Water and humidity-induced shape memory cellulose nanopaper with quick response, excellent wet strength and folding resistance

Integrated and sustainable preparation of functional nanocellulose via formic acid/choline chloride solvents pretreatment

“…2b). In the spectra of all cellulose samples, there are two peaks at 3342 and 2899 cm − 1 assigning to O-H bonds and C-H bonds in the cellulose chain, and the peaks appearing at 1644 and 1430 cm − 1 are attributed to O-H bonds from water and C-H bonds, respectively (Wu et al 2020). Specially, compared with MCC and U-MCC, an absorption peak at 1720 cm − 1 is shown in the spectrum of F-MCC, which belongs to the newly formed ester groups (Zhang et al 2021).…”

“…Cellulose with the structure of β-1, 4 linked D-glucose units is an abundant, sustainable and renewable resources (Yang et al 2021). Researchers have been working on the application of cellulose and cellulose derivatives in various elds, such as membrane materials (Wu et al 2020), packaging materials (Ferrer et al 2017) and gel materials (Ajdary et al 2020). In recent years, nanocellulose (NC) as a nano-sized cellulosic material has attracted great attention due to its unique physicochemical properties (e.g.…”

Hybrid covalent adaptable networks from cross-reactive poly(ε-caprolactone) and poly(ethylene oxide) stars towards advanced shape-memory materials

“…When biomedical applications are envisioned, water responsive SMPs, that recover their shape by immersing the sample in water at constant body temperature, are particularly appealing. [16][17][18][19] To impart such water sensitivity to polyesters based SMPs, they have been combined notably with poly(ethylene oxide) (PEO), a highly hydrophilic and bioeliminable component. PCL and PEO were combined in multiblock polyurethanes leading to water-triggered SM thermoplastics.…”

Synthesis and Properties of a New Chitosan‐Based Shape Memory Polymer and its Composites

“…% of CH and developed printed scaffold that displayed18.8 % shape recovery at the optimized process parametric settings. Wu et al [22] developed a robust cellulose nanopaper (CNP) by first preparing cellulose nanofibrils from formic acid hydrolysis followed by immersing it in CH solution. The CH coated CNP film with a thickness of 0.03 mm displayed a recovery time of < 3 s. A novel dualresponsive interpenetrating polymer network hydrogel has been prepared by incorporating pH-responsive CH into thermoplastic elastomer agarose (agar) matrix using the ice-templating method, which exhibited > 95 % porosity and water-induced shape recovery ratio > 90 % with a response time < 1 min.…”