Gubitosi, Marta; Nosrati, Pegah; Hamid, Mona Koder; Kuczera, Stefan; Behrens, Manja A.; Johansson, Eric G.; Olsson, Ulf
Stable, metastable and unstable cellulose solutions
We have characterized the dissolution state of microcrystalline cellulose (MCC) in aqueous tetrabutylammonium hydroxide, TBAH(aq), at different concentrations of TBAH, by means of turbidity and small-angle X-ray scattering. The solubility of cellulose increases with increasing TBAH concentration, which is consistent with solubilization driven by neutralization. When comparing the two polymorphs,…
Foundation of the Outstanding Toughness in Biomimetic and Natural Spider Silk
Anton, Arthur Markus; Heidebrecht, Aniela; Mahmood, Nasir; Beiner, Mario; Scheibel, Thomas; Kremer, Friedrich
Spider dragline silk is distinguished through the highest toughness of all natural as well as artificial fiber materials. To unravel the toughness’s molecular foundation and to enable manufacturing biomimetic analogues, we investigated the morphological and functional structure of recombinant fibers, which exhibit toughness similar to that of the natural template,…
Morphology orientation of comb-like polymers with rigid backbones under the influence of shear fields
Gupta, Gaurav; Danke, Varun; Babur, Tamoor; Beiner, Mario
The influence of shear fields on the packing behavior and morphology orientation arestudied for two comb-like polymers viz. poly(1,4-phenylene-2,5-didecyloxy terephthalate) (PPDOT)and poly(2,5-didecyloxy-1,4-phenylenevinylene) (DOPPV) with different rigid backbones having C =10 alkyl carbons per side chain. Crystallographic analysis based on X-ray diffractometry measurementsshows that both PPDOT…
Synthesis of supramolecular precision polymers: Crystallization under conformational constraints
Reimann, Sophie; Danke, Varun; Beiner, Mario; Binder, Wolfgang H.
Placing artificial folding elements into precision polymers is an important strategy to systematically study structure formation in self-assembly, particularly in the semicrystalline state. To this purpose, a series of precision polymers bearing either a N-protected or N-unprotected diaminopyridine (DAP) unit after every 16th, 18th, and 20th carbon as well as…
Rheological Link Between Polymer Melts with a High Molecular Weight Tail and Enhanced Formation of Shish-Kebabs
Wingstrand, Sara L.; Shen, Bo; Kornfield, Julie A.; Mortensen, Kell; Parisi, Daniele; Vlassopoulos, Dimitris; Hassager, Ole
Presence of an ultra high molecular weight (UHMw) fraction in flowing polymer melts is known to facilitate formation of oriented crystalline structures significantly. The UHMw fraction manifests itself as a minor tail in the molar mass distribution and is hardly detectable in the canonical characterization methods. In this study, alternatively,…
End Groups of Functionalized Siloxane Oligomers Direct Block-Copolymeric or Liquid-Crystalline Self-Assembly Behavior
Zha, R. Helen; de Waal, Bas F. M.; Lutz, Martin; Teunissen, Abraham J. P.; Meijer, E. W.
Monodisperse oligodimethylsiloxanes end-functionalized with the hydrogen-bonding ureidopyrimidinone (UPy) motif undergo phase separation between their aromatic end groups and dimethylsiloxane midblocks to form ordered nanostructures with domain spacings of
Pathway Complexity in the Enantioselective Self-Assembly of Functional Carbonyl-Bridged Triarylamine Trisamides
Haedler, Andreas T.; Meskers, Stefan C. J.; Zha, R. Helen; Kivala, Milan; Schmidt, Hans-Werner; Meijer, E. W.
Functional supramolecular systems like carbonyl-bridged triarylamine (CBT) trisamides are known for their long-range energy transport at room temperature. Understanding the complex self-assembly processes of this system allows for control over generated structures using controlled supramolecular polymerization. Here, we present two novel CBT trisamides with (S)- or (R)-chiral side chains which…
Electrostatic Effect on the Solution Structure and Dynamics of PEDOT:PSS
Leaf, Michael A.; Muthukumar, Murugappan
Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) is a material consisting of two oppositely charged polymers and is available as aqueous dispersions. Various annealing and doping methods dramatically enhance PEDOT:PSS conductivity, rendering it competitive with inorganic conductors like indium tin oxide. Yet a comprehensive understanding of PEDOT:PSS conductivity…
Flocculated Laponite-PEG/PEO Dispersions with Multivalent Salt: A SAXS, Cryo-TEM, and Computer Simulation Study
Thuresson, Axel; Segad, M.; Plivelic, Tomás S.; Skepö, Marie
The aim of this study is to scrutinize the mechanism behind aggregation, i.e., tactoid formation of nanostructures with the shape of a platelet. For that purpose, the clay minerals Laponite and montmorillonite have been used as model systems. More specifically, we are interested in the role of: the platelet size,…
On the properties of poly(isoprene-b-ferrocenylmethyl methacrylate) block copolymers
Chernyy, Sergey; Kirkensgaard, Jacob Judas Kain; Bakke, Anders; Mortensen, Kell; Almdal, Kristoffer
By combining poly(1,4-isoprene) (PI) with poly(ferrocenylmethyl methacrylate) (PFMMA) in a diblock copolymer structure by means of anionic polymerization we obtained narrowly dispersed PI-b-PFMMA copolymers with molecular weight ranging from 13000 to 62000 g/mol. The products were stable up to 228 °C, according to thermal gravimetry, which allowed us to further investigate their…