Orientation of Cellulose Nanocrystals Controlled in Perpendicular Directions by Combined Shear Flow and Ultrasound Waves Studied by Small-Angle X-ray Scattering

Pignon, Frédéric; Semeraro, Enrico F.; Chèvremont, William; Bodiguel, Hugues; Hengl, Nicolas; Karrouch, Mohamed; Sztucki, Michael

doi:10.1021/acs.jpcc.1c03506

Cited by 7 publications

(8 citation statements)

References 75 publications

(234 reference statements)

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“…For concentrated CNC suspensions, flows are incompatible with maintaining a cholesteric order. The application of shear tends to reduce the viscosity of cholesteric suspensions (rheo-thinning), which is usually interpreted as due to the progressive alignment of cholesteric domains, with unwinding of the cholesteric occurring at higher shear rates. ,, An investigation of the relaxation of a shear-aligned nematic-like suspension into an equilibrium cholesteric, observed by POM, postulated the presence of transient twist-bend structure . From a theoretical point of view, the effect of alignment occurring in cholesterics under various constraints is part of what is called nematodynamics.…”

Section: Collective Alignment Of Cncs In Suspensionmentioning

confidence: 99%

Structural Color from Cellulose Nanocrystals or Chitin Nanocrystals: Self-Assembly, Optics, and Applications

Frka-Petesic,

Parton,

Honorato-Rios

et al. 2023

Chem. Rev.

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Widespread concerns over the impact of human activity on the environment have resulted in a desire to replace artificial functional materials with naturally derived alternatives. As such, polysaccharides are drawing increasing attention due to offering a renewable, biodegradable, and biocompatible feedstock for functional nanomaterials. In particular, nanocrystals of cellulose and chitin have emerged as versatile and sustainable building blocks for diverse applications, ranging from mechanical reinforcement to structural coloration. Much of this interest arises from the tendency of these colloidally stable nanoparticles to self-organize in water into a lyotropic cholesteric liquid crystal, which can be readily manipulated in terms of its periodicity, structure, and geometry. Importantly, this helicoidal ordering can be retained into the solid-state, offering an accessible route to complex nanostructured films, coatings, and particles. In this review, the process of forming iridescent, structurally colored films from suspensions of cellulose nanocrystals (CNCs) is summarized and the mechanisms underlying the chemical and physical phenomena at each stage in the process explored. Analogy is then drawn with chitin nanocrystals (ChNCs), allowing for key differences to be critically assessed and strategies toward structural coloration to be presented. Importantly, the progress toward translating this technology from academia to industry is summarized, with unresolved scientific and technical questions put forward as challenges to the community.

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Section: Collective Alignment Of Cncs In Suspensionmentioning

confidence: 99%

Structural Color from Cellulose Nanocrystals or Chitin Nanocrystals: Self-Assembly, Optics, and Applications

Frka-Petesic,

Parton,

Honorato-Rios

et al. 2023

Chem. Rev.

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“…Shear-flow-induced self-assembly of CNC is essential in fundamental science and advanced anisotropic material development. Shear flow in the confined microchannel induces preferred CNC alignments, providing versatile opportunities for advanced application. ,, More recently, shear-flow-induced CNC assembly into concentric chiral nematic fiber structures in microfluidic devices and 3D printers has attracted considerable attention. , Wu et al utilized a microfluidics device to create hierarchical core–sheath architectures with concentric chiral nematic CNC arrangements in an in situ formed calcium alginate hydrogel sheath in Figure a . The structure evolution of CNC suspensions during flow and after flow cessation was extensively characterized with POM. ,, It was indicated that the CNC arrangements are closely related to the shear flow forces inside the microfluidic tube.…”

Section: Shear-flow-accelerated Cnc Self-assembly For Liquid Crystalsmentioning

confidence: 99%

“…Shear flow in the confined microchannel induces preferred CNC alignments, providing versatile opportunities for advanced application. 186,218,219 More recently, shear-flowinduced CNC assembly into concentric chiral nematic fiber structures in microfluidic devices and 3D printers has attracted considerable attention. 204,220 Wu et al utilized a microfluidics device to create hierarchical core−sheath architectures with concentric chiral nematic CNC arrangements in an in situ formed calcium alginate hydrogel sheath in Figure 16a.…”

Section: Shear-flow-accelerated Cnc Self-assembly For Liquid Crystalsmentioning

confidence: 99%

Accelerating Cellulose Nanocrystal Assembly into Chiral Nanostructures

et al. 2023

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Cellulose nanocrystal (CNC) suspensions self-assembled into chiral nematic liquid crystals. This property has enabled the development of versatile optical materials with fascinating properties. Nevertheless, the scale-up production and commercial success of chiral nematic CNC superstructures face significant challenges. Fabrication of chiral nematic CNC nanostructures suffers from a ubiquitous pernicious trade-off between uniform chiral nematic structure and rapid self-assembly. Specifically, the chiral nematic assembly of CNCs is a time-consuming, spontaneous process that involves the organization of particles into ordered nanostructures as the solvent evaporates. This review is driven by the interest in accelerating chiral nematic CNC assembly and promoting a long-range oriented chiral nematic CNC superstructure. To start this review, the chirality origins of CNC and CNC aggregates are analyzed. This is followed by a summary of the recent advances in stimuli-accelerated chiral nematic CNC self-assembly procedures, including evaporation-induced self-assembly, continuous coating, vacuum-assisted self-assembly, and shear-induced CNC assembly under confinement. In particular, stimuli-induced unwinding, alignment, and relaxation of chiral nematic structures were highlighted, offering a significant link between the accelerated assembly approaches and uniform chiral nematic nanostructures. Ultimately, future opportunities and challenges for rapid chiral nematic CNC assembly are discussed for more innovative and exciting applications.

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“…It is important to note that when the CNC is ordering in chiral structures upon drying. Several attempts to control CNC director orientation have focused on the use of external fields, mechanical (shearing), electrical, or magnetic . The only technique reported for controlling the direction of the cholesteric helix is using a magnetic field.…”

Section: Introductionmentioning

confidence: 99%

“…Several attempts to control CNC director orientation have focused on the use of external fields, mechanical (shearing), electrical, or magnetic. 17 The only technique reported for controlling the direction of the cholesteric helix is using a magnetic field. Sugiyama was the first to show that the magnetic dipole of individual C−O, C− H, and O−H bonds and their relative orientations in the cellulose polymer chain led to a material with anisotropy diamagnetic susceptibility.…”

Section: ■ Introductionmentioning

confidence: 99%

Spin-Induced Organization of Cellulose Nanocrystals

et al. 2022

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Cellulose nanocrystals (CNCs) are composed of chiral cellulose units, which form chiral nematic liquid crystals in water that, upon drying, self-assemble to more complex spiral chiral sheets. This secondary structure arrangement is found to change with an external magnetic or electric field. Here, we show that one of the basic organization driving forces is electron spin, which is produced as the charge redistributes in the organization process of the chiral building blocks. It is important to stress that the electron spinexchange interactions supply the original driving force and not the magnetic field per se. The results present the first utilization of the chiral-induced spin selectivity (CISS) effect in sugars, enabling one to regulate the CNC bottom-up fabrication process. Control is demonstrated on the organization order of the CNC by utilizing different magnetization directions of the ferromagnetic surface. The produced spin is probed using a simple Hall device. The measured Hall resistance shows that the CNC sheets' arrangement is affected during the first four hours as long as the CNC is in its wet phase. On introducing the 1,2,3,4-butanetetracarboxylic acid cross-linker into the CNC sheet, the packing density of the CNC helical structure is enhanced, presenting an increase in the Hall resistance and the chiral state.

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Orientation of Cellulose Nanocrystals Controlled in Perpendicular Directions by Combined Shear Flow and Ultrasound Waves Studied by Small-Angle X-ray Scattering

Cited by 7 publications

References 75 publications

Structural Color from Cellulose Nanocrystals or Chitin Nanocrystals: Self-Assembly, Optics, and Applications

Structural Color from Cellulose Nanocrystals or Chitin Nanocrystals: Self-Assembly, Optics, and Applications

Accelerating Cellulose Nanocrystal Assembly into Chiral Nanostructures

Spin-Induced Organization of Cellulose Nanocrystals

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