Controllable Hierarchical Surface Patterns of Supramolecular Hydrogels: Harnessing Buckling Instability by Confinement. Issue 69 (23rd November 2017)

• Record Type: Journal Article
• Authors: Li, Xiaohui; Guo, Mingyu; Wang, Fang; Shen, Xuezhen; Weng, Yuyan; Hu, Zhijun
• Is Part Of: Chemistry. Volume 23:Issue 69(2017)
• Page Start: 17444
• Page End: 17448
• Publication Date: 2017-11-23
• Subjects: aspect ratio -- confinement -- hydrogels -- supramolecular assembly -- surface folding; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201703155
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Patterned surfaces of responsive polymers find applications in diverse fields. However, it is still a great challenge to fabricate hierarchical patterns with long‐range orders. Herein controllable hierarchical surface patterns that can be fabricated by combining nanoembossing techniques with the surface instability of supramolecular hydrogels are presented. Nanoembossed nanostripe arrays of polyethylene glycol (PEG)‐based polyurethane–urea supramolecular hydrogels are fabricated and exposed to water, whereby the lateral expansion of nanostripes is confined and leads to the formation of folded in‐plane or out‐of‐plane patterns depending on the aspect ratios. The direction of folds is perpendicular to the nanostripes. Both the amplitude and the wavelength of out‐of‐plane folds are proportional to the thickness of nanostripes. Therefore, hierarchical structures, in which one periodicity is defined by the nanoembossing processes and the other is determined by surface buckling, can be quickly fabricated in supramolecular hydrogel thin films. Abstract : Spiked up with gel : Controllable hierarchical surface patterns fabricated by combining nanoembossing techniques with the surface instability of supramolecular hydrogels are presented. Nanostripe arrays of polyethylene glycol‐based polyurethane–urea hydrogels exposed to water leads to the formation of folded in‐plane or out‐of‐plane patterns depending on the aspect ratios. Hierarchical structures defined by the nanoembossing processes and the degree of surface buckling can be quickly fabricated in supramolecular hydrogel thin films.