Article
Polymer Science
Mo Yang, Swapnil L. Sonawane, Zachary A. Digby, Jin G. Park, Joseph B. Schlenoff
Summary: Various types of specific interactions, including hydrophobicity, supplement the major entropic driving forces responsible for liquid-liquid phase separations in mixtures of oppositely charged polyelectrolytes. This study focused on the effects of hydrophobicity on the stability, salt concentration, and properties of polyelectrolyte complexes (PECs). It was found that the length of alkane chains in the PECs influenced their stability, salt concentration, and properties, with longer chains leading to easier doping and lower critical salt concentration for dissolution.
Article
Chemistry, Physical
Larissa van Westerveld, Julien Es Sayed, Marijn de Graaf, Anton H. Hofman, Marleen Kamperman, Daniele Parisi
Summary: The rheology of complex coacervates can be finely tuned by manipulating specific non-covalent hydrophobic interactions between the polymer chains. This study introduces a method to control the hydrophobicity of the polymer chains in complex coacervates, allowing for the prediction of rheology and the optimization of aqueous pressure-sensitive adhesive (PSA) systems.
Article
Chemistry, Physical
Sai Vineeth Bobbili, Scott T. Milner
Summary: The study investigates the phase separation phenomenon of oppositely charged polyelectrolytes mixing in aqueous solutions, leading to the formation of coacervates. An idealized model and simple simulation technique are proposed to explore the phase behavior of coacervates. Experimental observations and simulations demonstrate the effects of charge density, chain length, and added salt on coacervate systems, providing insights into their behavior.
Article
Biochemistry & Molecular Biology
Meng Li, Razieh Mirshafian, Jining Wang, Harini Mohanram, Kollbe Ando Ahn, Shayan Hosseinzadeh, Konstantin V. Pervushin, J. Herbert Waite, Jing Yu
Summary: Polyelectrolyte coacervates play a crucial role in the formation of load-bearing macromolecular materials in living organisms and industrial material fabrication. However, the study of their useful attributes is challenging due to the metastability of coacervate colloidal droplets and the lack of suitable analytical methods. By using solution electrochemistry and nuclear magnetic resonance measurements, it is found that coacervates can act as solvent media for low-molecular-weight catechols. Catechols preferentially partition into the coacervate phase and the coacervates stabilize catechol redox potentials, suggesting their potential for isolating redox-unstable chemicals.
Article
Polymer Science
Pengfei Zhang, Zhen-Gang Wang
Summary: We have developed a simple theory to study the interfacial structure and tension of polyelectrolyte complex coacervates. The interfacial tension was found to decrease with increasing stoichiometric asymmetry, added-salt concentration, and initial polymer concentration.
Article
Polymer Science
Xiangxi Meng, Yifeng Du, Yalin Liu, E. Bryan Coughlin, Sarah L. Perry, Jessica D. Schiffman
Summary: This study demonstrates for the first time that linear, nonentangled oligomeric polyelectrolytes can be electrospun into fibers. By using the complex coacervation phenomenon, the electrospinning efficiency was significantly improved compared to traditional studies investigating polymer solution parameters.
Article
Polymer Science
Philipp Schroeder, Monika Schoenhoff, Cornelia Cramer
Summary: Complex coacervates of chitosan and gum arabic, two naturally abundant weak polyelectrolytes, were studied using oscillatory shear rheology. The results showed that the shear moduli scaled with temperature, salt concentration, and pH, indicating the applicability of time-temperature superposition (TTSP), time-salt superposition (TSSP), and time-pH superposition (TpHSP). However, a breakdown of superposition occurred in the low-frequency regime at high salt concentrations and pH values near the pK (a) of chitosan. This breakdown was attributed to gelation, likely due to the associative interaction of chitosan chains and the formation of a chitosan network.
Article
Food Science & Technology
Rima Soussi Hachfi, Marie-Helene Famelart, Florence Rousseau, Pascaline Hamon, Said Bouhallab
Summary: Heteroprotein complex coacervation between lactoferrin and beta-lactoglobulin resulted in the formation of highly viscous coacervates, displaying liquid-like behavior. These coacervates could have potential applications as texturizing agents in food matrices.
LWT-FOOD SCIENCE AND TECHNOLOGY
(2022)
Review
Chemistry, Physical
Jenna K. A. Tom, Ashok A. Deniz
Summary: This article focuses on the roles of phase transitions and coacervates in natural and synthetic soft matter, with particular emphasis on dynamic cellular compartmentalization. It covers topics such as flexibility and conformational dynamics of polymeric species, noise modulation and feedback loops, and multicomponent systems. The fundamental concepts discussed have wide applicability in cellular function and material development.
CURRENT OPINION IN COLLOID & INTERFACE SCIENCE
(2021)
Article
Chemistry, Physical
Christopher Balzer, Pengfei Zhang, Zhen-Gang Wang
Summary: The wetting behavior of complex coacervates on solid surfaces was studied. It was found that the coacervate can wet the surface via a first order wetting transition and applying an electrostatic potential can improve the wettability. However, for asymmetric surface affinity, the wettability has a nonmonotonic dependence on the applied potential.
Article
Polymer Science
Sojeong Kim, Won Bo Lee, Nicolas R. de Souza, Soo-Hyung Choi
Summary: The segmental dynamics of complex coacervates were studied using quasi-elastic neutron scattering. It was found that the number of mobile chain segments and their dynamics increase with salt concentration in ammonium-based coacervates, whereas guanidinium-based coacervates show slow and comparable segmental relaxation regardless of salt concentration, possibly due to non-electrostatic interactions. The combination of chemical structure, salt concentration, and temperature plays a significant role in determining polymer chain dynamics influenced by the strength of ionic bonding.
Article
Polymer Science
Artem M. Rumyantsev, Oleg V. Borisov, Juan J. de Pablo
Summary: We develop a scaling theory to describe the structure and dynamics of hybrid complex coacervates formed by linear polyelectrolytes (PEs) and oppositely charged colloids. The internal structure of these coacervates is determined by the adsorption strength and the ratio of shell thickness to colloid radius. The coacervates exhibit different regimes depending on the charge and radius of the colloids. The hybrid coacervates have higher average density and lower surface tension compared to their PE-PE counterparts.
Article
Polymer Science
Andrey Subbotin, Alexander N. Semenov
Summary: The study investigates the equilibrium structure of polyelectrolyte (PE) complex coacervates and homogeneous multilayers formed by polycations and polyanions in a poor solvent using a mean-field approach. It is found that interfacial tension between coexisting uniform PE phases vanishes at a certain line, allowing both phases to remain stable with distinct compositions and charges. The exponential growth rate of uniform multilayer thickness is predicted to increase with solution ionic strength.
Article
Chemistry, Physical
Zuzanna M. Jedlinska, Robert A. Riggleman
Summary: The coacervation of charged polymer chains is an important area of research in both polymer and biological sciences, as it is a subset of liquid-liquid phase separation (LLPS). LLPS plays a crucial role in cellular homeostasis and has potential for therapeutical applications. Recent studies have shown that LLPS is not driven by a simple mechanism, but by various weak interactions. This study investigates the effects of monomer polarizability and spatially varying dielectric constant on LLPS propensity and its resulting properties.
Article
Chemistry, Physical
Nanako Sakakibara, Tomoto Ura, Tsutomu Mikawa, Hiroka Sugai, Kentaro Shiraki
Summary: Complex coacervates are receiving increasing attention as simplified models of membrane-less organelles and microcapsule platforms. The incorporation of proteins into complex coacervates is crucial for understanding membrane-less organelles in cells and controlling microcapsules. This study investigated the incorporation process of client proteins into complex coacervates and discovered the primary driving force to be electrostatic factors. The formation of multi-phase droplets and the understanding of temporal changes at the droplet interface provide valuable insights for the development of microcapsules and understanding biological events associated with membrane-less organelles.