Two-Component Self-Assemblies: Investigation of a Synergy between Bisurea Stickers

Abstract

ABSTRACT. It is of interest to develop two-component systems for added flexibility in the design of supramolecular polymers, nanofibers or organogels. Bis-ureas are known to selfassemble by hydrogen bonding into long supramolecular objects. We show here that mixing aromatic bis-ureas with slightly different structures can yield surprisingly large synergistic effects. A strong increase in viscosity is observed when a bis-urea with the sterically demanding 2,4,6-trimethylbenzene spacer is combined with a bis-urea bearing no methyl group in position 2 of the aromatic spacer (i.e. 4-methylbenzene or 4,6-dimethylbenzene). This effect is the consequence of a change in supramolecular assembly triggered by the composition of the mixture. The mixture of complementary bis-ureas forms rod-like objects that are more stable by about 1 kJ/mol, and that are thicker than the rod-like objects formed by both parent systems.

Biomaterial screening of protein coatings and peptide additives: towards a simple synthetic mimic of a complex natural coating for a bio-artificial kidney

“…1B). [25][26][27][28][29] BU-moieties allow for more efficient surface functionalization compared to UPy-units, resulting in a more pronounced cellular response. 29 In combination with the aforementioned features, the intrinsic modular nature of supramolecular BU-moieties makes them eminently suitable for the creation of complex screening libraries.…”

Development of Poor Cell Adhesive Immersion Precipitation Membranes Based on Supramolecular Bis‐Urea Polymers

“…Biosci. 2019, 20,1900277 processing, hence similar properties between PCL-BU membranes and PCL-BU with PEG blended membranes. [32,40,41] Hydrophobicity measurements and cell adhesive results suggested that the bottom is enriched with PEG.…”

“…Supramolecular bis‐urea (BU) motifs have been successfully employed to achieve intimate mixing of components 19–21. The motifs are proposed to assemble through bifurcated hydrogen bonding into ribbon‐like structures, three to six ribbons are proposed to assemble into nanoscale fibers 22–26.…”

“…[16][17][18][19] Supramolecular bis-urea (BU) motifs have been successfully employed to achieve intimate mixing of components. [19][20][21] The motifs are proposed to assemble through bifurcated hydrogen bonding into ribbon-like structures, three to six ribbons are proposed to assemble into nanoscale fibers. [22][23][24][25][26] Therefore, BU-chemistry enables the modular design of materials through intimate mixing of separated components.…”

“…Biosci. 2019,20, 1900277 Chemical structures and schematic overview. A) Chemical structures of bis-urea (BU) modified polycaprolactone (PCL-BU) and poly(ethylene glycol) (PEG-BU).…”