TY  - JOUR
A1  - Schulze, Nicole
A1  - Prietzel, Claudia Christina
A1  - Koetz, Joachim
T1  - Polyampholyte-mediated synthesis of anisotropic gold nanoplatelets
JF  - Colloid and polymer science : official journal of the Kolloid-Gesellschaft
N2  - This paper focused on the synthesis of triangular nanoplatelets in the presence of a tubular network structure. The tubular network structure is formed by adding a strongly alternating polyampholyte, i.e., PalPhBisCarb, to a mixed vesicle system with a negatively charged bilayer containing phosphatidylcholin and AOT. Using the tubular network as a reducing agent in a one-step procedure, triangular and hexagonal nanoplatelets are formed. One can show that the nanoplatelet yield is enhanced by increasing the temperature and decreasing the reaction time. The platelet edge length can be decreased by heating the system up to 100 A degrees C. Due to specific interactions between PalPhBisCarb and the AOT/phospholipid bilayer, stacking and welding effects lead to the formation of ordered platelet structures. The reaction pathway to flat gold nanotriangles is discussed with regard to the twin plane growth model of gold nanoplates.
KW  - Polyampholytes
KW  - Tubular network structure
KW  - Anisotropic gold nanoplatelets
KW  - Nanocrystal growth
KW  - Nanotriangle stacking and welding
Y1  - 2016
U6  - https://doi.org/10.1007/s00396-016-3890-y
SN  - 0303-402X
SN  - 1435-1536
VL  - 294
SP  - 1297
EP  - 1304
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Schulze, Nicole
A1  - Tiersch, B.
A1  - Zenke, I.
A1  - Koetz, Joachim
T1  - Polyampholyte-tuned lyotrop lamellar liquid crystalline systems
JF  - COLLOID AND POLYMER SCIENCE
N2  - The influence of a polyampholyte, i.e., poly(N,N’-diallyl-N,N’-dimethyl-altmaleamic carboxylate) (PalH), on the lamellar liquid crystalline (LC) system sodium dodecyl sulfate (SDS)/decanol/water was investigated by means of microdifferential scanning calorimetry, small-angle X-ray diffraction (SAXS), and cryo-scanning electron microscopy. After incorporating PalH into the lamellar liquid crystalline system, SAXS measurements show that three different LC phases exist: i.e., a swelling, slightly swelling, and non-swelling one. At pH 4, the positively charged polymer with an extended conformation can directly adsorb at the anionic head groups of the surfactant and more compact vesicles are formed at room temperature. At pH 9, the electrostatic interactions between the polyampholyte (in a more coiled conformation) and the sulfate head groups of the SDS are leveled off and incompact vesicles are formed at room temperature. That means in presence of the polyampholyte the morphology of the LC phase, i.e., the supramolecular vesicle structure, can be tuned by varying the pH and/or the temperature.
KW  - Polyampholytes
KW  - Lamellar liquid crystals
KW  - Vesicle formation
KW  - SAXS
KW  - Cryo-SEM
KW  - mu-DSC
Y1  - 2013
U6  - https://doi.org/10.1007/s00396-013-2999-5
SN  - 0303-402X
SN  - 1435-1536
VL  - 291
IS  - 11
SP  - 2551
EP  - 2559
PB  - SPRINGER
CY  - NEW YORK
ER  - 
TY  - GEN
A1  - Schulze, Nicole
A1  - Koetz, Joachim
T1  - Kinetically Controlled Growth of Gold Nanotriangles in a Vesicular Template Phase by Adding a Strongly Alternating Polyampholyte
N2  - This paper is focused on the temperature dependent synthesis of gold nanotriangles in a vesicular template phase, containing phosphatidylcholin 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 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.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 271 
KW  - Polyampholytes
KW  - Nanotriangles
KW  - Kinetically controlled nanocrystal growth
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-98380
ER  -