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Lin D, Bagnani M, Almohammadi H, Yuan Y, Zhao Y, Mezzenga R. Single-Step Control of Liquid-Liquid Crystalline Phase Separation by Depletion Gradients. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2312564. [PMID: 38692672 DOI: 10.1002/adma.202312564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 04/26/2024] [Indexed: 05/03/2024]
Abstract
Fine-tuning nucleation and growth of colloidal liquid crystalline (LC) droplets, also known as tactoids, is highly desirable in both fundamental science and technological applications. However, the tactoid structure results from the trade-off between thermodynamics and nonequilibrium kinetics effects, and controlling liquid-liquid crystalline phase separation (LLCPS) in these systems is still a work in progress. Here, a single-step strategy is introduced to obtain a rich palette of morphologies for tactoids formed via nucleation and growth within an initially isotropic phase exposed to a gradient of depletants. The simultaneous appearance is shown of rich LC structures along the depleting potential gradient, where the position of each LC structure is correlated with the magnitude of the depleting potential. Changing the size (nanoparticles) or the nature (polymers) of the depleting agent provides additional, precise control over the resulting LC structures through a size-selective mechanism, where the depletant may be found both within and outside the LC droplets. The use of depletion gradients from depletants of varying sizes and nature offers a powerful toolbox for manipulation, templating, imaging, and understanding heterogeneous colloidal LC structures.
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Affiliation(s)
- Dongdong Lin
- School of Physical Science and Technology, Ningbo University, 818 Fenghua Road, Ningbo, 315211, P. R. China
- ETH Zurich, Department of Health Sciences & Technology, Schmelzbergstrasse 9, Zurich, 8092, Switzerland
- Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, 818 Fenghua Road, Ningbo, 315211, P. R. China
| | - Massimo Bagnani
- ETH Zurich, Department of Health Sciences & Technology, Schmelzbergstrasse 9, Zurich, 8092, Switzerland
| | - Hamed Almohammadi
- ETH Zurich, Department of Health Sciences & Technology, Schmelzbergstrasse 9, Zurich, 8092, Switzerland
| | - Ye Yuan
- ETH Zurich, Department of Health Sciences & Technology, Schmelzbergstrasse 9, Zurich, 8092, Switzerland
| | - Yufen Zhao
- Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, 818 Fenghua Road, Ningbo, 315211, P. R. China
| | - Raffaele Mezzenga
- ETH Zurich, Department of Health Sciences & Technology, Schmelzbergstrasse 9, Zurich, 8092, Switzerland
- ETH Zurich, Department of Materials, Zurich, 8093, Switzerland
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2
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Jin T, Yuan Y, Bagnani M, Wu C, Liu B, Mezzenga R. Structural Colors from Amyloid-Based Liquid Crystals. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2308437. [PMID: 37804231 DOI: 10.1002/adma.202308437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Revised: 10/01/2023] [Indexed: 10/09/2023]
Abstract
The helical periodicity and layered structure in cholesteric liquid crystals (CLCs) may be tuned to generate structural color according to the Bragg's law of diffraction. A wide range of natural-based materials such as condensed DNA, collagen, chitin, cellulose, and chiral biopolymers exhibit cholesteric phases with left-handed helixes and ensued structural colors. Here, the possibility of using amyloid CLCs is reported to prepare films with iridescent color reflection and opposite handedness. Right-handed CLCs assembled by left-handed amyloid fibrils are dried into layered structures with variable pitch controlled by the addition of glucose. Circularly polarized light with the same handedness of amyloid CLCs helix is reflected in the Bragg regime. Varying the drying speed leads to the switching between films with a rainbow-like color gradient and large area uniform color. It is confirmed that the origin of the colors derives from the layered structures of the amyloid CLCs, given the negligeable birefringence of the films, calculated from optical rotatory dispersion. These findings provide a facile approach to constructing biosourced cholesteric materials and introduce an original class of proteinaceous materials for the generation of structural colors from right-handed circularly polarized light.
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Affiliation(s)
- Tonghui Jin
- Department of Health Sciences and Technology, ETH Zürich, Zürich, 8092, Switzerland
| | - Ye Yuan
- Department of Health Sciences and Technology, ETH Zürich, Zürich, 8092, Switzerland
| | - Massimo Bagnani
- Department of Health Sciences and Technology, ETH Zürich, Zürich, 8092, Switzerland
| | - Chao Wu
- Department of Health Sciences and Technology, ETH Zürich, Zürich, 8092, Switzerland
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, 116034, China
| | - Bin Liu
- Department of Nutrition and Health, China Agricultural University, Beijing, 100091, P. R. China
- Key Laboratory of Precision Nutrition and Food Quality, Research Center of Food Colloids and Delivery of Functionality, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, P. R. China
| | - Raffaele Mezzenga
- Department of Health Sciences and Technology, ETH Zürich, Zürich, 8092, Switzerland
- Department of Materials, ETH Zürich, Wolfgang-Pauli-Strasse 10, Zürich, 8093, Switzerland
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3
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Ackroyd AJ, De Paolis A, Xu YT, Momeni A, Hamad WY, MacLachlan MJ. Self-assembly of cellulose nanocrystals confined to square capillaries. NANOSCALE 2023; 15:14388-14398. [PMID: 37609826 DOI: 10.1039/d3nr02650g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Biological systems exploit restricted degrees of freedom to drive self-assembly of nano- and microarchitectures. Simplified systems, such as colloidal nanoparticles that behave as lyotropic liquid crystalline mesophases in confined geometric spaces, may be used to mimic biological structures. Cellulose nanocrystals (CNCs) are colloidally stable nanoparticles that self-assemble into chiral nematic (ChN) liquid crystalline mesophases. To date, the self-assembly of ChN mesophases of CNCs has been studied under confinement conditions within curved surfaces or under drying conditions that impose curvatures that can be exploited to control ChN ordering; however, their self-assembly has not been investigated in geometries with square cross-sections under static conditions. Here, we show that because of surface anchoring on perpendicular surfaces, the ChN CNC phase is unable to bend with the 90° angle of the square capillary under increasing confinement. Instead, the ChN phase forms radial layers in the shape of concentric squircle shells. With increasing layer distance from the capillary wall, the squircles transition into concentric cylinder shells. In larger capillaries, the radial shell layers appear as a continuous spiral pattern that engulfs fragmented ChN pseudolayers, a defect to accommodate the cylindrical confinement of the mesophase. These results are useful for understanding the fundamentals of self-assembling systems and development of new technologies.
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Affiliation(s)
- Amanda J Ackroyd
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
| | - Adam De Paolis
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
| | - Yi-Tao Xu
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
| | - Arash Momeni
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
| | - Wadood Y Hamad
- Transformation and Interfaces Group, Bioproducts Innovation Centre of Excellence, FPInnovations, 2665 East Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Mark J MacLachlan
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
- Stewart Blusson Quantum Matter Institute, 2355 East Mall, Vancouver, British Columbia V6T 1Z4, Canada
- WPI Nano Life Science Institute, Kanazawa University, Kanazawa, 920-1192, Japan
- UBC BioProducts Institute, 2385 East Mall, Vancouver, British Columbia V6T 1Z4, Canada
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4
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Joynul Abedin M, van der Schoot P, Garnier G, Majumder M. Nematic to Cholesteric Transformation in the Cellulose Nanocrystal Droplet Phase. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:6142-6150. [PMID: 37022793 DOI: 10.1021/acs.langmuir.3c00284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Nucleation, growth, and transformation of chirality in nanomaterial systems is a growing research topic with broad interest in tunable and configurable chiroptical materials. Similar to other one-dimensional nanomaterials, cellulose nanocrystals (CNCs), which are nanorods of naturally abundant biopolymer cellulose, display chiral or cholesteric liquid crystal (LC) phases in the form of tactoids. However, the nucleation and growth of the cholesteric CNC tactoids to equilibrium chiral structures and their morphological transformations are yet to be critically assessed. We noticed that the onset of liquid crystal formation in CNC suspensions is characterized by the nucleation of a nematic tactoid that grows in volume and spontaneously transforms into a cholesteric tactoid. The cholesteric tactoids merge with the neighboring tactoids to form bulk cholesteric mesophases with various configurational palettes. We applied scaling laws from the energy functional theory and found suitable agreement with the morphological transformation of the tactoid droplets monitored for their fine structure and orientation by quantitative polarized light imaging.
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Affiliation(s)
- Md Joynul Abedin
- Nanoscale Science and Engineering Laboratory (NSEL), Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Paul van der Schoot
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Gil Garnier
- Bioresource Processing Research Institute of Australia (BioPRIA), Department of Chemical & Biological Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Mainak Majumder
- Nanoscale Science and Engineering Laboratory (NSEL), Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia
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Azzari P, Mezzenga R. LLPS vs. LLCPS: analogies and differences. SOFT MATTER 2023; 19:1873-1881. [PMID: 36806460 PMCID: PMC9993225 DOI: 10.1039/d2sm01455f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
We compare the process of Liquid-Liquid Phase Separation (LLPS) of flexible macromolecular solutions, with the Liquid-Liquid Crystalline Phase Separation (LLCPS) of semiflexible polymers and rigid filamentous colloids, which involves the formation of a liquid phase that possesses a directional alignment. Although the observed phase separation follows a similar dynamic path, namely nucleation and growth or spinodal decomposition separating two phases of dilute and concentrated compositions, the underlying physics that defines the theoretical framework of LLCPS is completely different from the one of LLPS. We review the main theories that describe the phase separation processes and relying on thermodynamics and dynamical arguments, we highlight the differences and analogies between these two phase separation phenomena, attempting to clarify the inner mechanisms that regulate those two processes. A particular focus is given to metastable phases, as these intermediate states represent a key element in understanding how phase separation works.
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Affiliation(s)
- Paride Azzari
- Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland.
| | - Raffaele Mezzenga
- Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland.
- Department of Materials, ETH Zürich, Wolfgang Pauli Strasse 10, 8093 Zurich, Switzerland
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6
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Almohammadi H, Fu Y, Mezzenga R. Evaporation-Driven Liquid-Liquid Crystalline Phase Separation in Droplets of Anisotropic Colloids. ACS NANO 2023; 17:3098-3106. [PMID: 36719319 DOI: 10.1021/acsnano.2c12065] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Drying a colloidal droplet involves complex physics that is often accompanied by evaporation-induced concentration gradients inside of the droplet, offering a platform for fundamental and technological opportunities, including self-assembly, thin film deposition, microfabrication, and DNA stretching. Here, we investigate the drying, liquid crystalline structures, and deposit patterns of colloidal liquid crystalline droplets undergoing liquid-liquid crystalline phase separation (LLCPS) during evaporation. We show that evaporation-induced progressive up-concentration inside the drying droplets makes it possible to cross, at different speeds, various thermodynamic stability states in solutions of amyloid fibril rigid filamentous colloids, thus allowing access to both metastable states, where phase separation occurs via nucleation and growth, as well as to unstable states, where phase separation occurs via the more elusive spinodal decomposition, leading to the formation of liquid crystalline microdroplets (or tactoids) of different shapes. We present the tactoids "phase diagram" as a function of the position within the droplet and elucidate their hydrodynamics. Furthermore, we demonstrate that the presence of the amyloid fibrils not only does not enhance the pinning behavior during droplet evaporation but also slightly suppresses it, thus minimizing the coffee-ring effect. We observed that microsize domains with cholesteric structure emerge in the drying droplet close to the droplet's initial edge, yet such domains are not connected to form a uniform cholesteric dried film. Finally, we demonstrate that a fully cholesteric dried layer can be generated from the drying droplets by regulating the kinetics of the evaporation process.
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Affiliation(s)
- Hamed Almohammadi
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Yutong Fu
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Raffaele Mezzenga
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
- Department of Materials, ETH Zurich, 8092 Zurich, Switzerland
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7
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Žganec M, Taler Verčič A, Muševič I, Škarabot M, Žerovnik E. Amyloid Fibrils of Stefin B Show Anisotropic Properties. Int J Mol Sci 2023; 24:ijms24043737. [PMID: 36835149 PMCID: PMC9962164 DOI: 10.3390/ijms24043737] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 01/30/2023] [Accepted: 02/11/2023] [Indexed: 02/16/2023] Open
Abstract
Human stefin B, a member of the cystatin family of cysteine protease inhibitors, tends to form amyloid fibrils under relatively mild conditions, which is why it is used as a model protein to study amyloid fibrillation. Here, we show for the first time that bundles of amyloid fibrils, i.e., helically twisted ribbons, formed by human stefin B exhibit birefringence. This physical property is commonly observed in amyloid fibrils when stained with Congo red. However, we show that the fibrils arrange in regular anisotropic arrays and no staining is required. They share this property with anisotropic protein crystals, structured protein arrays such as tubulin and myosin, and other anisotropic elongated materials, such as textile fibres and liquid crystals. In certain macroscopic arrangements of amyloid fibrils, not only birefringence is observed, but also enhanced emission of intrinsic fluorescence, implying a possibility to detect amyloid fibrils with no labels by using optical microscopy. In our case, no enhancement of intrinsic tyrosine fluorescence was observed at 303 nm; instead, an additional fluorescence emission peak appeared at 425 to 430 nm. We believe that both phenomena, birefringence and fluorescence emission in the deep blue, should be further explored with this and other amyloidogenic proteins. This may allow the development of label-free detection methods for amyloid fibrils of different origins.
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Affiliation(s)
- Matjaž Žganec
- Department of Biochemistry and Molecular and Structural Biology, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
| | - Ajda Taler Verčič
- Department of Biochemistry and Molecular and Structural Biology, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
- Jožef Stefan International Postgraduate School, Jamova 39, 1000 Ljubljana, Slovenia
- Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia
| | - Igor Muševič
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
- Department of Condensed Matter Physics, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
| | - Miha Škarabot
- Department of Condensed Matter Physics, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
| | - Eva Žerovnik
- Department of Biochemistry and Molecular and Structural Biology, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
- Jožef Stefan International Postgraduate School, Jamova 39, 1000 Ljubljana, Slovenia
- Correspondence:
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8
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Sun Q, Lutz-Bueno V, Zhou J, Yuan Y, Fischer P. Polymer induced liquid crystal phase behavior of cellulose nanocrystal dispersions. NANOSCALE ADVANCES 2022; 4:4863-4870. [PMID: 36381514 PMCID: PMC9642361 DOI: 10.1039/d2na00303a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 10/02/2022] [Indexed: 06/16/2023]
Abstract
Cellulose nanocrystals (CNCs) are a promising bio-based material that has attracted significant attention in the fabrication of functional hybrid materials. The rod-like shape and negative surface charge of CNCs enable their rich colloidal behavior, such as a liquid crystalline phase and hydrogel formation that can be mediated by different additives. This study investigates the effect of depletion-induced attraction in the presence of non-absorbing polyethylene glycol (PEG) of different molecular weights in CNC aqueous dispersions, where the polymer molecules deplete the space around particles, apply osmotic pressure and drive the phase transition. Polarized light microscopy (PLM), rheology, small angle X-ray scattering (SAXS) and atomic force microscopy (AFM) are used to characterize the phase behavior over a time period of one month. In our results, pure CNC dispersion shows three typical liquid crystal shear rheology regimes and cholesteric self-assembly behavior. Tactoid nucleation, growth and coalescence are observed microscopically, and eventually the dispersion presents macroscopic phase separation. PEG with lower molecular weight induces weak attractive depletion forces. Tactoid growth is limited, and the whole system turns into a fully nematic phase macroscopically. With PEG of higher molecular weight, attractive depletion force becomes predominant, thus CNC self-assembly is inhibited and nematic hydrogel formation is triggered. Overall, we demonstrate that depletion induced attraction forces by the addition of PEG enable precise tuning of CNC self-assembly and phase behavior with controllable mechanical strength and optical activity. These findings deepen our fundamental understanding of cellulose nanocrystals and advance their application in colloidal systems and nanomaterials.
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Affiliation(s)
- Qiyao Sun
- Department of Health Science and Technology, ETH Zurich 8092 Zurich Switzerland +41 44 632 9710
| | - Viviane Lutz-Bueno
- Department of Health Science and Technology, ETH Zurich 8092 Zurich Switzerland +41 44 632 9710
- Paul Scherrer Institute 5232 Villigen PSI Switzerland
| | - Jiangtao Zhou
- Department of Health Science and Technology, ETH Zurich 8092 Zurich Switzerland +41 44 632 9710
| | - Ye Yuan
- Department of Health Science and Technology, ETH Zurich 8092 Zurich Switzerland +41 44 632 9710
| | - Peter Fischer
- Department of Health Science and Technology, ETH Zurich 8092 Zurich Switzerland +41 44 632 9710
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9
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Shape and structural relaxation of colloidal tactoids. Nat Commun 2022; 13:2778. [PMID: 35589676 PMCID: PMC9120485 DOI: 10.1038/s41467-022-30123-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 04/19/2022] [Indexed: 11/16/2022] Open
Abstract
Facile geometric-structural response of liquid crystalline colloids to external fields enables many technological advances. However, the relaxation mechanisms for liquid crystalline colloids under mobile boundaries remain still unexplored. Here, by combining experiments, numerical simulations and theory, we describe the shape and structural relaxation of colloidal liquid crystalline micro-droplets, called tactoids, where amyloid fibrils and cellulose nanocrystals are used as model systems. We show that tactoids shape relaxation bears a universal single exponential decay signature and derive an analytic expression to predict this out of equilibrium process, which is governed by liquid crystalline anisotropic and isotropic contributions. The tactoids structural relaxation shows fundamentally different paths, with first- and second-order exponential decays, depending on the existence of splay/bend/twist orientation structures in the ground state. Our findings offer a comprehensive understanding on dynamic confinement effects in liquid crystalline colloidal systems and may set unexplored directions in the development of novel responsive materials. Tactoids, consisting of micro-confined liquid crystalline colloids with self-selected shape, bear both fundamental and technological significance. The authors show that the shape relaxation of tactoids follows an exponential decay and develop a model to predict this out-of-the-equilibrium process.
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10
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Safdari M, Zandi R, van der Schoot P. Effect of electric fields on the director field and shape of nematic tactoids. Phys Rev E 2021; 103:062703. [PMID: 34271629 DOI: 10.1103/physreve.103.062703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 04/06/2021] [Indexed: 01/30/2023]
Abstract
Tactoids are spindle-shaped droplets of a uniaxial nematic phase suspended in the coexisting isotropic phase. They are found in dispersions of a wide variety of elongated colloidal particles, including actin, fd virus, carbon nanotubes, vanadium peroxide, and chitin nanocrystals. Recent experiments on tactoids of chitin nanocrystals in water show that electric fields can very strongly elongate tactoids even though the dielectric properties of the coexisting isotropic and nematic phases differ only subtly. We develop a model for partially bipolar tactoids, where the degree of bipolarness of the director field is free to adjust to optimize the sum of the elastic, surface, and Coulomb energies of the system. By means of a combination of a scaling analysis and a numerical study, we investigate the elongation and director field's behavior of the tactoids as a function of their size, the strength of the electric field, the surface tension, anchoring strength, the elastic constants, and the electric susceptibility anisotropy. We find that tactoids cannot elongate significantly due to an external electric field, unless the director field is bipolar or quasibipolar and somehow frozen in the field-free configuration. Presuming that this is the case, we find reasonable agreement with experimental data.
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Affiliation(s)
- Mohammadamin Safdari
- Department of Physics, University of California, Riverside, California 92521, USA
| | - Roya Zandi
- Department of Physics, University of California, Riverside, California 92521, USA
| | - Paul van der Schoot
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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11
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Azzari P, Bagnani M, Mezzenga R. Liquid-liquid crystalline phase separation in biological filamentous colloids: nucleation, growth and order-order transitions of cholesteric tactoids. SOFT MATTER 2021; 17:6627-6636. [PMID: 34143859 PMCID: PMC8279111 DOI: 10.1039/d1sm00466b] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 05/28/2021] [Indexed: 05/19/2023]
Abstract
The process of liquid-liquid crystalline phase separation (LLCPS) in filamentous colloids is at the very core of multiple biological, physical and technological processes of broad significance. However, the complete theoretical understanding of the process is still missing. LLCPS involves the nucleation, growth and up-concentration of anisotropic droplets from a continuous isotropic phase, until a state of equilibrium is reached. Herein, by combining the thermodynamic extremum principle with the Onsager theory, we describe the nucleation and growth of liquid crystalline droplets, and the evolution of their size and concentration during phase separation, eventually leading to a multitude of order-order phase transitions. Furthermore, a decreasing pitch behaviour can be predicted using this combined theory during tactoid growth, already observed experimentally but not yet explained by present theories. The results of this study are compared with the experimental data of cholesteric pitch, observed in three different systems of biological chiral liquid crystals. These findings give an important framework for predicting the formation, growth and phase behaviour of biological filamentous colloids undergoing LLCPS, advancing our understanding of liquid-liquid phase separation and self-assembly mechanisms in biological systems, and provide a valuable rationale for developing nanomaterials and applications in nanotechnology.
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Affiliation(s)
- Paride Azzari
- Department of Health Sciences and Technology, ETH Zürich, 8092 Zürich, Switzerland.
| | - Massimo Bagnani
- Department of Health Sciences and Technology, ETH Zürich, 8092 Zürich, Switzerland.
| | - Raffaele Mezzenga
- Department of Health Sciences and Technology, ETH Zürich, 8092 Zürich, Switzerland. and Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
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12
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Bagnani M, Azzari P, De Michele C, Arcari M, Mezzenga R. Elastic constants of biological filamentous colloids: estimation and implications on nematic and cholesteric tactoid morphologies. SOFT MATTER 2021; 17:2158-2169. [PMID: 33443281 DOI: 10.1039/d0sm01886d] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Biological liquid crystals, originating from the self-assembly of biological filamentous colloids, such as cellulose and amyloid fibrils, show a complex lyotropic behaviour that is extremely difficult to predict and characterize. Here we analyse the liquid crystalline phases of amyloid fibrils, and sulfated and carboxylated cellulose nanocrystals and measure their Frank-Oseen elastic constants K1, K2 and K3 by four different approaches. The first two approaches are based on the benchmark of the predictions of: (i) a scaling form and (ii) a variational form of the Frank-Oseen energy functional with the experimental critical volumes at order-order liquid crystalline transitions of the tactoids. The third and the fourth methods imply: (iii) the direct scaling equations of elastic constants and (iv) a molecular theory predicting the elastic constants from the experimentally accessible contour length distributions of the filamentous colloids. These three biological systems exhibit diverse liquid crystalline behaviour, governed by the distinct elastic constants characterizing each colloid. Differences and similarities among the three systems are highlighted and interpreted based on the present analysis, providing a general framework to study dispersed liquid crystalline systems.
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Affiliation(s)
- Massimo Bagnani
- ETH Zurich, Department of Health Sciences and Technology, Schmelzbergstrasse 9, LFO E23 Zurich 8092, Switzerland
| | - Paride Azzari
- ETH Zurich, Department of Health Sciences and Technology, Schmelzbergstrasse 9, LFO E23 Zurich 8092, Switzerland
| | - Cristiano De Michele
- "Sapienza" Universita' di Roma, Dipartimento di Fisica, P.le A. Moro 2, 00185 Roma, Italy
| | - Mario Arcari
- ETH Zurich, Department of Health Sciences and Technology, Schmelzbergstrasse 9, LFO E23 Zurich 8092, Switzerland
| | - Raffaele Mezzenga
- ETH Zurich, Department of Health Sciences and Technology, Schmelzbergstrasse 9, LFO E23 Zurich 8092, Switzerland and ETH Zurich, Department of Materials, Wolfgang-Pauli-Strasse 10, Zurich 8093, Switzerland.
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13
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Khadem SA, Rey AD. Nucleation and growth of cholesteric collagen tactoids: A time-series statistical analysis based on integration of direct numerical simulation (DNS) and long short-term memory recurrent neural network (LSTM-RNN). J Colloid Interface Sci 2021; 582:859-873. [DOI: 10.1016/j.jcis.2020.08.052] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 07/13/2020] [Accepted: 08/13/2020] [Indexed: 12/12/2022]
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14
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Almohammadi H, Bagnani M, Mezzenga R. Flow-induced order-order transitions in amyloid fibril liquid crystalline tactoids. Nat Commun 2020; 11:5416. [PMID: 33110064 PMCID: PMC7591495 DOI: 10.1038/s41467-020-19213-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 09/25/2020] [Indexed: 11/15/2022] Open
Abstract
Liquid crystalline droplets, also known as tactoids, forming by nucleation and growth within the phase diagram region where isotropic and nematic phases coexist, challenge our understanding of liquid crystals under confinement due to anisotropic surface boundaries at vanishingly small interfacial tension, resulting in complex, non-spherical shapes. Little is known about their dynamical properties, since they are mostly studied under quiescent, quasi-equilibrium conditions. Here we show that different classes of amyloid based nematic and cholesteric tactoids undergo order–order transitions by flow-induced deformations of their shape. Tactoids align under extensional flow, undergoing extreme deformation into highly elongated prolate shapes, with the cholesteric pitch decreasing as an inverse power-law of the tactoids aspect ratio. Free energy functional theory and experimental measurements are combined to rationalize the critical elongation above which the director-field configuration of tactoids transforms from bipolar and uniaxial cholesteric to homogenous and to debate on the thermodynamic nature of these transitions. Tactoids are liquid crystal droplets with nearly vanishing interfacial tension. Almohammadi et al. show using a microfluidic focusing device how to manipulate them gently enough to facilitate the study of amyloid liquid crystal phase transitions subject to non-equilibirum forcing and shape changes.
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Affiliation(s)
- Hamed Almohammadi
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Massimo Bagnani
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Raffaele Mezzenga
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland. .,Department of Materials, ETH Zurich, Zurich, Switzerland.
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15
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Khadem SA, Bagnani M, Mezzenga R, Rey AD. Relaxation dynamics in bio-colloidal cholesteric liquid crystals confined to cylindrical geometry. Nat Commun 2020; 11:4616. [PMID: 32934229 PMCID: PMC7493995 DOI: 10.1038/s41467-020-18421-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 08/12/2020] [Indexed: 12/22/2022] Open
Abstract
Para-nematic phases, induced by unwinding chiral helices, spontaneously relax to a chiral ground state through phase ordering dynamics that are of great interest and crucial for applications such as stimuli-responsive and biomimetic engineering. In this work, we characterize the cholesteric phase relaxation behaviors of β-lactoglobulin amyloid fibrils and cellulose nanocrystals confined into cylindrical capillaries, uncovering two different equilibration pathways. The integration of experimental measurements and theoretical predictions reveals the starkly distinct underlying mechanism behind the relaxation dynamics of β-lactoglobulin amyloid fibrils, characterized by slow equilibration achieved through consecutive sigmoidal-like steps, and of cellulose nanocrystals, characterized by fast equilibration obtained through smooth relaxation dynamics. Particularly, the specific relaxation behaviors are shown to emerge from the order parameter of the unwound cholesteric medium, which depends on chirality and elasticity. The experimental findings are supported by direct numerical simulations, allowing to establish hard-to-measure viscoelastic properties without applying magnetic or electric fields.
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Affiliation(s)
- Sayyed Ahmad Khadem
- Department of Chemical Engineering, McGill University, Montreal, QC, H3A 2B2, Canada
- Quebec Centre for Advanced Materials, Canada (QCAM/CQMF), Montreal, QC, H3A 2K6, Canada
| | - Massimo Bagnani
- Department of Health Sciences and Technology, ETH Zurich, Schmelzbergstrasse 9, Zurich, 8092, Switzerland
| | - Raffaele Mezzenga
- Department of Health Sciences and Technology, ETH Zurich, Schmelzbergstrasse 9, Zurich, 8092, Switzerland
- Department of Materials, ETH Zurich, Wolfgang-Pauli-Strasse 10, Zurich, 8093, Switzerland
| | - Alejandro D Rey
- Department of Chemical Engineering, McGill University, Montreal, QC, H3A 2B2, Canada.
- Quebec Centre for Advanced Materials, Canada (QCAM/CQMF), Montreal, QC, H3A 2K6, Canada.
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16
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Sadati M, Martinez-Gonzalez JA, Zhou Y, Qazvini NT, Kurtenbach K, Li X, Bukusoglu E, Zhang R, Abbott NL, Hernandez-Ortiz JP, de Pablo JJ. Prolate and oblate chiral liquid crystal spheroids. SCIENCE ADVANCES 2020; 6:eaba6728. [PMID: 32832603 PMCID: PMC7439570 DOI: 10.1126/sciadv.aba6728] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 05/28/2020] [Indexed: 05/15/2023]
Abstract
Liquid crystals are known to exhibit intriguing textures and color patterns, with applications in display and optical technologies. This work focuses on chiral materials and examines the palette of morphologies that arises when microdroplets are deformed into nonspherical shapes in a controllable manner. Specifically, geometrical confinement and mechanical strain are used to manipulate orientational order, phase transitions, and topological defects that arise in chiral liquid crystal droplets. Inspired by processes encountered in nature, where insects and animals often rely on strain and temperature to alter the optical appearance of dispersed liquid crystalline elements, chiral droplets are dispersed in polymer films and deformation induced by uniaxial or biaxial stretching. Our measurements are interpreted by resorting to simulations of the corresponding systems, thereby providing an in-depth understanding of the morphologies that arise in these materials. The reported structures and assemblies offer potential for applications in smart coatings, smart fabrics, and wearable sensors.
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Affiliation(s)
- Monirosadat Sadati
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
- Department of Chemical Engineering, Swearingen Engineering Center, University of South Carolina, Columbia, SC 29208, USA
| | - Jose A. Martinez-Gonzalez
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
- Facultad de Ciencias, Universidad Autónoma de San Luis Potosí, Av. Parque Chapultepec 1570, San Luis Potosí 78295, SLP, México
| | - Ye Zhou
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Nader Taheri Qazvini
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
- Department of Chemical Engineering, Swearingen Engineering Center, University of South Carolina, Columbia, SC 29208, USA
| | - Khia Kurtenbach
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Xiao Li
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
- Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203, USA
| | - Emre Bukusoglu
- Chemical Engineering Department, Middle East Technical University, Ankara 06800, Turkey
| | - Rui Zhang
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Nicholas L. Abbott
- Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Juan Pablo Hernandez-Ortiz
- Departamento de Materiales y Minerales, Facultad de Minas, Universidad Nacional de Colombia, Sede Medellín, Calle 75 # 79A-51, Bloque M17, Medellín, Colombia
| | - Juan J. de Pablo
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
- Argonne National Laboratory, 9700 Cass Avenue, Lemont, IL 60439, USA
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17
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Li X, Sánchez-Ferrer A, Bagnani M, Adamcik J, Azzari P, Hao J, Song A, Liu H, Mezzenga R. Metal ions confinement defines the architecture of G-quartet, G-quadruplex fibrils and their assembly into nematic tactoids. Proc Natl Acad Sci U S A 2020; 117:9832-9839. [PMID: 32317383 PMCID: PMC7211958 DOI: 10.1073/pnas.1919777117] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
G-quadruplex, assembled from a square array of guanine (G) molecules, is an important structure with crucial biological roles in vivo but also a versatile template for ordered functional materials. Although the understanding of G-quadruplex structures is the focus of numerous studies, little is known regarding the control of G-quartet stacking modes and the spontaneous orientation of G-quadruplex fibrils. Here, the effects of different metal ions and their concentrations on stacking modes of G-quartets are elucidated. Monovalent cations (typically K+) facilitate the formation of G-quadruplex hydrogels with both heteropolar and homopolar stacking modes, showing weak mechanical strength. In contrast, divalent metal ions (Ca2+, Sr2+, and Ba2+) at given concentrations can control G-quartet stacking modes and increase the mechanical rigidity of the resulting hydrogels through ionic bridge effects between divalent ions and borate. We show that for Ca2+ and Ba2+ at suitable concentrations, the assembly of G-quadruplexes results in the establishment of a mesoscopic chirality of the fibrils with a regular left-handed twist. Finally, we report the discovery of nematic tactoids self-assembled from G-quadruplex fibrils characterized by homeotropic fibril alignment with respect to the interface. We use the Frank-Oseen elastic energy and the Rapini-Papoular anisotropic surface energy to rationalize two different configurations of the tactoids. These results deepen our understanding of G-quadruplex structures and G-quadruplex fibrils, paving the way for their use in self-assembly and biomaterials.
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Affiliation(s)
- Xiaoyang Li
- Key Laboratory of Colloid and Interface Chemistry, Shandong University, Jinan, Shandong 250100, China
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, China
- Department of Health Sciences and Technology, ETH Zürich, 8092 Zürich, Switzerland
| | | | - Massimo Bagnani
- Department of Health Sciences and Technology, ETH Zürich, 8092 Zürich, Switzerland
| | - Jozef Adamcik
- Department of Health Sciences and Technology, ETH Zürich, 8092 Zürich, Switzerland
| | - Paride Azzari
- Department of Health Sciences and Technology, ETH Zürich, 8092 Zürich, Switzerland
| | - Jingcheng Hao
- Key Laboratory of Colloid and Interface Chemistry, Shandong University, Jinan, Shandong 250100, China;
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, China
| | - Aixin Song
- Key Laboratory of Colloid and Interface Chemistry, Shandong University, Jinan, Shandong 250100, China
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, China
| | - Hongguo Liu
- Key Laboratory of Colloid and Interface Chemistry, Shandong University, Jinan, Shandong 250100, China
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, China
| | - Raffaele Mezzenga
- Department of Health Sciences and Technology, ETH Zürich, 8092 Zürich, Switzerland;
- Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
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