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  -