Block supramolecular

A general strategy developed for the synthesis of supramolecular block copolymers involves the preparation of macromolecular chains end-capped with a 2,2 6/,2//-terpyridine ligand which can be selectively complexed with RUCI3. Under these conditions only the mono-complex between the ter-pyridine group and Ru(III) is formed. Subsequent reaction with another 2,2 6/,2"-terpyridine terminated polymer under reductive conditions for the transformation of Ru(III) to Ru(II) leads to the formation of supramolecular block copolymers. Using this methodology the copolymer with PEO and PS blocks was prepared (Scheme 42) [ 107]. 

The synthesis of the supramolecular block copolymer PEO-[Ru]-poly-(ethylene-co-butylene) was described employing the same procedure [108]. 

The morphology of this supramolecular diblock copolymer library has been investigated by means of atomic force microscopy (AFM) measurements. As illustrated in Fig. 21, at first glance different morphologies were obtained for different compositions. However, interpreting the phase behavior of supramolecular block copolymers is not straightforward. There are several important parameters that play a role in the phase behavior. For instance, the amorphous phase of PEG, the crystalline phase of PEG, the metal complex, and the amorphous PSt contribute to... 

Gohy JF, Lohmeijer BGG, Schubert US (2003) From supramolecular block copolymers to advanced nano-objects. Chem Eur J 9 3472-3479... 

Lohmeijer BGG, Schubert US (2004) Expanding the supramolecular polymer LEGO system nitroxide mediated living free radical polymerization for metallo-supramolecular block copolymers with a polystyrene block. J Polym Sci Part A Polym Chem 42 4016-4027... 

Fustin C-A, Guillet P, Schubert US, Gohy J-F. MetaUo-supramolecular block copolymers. Adv Mater 2007 19 1665-1673. 

DIRECTED ASSEMBLY FORMATION OF [8-SHEETS AND SUPRAMOLECULAR BLOCK COPOLYMERS... 

Figure 9.10 Design of supramolecular block copolymers based on the 6-H bonded hetero-duplex 15 16. Mixing three templated PS chains with three complementarily templated PEG chains leads to nine block copolymers.

Figure 9.12 (a) AFM image of spin-cast 15d 16d from benzene showing cylindrical nanodomains from the microphase separation of the supramolecular block copolymer and (b) AFM image of spin-cast 15b 16b from benzene showing self-assembled fibers. 

The generation of supramolecular block copolymers certainly is among the most important topics for a polymer chemist. Since the ureidopyrimidone moiety is a self-complementing hydrogen bond, this issue is difficult to ad-... 

Fig. 58 Generation of mesoporous structures from supramolecular block copolymers. TEM-micrograph after extraction of the zinc-dodecylbenzenesolphonate from a PS-P4VP diblock copolymer mixture. Reprinted with permission from [212]...

Fig. 29 Schematic illustration of the self-assembly of amphiphilic metallo-supramolecular block copolymers under encapsulation of cargo into micelles and disassembly of the micelles under release of the drug upon ultrasound sonication via dissociation of the metal-ligand complex. Upon cessation of the ultrasonication, the micelles re-assemble again [96]...

Gohy, J.F. Lohmeijer. B.G.G. Schubert, U.S. Reversible metallo-supramolecular block copolymer micelles containing a soft core. Macromol. Rapid Commun. 2002, 23. 555. 

Hentschel J, Kushner AM, Ziller J, Guan ZB (2012) Self-healing supramolecular block copolymers. Angew Chem hit Ed 51(42) 10561-10565... 

Yang SK, Ambade AV, Week M (2011) Main-chain supramolecular block copolymers. Chem Soc Rev 40(1) 129-137... 

Bertrand A, Chen SB, Souharce G, Ladaviere C, Fleury E, Bernard J (2011) Straightforward preparation of telechelic H-bonding polymers from difunctional trithiocarbonates and supramolecular block copolymers thereof. Macromolecules 44(10) 3694-3704... 

Pitet LM, van Loon AHM, Kramer EJ, Hawker CJ, Meijer EW (2013) Nanostructured supramolecular block copolymers based on polydimethylsiloxane and polylactide. ACS Macro Lett 2(11) 1006-1010... 

Pseudo-Block Copolymers or Supramolecular Block Copolymers... 

Figure 34.5 Supramolecular polymers from hydrogen-bonding r 2-ureido-pyrimidinone (UPy) motif by Meijer et al. (Reprinted wil (b) Supramolecular block copolymer based on the ureido-guano permission from Ref. [15] 2006, American Chemical Society) acid motif as reported by Lehn et al. (Reprinted with permissiot...

Figure 13 (a) Chemical structure of bi-UPy 18 and bi-NaPy 19 telechelic poly(octene) polymers prepared via ROMP, (b) Solution characterization of a supramolecular block copolymer double-logarithmic plot of specific viscosity as a function of concentration in chloroform for the 1 1 mix of bi-NaPy 19 telechelic polymer and the bi-UPy CTA used to prepare 18 (slope=3.48) and for the bi-NaPy 19 telechelic polymer alone, demonstrating the overlap concentration (slope = 1.68 and Z39 below and above the overlap concentration, respectively). Reproduced from Folmer, B. J. B. Sijbesma, R. P. ... 

Supramolecular block copolymers can also be aeated from binary host-guest complexes, although it requires the host molecules to be tethered covalently to the polymer chains. In this fashion, Zeng et al prepared (3-cyclodextrin functional P4VP and Ad functional poly(iV-isopropylacrylamide) polymers. Complexation of both chains yielded supramolecular AB diblock... 

Figure 6.11 (a) Chemical structure of the block copolymer components designed to self-assemble hierarchically by H-bonding interactions between the blocks. PEO-b-P(S-r-4HS), poly(ethylene oxide)-b-poly(styrene-r-4-hydroxystyrene) P(S-r-4VP)-b-PMMA), poly (styrene-r-4-vinylpyridine)-b-poly(methyl methacrylate)], (b) Transmission electron microscopy image of a solvent-annealed blend fibn of supramolecular block copolymers, (c) A cartoon illustrating the final fibn structure and the block copolymer chain packing. 

We also realized viscosity oscillations of a polymer solution based on different mechanisms [26]. It is known that a terpyridine ligand binds or dissociates with a Ru metal ion depending on the redox states of the Ru metal ion [29]. Generally, when the Ru metal ion is in the reduced Ru(II) state, the Ru(II) metal ion forms bis-complexes with terpyridine (Ru(terpy)2). However, when the Ru metal ion is in the oxidized Ru(III) state, the Ru(in) metal ion forms a monocomplex with terpyridine (Ru(terpy)) (Fig. 11.7). Therefore, supramolecular block copolymers have been made by using Ru(terpy)2 as a junction point [29], If the Ru-terpyridine complex acts as a catalyst of the BZ reaction, the redox oscillation may cause periodical binding/dissociation of the Ru-terpyridine complex. Recently, a theoretical computational simulation in the case that the Ru-terpyridine complex acts as a reversible crosslinking point of polymer network during the BZ reaction has been reported by Balazs et al. [30]. The... 

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