Liquid Phase Behavior Research Articles

Liquid-liquid phase behavior for water + 2,2-difluoroethanol with three imidazole-based ionic liquids

2,2-difluoroethanol (DFE) is a significant fine chemical in chemical industry. During its applications, an aqueous solution is often observed. Because DFE and water will form azeotropic mixture, it is infeasible to regenerate DFE from the mixture (DFE + water) by general distillation. In this research, for regenerating 2,2-difluoroethanol from its aqueous mixture by extraction, three hydrophobic imidazole-based ionic liquids (ILs), 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Hmim][NTf2]), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Bmim][NTf2]) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][NTf2]) were picked as the extraction agents. The liquid–liquid phase behavior of the systems (water + DFE + ILs) were explored at 298.15 K and 101.3 kPa. The NRTL model was applied to regress the determined tie-line data. To assess the separating power of the three ionic liquids, selectivity (S) and distribution coefficient (D) for ILs were computed and compared. In addition, the σ-profiles, interaction energy, hydrogen bond length between the ionic liquids and (DFE/water) were computed to ascertain the interactions between the ILs and (DFE/water).

Coarse‐Grained Molecular Simulation of Polymers Supported by the Use of the SAFT‐γ$\gamma$ Mie Equation of State

AbstractA framework to self‐consistently combine a classical equation of state (EoS) and a molecular force field to model polymers and polymer mixtures is presented. The statistical associating fluid theory (SAFT‐ Mie) model is used to correlate the thermophysical properties of oligomers and generate robust and transferrable coarse‐grained (CG) molecular parameters which can be used both in particle based molecular simulations and in equations of state (EoS) calculations. Examples are provided for polyethylene, polypropylene, polyisobutylene atactic polystyrene, 1,4‐cis‐butadiene, polyisoprene, their blends and mixtures with low molecular weight solvents. Different types of liquid–liquid phase behavior are quantitatively captured both by the EoS and by direct molecular dynamics simulations. The use of CG models following this top‐down approach extends the time and length scales accessible to molecular simulation while retaining quantitative accuracy as compared to experimental results.

Does Explicit Polarizability Improve Simulations of Phase Behavior of Ionic Liquids?

Molecular dynamics simulations are performed for a test set of 20 aprotic ionic liquids to investigate whether including an explicit polarizability model in the force field leads to higher accuracy and reliability of the calculated phase behavior properties, especially the enthalpy of fusion. A classical nonpolarizable all-atom optimized potentials for liquid simulations (OPLS) force-field model developed by Canongia Lopes and Pádua (CL&P) serves as a reference level of theory. Polarizability is included either in the form of Drude oscillators, resulting in the CL&P-D models, or in the framework of the atomic multipole optimized energetics for biomolecular application (AMOEBA) force field with polarizable atomic sites. Benchmarking of the calculated fusion enthalpy values against the experimental data reveals that overall the nonpolarizable CL&P model and polarizable CL&P-D models perform similarly with average deviations of about 30%. However, fusion enthalpies from the CL&P-D models exhibit a stronger correlation with their experimental counterparts. The least successful predictions are interestingly obtained from AMOEBA (deviation ca. 60%), which may indicate that a reparametrization of this force-field model is needed to achieve improved predictions of the fusion enthalpy. In general, all FF models tend to underestimate the fusion enthalpies. In addition, quantum chemical calculations are used to compute the electronic cohesive energies of the crystalline phases of the ionic liquids and of the interaction energies within the ion pair. Significant positive correlations are found between the fusion enthalpy and the cohesive energies. The character of the present anions predetermines the magnitude of individual mechanistic components of the interaction energy and related enthalpic and cohesive properties.

Deep Eutectic Solvents and Pharmaceuticals

Deep eutectic solvents (DES) are eutectic mixtures that present a deviation from the ideal thermodynamic solid–liquid phase behavior, where a significant depression in the melting temperature occurs. If properly designed and chosen, DES may be liquid at room and the human body’s temperatures and display a biocompatible character, thus representing relevant options in the pharmaceutical field. Accordingly, DES have been studied as alternative solvents or in formulations of pharmaceuticals to improve their solubility and stability. Depending on the DES components, these mixtures might exhibit interesting biological activities compatible with several applications. The use of DES as functional agents or as novel liquid forms of active pharmaceutical ingredients (API-DES) with the goal of improving bioavailability, permeability and therapeutic efficacy of a given API stands as alternative strategies in the pharmaceutical field for drug delivery purposes.

Long-wavelength fluctuations and dimensionality crossover in confined liquids

The phase behavior of liquids confined in a slit geometry does not reveal a crossover from a three- to a two-dimensional behavior as the gap size decreases. Indeed, the prototypical two-dimensional hexatic phase only occurs in liquids confined to a monolayer. Here, we demonstrate that the dimensionality crossover is apparent in the lateral size dependence of the relaxation dynamics of confined liquids, developing a Debye model for the density of vibrational states of confined systems and performing extensive numerical simulations. In confined systems, Mermin-Wagner fluctuations enhance the amplitude of vibrational motion---or the Debye-Waller factor---by a quantity scaling as the inverse gap width and proportional to the logarithm of the aspect ratio, as a clear signature of a two-dimensional behavior. As the temperature or lateral system size increases, the crossover to a size-independent relaxation dynamics occurs when structural relaxation takes place before the vibrational modes with the longest wavelength develop.

Structure and Self-Assembly of Lytic Polysaccharide Monooxygenase-Oxidized Cellulose Nanocrystals

Cellulose-derived nanomaterial building blocks, including cellulose nanocrystals (CNCs), have become increasingly important in sustainable materials development. However, the preparation of CNCs requires hazardous chemicals to introduce surface charges that enable liquid crystalline phase behavior, a key parameter for obtaining self-organized, nanostructured materials from CNCs. Lytic polysaccharide monooxygenases (LPMOs), oxidative enzymes that introduce charged carboxyl groups on their cleavage sites in aqueous reaction conditions, offer an environmentally friendly alternative. In this work, two C1-oxidizing LPMOs from fungus Neurospora crassa, one of which contained a carbohydrate-binding module (CBM), were investigated for CNC preparation. The LPMO-oxidized CNCs shared similar features with chemical-derived CNCs, including colloidal stability and a needle-like morphology with typical dimensions of 7 ± 3 nm in width and 142 ± 57 nm in length for CBM-lacking LPMO-oxidized CNCs. The self-organization of the LPMO-oxidized CNCs was characterized in suspensions and solution cast films. Both LPMO-oxidized CNCs showed electrostatically driven self-organization in aqueous colloidal suspension and pseudo-chiral nematic ordering in solid films. The CBM-lacking LPMO generated a higher carboxyl content (0.70 mmol g–1), leading to a more uniform CNC self-organization, favoring LPMOs without CBMs for CNC production. The obtained results demonstrate production of stable colloidal CNCs with self-assembly by C1-oxidizing LPMOs toward a completely green production of advanced, nanostructured cellulose materials.

Effects of surface wettability on pool boiling process: Dynamic and thermal behaviors of dry spots and relevant critical heat flux triggering mechanism

In this paper, we investigate experimentally and numerically the influences of surface wettability on the boiling process from nucleate boiling to critical heat flux (CHF). The boiling surfaces with four different wettabilities (apparent contact angles) are examined. Using a simple optic setup, sequential phase distribution images on the boiling surfaces were acquired, and we analyzed the dynamics of microlayer, bulk liquid region, and dry spots with the processed images. The variation of surface wettability significantly affected the liquid and vapor phase behaviors on the boiling surface, such as the growth and shrinkage of the microlayer and dry spot, wetting velocity and area portion of the dry spot. As a result, the CHF increased with the surface wettability, and we found the CHF is triggered from a local dry spot where the liquid wets the spot no longer and is violently scattered by strong evaporation at the triple contact line. Our numerical simulation results, in which the three-dimensional transient heat diffusion equation was solved for the boiling substrate using the phase distribution images as boundary conditions, indicated that certain dry spots (critical dry spot) can be highly overheated under high heat flux condition, and they lead significant heat transfer degradation and, eventually, the CHF. With the numerical results and observation of the phase distribution images at the CHF conditions, we postulated the allowable wetting temperature and formulated it as a function of surface wettability through considering the balance between vapor recoil and surface tension forces. The wetting temperature increased with surface wettability, and it was confirmed by the numerical results. Finally, we proposed a qualitative relation to elucidate the influence of surface wettability on the CHF based on the heat conduction via the vapor on a critical dry spot and heat flux partitioning concept.

A theoretical extension applied to Pure Acids with Long Carbon Chain in Liquid Phase to analyse their behavior in Solid Phase

In this work, Peng-Robinson EOS (equation of state) was chosen to represent liquid phase behavior. Then, regarding the three acids, Lauric, Palmitic and Stearic, bulk modulus coefficients were calculated in three values of pressures (0.1, 1.0 and 2.0 GPa) and a range of temperature of 350-450 K. According to the literature, results for carbon dioxide, bulk modulus in the liquid phase is in the same line for the one in the solid phase considering the temperature dimension. Based on it, in this work, the bulk modulus was estimated at three temperatures for three acids in solid-phase by extrapolating the results in the liquid phase. Despite there are no experimental data available in the literature, these results seem to be consistent with the thermodynamic constraints, and useful discussions were provided.

Mesostructuring in Liquid-Liquid Extraction Organic Phases Originating from Critical Points.

Organic phase structure plays an important role in solute extraction energetics and phase behavior of liquid-liquid extraction (LLE) systems. For a binary extractant (amphiphile)/solvent mixture of relevance to LLE, we find that the organic phase mesostructuring is consistent with extractant concentration fluctuations as the compositional isotherm traverses the Widom line above its liquid-liquid critical point. This reveals a different mechanism for the well-documented heterogeneities in LLE organic phases that are typically attributed to micellization.

Ternary Liquid–Liquid Equilibrium for Phosphoric Acid Extraction from Aqueous Solutions with 1-Pentanol or Methyl Butyl Ketone at T = (298.2, 308.2, and 318.2) K

The tie-line values of the aqueous mixture (H2O + phosphoric acid + organic solvents) were checked at several temperatures and air pressures. Methyl butyl ketone or 1-pentanol was selected as the organic solvent. Solubility data were specified for an aqueous ternary mixture employing the cloud point measurements. All the ternary mixtures exhibit the type-1 liquid–liquid phase behavior system. Experimental data were determined employing the refractive index method, the Karl–Fischer technique, and acidimetric titration. Binary interaction parameters were predicted employing liquid–liquid equilibrium modeling. The NRTL and UNIQUAC models were employed to define which model is more reliable. The trustworthiness of the experiment outcome was approved by considering the Hand and Othmer-Tobias equations. Selectivity factors and distribution coefficients were derived to determine the solvents’ extraction capacity. The effect of temperature change was checked on the solubility curve and extraction process at different temperatures.

Electro-optical properties of a liquid crystalline colloidal solution of rod shaped V2O5 nanoparticles and carbon nanotubes in an alternating current electric field

ABSTRACT We study the liquid crystalline phase behaviour of the two-component aqueous colloidal suspensions of multiwalled carbon nanotubes (MWCNTs) and rod-like vanadium pentoxide (V2O5) nanoparticles. The phase diagram features a stable nematic phase in a wide range of concentration of solid components. The oriented nematic phase of the two-component suspension was exposed to the action of alternating current electric field. A variation in MWCNTs concentration within 0.01–0.51 wt.% demonstrates a significant increase in the optical response of the system to the applied electric field.

Comprehensive evaluation of the role of phenolate based ionic liquid on extracting pyrrole from diverse sources: A combined molecular dynamics simulation study and experiment validation

Ionic liquids have acted as a hopeful solvent in separation field over the past decade due to its functional groups contributed in separation process. Thus, to test the effect of the phenolate anion on extracting typical heterocyclic N-compound, pyrrole was selected as the representative compounds due to its high content from diverse sources. In this work, the simple structure and easy prepared functional phenolate-based ionic liquid, 1-ethyl-3-methylimidazolium phenolate ([emim][Phe]), is evaluated to separate pyrrole with the polarity analysis by COSMO-SAC model. After understanding the H-bond donor or acceptor relationship of the studied regents, the interaction mechanism between the phenolate based ionic liquid extractant itself and its complex system with pyrrole are visual demonstrated by the RDF, SDF plots etc. analysis and experimental research, which can contribute to understand the H-bonds interaction, hydrogen atom connected to the heteroatoms in pyrrole and oxygen atom in phenolate anion, more indicative. Additionally, the liquid–liquid phase behavior of the methylbenzene + pyrrole + [emim][Phe] system was determined to verify the effect at the perspective of phase equilibrium, the values of D and S was calculated and a highly selectivity for pyrrole could be confirmed. This will lay a solid foundation for developing a new separation technology about the extraction of heterocyclic N-compounds such as pyrrole.

The liquid crystalline phase behaviour of a nasal formulation modifies the brain disposition of donepezil in rats in the treatment of Alzheimer's disease

Although nanoparticles, polymeric micelles, liposomes, nanoemulsions, and microemulsions were extensively evaluated as formulations for nasal administration of drugs, lyotropic liquid crystal (LLC) mesophases have been few studied. The phase transition from a low-viscosity microemulsion to a more viscous LLC may improve the mucoadhesion of the formulation. Donepezil is a drug administered orally in the treatment of Alzheimer’s disease, and with gastrointestinal side effects that are typical of acetylcholinesterase inhibitors. Based on this, donepezil administration by nasal pathway using a mucoadhesive LLC may be a feasible alternative. A colloidal formulation was selected from a ternary diagram, combining CETETH-10, oleic acid, and water (40:45:15, w/w). Donepezil was incorporated into the formulation, and the characterisation included in vitro studies, such as mucoadhesion and drug release. Pharmacokinetics in Wistar rats included evaluations by the nasal pathway with donepezil incorporated into microemulsion. A phase transition from an isotropic to an anisotropic system was observed after the swelling of the microemulsion with artificial nasal fluid (12–20 %). The release of donepezil in vitro occurred in a sustained manner. Significant levels of donepezil were achieved in the brain after nasal administration of the microemulsion, as a promising strategy for the treatment of Alzheimer’s disease.

Brillouin light scattering study of microscopic structure and dynamics in pyrrolidinium salt based ionic liquids

Pyrrolidinium salts based ionic liquids are known to be good ionic conductors even in solid-state around room temperature, which is attributed to the highly disordered plastic crystalline phase. Moreover, these salts are characterized by multiple phase transitions which include plastic, structural glass, and glassy crystal phases with varying levels of molecular disorder. Temperature-dependent Brillouin light scattering is used to investigate the phase transitions in a series of alkylmethylpyrrolidinium Bis(trifluoromethanesulfonyl) imides (P1nTFSI, n = 1,2,4). Brillouin spectral features such as the number of acoustic modes, their shape, and linewidths provide the picture of different disordered phases resultant of dynamics at the microscopic scale. The longitudinal and transverse acoustic velocities in different phases are determined from the corresponding acoustic mode frequencies (Brillouin shift). Extremely low acoustic velocities in the solid phase of P11TFSI and P12TFSI are a consequence of a high degree of disorder and plasticity present in these systems. Anomalous temperature-dependent behavior of linewidths and asymmetric (Fano) line shape of acoustic modes observed in certain phases of P1nTFSI could be due to the strong coupling between the Brillouin central peak and the acoustic phonons. The present results establish that the Brillouin light scattering technique can be efficiently used to understand the complex phase behavior, microscopic structure, and dynamics of ionic liquids.

Liquid–Liquid Phase Behavior of Diesel/Biofuel Blends: Ternary Mixtures of n-Hexadecane, 2,2,4,4,6,8,8-Heptamethylnonane, and Ethanol and the Binary Subsystems

Mixtures of n-hexadecane and 2,2,4,4,6,8,8-heptamethylnonane are common diesel fuel surrogates. This paper describes a systematic investigation of the liquid–liquid phase behavior of the ternary mixtures of the normal alkane n-hexadecane and its isomer 2,2,4,4,6,8,8-heptamethylnonane (both CnH2n+2; n = 16) with ethanol as a model system of surrogate fuels. By applying the cloud point method in the temperature range of T = 240–330 K at ambient pressure (p = 1013 mbar), the complete liquid–liquid phase diagram is obtained. The binary mixtures of the alcohol with both isomeric alkanes show partial miscibility with upper critical solution points. The behavior of the ternary mixtures is examined by investigating the quasi-binary subsystems of mixtures of the alcohol with mixtures of the two isomers for various fixed mole ratios. By changing the ratio of the different isomers, the region of the phase diagram of the alcohol mixture with the n-alkane is gradually shifted toward lower temperatures when adding the branched isomer toward the phase diagram of the binary mixture of the alcohol with the isomeric compound. The general shape of the phase bodies of the pseudobinaries, predefined by the ratio of the isomeric components, shows only a slight change. For the numerical analysis of the measured phase behavior of the pseudobinary mixtures, concepts are used that are applied for binary solutions presuming Ising criticality. A master curve is obtained when applying the corresponding state principle on the binary and the pseudobinary mixtures. Superposition of the different results allows for a comprehensive description of the liquid–liquid phase behavior, and it estimates the loci of critical line and tie lines. The limits of the range of validity of the descriptions are determined by the appearance of solid phases, which are also reported here. This study is expected to establish a basis for optimizing blends of petrochemical fuels and fuels from renewable sources.

Chemistry and Geometry of Counterions Used in Hydrophobic Ion Pairing Control Internal Liquid Crystal Phase Behavior and Thereby Drug Release.

The combination of Flash NanoPrecipitation and hydrophobic ion pairing (HIP) is a valuable approach for generating nanocarrier formulations of ionic water-soluble drugs with controllable release properties dictated by liquid crystalline structuring of the ion pairs. However, there are few examples of this in practice in the literature. This work aims to decipher the influence of the nature of the hydrophobic counterion used in HIP and its consequent impact on liquid crystalline structuring and drug release. The hypothesis of this study was that hydrophobic counterions with different head and tail groups used for FNP with HIP would give rise to different liquid crystalline structures, which in turn would result in different drug release behavior. A cationic, water-soluble antibiotic, polymixin B, was complexed with eight different hydrophobic counterions with varying head and tail groups and encapsulated into nanocarriers 100-400 nm in size prepared using FNP. Sixteen formulations were assessed for internal structure by synchrotron small-angle X-ray scattering, and drug release was measured in vitro in physiological conditions. The liquid crystalline phases formed depended on the counterion head group and tail geometry, drug:counterion charge ratio, and the ionic strength and pH of the release medium. Drug release occurred more rapidly when no liquid crystalline phases were present and more slowly when higher-ordered phases existed. Specific findings include that phosphonic acid counterions lead to the formation of lamellar structures that persisted at pH 2.0 but were not present at pH 7.3. In contrast, sulfonic acids lead to lamellar or hexagonal phases that persisted at both pH 7.3 and 2.0, while hydrophobic counterions without alkyl tails did not form internal structures. It was also clear that the lipophilicity of the counterion does not dictate drug release. These findings confirm that the liquid crystalline phase behavior of the drug:counterion complex dictates drug release and significantly improves our understanding of the types of controlled release formulations that are possible using FNP with HIP.

Giant zirconium-bisphosphonate nano-ribbons and their liquid crystalline phase behaviour in water.

In decimolar aqueous solutions, zirconium oxychloride octahydrate forms several micrometer long and approximately 15 nm wide thin ribbons through the reaction with excess amounts of the sodium salt of 1-hydroxyethane-1,1-diphosphonic acid (HEDP, known as etidronic acid). Primarily deduced from SAXS, TEM, EXAFS and solid-state NMR analyses, a consistent structural model enables congruous explanations for the colloidal behaviour of the purified ribbons as well as of their reaction products with ammonia and amines, respectively. Properties of the lyotropic, liquid crystalline phases are discussed in the light of potential applications in aqueous coatings.

Applications of Artificial Intelligence for Analysis of Two-Phase Flow in PEM Fuel Cell Flow Fields

Many electrochemical devices rely upon flow-field channels to transport reactants and byproducts to and from critical electrode sites. Often, this results in multiphase flow, which, if not managed properly, can reduce system performance and lifespan. In the case of PEM fuel cells, two-phase flow occurs when liquid water forms as a byproduct of the cathode oxygen reduction reaction. Over the past two-decades much effort has been invested to understand the nature of this stochastic transport phenomena and how to optimize flow-field design to mitigate its effects. This work probes the use of artificial intelligence to guide our understanding of complex relationships between liquid phase behavior and pressure drop in these reactant channels [1]. Using a supervised decision tree (DT) machine learning algorithm, the liquid distributions in ex-situ experimental reactant channels are correlated to the induced pressure drop for a range of air flow rates; this process is diagrammed in Fig. 1. Liquid phase data collection is accomplished by capturing 2D images via a CCD camera of liquid water distributions in a transparent flow channel simulating PEM fuel cell conditions. In this setup, liquid water is injected through the bottom of the GDL in the same manner that water must travel from the catalyst layer through the GDL to reach the channel an operating cell. Pressure transducers measure pressure drop along the length of the channel and are synchronized with the image collection. The images are processed for noise reduction and feature extraction and then used with pressure data to train a regression DT. The models produced using the DT show the potential to improve predictions over earlier methods that relied solely upon liquid area [2]. Overall, the DT models predicted pressure drop using liquid distributions with 88.9% to 98.54% accuracy and were able to capture complex behavior such as pressure changes due to the breakup of liquid slugs. In general, the methods may be valuable for attaining deeper understanding of the impact variables such as geometry, hydrophobicity, and system operating conditions have on two-phase flow pressure drop trends. Additionally, these models may serve as a validation tool for numerical efforts aimed at flow-field design. A reliable model that can accurately predict the liquid-gas two-phase flow pressure drop may be used to estimate the amount and potentially the distribution of the water content within the flow channel by inputting the pressure drop measured during the operation of the cell.Figure 1: Overview of the regression DT training and testing processes.[1] Santamaria AD, Mortazavi M, Chauhan V, Benner J. Two-Phase Flow Characterization in PEM Fuel Cells Using Machine Learning. In Meeting s 2019 May 1 (No. 30, pp. 1538-1538). The Electrochemical Society.[2] Hussaini IS, Wang CY. Visualization and quantification of cathode channel flooding in PEM fuel cells. Journal of Power Sources. 2009 Feb 15;187(2):444-51. Figure 1

Effect of pressure, temperature and homogenization on the dissolution behavior and mechanical properties of IN718/AISI 304 during transient liquid phase bonding

• Higher applied pressure widened the joint zone. • Increasing holding temperature led to greater dissolution. • Homogenization dissolved DAZ precipitates. • Strength improved by increasing bonding pressure and temperature. This research focuses on the effect of bonding pressure, bonding temperature and post-bonding homogenization on the dissolution behavior and mechanical properties of transient liquid phase (TLP) bonding of Inconel 718 and AISI 304 L stainless steel. The findings revealed that higher applied pressure resulted in substantial widening of bond line, due to greater inter-diffusion between insert and base materials. Intermetallic phases in bonded sample under 5 MPa mostly comprised of Nb and Mo borides, while 1-MPa bond consisted of Ni-, Cr-, Ni-Si borides and Ni-Si precipitates. Results of shear strength evaluation implied that higher applied pressure improved the strength attributed to higher dissolution. Increasing holding temperature from 1000 to 1100 °C led to a noticeable widening of bond line and increasing boride phases. Eventually, the obtained joint at 1200 °C was fully mixed into Inconel 718 base material, although coarser eutectic phases were formed in this sample. Shear strength increased up to 450 MPa by increment in holding temperature from 1000 to 1100 °C, while it fell to 433 MPa after TLP bonding at 1200 °C. Post-bonding homogenization of samples at 700−900 °C caused elimination of eutectic phases in athermally solidified samples, dissolution of diffusion-induced precipitates, and also enhancement of their strength. Fracture studies revealed that the preferred path for crack propagation in the sample containing intermetallic phases was at those eutectic phases.

Expansion of Intrinsically Disordered Proteins Increases the Range of Stability of Liquid-Liquid Phase Separation.

Proteins containing intrinsically disordered regions (IDRs) are ubiquitous within biomolecular condensates, which are liquid-like compartments within cells formed through liquid–liquid phase separation (LLPS). The sequence of amino acids of a protein encodes its phase behaviour, not only by establishing the patterning and chemical nature (e.g., hydrophobic, polar, charged) of the various binding sites that facilitate multivalent interactions, but also by dictating the protein conformational dynamics. Besides behaving as random coils, IDRs can exhibit a wide-range of structural behaviours, including conformational switching, where they transition between alternate conformational ensembles. Using Molecular Dynamics simulations of a minimal coarse-grained model for IDRs, we show that the role of protein conformation has a non-trivial effect in the liquid–liquid phase behaviour of IDRs. When an IDR transitions to a conformational ensemble enriched in disordered extended states, LLPS is enhanced. In contrast, IDRs that switch to ensembles that preferentially sample more compact and structured states show inhibited LLPS. This occurs because extended and disordered protein conformations facilitate LLPS-stabilising multivalent protein–protein interactions by reducing steric hindrance; thereby, such conformations maximize the molecular connectivity of the condensed liquid network. Extended protein configurations promote phase separation regardless of whether LLPS is driven by homotypic and/or heterotypic protein–protein interactions. This study sheds light on the link between the dynamic conformational plasticity of IDRs and their liquid–liquid phase behaviour.