Thermodynamically controlled multiphase separation of heterogeneous liquid crystal colloids

Abstract

Phase separation is a universal physical transition process whereby a homogeneous mixture splits into two distinct compartments that are driven by the component activity, elasticity, or compositions. In the current work, we develop a series of heterogeneous colloidal suspensions that exhibit both liquid-liquid phase separation of semiflexible binary polymers and liquid crystal phase separation of rigid, rod-like nanocellulose particles. The phase behavior of the multicomponent mixture is controlled by the trade-off between thermodynamics and kinetics during the two transition processes, displaying cholesteric self-assembly of nanocellulose within or across the compartmented aqueous phases. Upon thermodynamic control, two-, three-, and four-phase coexistence behaviors with rich liquid crystal stackings are realized. Among which, each relevant multiphase separation kinetics shows fundamentally different paths governed by nucleation and growth of polymer droplets and nanocellulose tactoids. Furthermore, a coupled multiphase transition can be realized by tuning the composition and the equilibrium temperature, which results in thermotropic behavior of polymers within a lyotropic liquid crystal matrix. Finally, upon drying, the multicomponent mixture undergoes a hierarchical self-assembly of nanocellulose and polymers into stratified cholesteric films, exhibiting compartmentalized polymer distribution and anisotropic microporous structure.

Self-assembly of stabilized droplets from liquid–liquid phase separation for higher-order structures and functions

“…Liquid-liquid crystalline phase separation LLPS and liquid crystalline (LC) ordering occur together in Nature; however, we are only beginning to understand the connections between LLPS and LC ordering and use synthetic systems to mimic these processes 110 . In an illustrative example, self-assembly of cellulose nanocrystals in PEG/dextran two phases system leads to multiphase separation, generating overlapping behaviors of LLPS and LC termed liquid-liquid crystal phase separation (LLCPS) 111 . Excitingly, it has been shown that LCs give rise to enhanced functionality of LLPS droplets 85 (Fig.…”

Coaxial 3D Bioprinting Process Research and Performance Tests on Vascular Scaffolds

“…Patients transplanted with these blood vessels need to take long-term medication to prevent blood coagulation and the formation of blood clots and are also prone to endothelial hyperplasia at the junction of small-diameter blood vessel grafts, which can lead to vascular occlusion [6][7][8]. Conventional methods for artificial vascular construction include vacuum freeze-drying [9,10], thermotropic phase separation [10][11][12][13][14][15], and electrostatic spinning [16][17][18].…”

Modulation of Tannic Acid on the Cholesteric Structure of Cellulose Nanocrystals

“…34 Polyanions, such as sodium polyacrylate (PAAS) 35 and poly[3-(potassium-4-butanoate) thiophene-2,5diyl] (PPBT), 36 decrease the pitch of the CNC liquid crystal phase. On the other hand, additives like polyvinyl alcohol (PVA), 37 Pluronic F127, 38 dextran, 39 xyloglucan, 40 gum arabic, 41 poly(ethylene glycol) (PEG), 39,42 and poly-(vinylpyrrolidone) (PVP) 43 affect phase separation through adsorption or depletion. They can induce changes in the anisotropic volume fraction and cholesteric pitch of the CNC suspension.…”