%0 journal article
%@ 0743-7463
%A Meister, A.,Bastrop, M.,Koschoreck, S.,Haramus, V.M.,Sinemus, T.,Hempel, G.,Drescher, S.,Dobner, B.,Richtering, W.,Huber, K.,Blume, A.

%D 2007
%J Langmuir
%N 14
%P 7715-7723 
%R doi:10.1021/la7003479
%T Structure-Property Relationship in Stimulus-Responsive Bolaamphiphile Hydrogels
%U https://doi.org/10.1021/la7003479
14 
%X The formation of temperature-, concentration-, and pH-responsive hydrogels composed of the symmetric long-chain bolaamphiphile dotriacontane-1,1'-diyl bis[[2-(dimethylammonio)ethyl]phosphate] (Me2PE-C32-Me2PE) was investigated by rheological, scattering, and spectroscopic techniques. At pH 5, this bolaamphiphile is known to form a dense network of helically structured nanofibers (Köhler et al. Soft Matter 2006, 2, 77-86). Rheological measurements and dynamic light scattering were used to describe the macroscopic behavior of the hydrogels. Small-angle neutron scattering (SANS) and time-resolved static light scattering were applied to get information about the morphology of the self-assembled aggregates. Finally, solid-state 31P NMR spectroscopy was used to gain insight into the mobility of the bolaamphiphile molecules within the fiber aggregates. In comparison with the previously examined trimethylammonio analogue PC-C32-PC, which forms temperature-dependent hydrogels, Me2PE-C32-Me2PE exhibits additional concentration- and pH-dependent gelling properties. The significantly higher stability of the Me2PE-C32-Me2PE hydrogel is supported by the SANS data, which indicate the presence of fiber aggregates up to 50 C.