TY  - JOUR
A1  - Radziuk, Darya
A1  - Skirtach, Andre
A1  - Gessner, Andre
A1  - Kumke, Michael Uwe
A1  - Zhang, Wei
A1  - Möhwald, Helmuth
A1  - Shchukin, Dmitry
T1  - Ultrasonic Approach for Formation of Erbium Oxide Nanoparticles with Variable Geometries
JF  - Langmuir
N2  - Ultrasound (20 kHz, 29 W. cm(-2)) is employed to form three types of erbium oxide nanoparticles in the presence of multiwalled carbon nanotubes as a template material in water. The nanoparticles are (i) erbium carboxioxide nanoparticles deposited on the external walls of multiwalled carbon nanotubes and Er(2)O(3) in the bulk with (ii) hexagonal and (iii) spherical geometries. Each type of ultrasonically formed nanoparticle reveals Er(3+) photoluminescence from crystal lattice. The main advantage of the erbium carboxioxide nanoparticles on the carbon nanotubes is the electromagnetic emission in the visible region, which is new and not examined up to the present date. On the other hand, the photoluminescence of hexagonal erbium oxide nanoparticles is long-lived (mu s) and enables the higher energy transition ((4)S(3/2)-(4)I(15/2)), which is not observed for spherical nanoparticles. Our work is unique because it combines for the first time spectroscopy of Er(3+) electronic transitions in the host crystal lattices of nanoparticles with the geometry established by ultrasound in aqueous solution of carbon nanotubes employed as a template material. The work can be of great interest for "green" chemistry synthesis of photoluminescent nanoparticles in water.
Y1  - 2011
U6  - https://doi.org/10.1021/la203622u
SN  - 0743-7463
VL  - 27
IS  - 23
SP  - 14472
EP  - 14480
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Löbbicke, Ruben
A1  - Chanana, Munish
A1  - Schlaad, Helmut
A1  - Pilz-Allen, Christine
A1  - Günter, Christina
A1  - Möhwald, Helmuth
A1  - Taubert, Andreas
T1  - Polymer Brush Controlled Bioinspired Calcium Phosphate Mineralization and Bone Cell Growth
JF  - Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences
N2  - Polymer brushes on thiol-modified gold surfaces were synthesized by using terminal thiol groups for the surface initiated free radical polymerization of methacrylic acid and dimethylaminotheyl methacrylate, respectively. Atomic force microscopy shows that the resulting poly(methacrylic acid (PMAA) and poly(dimethylaminothyl methacrylate) (PDM- AEMA) brushes are homogeneous. Contact angle measurements show that the brushes are pH responsive and can reversibly be protonated and deprotonated. Mineralization of the brushes with calcium phosphate at different pH yields homogeneously mineralized surfaces, and preosteoblastic cells proliferate-on be number of living cells on the mineralized hybrid surface is ca. 3 times (P corresponding nonmineralized brushes.
Y1  - 2011
U6  - https://doi.org/10.1021/bm200991b
SN  - 1525-7797
VL  - 12
IS  - 10
SP  - 3753
EP  - 3760
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Li, Hongguang
A1  - Babu, Sukumaran Santhosh
A1  - Turner, Sarah T.
A1  - Neher, Dieter
A1  - Hollamby, Martin J.
A1  - Tomohito, Seki
A1  - Yagai, Shiki
A1  - deguchi, Yonekazu
A1  - Möhwald, Helmuth
A1  - Nakanishi, Takashi
T1  - Alkylated-C60 based soft materials: regulation of self-assembly and optoelectronic properties by chain branching
N2  - Derivatization of fullerene (C60) with branched aliphatic chains softens C60-based materials and enables the formation of thermotropic liquid crystals and room temperature nonvolatile liquids. This work demonstrates that by carefully tuning parameters such as type, number and substituent position of the branched chains, liquid crystalline C60 materials with mesophase temperatures suited for photovoltaic cell fabrication and room temperature nonvolatile liquid fullerenes with tunable viscosity can be obtained. In particular, compound 1, with branched chains, exhibits a smectic liquid crystalline phase extending from 84°C to room temperature. Analysis of bulk heterojunction (BHJ) organic solar cells with a ca. 100 nm active layer of compound 1 and poly(3-hexylthiophene) (P3HT) as an electron acceptor and an electron donor, respectively, reveals an improved performance (power conversion efficiency, PCE: 1.6 ñ 0.1%) in comparison with another compound, 10 (PCE: 0.5 ñ 0.1%). The latter, in contrast to 1, carries linear aliphatic chains and thus forms a highly ordered solid lamellar phase at room temperature. The solar cell performance of 1 blended with P3HT approaches that of PCBM/P3HT for the same active layer thickness. This indicates that C60 derivatives bearing branched tails are a promising class of electron acceptors in soft (flexible) photovoltaic devices.
Y1  - 2013
UR  - http://pubs.rsc.org/en/content/articlepdf/2013/tc/c3tc00066d
U6  - https://doi.org/10.1039/C3TC00066D
ER  -