Figure 8
From: Hydrogels with self-assembling ordered structures and their functions
(a) Scheme for the synthesis of a polyacrylamide hydrogel with unidirectional alignment of lamellar bilayers. (b) Change in swelling ratio, birefringence (Δn), Bragg reflection peak wavelength (λmax) and lamellar distance (d) at an incident angle of 60° for gels synthesized with various DGI concentrations. (c) Relationship of λmax and d with compressional strain (ɛ) of the gel. The compressional strain is mainly localized in the soft PAAm network layers of the gel, which causes a decrease in lamellar distance in the perpendicular direction. (d) The letters ‘LSW’ in a rubber stamp (top) cause a color change in a gel sheet when pressed onto the stamp (lower panels). The color change is dependent on the compressional force applied (g). Adapted from Ref. 78 (© 2010 Wiley-VCH).
