Poly aggregation

ZB Zhang, M Fujiki, M Motonaga, and CE McKenna, Control of chiral ordering in aggregated poly 3-(S)-[2-methylbutyl]thiophene by a doping-dedoping process, J. Am. Chem. Soc., 125 7878-7881, 2003. 

P. Sansdrap, A.J. Moes. In vitro evaluation of the hydrolytic degradation of dispersed and aggregated poly(dj-lactide-co-glycolide) microspheres. / Control Release 43,47-58,1997. 

Shibayama, M., Suetoh, Y., Nomura, S. (1996). Structure relaxation of hydrophobically aggregated poly(V-isopropylacrylamide) in water. Macromolecules, 29, 6966-6968. 

The original idea to exploit excimer-forming dyes as mechanochromic transducers in polymers (as opposed to neat low-molecular-weight compounds) was inspired by the work of Trabesinger et al. [50] who showed that aggregated poly(phenylene ethynylene) guest molecules in a polymeric matrix could be dispersed by simple deformation of the material. This deformation transformed the material from a... 

Wanka G, Floffman FI and Ulbrict W 1990 The aggregation behavior of poly-(oxyethylene)-poly(oxypropylene)-poly-(oxyethylene)-block copolymers in aqueous solutions Colloid Polym. Sc/. 268 101-17... 

In systems of LP the dynamic response to a temperature quench is characterized by a different mechanism, namely monomer-mediated equilibrium polymerization (MMEP) in which only single monomers may participate in the mass exchange. For this no analytic solution, even in terms of MFA, seems to exist yet [70]. Monomer-mediated equilibrium polymerization (MMEP) is typical of systems like poly(a-methylstyrene) [5-7] in which a reaction proceeds by the addition or removal of a single monomer at the active end of a polymer chain after a radical initiator has been added to the system so as to start the polymerization. The attachment/detachment of single monomers at chain ends is believed to be the mechanism of equilibrium polymerization also for certain liquid sulphur systems [8] as well as for self-assembled aggregates of certain dyes [9] where chain ends are thermally activated radicals with no initiators needed. 

Suppression of the aggregate emission is possible in two quite different ways. At first, the aggregate emission could be almost completely shut out by simply diluting the LPPP 12 with a matrix polymer. LEDs with 1% LPPP 12 in poly(9-vinylcarbazole) PVK as emitter material are characterized by a pure blue light emission with a quantum efficiency of ca. 0.15% in single-layer configuration (lTO/1% LPPP 12 in PVK/Ca) 135],... 

The pioneering work on amphiphilic polyelectrolytes goes back to 1951, when Strauss et al. [25] first synthesized amphiphilic polycations by quaternization of poly(2-vinylpyridine) with n-dodecyl bromide. They revealed that the long alkyl side chains attached to partially quaternized poly(vinylpyridine)s tended to aggregate in aqueous solution so that the polymers assumed a compact conformation when the mole fraction of the hydrophobic side chains exceeded a certain critical value. Thus, Strauss et al. became the first to show experimentally the intramolecular micellation of amphiphilic polymers and the existence of a critical content of hydrophobic residues which may be compared to the critical micelle concentration of ordinary surfactants. They called such amphiphilic polyelectrolytes polysoaps [25],... 

As has been described in Chapter 4, random copolymers of styrene (St) and 2-(acrylamido)-2-methylpropanesulfonic acid (AMPS) form a micelle-like microphase structure in aqueous solution [29]. The intramolecular hydrophobic aggregation of the St residues occurs when the St content in the copolymer is higher than ca. 50 mol%. When a small mole fraction of the phenanthrene (Phen) residues is covalently incorporated into such an amphiphilic polyelectrolyte, the Phen residues are hydrophobically encapsulated in the aggregate of the St residues. This kind of polymer system (poly(A/St/Phen), 29) can be prepared by free radical ter-polymerization of AMPS, St, and a small mole fraction of 9-vinylphenanthrene [119]. 

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