrophilic micelle cores are reported. Successftil shell crosslinking relies on. selective quatemisation of the A block, which comprises 2-(dimethylamino)ethyl methacrylate (DMAEMA) residues. The B block comprises 2-(N-morpholino)ethyl methacrylate (MEM A) and forms the micelle core. The second class is zwitterionic SCK micelles, prepared from precursor DMAEMA-2-tetrahydropyranyl methacrylate diblock copolymers. Depending on the synthetic route employed, two types of zwitterionic SCK micelles can be obtained Type I micelles, with anionic cores and cationic coronas, and Type II micelles, with cationic cores and anionic coronas. These zwitterionic SCK micelles exhibit isoelectric points in aqueous solution. 14 refs. 

Recently, Kissel et al. reported that the core crosslinking of the PEO-fc-PCL micelles not only improved the thermodynamic stability of the micelles... 

Yuan XF, Yamasaki Y, Harada A, Kataoka K (2005) Characterization of stable lysozyme-entrapped polyion complex (PIC) micelles with crosslinked core by glutaraldehyde. Polymer 46 7749-7758. doi 10.1016/j.polymer.2005.02.121... 

Talelli, M., Iman, M., Varkouhi, A. K., Rijcken, C. I, Schiffelers, R. M., Etrych, T, Ulbrich, K., van Nostrum, C. E, Lammers, T, Storm, G. and Hennink, W. E. (2010a) Core-crosslinked polymeric micelles with controlled release of covalently entrapped doxorubicin. Biomaterials, 31,7797-804. 

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