Macromolecular Rapid Communications
Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Editors: Kirsten Severing , Stefan Spiegel
Online ISSN: 1521-3927
Materials Science Weekly Newsletter
Recently Published Articles
- Conjugated Polymer Composite Nanoparticles by Rapid Mixing
Christoph Jung, Tjaard de Roo and Stefan Mecking
Article first published online: 31 OCT 2014 | DOI: 10.1002/marc.201400384
Hybrid particles from the conjugated polymers poly(9,9-di-n-hexylfluoren-2,7-diyl) (PF) and poly[(9,9-di-n-octylfluoren-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,8-diyl)] (F8BT) and the inorganic nanocrystals TiO2, CdSe, and CdSe/CdS are obtained by rapid mixing. Tetrahydrofuran (THF) solutions of the polymer/inorganic particles are subjected to kinetic trapping by turbulent mixing with aqueous sodium dodecyl sulfate (SDS) solutions in a multi-inlet vortex mixer (MIVM). Small, homogenous composite particles are obtained, showing close spatial and electronic proximity as evidenced by an energy transfer between the organic and inorganic constituents.
- Synthesis and Sequential Deprotection of Triblock Copolypept(o)ides Using Orthogonal Protective Group Chemistry
Philipp Heller, Benjamin Weber, Alexander Birke and Matthias Barz
Article first published online: 30 OCT 2014 | DOI: 10.1002/marc.201400466
The synthesis of orthogonally deprotectable triblock copolypept(o)ides is described. These polymers are based on polysarcosine, poly-N-ε-t-butyloxycarbonyl-l-lysine, and poly-N-ε-t-trifluoroacetyl-l-lysine. They are prepared by ring-opening polymerization of the corresponding α-amino acid N-carboxyanhydrides (NCAs). For the synthesis of N-ε-t-butyloxycarbonyl-l-lysine (lysine(Boc)) NCAs, an acid-free method using trimethylsilylchloride/triethylamine as hydrochloric acid (HCl) scavengers is presented.
- Zirconium-Allyl Complexes as Resting States in Zirconocene-Catalyzed α-Olefin Polymerization
Valentina N. Panchenko, Dmitrii E. Babushkin and Hans H. Brintzinger
Article first published online: 30 OCT 2014 | DOI: 10.1002/marc.201400444
Formation of zirconocene cations with Zr-bound allylic chain ends is shown to be a general phenomenon when olefins are polymerized with a zirconocene catalyst. The rate and the extent of Zr-allyl formation depend on the kinds of zirconocene precatalysts and activators used for the catalyst system considered.
- Direct Access to Dithiobenzoate RAFT Agent Fragmentation Rate Coefficients by ESR Spin-Trapping
Kayte Ranieri, Guillaume Delaittre, Christopher Barner-Kowollik and Thomas Junkers
Article first published online: 30 OCT 2014 | DOI: 10.1002/marc.201400518
The activation energy of the dithiobenzoates RAFT (reversible addition–fragmentation chain transfer) intermediate fragmentation rate coefficient is determined via ESR (electron spin resonance) spin trapping experiments, which unambiguously demonstrate that these intermediate radicals are associated with a comparatively high stability as predicted by theoretical calculations.
- Core–Shell–Shell and Hollow Double-Shell Microgels with Advanced Temperature Responsiveness
Janine Dubbert, Katja Nothdurft, Matthias Karg and Walter Richtering
Article first published online: 29 OCT 2014 | DOI: 10.1002/marc.201400495
The synthesis of doubly thermoresponsive hollow microgels with two concentric shells is reported. Unique swelling properties are observed for the particles at different temperatures: at temperatures below 32 °C, both shells are swollen, at temperatures between 32 °C and 42 °C only the inner shell, and above 42 °C both polymer shells are collapsed.