Liquid crystal templating of nanomaterials with nature's toolbox

Abstract

Naturally occurring biomolecules are sustainable and green precursors for the development of new materials. Within this family of natural materials, cellulose nanocrystals (CNCs) have emerged as one of the most promising materials because of their outstanding physico-chemical properties and the possibility to produce them in large quantities. One key trait of CNCs is their ability to self-assemble into a chiral nematic liquid crystalline phase. In this review, we discuss how templating can be used to transfer the three-dimensional structure of liquid crystalline phases onto solid materials. This is followed by examples that illustrate the fascinating properties and potential applications that arise from the resulting nanostructured materials such as sensing and catalysis. We then summarize efforts to use the liquid crystalline phase of a selection of other biopolymers for templating. While nanocrystalline chitin, having very similar properties to CNCs, has been successfully employed to make a variety of new materials, efforts to template liquid crystal phases of other biomolecules have been met with limited success. However, we discuss virus nanoparticles and collagen as examples to highlight further possibilities for materials research.

Hierarchically-structured metalloprotein composite coatings biofabricated from co-existing condensed liquid phases

“…T he ability to endow polymeric materials with nano-scale and meso-scale structural hierarchy via self-assembly is an important materials design challenge with implications for tissue engineering, drug delivery and smart polymer engineering [1][2][3][4] . Polymer scientists aim to achieve control of multiscale organization through precisely defined chemical structure and engineered supramolecular interactions 2,5,6 , which can be employed for example, as scaffolds for guiding polymerization of materials with defined hierarchy (e.g., mesoporous silica) [7][8][9] . Similarly, proteins also possess an inherent capacity for supramolecular self-organization-determined by amino acid sequence -that has been harnessed through evolution for fabricating bulk materials/tissues with enhanced function, controlled through multiscale hierarchical structure [10][11][12][13][14][15] .…”

Orientation Control of Molecularly Functionalized Surfaces Applied to the Simultaneous Alignment and Sorting of Carbon Nanotubes

“…Notably, liquid crystals can be aligned over long distances by magnetic fields, electric fields, polarized light, and rubbed polyimide‐coated surfaces . Recent reports have shown the use of liquid crystals as templates for the alignment of organic materials . Additionally, Long and Swager demonstrated the ability of triptycenes and, to a greater extent, higher iptycenes to align in nematic liquid crystal solutions in order to minimize free volume .…”

The Self‐Assembly of Cellulose Nanocrystals: Hierarchical Design of Visual Appearance

“…Importantly, cellulose nanocrystals (CNCs) extracted from natural cellulose fibrils can spontaneously self‐assemble at the nanoscale to produce similar architectures capable of reflecting light in the visible spectrum . Nanocellulose‐based optical materials are nonbleaching, biocompatible, biodegradable, low‐cost, and scalable, and as such offer enormous potential to sustainably replace traditional, potentially hazardous colorants used industrially for food, cosmetics, art, textiles, sensing, and security labeling . In this Research News article, we describe the liquid crystalline behavior of cellulose nanocrystals in suspension and provide an overview of the toolbox available to control their self‐assembly into vivid, structurally colored materials.…”