Multifunctional Reversible Self‐Assembled Structures of Cellulose‐Derived Phase‐Change Nanocrystals

Abstract

Owing to advantageous properties attributed to well‐organized structures, multifunctional materials with reversible hierarchical and highly ordered arrangement in solid‐state assembled structures have drawn tremendous interest. However, such materials rarely exist. Based on the reversible phase transition of phase‐change materials (PCMs), phase‐change nanocrystals (C18‐UCNCs) are presented herein, which are capable of self‐assembling into well‐ordered hierarchical structures. C18‐UCNCs have a core–shell structure consisting of a cellulose crystalline core that retains the basic structure and a soft shell containing octadecyl chains that allow phase transition. The distinct core–shell structure and phase transition of octadecyl chains allow C18‐UCNCs to self‐assemble into flaky nano/microstructures. These self‐assembled C18‐UCNCs exhibit efficient thermal transport and light‐to‐thermal energy conversion, and thus are promising for thermosensitive imaging. Specifically, flaky self‐assembled nano/microstructures with manipulable surface morphology, surface wetting, and optical properties are thermoreversible and show thermally induced self‐healing properties. By using phase‐change nanocrystals as a novel group of PCMs, reversible self‐assembled multifunctional materials can be engineered. This study proposes a promising approach for constructing self‐assembled hierarchical structures by using phase‐change nanocrystals and thereby significantly expands the application of PCMs.

Nanocellulose‐Based Functional Materials: From Chiral Photonics to Soft Actuator and Energy Storage

“…Inspired by and benefiting from this regular nanostructure, extensive efforts have been devoted to the development of CNC-based chiral photonics for diverse applications, such as in cosmetics, sensors, and flexible displays. [119][120][121][122][123] In this context, the origin of structural color in CNCs, chirality manipulation of CNC films, and development of novel CNC composites that can produce flexible photonic films in this field are discussed.…”

Nanocellulose and Its Interface: On the Road to the Design of Emerging Materials

“…The phase transition of the shell conferred on the flaky structures superior thermoinduced self-healing and thermoreversible properties (Figure 7d). [126] Figure 6. Functionalization of films of CNFs.…”

“…The inset in (a) shows the dyed water droplets on the surface of the C 18 -UCNCs film. c) SAXS curves of a C 18 -UCNCs film measured under different conditions: as-prepared films at 25 °C, heated at 80 °C and cooled from 80 to 25 °C and aging for 24 h. d) Schematic of the formation of a thermoreversible flaky structure.Reproduced with permission [126]. Copyright 2020, Wiley-VCH.…”

Flexible engineering of advanced phase change materials

“…( Kumar et al., 2020 ; Shao et al., 2021a ), and porous encapsulation (MOFs, EG, etc.) ( Chen et al., 2020e , 2020h , 2021 ; Huang et al., 2020 ; Kashyap et al., 2019 ; Liu et al., 2021d ; Wang et al., 2021b ). Unfortunately, the shape-stabilized composite PCMs usually exhibit strong rigidity and poor flexibility, resulting in difficult installation, easy brittle failure and poor surface contact ( Abdelrazik et al., 2020 ; Ashraf et al., 2017 ; Graham et al., 2020 ; Liu et al., 2020 ).…”