@article{deMolinaIhlefeldtPrevostetal.2015,
  author    = {de Molina, Paula Malo and Ihlefeldt, Franziska Stefanie and Prevost, Sylvain and Herfurth, Christoph and Appavou, Marie-Sousai and Laschewsky, Andr{\´e} and Gradzielski, Michael},
  title     = {Phase Behavior of Nonionic Microemulsions with Multi-end-capped Polymers and Its Relation to the Mesoscopic Structure},
  series = {Langmuir},
  volume    = {31},
  journal   = {Langmuir},
  number    = {18},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0743-7463},
  doi       = {10.1021/acs.langmuir.5b00817},
  pages     = {5198 -- 5209},
  year      = {2015},
  abstract  = {The polymer architecture of telechelic or associative polymers has a large impact on the bridging of self-assembled structures. This Work presents: the phase behavior, small angle neutron scattering (SANS), dynamic light scattering (DLS), and fluorescence correlation spectroscopy (FCS) of a nonionic oil-in-water (O/W) microemulsion with hydrophobically end-capped multiarm polymers With functionalities f = 2, 3, and 4. For high polymer concentrations and large average interdroplet distance relative to the end-to-end distance of the polymer, d/R-ee; the system phase separates into a dense, highly connected droplet network phase, in equilibrium with a dilute phase. The extent of the two-phase region is larger for polymers With similar length but higher f. The Interaction potential between the droplets in the presence of polymer has both a repulsive and an attractive contribution as a result of the counterbalancing effects of the exclusion by polymer chains and bridging between droplets. This study experimentally demonstrates that higher polymer functionalities induce a stronger attractive force between droplets, which is responsible for a more extended phase separation region., and correlate with lower Collective droplet diffusivities and higher amplitude of the second relaxation time in DLS. The viscosity and the droplet self-diffusion obtained from FCS, however, are dominated by the end-capped chain concentration.},
  language  = {en}
}
@article{HerfurthdeMolinaWielandetal.2012,
  author    = {Herfurth, Christoph and de Molina, Paula Malo and Wieland, Christoph and Rogers, Sarah and Gradzielski, Michael and Laschewsky, Andr{\´e}},
  title     = {One-step RAFT synthesis of well-defined amphiphilic star polymers and their self-assembly in aqueous solution},
  series = {Polymer Chemistry},
  volume    = {3},
  journal   = {Polymer Chemistry},
  number    = {6},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1759-9954},
  doi       = {10.1039/c2py20126g},
  pages     = {1606 -- 1617},
  year      = {2012},
  abstract  = {Multifunctional chain transfer agents for RAFT polymerisation were designed for the one-step synthesis of amphiphilic star polymers. Thus, hydrophobically end-capped 3- and 4-arm star polymers, as well as linear ones for reference, were made of the hydrophilic monomer N,N-dimethylacrylamide (DMA) in high yield with molar masses up to 150 000 g mol(-1), narrow molar mass distribution (PDI <= 1.2) and high end group functionality (similar to 90\%). The associative telechelic polymers form transient networks of interconnected aggregates in aqueous solution, thus acting as efficient viscosity enhancers and rheology modifiers, eventually forming hydrogels. The combination of dynamic light scattering (DLS), small angle neutron scattering (SANS) and rheology experiments revealed that several molecular parameters control the structure and therefore the physical properties of the aggregates. In addition to the size of the hydrophilic block (maximum length for connection) and the length of the hydrophobic alkyl chain ends (stickiness), the number of arms (functionality) proved to be a key parameter.},
  language  = {en}
}
@inproceedings{LaschewskyHerfurthMiasnikovaetal.2012,
  author    = {Laschewsky, Andr{\´e} and Herfurth, Christoph and Miasnikova, Anna and Wieland, Christoph and Wischerhoff, Erik and Gradzielski, Michael and de Molina, Paula Malo and Weiss, Jan},
  title     = {Stars and blocks tailoring polymeric rheology modifiers for aqueous media by controlled free radical polymerization},
  series = {Abstracts of papers : joint conference / The Chemical Institute of Cananda, CIC, American Chemical Society, ACS},
  volume    = {244},
  booktitle = {Abstracts of papers : joint conference / The Chemical Institute of Cananda, CIC, American Chemical Society, ACS},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0065-7727},
  pages     = {1},
  year      = {2012},
  language  = {en}
}
@article{deMolinaHerfurthLaschewskyetal.2012,
  author    = {de Molina, Paula Malo and Herfurth, Christoph and Laschewsky, Andr{\´e} and Gradzielski, Michael},
  title     = {Structure and dynamics of networks in mixtures of hydrophobically modified telechelic multiarm polymers and oil in water microemulsions},
  series = {Langmuir},
  volume    = {28},
  journal   = {Langmuir},
  number    = {45},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0743-7463},
  doi       = {10.1021/la303673a},
  pages     = {15994 -- 16006},
  year      = {2012},
  abstract  = {The structural and dynamical properties of oil-in-water (O/W) microemulsions (MEs) modified with telechelic polymers of different functionality (e.g., number of hydrophobically modified arms, f) were studied by means of dynamic light scattering (DLS), small-angle neutron scattering (SANS), and high frequency rheology measurements as a function of the polymer architecture and the amount of added polymer. For this purpose, we employed tailor-made hydrophobically end-capped poly(N,N-dimethylacrylamide) star polymers of a variable number of endcaps, f, of different alkyl chain lengths, synthesized by the reversible addition-fragmentation chain transfer method. The addition of the different end-capped polymers to an uncharged ME of O/W droplets leads to a large enhancement of the viscosity of the systems. SANS experiments show that the O/W ME droplets are not changed upon the addition of the polymer, and its presence only changes the interdroplet interactions. The viscosity increases largely upon addition of a polymer, and this enhancement depends pronouncedly on the alkyl length of the hydrophobic sticker as it controls the residence time in a ME droplet. Similarly, the high frequency modulus G(0) depends on the amount of added polymer but not on the sticker length. G(0) was found to be directly proportional to f - 1. The onset of network formation is shifted to a lower number of stickers per ME droplet with increasing f, and the network formation becomes more effective. Thus, the dynamics of network formation are controlled by the polymer architecture. The effect on the dynamics seen by DLS is even more pronounced. Upon increasing the polymer concentration, slower relaxation modes appear that become especially pronounced with increasing number of arms. The relaxation dynamics are correlated to the rheological relaxation, and both are controlled by the polymer architecture.},
  language  = {en}
}