TY  - JOUR
A1  - Kathrein, Christine C.
A1  - Bai, Wubin
A1  - Nunns, Adam
A1  - Gwyther, Jessica
A1  - Manners, Ian
A1  - Böker, Alexander
A1  - Tsarkova, Larisa
A1  - Ross, Caroline A.
T1  - Electric field manipulated nanopatterns in thin films of metalorganic 3-miktoarm star terpolymers
JF  - Soft matter
N2  - We report the effect of electric field on the morphological transitions and ordering behavior of polyferrocenylethylmethylsilane block (PFEMS)-containing copolymers. By analyzing structures in solvent-annealed films of metalorganic sphere-and cylinder-forming diblock copolymers, as well as of 3-miktoarm polyisoprene-arm-polystyrene-arm-PFEMS (3 mu-ISF) terpolymers, we decouple two types of responses to the electric field: morphological transformations as a result of an increase in the volume fraction of the PFEMS block by oxidation of the ferrocenyl groups, and the orientation of the dielectric interfaces of microdomains parallel to the electric field vector. In the case of 3m-ISF, the former effect dominates at high electric field strengths which results in an unexpected cylinder-to-sphere transition, leading to a well-ordered hexagonal dot pattern. Our results demonstrate multiple tunability of ordered microdomain morphologies, suggesting future applications in nanofabrication and surface patterning.
Y1  - 2016
U6  - https://doi.org/10.1039/c6sm00451b
SN  - 1744-683X
SN  - 1744-6848
VL  - 12
SP  - 4866
EP  - 4874
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Kathrein, Christine C.
A1  - Pester, Christian
A1  - Ruppel, Markus
A1  - Jung, Maike
A1  - Zimmermann, Marc
A1  - Böker, Alexander
T1  - Reorientation mechanisms of block copolymer/CdSe quantum dot composites under application of an electric field
JF  - Soft matter
N2  - Time- and temperature-resolved in situ birefringence measurements were applied to analyze the effect of nanoparticles on the electric field-induced alignment of a microphase separated solution of poly(styrene)-block-poly(isoprene) in toluene. Through the incorporation of isoprene-confined CdSe quantum dots the reorientation behavior is altered. Particle loading lowers the order-disorder transition temperature, and increases the defect density, favoring nucleation and growth as an alignment mechanism over rotation of grains. The temperature dependent alteration in the reorientation mechanism is analyzed via a combination of birefringence and synchrotron SAXS. The detailed understanding of the effect of nanoparticles on the reorientation mechanism is an important prerequisite for optimization of electricfield-induced alignment of block copolymer/nanoparticle composites where the block copolymer guides the nanoparticle self-assembly into anisotropic structures.
Y1  - 2016
U6  - https://doi.org/10.1039/c6sm01073c
SN  - 1744-683X
SN  - 1744-6848
VL  - 12
SP  - 8417
EP  - 8424
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  -