TY  - JOUR
A1  - Koeth, Anja
A1  - Tiersch, Brigitte
A1  - Appelhans, Dietmar
A1  - Gradzielski, Michael
A1  - Cölfen, Helmut
A1  - Koetz, Joachim
T1  - Synthesis of Core-Shell Gold Nanoparticles with Maltose-Modified Poly(Ethyleneimine)
JF  - Journal of dispersion science and technology
N2  - The synthesis of ultrafine gold nanoparticles in presence of maltose-modified hyperbranched poly(ethyleneimines) (PEI) is described. The polymer acted as both a reducing and stabilising agent in the particle formation process. The nanoparticles were characterized by means of dynamic light scattering (DLS), transmission electron microscopy (TEM), analytical ultracentrifugation (AUC), small-angle x-ray scattering (SAXS), and small-angle neutron scattering (SANS). The mechanism of nanoparticle formation can be described in two steps. The reduction process of the Au3+ ions located in the inner coil region of the hyperbranched PEI led to the formation of a compact gold core, and is accompanied by a collapse of the polymer coil. Therefore, in the subsequent reduction process a gold-polymer hybrid shell is formed. By using the PEI of higher molar mass, core-shell gold nanoparticles of about 3.6 nm size with a more narrow size distribution and special fluorescence behavior could be synthesized.
KW  - Gold nanoparticles
KW  - gold-polymer hybrid shell
KW  - maltose-modified poly(ethyleneimine)
Y1  - 2012
U6  - https://doi.org/10.1080/01932691.2010.530084
SN  - 0193-2691
VL  - 33
IS  - 1-3
SP  - 52
EP  - 60
PB  - Taylor & Francis Group
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Koeth, Anja
A1  - Appelhans, Dietmar
A1  - Prietzel, Claudia Christina
A1  - Koetz, Joachim
T1  - Asymmetric gold nanoparticles synthesized in the presence of maltose-modified poly(ethyleneimine)
JF  - Colloids and surfaces : an international journal devoted to the principles and applications of colloid and interface science ; A, Physicochemical and engineering aspects
N2  - A self-assembled tube-like network, spontaneously formed by adding maltose-modified poly(ethyleneimine) (mal-PEI5000) to mixed phospholipid vesicles, can be used as a template for the formation of gold nanoparticles. High resolution TEM indicates that the growing process leads not only to the formation of spherical gold nanoparticles with an absorption maximum at 520 nm, but also very flat triangles, hexagons, and long bent rods are formed, revealing an absorption maximum in the NIR at about 850 nm.
 One can conclude that nanorods, nanotriangles and nanohexagons are predominantly formed in the tubular network structure.
KW  - Gold triangles
KW  - Hexagons and nanorods
KW  - Tube-like template phase
KW  - Maltose-modified PEI
Y1  - 2012
U6  - https://doi.org/10.1016/j.colsurfa.2012.08.004
SN  - 0927-7757
VL  - 414
IS  - 21
SP  - 50
EP  - 56
PB  - Elsevier
CY  - Amsterdam
ER  -