TY  - JOUR
A1  - Ihlenburg, Ramona
A1  - Mai, Tobias
A1  - Thünemann, Andreas F.
A1  - Baerenwald, Ruth
A1  - Saalwächter, Kay
A1  - Koetz, Joachim
A1  - Taubert, Andreas
T1  - Sulfobetaine hydrogels with a complex multilength-scale hierarchical structure
JF  - The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces & biophysical chemistry
N2  - Hydrogels with a hierarchical structure were prepared from a new highly water-soluble crosslinker N,N,N',N'-tetramethyl-N,N'-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and from the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The free radical polymerization of the two compounds is rapid and yields near-transparent hydrogels with sizes up to 5 cm in diameter. Rheology shows a clear correlation between the monomer-to-crosslinker ratio and the storage and loss moduli of the hydrogels. Cryo-scanning electron microscopy, low-field nuclear magnetic resonance (NMR) spectroscopy, and small-angle X-ray scattering show that the gels have a hierarchical structure with features spanning the nanometer to the sub-millimeter scale. The NMR study is challenged by the marked inhomogeneity of the gels and the complex chemical structure of the sulfobetaine monomer. NMR spectroscopy shows how these complications can be addressed via a novel fitting approach that considers the mobility gradient along the side chain of methacrylate-based monomers.
KW  - Defects
KW  - Hydrogels
KW  - Nuclear magnetic resonance spectroscopy
KW  - Scattering
KW  - X-ray scattering
Y1  - 2021
U6  - https://doi.org/10.1021/acs.jpcb.0c10601
SN  - 1520-6106
SN  - 1520-5207
VL  - 125
IS  - 13
SP  - 3398
EP  - 3408
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Machatschek, Rainhard Gabriel
A1  - Schöne, Anne-Christin
A1  - Raschdorf, Elisa
A1  - Ihlenburg, Ramona
A1  - Schulz, Burkhard
A1  - Lendlein, Andreas
T1  - Interfacial properties of morpholine-2,5-dione-based oligodepsipeptides and multiblock copolymers
JF  - MRS Communications
N2  - Oligodepsipeptides (ODPs) with alternating amide and ester bonds prepared by ring-opening polymerization of morpholine-2,5-dione derivatives are promising matrices for drug delivery systems and building blocks for multifunctional biomaterials. Here, we elucidate the behavior of three telechelic ODPs and one multiblock copolymer containing ODP blocks at the air-water interface. Surprisingly, whereas the oligomers and multiblock copolymers crystallize in bulk, no crystallization is observed at the air-water interface. Furthermore, polarization modulation infrared reflection absorption spectroscopy is used to elucidate hydrogen bonding and secondary structures in ODP monolayers. The results will direct the development of the next ODP-based biomaterial generation with tailored properties for highly sophisticated applications.
Y1  - 2019
U6  - https://doi.org/10.1557/mrc.2019.21
SN  - 2159-6859
SN  - 2159-6867
VL  - 9
IS  - 1
SP  - 170
EP  - 180
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Ihlenburg, Ramona
A1  - Lehnen, Anne-Catherine
A1  - Koetz, Joachim
A1  - Taubert, Andreas
T1  - Sulfobetaine Cryogels for Preferential Adsorption of Methyl Orange from Mixed Dye Solutions
JF  - Polymers / Molecular Diversity Preservation International
N2  - New cryogels for selective dye removal from aqueous solution were prepared by free radical polymerization from the highly water-soluble crosslinker N,N,N’,N’-tetramethyl-N,N’-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The resulting white and opaque cryogels have micrometer sized pores with a smaller substructure. They adsorb methyl orange (MO) but not methylene blue (MB) from aqueous solution. Mixtures of MO and MB can be separated through selective adsorption of the MO to the cryogels while the MB remains in solution. The resulting cryogels are thus candidates for the removal of hazardous organic substances, as exemplified by MO and MB, from water. Clearly, it is possible that the cryogels are also potentially interesting for removal of other compounds such as pharmaceuticals or pesticides, but this must be investigated further.
KW  - cryogel
KW  - water treatment
KW  - dye removal
KW  - methyl orange
KW  - methylene blue
KW  - dye mixture
Y1  - 2020
U6  - https://doi.org/10.3390/polym13020208
SN  - 2073-4360
VL  - 13
IS  - 2
PB  - MDPI
CY  - Basel
ER  -