TY  - JOUR
A1  - Fechner, Mabya
A1  - Koetz, Joachim
T1  - Potentiometric behavior of Polyampholytes based on N,N'-diallyl-N,N'-dimethylammonium chloride and maleamic acid derivatives
JF  - Macromolecular chemistry and physics
N2  - Strongly alternating copolymers (PalH, PalPh, PalPhBisCarb) composed of N,N'-diallyl-N,N'-dimethyl-ammonium chloride (DADMAC) and maleamic acid derivatives (MAD) are synthesized by a water-based free radical copolymerization using 4,4-azobis(4-cyanovaleric acid) (V501) as the initiator. The structure of the copolymers is verified by 1H-NMR, elemental analysis, and thermogravimetric measurements, and the physicochemical properties are investigated by viscometric and potentiometric techniques. Potentiometric titration curves show that the acidity of the carboxylic groups strongly depends on the degree of dissociation and the ionic strength. Since all copolymers behave as polycations at low degree of dissociation, a transition from an extended chain to a coil conformation can be identified by reaching the isoelectric point (IEP).
KW  - acidity constants
KW  - radical polymerization
KW  - polyampholytes
KW  - viscosity
KW  - conformational transitions
Y1  - 2011
U6  - https://doi.org/10.1002/macp.201100532
SN  - 1022-1352
VL  - 212
IS  - 24
SP  - 2691
EP  - 2699
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Schulze, Nicole
A1  - Koetz, Joachim
T1  - Kinetically controlled growth of gold nanotriangles in a vesicular template phase by adding a strongly alternating polyampholyte
JF  - Journal of dispersion science and technology
N2  - This paper is focused on the temperature-dependent synthesis of gold nanotriangles in a vesicular template phase, containing phosphatidylcholine and AOT, by adding the strongly alternating polyampholyte PalPhBisCarb.
UV-vis absorption spectra in combination with TEM micrographs show that flat gold nanoplatelets are formed predominantly in the presence of the polyampholyte at 45°C. The formation of triangular and hexagonal nanoplatelets can be directly influenced by the kinetic approach, i.e., by varying the polyampholyte dosage rate at 45°C. Corresponding zeta potential measurements indicate that a temperature-dependent adsorption of the polyampholyte on the {111} faces will induce the symmetry breaking effect, which is responsible for the kinetically controlled hindered vertical and preferred lateral growth of the nanoplatelets.
KW  - Kinetically controlled nanocrystal growth
KW  - nanotriangles
KW  - polyampholytes
Y1  - 2016
U6  - https://doi.org/10.1080/01932691.2016.1220318
SN  - 0193-2691
SN  - 1532-2351
VL  - 38
IS  - 8
SP  - 1073
EP  - 1078
PB  - Taylor & Francis
CY  - Philadelphia
ER  -