Cholesteric cellulose liquid crystal ink for three-dimensional structural coloration

Zhang, Zhuohao; Wang, Chong; Wang, Qiao; Zhao, Yuanjin; Shang, Luoran

doi:10.1073/pnas.2204113119

Cited by 25 publications

(32 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As such, printed structures of different colors can be accessed using a single feedstock. This approach has since been expanded by adding a chemical cross-linker (leading to increased buckling and a noniridescent appearance), or by mixing HPC with gelatin and a photoresponsive monomer (resulting in a printable photonic hydrogel with thermochromic behavior) …”

Section: Polymer Mesophases For Responsive Structural Colormentioning

confidence: 99%

Bioinspired Photonic Materials from Cellulose: Fabrication, Optical Analysis, and Applications

et al. 2023

View full text Add to dashboard Cite

Metrics & MoreArticle RecommendationsCONSPECTUS: Polysaccharides are a class of biopolymers that are widely exploited in living organisms for a diversity of applications, ranging from structural reinforcement to energy storage. Among the numerous types of polysaccharides found in the natural world, cellulose is the most abundant and widespread, as it is found in virtually all plants. Cellulose is typically organized into nanoscale crystalline fibrils within the cell wall to give structural integrity to plant tissue. However, in several species, such fibrils are organized into helicoidal nanostructures with a periodicity comparable to visible light (i.e., in the range 250−450 nm), resulting in structural coloration. As such, when taking bioinspiration as a design principle, it is clear that helicoidal cellulose architectures are a promising approach to developing sustainable photonic materials. Different forms of cellulose-derived materials have been shown to produce structural color by exploiting self-assembly processes. For example, crystalline nanoparticles of cellulose can be extracted from natural sources, such as cotton or wood, by strong acid hydrolysis. Such "cellulose nanocrystals" (CNCs) have been shown to form colloidal suspensions in water that can spontaneously self-organize into a cholesteric liquid crystal phase, mimicking the natural helicoidal architecture. Upon drying, this nanoscale ordering can be retained into the solid state, enabling the specific reflection of visible light. Using this approach, colors from across the entire visible spectrum can be produced, alongside striking visual effects such as iridescence or a metallic shine. Similarly, polymeric cellulose derivatives can also organize into a cholesteric liquid crystal. In particular, edible hydroxypropyl cellulose (HPC) is known to produce colorful mesophases at high concentrations in water (ca. 60−70 wt %). This solution state behavior allows for interesting visual effects such as mechanochromism (enabling its use in low-cost colorimetric pressure or strain sensors), while trapping the structure into the solid state enables the production of structurally colored films, particles and 3D printed objects.In this article, we summarize the state-of-the-art for CNC and HPC-based photonic materials, encompassing the underlying selfassembly processes, strategies to design their photonic response, and current approaches to translate this burgeoning green technology toward commercial application in a wide range of sectors, from packaging to cosmetics and food. This overview is supported by a summary of the analytical techniques required to characterize these photonic materials and approaches to model their optical response. Finally, we present several unresolved scientific questions and outstanding technical challenges that the wider community should seek to address to develop these sustainable photonic materials.

show abstract

Section: Polymer Mesophases For Responsive Structural Colormentioning

confidence: 99%

Bioinspired Photonic Materials from Cellulose: Fabrication, Optical Analysis, and Applications

et al. 2023

View full text Add to dashboard Cite

show abstract

Section: Biomedical Applications Of Lc Materialsmentioning

confidence: 99%

Liquid Crystal Materials for Biomedical Applications

et al. 2023

Self Cite

View full text Add to dashboard Cite

Liquid crystal is a state of matter being intermediate between solid and liquid. Liquid crystal materials exhibit both orientational order and fluidity. While liquid crystals have long been highly recognized in the display industry, in recent decades, liquid crystals provide new opportunities into the cross‐field of material science and biomedicine due to their biocompatibility, multifunctionality, and responsiveness. In this review, the latest achievements of liquid crystal materials applied in biomedical fields are summarized. The start is made by introducing the basic concepts of liquid crystals, and then shifting to the components of liquid crystals as well as functional materials derived therefrom. After that, the ongoing and foreseeable applications of liquid crystal materials in the biomedical field with emphasis put on several cutting‐edge aspects, including drug delivery, bioimaging, tissue engineering, implantable devices, biosensing, and wearable devices are discussed. It is hoped that this review will stimulate ingenious ideas for the future generation of liquid crystal‐based drug development, artificial implants, disease diagnosis, health status monitoring, and beyond.

show abstract

“…Generally, a higher concentration leads to a smaller pitch and a blue-shift of the reflection spectrum of the chains as more closely packed. 9,16,17,21,25,[28][29][30]32,33,37,42,43,45,55,69 Specifically, a power law dependence between the pitch p (units of μm) and concentration ϕ p (units of wt %) is repeatedly reported like in eq 7. 39,43,44 = p p p m 0 (7) For polypeptide liquid crystals, in which this relationship was first observed, the exponent controlling this relationship is between −1 and −2, while a value near −3 is more commonly observed for cholesteric mesophases of HPC.…”

Section: ■ Introductionmentioning

confidence: 99%

“…9,70 Additionally, the power law exponent is solvent-dependent, as seen for suspensions of HPC where m typically fluctuates between −3 and −4 but is significantly higher (−6.92) in acetic acid. 14 Previously, it has been asserted that a theoretical framework describing the relationship between pitch and concentration may hinge upon molecular shape asymmetry, chirality, 37,55 (b) mesophases prepared with HPC, 9,14,16,32,33 and (c) mesophases prepared in acetic acid. 9,55 The exponents from these curves are plotted in parts (d)−(f) against the difference between the Hansen hydrogen bonding solubility parameter of the polymer, δ h,p , and that of the solvent, δ h,s , with the corresponding fit and confidence interval for this relationship.…”

Section: ■ Introductionmentioning

confidence: 99%

Unraveling the Governing Mechanisms Behind the Chiral Nematic Self-Assembly of Cellulose-Based Polymers

Fine,

Chazot

2023

Chem. Mater.

View full text Add to dashboard Cite

Thanks to their abundance and ability to selfassemble into photonic crystals that selectively reflect light, chiral nematic liquid crystalline cellulose polymers have been investigated as the basis for colorimetric sensors responsive to humidity, pressure, temperature, and other stimuli. In this perspective, we start by revisiting the early research on these materials to explain how different geometric and thermodynamic factors influence the self-assembly and optical properties of cholesteric phases constructed from cellulose derivatives. We explore how solubility, viscosity, and hydrogen bonding impact the onset of mesophase formation and the helicoidal arrangement. Having elucidated the controlling factors influencing the pitch−concentration relationship in these materials, we discuss efforts to preserve liquid crystalline order in solids and underscore the critical knowledge gaps in understanding how the kinetics of self-assembly affects both cholesteric order formation and retention.

show abstract

Cholesteric cellulose liquid crystal ink for three-dimensional structural coloration

Cited by 25 publications

References 33 publications

Bioinspired Photonic Materials from Cellulose: Fabrication, Optical Analysis, and Applications

Bioinspired Photonic Materials from Cellulose: Fabrication, Optical Analysis, and Applications

Liquid Crystal Materials for Biomedical Applications

Unraveling the Governing Mechanisms Behind the Chiral Nematic Self-Assembly of Cellulose-Based Polymers

Contact Info

Product

Resources

About