Multi-responsive nanocomposite membranes of cellulose nanocrystals and poly(N-isopropyl acrylamide) with tunable chiral nematic structures

Yanqiu Sui; Xiaofeng Li; Wei Chang; Hao Wan; Wei Li; Fan Yang; Zhong-Zhen Yu

doi:10.1016/j.carbpol.2019.115778

Multi-responsive nanocomposite membranes of cellulose nanocrystals and poly(N-isopropyl acrylamide) with tunable chiral nematic structures

Carbohydr Polym. 2020 Mar 15:232:115778. doi: 10.1016/j.carbpol.2019.115778. Epub 2019 Dec 23.

Authors

Yanqiu Sui¹, Xiaofeng Li², Wei Chang³, Hao Wan⁴, Wei Li⁵, Fan Yang⁵, Zhong-Zhen Yu⁶

Affiliations

¹ State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China; Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing 100029, China.
² State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China. Electronic address: xfli@mail.buct.edu.cn.
³ State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
⁴ Department of Polymer Science and Engineering, University of Massachusetts Amherst, Amherst 01003, United States.
⁵ Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing 100029, China.
⁶ State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China; Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing 100029, China. Electronic address: yuzz@mail.buct.edu.cn.

PMID: 31952587
DOI: 10.1016/j.carbpol.2019.115778

Abstract

By imitating the unique structure of nature creatures, photonic membranes with periodic chiral helical structure can be assembled by cellulose nanocrystals (CNCs). It is still an issue to fabricate CNC photonic structures tunable in the entire visible spectrum with multiple stimuli-response capacities. Herein, a multi-responsive nanocomposite photonic membrane is fabricated by co-assembly of poly(N-isopropyl acrylamide) (PNIPAM) grafted CNCs with waterborne polyurethane (WPU) latex on the basis of the chiral nematic structure of CNCs, the thermo-responsibility of PNIPAM, and the flexibility of WPU. The flexible photonic membranes with uniform structural colors from blue to red are obtained by tuning the PNIPAM content. The membrane exhibits reversible responses to solvents, and iridescence changes in response to relative humidity with excellent repeatability. Interestingly, the membrane can be transparent or opaque depending on the ambient temperature. The photonic membranes are appealing in applications as humidity sensor, camouflage materials, and even smart windows.

Keywords: Cellulose nanocrystals; Glutaraldehyde; K(2)SO(4); Lithium bromide; NaCl; Nanocomposite membranes; Poly(N-isopropyl acrylamide); Potassium persulfate; Stimulus response; Waterborne polyurethane; n-Hexane; poly(N-isopropyl acrylamide).