title: Host-Guest Binding-Site-Tunable Self-Assembly of Stimuli-Responsive Supramolecular Polymers.
abstract: Despite the remarkable progress made in controllable self-assembly of stimuli-responsive supramolecular polymers (SSPs), a basic issue that has not been consideration to date is the essential binding site. The noncovalent binding sites, which connect the building blocks and endow supramolecular polymers with their ability to respond to stimuli, are expected to strongly affect the self-assembly of SSPs. Herein, the design and synthesis of a dual-stimuli thermo- and photoresponsive Y-shaped supramolecular polymer (SSP2) with two adjacent β-cyclodextrin/azobenzene (β-CD/Azo) binding sites, and another SSP (SSP1) with similar building blocks, but only one β-CD/Azo binding site as a control, are described. Upon gradually increasing the polymer solution temperature or irradiating with UV light, SSP2 self-assemblies with a higher binding-site distribution density; exhibits a flower-like morphology, smaller size, and more stable dynamic aggregation process; and greater controllability for drug-release behavior than those observed with SSP1 self-assemblies. The host-guest binding-site-tunable self-assembly was attributed to the positive cooperativity generated among adjacent binding sites on the surfaces of SSP2 self-assemblies. This work is beneficial for precisely controlling the structural parameters and controlled release function of SSP self-assemblies.
authors.affiliation: The Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education and Shanxi Key Laboratory of Macromolecular Science and Technology, School of Science, Northwestern Polytechnical University, Xi'an, 710072, P.R. China.
authors.forename: Hao
authors.initials: H
authors.lastname: Yao
authors.affiliation: The Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education and Shanxi Key Laboratory of Macromolecular Science and Technology, School of Science, Northwestern Polytechnical University, Xi'an, 710072, P.R. China.
authors.forename: Miao
authors.initials: M
authors.lastname: Qi
authors.affiliation: The Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education and Shanxi Key Laboratory of Macromolecular Science and Technology, School of Science, Northwestern Polytechnical University, Xi'an, 710072, P.R. China.
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: The Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education and Shanxi Key Laboratory of Macromolecular Science and Technology, School of Science, Northwestern Polytechnical University, Xi'an, 710072, P.R. China. happytw_3000@nwpu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Tian
keywords: cyclodextrins; host-guest systems; polymers; self-assembly; supramolecular chemistry