title: Mechanically-sensitive hydrogels formed from β-cyclodextrin and an anionic surfactant containing a biphenyl group.
abstract: Hydrogels are important soft materials with intriguing properties. By taking advantage of the host-guest interactions and multiple molecular interactions, it is expected that novel hydrogel systems can be formed. This strategy has been implemented here, transparent hydrogels were formed by using a newly-synthesized anionic surfactant, sodium 2-(4-phenylphenoxy)dodecanoate (C12biphNa), and β-cyclodextrin (β-CD) in different proportions and their properties were investigated. Gelation of water occurs at extremely low surfactant concentrations (5 mM for a 1:3 C12biphNa: β-CD system), and a single C12biphNa with its associated β-CDs can trap about 11,000 water molecules on average. In addition, the systems are fragile to mechanical stimulus and thus show mechanical sensitivity. Cryo-TEM reveals that the hydrogels have a microstructure consisting of rigid nanowire-like aggregates (with cross-sectional diameters of about 7-8 nm) locally distributed in a parallel manner in solution. These microstructural features are responsible for the peculiar properties of the hydrogel systems presented. The inclusion complexes formed by C12biphNa and β-CD were investigated using (1)H NMR and 2D nuclear overhauser effect spectroscopy and their aggregation state was proposed. This work enriches the connotation of nonamphiphilic self-assembly and provides inspiration for constructing new functional soft materials.
authors.affiliation: Key Laboratory of Food Colloids and Biotechnology Ministry of Education, School of Chemical & Materials Engineering, Jiangnan University, 214122 Wuxi, People's Republic of China. ccfsbl@jiangnan.edu.cn.
authors.forename: Zhaolan
authors.initials: Z
authors.lastname: Zhai
authors.forename: Lan
authors.initials: L
authors.lastname: Lei
authors.forename: Jiayu
authors.initials: J
authors.lastname: Song
authors.forename: Binglei
authors.initials: B
authors.lastname: Song
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Pei
authors.forename: Zhenggang
authors.initials: Z
authors.lastname: Cui