TY  - JOUR
A1  - Vacogne, Charlotte Dominique
A1  - Wei, Chunxiang
A1  - Tauer, Klaus
A1  - Schlaad, Helmut
T1  - Self-assembly of alpha-helical polypeptides into microscopic and enantiomorphic spirals
JF  - Journal of the american chemical society
N2  - Helical structures are ubiquitous in biological materials and often serve a structural purpose. Bioinspired helical materials can be challenging to synthesize and rarely reach the degree of hierarchy of their natural counterparts. Here we report the first example of particles synthesized by direct emulsification of polypeptides found to display spiral morphologies in the dry state. The polypeptides were alpha-helical homo- and copolypeptides of gamma-benzyl glutamate and allylglycine. The chirality of the spirals was controlled by the chirality of the alpha-helices. Notably, right-handed alpha-helical polypeptides (rich in 1, residues) produced clockwise spirals, whereas left-handed alpha-helical polypeptides (rich in D residues) produced the enantiomorphs, i.e., counterclockwise spirals. The disruption of the alpha-helical conformation by the introduction of chiral defects led to less regular spirals and in some cases their suppression. A hypothesis for the transmission of helicity and chirality from a molecular to a higher hierarchical level, involving fibril bundling of coiled alpha-helices, is proposed.
Y1  - 2018
U6  - https://doi.org/10.1021/jacs.8b06503
SN  - 0002-7863
VL  - 140
IS  - 36
SP  - 11387
EP  - 11394
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Peh, Eddie
A1  - Liedel, Clemens
A1  - Taubert, Andreas
A1  - Tauer, Klaus
T1  - Composition inversion to form calcium carbonate mixtures
JF  - CrystEngComm
N2  - Composition inversion takes place in equimolar solid mixtures of sodium or ammonium carbonate and calcium chloride with respect to the combination of anions and cations leading to the corresponding chloride and calcite in complete conversion. The transformation takes place spontaneously under a variety of different situations, even in a powdery mixture resting under ambient conditions. Powder X-ray diffraction data and scanning electron microscopy micrographs are presented to describe the course of the reaction and to characterize the reaction products. The incomplete reaction in the interspace between two compressed tablets of pure starting materials leads to an electric potential due to the presence of uncompensated charges.
Y1  - 2017
U6  - https://doi.org/10.1039/c7ce00433h
SN  - 1466-8033
VL  - 19
SP  - 3573
EP  - 3583
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Weber, Nancy
A1  - Tiersch, Brigitte
A1  - Unterlass, Miriam M.
A1  - Heilig, Anneliese
A1  - Tauer, Klaus
T1  - "Schizomorphic" Emulsion Copolymerization Particles
JF  - Macromolecular rapid communications
N2  - Cryo-electron microscopy, atomic force microscopy, and light microscopy investigations provide experimental evidence that amphiphilic emulsion copolymerization particles change their morphology in dependence on concentration. The shape of the particles is spherical at solids content above 1%, but it changes to rod-like, ring-like, and web-like structures at lower concentrations. In addition, the shape and morphology of these particles at low concentrations are not fixed but very flexible and vary with time between spheres, flexible pearlnecklace structures, and stretched rods.
KW  - amphiphilic particles
KW  - emulsion polymerization
KW  - morphology
Y1  - 2011
U6  - https://doi.org/10.1002/marc.201100491
SN  - 1022-1336
VL  - 32
IS  - 23
SP  - 1925
EP  - 1929
PB  - Wiley-Blackwell
CY  - Malden
ER  -