Amphiphilic comb copolymers

An amphiphilic comb copolymer could be synthesized from the free-radical copolymerization of an 1,1-didydroperfluorooctyl acrylate monomer with a... 

The end groups of an amphiphilic comb copolymer used to create a robust hydrophilic coating on the final particles were selectively functionalized to obtain latex particles with a controlled density of ligands tethered to their surfaces [125]. The final latexes were used to form cell-resistant and cell-interactive surfaces. 

A particularly interesting example of graft copolymers produced via active ester synthesis is that of the comb structure (25, Fig. 19) with a hydrophobic backbone and hydrophilic grafts. A series of these amphiphilic graft copolymers have been produced by partial displacement of the trichlorophenoxyl groups... 

Essential details of four graft copolymer samples (25a-25d) thus obtained are given in Table 11. The samples have been briefly examined by sedimentation equilibrium analysis. The molecular weights (M ) obtained by this method are consistent with, but lower than, the expected values recorded in Table 11. Another series of amphiphilic graft copolymers with a double comb structure has also been synthesized (26, in Fig. 19) [47]. Similarly, type 27 graft copolymers have been prepared by the reaction of the activated copolymer with hydroxy-terminated polyurethanes, but these have not so far been characterized. 

Grafting onto reactions. This method of anionic polymerization has contributed to the development of tailor made synthetic molecules. It is used to synthesize amphiphilic graft copolymers in which hydrophilic grafts are linked to a hydrophobic backbone. Well defined comb-like homopolymers were made by the same technique.In spite of its tremendous potential, the "grafting onto" anionic polymerization process has yet to be applied to the synthesis of cellulosic graft copol3nners. 

The same coarse-grained model is used for studying block copolymers with complex architecture, for example, of a comb-tail type. Usually, such copolymers consist of amphiphilic and monophilic (nonamphiphilic) blocks, which have different segmental volume. The top right Panel shows (a) amphiphilic AB monomer unit, (b) conventional (linear) AB diblock copolymer, and (c) amphiphilic comb-tail diblock copolymer. 

The bottom right Panel shows an alternative representation of the amphiphilic comb-tail diblock copolymer. This continuous monophilic/amphiphilic model looks like a jackknife (a) conventional linear AB diblock copolymer (b) and (c) rotation of the shorter section B around the crankshaft connecting the A and B sections and (d) conformationally asymmetric AC diblock copolymer with A units of the segmental volume and C units of the segmental volume 2. ... 

FIGURE 13.23 Molecular structures of amphiphilic comb and graft block copolymers. 

Micelle formation with amphiphilic graft and comb copolymers has received much less attention than that of block copolymers, although brush structures are gaining interest, mainly for biomedical applications (see Section 7.4). As already mentioned in Section 7.2, this is mainly due to the fact that these branched copolymers are not as well defined in structure, composition and molecular weight as the corresponding block copolymer, even if they are synthesized by controlled polymerization and macromonomer techniques. 

Street, G., lUsley, D. and Holder, S.J. (2005) Optimization of the synthesis of poly(octadecyl acrylate) by ATRP and the preparation of aU comb-like amphiphilic diblock copolymers. J. Polym. Sci. Part A Polym. Chem., 43,1129-1143. 

Polyphosphazenes form amphiphilic block copolymers with organic polymers, such as poly (ethylene oxide), polystyrene, or poly(dimethylsiloxane). Comb, star, and dendritic architectures were also obtained. There are also... 

Tian L, Hammond PT. Comb-dendritic block copolymers as tree-shaped macromolecular amphiphiles for nanoparticle self-assembly. Chem Mater 2006 18 3976-3984. 

Compared to block copolymers, there have been relatively fewer examples of using homopolymers for nanofabrication. Nevertheless, some polymers with amphiphilic properties were also used in the fabrication of nanostructures with various metal salts/complexes. For example, polyaniline (PANI) emeraldine base formed self-organized mesomorphic structures when mixed with Zn(DBS)2 by the coordination between Zn2+ and the imine nitrogen atoms on the polymer main chain.100 The resulting supramolecule PANI[Zn(DBS)2]0.5 had a comb-shaped... 

WUG Wu, G., Chen, S.-C., Zhan, Q., and Wang, Y.-Z., Well-defined amphiphilic biodegradable comb-like graft copolymers Their rmique architecture-determined LCST and UCST thermoresponsivity. Macromolecules, 44, 999, 2011. 

Figure 4.10 Example of pigment encapsulation through the adsorption of a comb-like stabilizer in conjunction with an amphiphilic copolymer. Redrawn from [74],...

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