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In this paper, a simple approach, using interfacial self-assembly of block copolymers (BCPs) on self-sacrificial templates, for preparing mesoporous carbons with in-plane holey pores, including nitrogen atom-doped carbon nanosheets and nanoflowers (denoted as NHCSs and NHCFs), is reported. The approach employs sheet- or flower-like layered double hydroxide as the templates, P123 copolymer as the pore-directing agent, and m-phenylenediamine as the carbon source. The holey mesopores may shorten the mass transfer distance in the internal active sites of stacked nanosheets, while the 3D packing mode of nanosheets can reduce pore blockage caused by their tight stacking. Profiting from these structural advantages, acting as electrocatalysts for oxygen reduction reaction (ORR), both NHCSs and NHCFs show excellent catalytic performance better than that of carbon nanosheets without holey pores. Particularly, NHCFs exhibit a high half-wave-potential (0.82 V) and a limiting current density (5.4 mA cm-2 ), close to those of commercial Pt-C catalysts. This study provides valuable clues on building mesoporous materials with in-plane holey pores as well as on the effect of pore structure and stacking mode of 2D materials on their electrocatalytic ORR performance.
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The control of cargo phase-transfer is of interest for many applications in science and technology. Herein, we report a simple, versatile and robust method to block the phase-transfer of cargo colloids by interfacial self-assembled amphiphilic polymer molecules. After simply increasing the concentration of amphiphilic polymers, the orientation of interfacial polymer molecules changed from flat to upright, forming a thick three-dimensional polymer layer at the oil-water interface. Even under fierce external force, this thick interfacial layer robustly prevented the phase-transfer of cargo colloids, resulting in an ultrahigh encapsulation efficiency (up to 97.1 %) for proteins and peptides. One single injection of high insulin-loaded microcomposites (58.3â wt%) kept the blood glucose level within the normoglycemic state for 10â days in typeâ 1 diabetic rats. The mass of administrated amphiphilic polymers was 1889â times smaller than that of microcomposites prepared with non-amphiphilic ones.
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Diabetes Mellitus Experimental , Insulinas , Ratos , Animais , Polímeros/química , Glicemia , Diabetes Mellitus Experimental/tratamento farmacológico , Coloides/química , Água/químicaRESUMO
Here, we show that aqueous dispersions of inorganic nanoparticles bearing negative surface charges would trigger the chiral assembly of organic radical cations solubilized in organic solvent at the liquid-liquid interface, which consequently produces stable droplets covered by a layer of inorganic/organic chiral nanocomposites. We demonstrate that chirality transfer across the liquid-liquid interface from the chiral organic monomers to the nanoparticle assemblies is realized. Surprisingly, opposite handedness between molecular assemblies and nanoparticle assemblies is determined from both CD and CPL measurements. Moreover, the functionalities of these "chiral" droplets could be further engineered through either a simple mixing or a droplet merging strategy, which enables to produce fluorescent emissive-tunable, magnetic, as well as magnetofluorescent dual-functional droplets.
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The application of traditional electrode materials for high-performance capacitive deionization (CDI) has been persistently limited by their low charge-storage capacities, excessive co-ion expulsion and slow salt removal rates. Here we report a bottom-up approach to the preparation of a two-dimensional (2D) Ti3 C2 Tx MXene-polydopamine heterostructure having ordered in-plane mesochannels (denoted as mPDA/MXene). Interfacial self-assembly of mesoporous polydopamine (mPDA) monolayers on MXene nanosheets leads to the mPDA/MXene heterostructure, which exhibits several unique features: (1)â MXene undergoes reversible ion intercalation/deintercalation and possesses high conductivity; (2)â mPDA layers establish redox capacitive characteristics and Na+ selectivity, and also help to prevent self-stacking and oxidation of MXene; (3)â in-plane mesochannels enable the smooth transport of ions at the internal spaces of this stacked 2D material. When applied as an electrode material for CDI, mPDA/MXene nanosheets exhibit top-level CDI performance and cycling stability compared to those of the so far reported 2D materials. Our study opens an avenue for the rational construction of MXene-organic hybrid heterostructures, and further motivates the development of high-performance CDI electrode materials.
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Electronic devices comprised of nanocrystal (NC) thin film are projected to demonstrate enhanced figure of merit if NC building blocks self-assemble into highly uniform, 2-dimensional (2-D) superstructures with long-range order. Despite intensive research efforts and remarkable progress, long-range assembly of colloidal anisotropic NCs into thin films with orientational and positional order has remained to be addressed. One of the most promising approaches is to dissolve excess free molecules into NC solution, which has enabled the formation of NC monolayers with exceptional quality at air/solution interface. Nevertheless, the assembly mechanism and the role of free molecules have not been comprehensively elucidated, restricting the use of the approach. Here, we find that the interfacial assembly of CdSe/CdS core/shell nanorods (NRs) results in various ordered structures in the presence of free oleic acid molecules. The structures include a bundle of standing NRs, a belt of multilayered lying NRs, and a monolayer smectic phase, obtained by simple change in density of surface ligands on the NRs. Experimental observation and theoretical calculation reveal that the assembly is initiated at the air/solution interface due to the preferential depletion attraction of NRs to the interface. However, subsequent growth is significantly altered depending on the ligand density that determines the relative magnitude of interface-NR depletion attraction to inter-NR attraction. Highly ordered structures of NRs, especially for the monolayer smectic phase, are promising as a polarized light-emitting layer for thin-film optical devices. In addition, our findings on the depletion-mediated NR assembly provide important and universal design criteria for 2-D structuring of NCs with diverse geometries and compositions.
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The majority of bacteria in the natural environment live within the confines of a biofilm. The Gram-positive bacterium Bacillus subtilis forms biofilms that exhibit a characteristic wrinkled morphology and a highly hydrophobic surface. A critical component in generating these properties is the protein BslA, which forms a coat across the surface of the sessile community. We recently reported the structure of BslA, and noted the presence of a large surface-exposed hydrophobic patch. Such surface patches are also observed in the class of surface-active proteins known as hydrophobins, and are thought to mediate their interfacial activity. However, although functionally related to the hydrophobins, BslA shares no sequence nor structural similarity, and here we show that the mechanism of action is also distinct. Specifically, our results suggest that the amino acids making up the large, surface-exposed hydrophobic cap in the crystal structure are shielded in aqueous solution by adopting a random coil conformation, enabling the protein to be soluble and monomeric. At an interface, these cap residues refold, inserting the hydrophobic side chains into the air or oil phase and forming a three-stranded ß-sheet. This form then self-assembles into a well-ordered 2D rectangular lattice that stabilizes the interface. By replacing a hydrophobic leucine in the center of the cap with a positively charged lysine, we changed the energetics of adsorption and disrupted the formation of the 2D lattice. This limited structural metamorphosis represents a previously unidentified environmentally responsive mechanism for interfacial stabilization by proteins.
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Bacillus subtilis/química , Proteínas de Bactérias/química , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Estabilidade Proteica , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de ProteínaRESUMO
2D arrays of metal nanoparticles formed at liquid-liquid interfaces have been fixed in situ to a thin polymer support to create freestanding large (cm2 ) composite films where the particles remain exposed rather than being trapped within the polymer. Applications of these flexible robust 2D nanoparticle arrays as sensors, thin film conductors, antimicrobial coatings, and dip-in catalysts are shown.
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Nanopartículas/química , Nanotecnologia/métodos , Polímeros/química , Ácidos/química , Cloreto de Metileno/química , Propriedades de SuperfícieRESUMO
It is of great significance to study the effect of multi-enzyme aggregation behavior at the interface on the formation of multi-enzyme complexes and their co-catalytic characteristics, which is helpful for us to design and construct immobilized multi-enzyme complex systems for in vitro synthetic biology. Here, a magnetic microsphere with chelated Ni2+, was prepared to explore the self-assembly characteristics of PduQ-SpyTag (P-T) and Nox-SpyCatcher (NC) on its surface, based on the mixed interaction mode consisting the affinity of His-tag/Ni2+ and covalent binding of SpyTag/SpyCatcher. After studying the effect of saturated or unsaturated adsorption of P-T on the covalent binding between P-T and NC at the interface, a possible multienzyme interaction mechanism for the affinity-assisted covalent self-assembly on the Ni2+ chelating surface was proposed. The time evolution of NADH showed that the immobilized P-T/N-C complex formed by this method and the free P-T/N-C complex exhibited similar synergistic catalytic properties, and presented higher catalytic efficiency than the simple mixing of P-T and NC. The optimal catalytic conditions, stability and reusability of the immobilized multi-enzyme complexes prepared in this study were also discussed by comparing them with free enzymes. In this study, we demonstrate a simple and effective strategy for self-assembling SpyTag/SpyCatcher fusion proteins on the surface of magnetic beads, which is inspiring for the construction of more cascade enzyme systems at the interface. It provides a new method for facilitating the rapid construction of immobilized multi-enzyme complexes in vitro from the crude cell lysis.
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Enzimas Imobilizadas , Complexos Multienzimáticos , Microesferas , Catálise , Complexos Multienzimáticos/química , Fenômenos MagnéticosRESUMO
Semiconductor nanofilm fabrication with advanced technology is of great importance for next-generation electronics/optoelectronics. Fabrication of high-quality and perfectly oriented semiconductor thin films and integration into high-performance electronic devices with low cost and high efficiency are huge challenges. Here we exquisitely utilized the Marangoni effect to perfectly guide tin disulfide (SnS2) nanocoins into an ordered assembly in milliseconds, resulting in an uniaxial-oriented monolayer semiconductor film. Further exploration revealed that the formed "crumple zone" at the interface caused by the Marangoni force endows the nanofilm with a rapid healable capability, which can be easily transferred to arbitrary substrates. As a proof of concept, the nanocoin-monolayer was transferred onto a micro-interdigitated electrode substrate to form a high-performance chemiresistive sensor that can effectively monitor the trace amounts of toxic gases. In addition, the assembled monolayer nanofilms can be conformally printed on freeform surfaces: both flat and nonflat substrates. This efficient and low-cost Marangoni force-assisted surface self-assembly (MFA-SSA) strategy is promising for advanced microelectronics and real industrial applications.
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Noncontact alignment of liquid crystals (LCs) is crucial for large-area and ultrahigh definition (UHD) display manufacturing. This research presents an innovative approach to the photoalignment of LCs, aiming to overcome challenges associated with uniformity and assembly in large-sized and UHD displays. Using homogeneously dissolved, nonionic azobenzene chromophores sensitive to both visible and UV light, we demonstrate an in situ stepwise progression of dye-induced LC alignment and subsequent stabilization using reactive mesogen (RM). Both dual-wavelength and single-wavelength approaches enable stepwise interfacial modifications for LC alignment and stabilization. The dye-induced LC alignment is rewritable, allowing for the creation of various patterns and gray-level alignments. The stability of the alignment is ensured through cross-linked RM layers, providing a robust and permanent solution for LC alignment without the need for delicate mechanical treatments. Importantly, this method addresses the challenges associated with conventional photoalignments, including various dye-induced approaches and high-energy photoalignment. The proposed method exhibits high-quality electro-optical switching, azimuthal anchoring strength, and stability against thermal, radiation, and ac-field stresses, making it a promising candidate for commercial mass production, especially in the fabrication of large-sized and UHD LC displays.
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Agrichemical losses are a severe threat to the ecological environment. Additionally, some agrichemical compounds contain abundant salt, which increases the instability of formulations, leading to a lower agrichemical utilization and soil hardening. Fortunately, the biological amphiphilic emulsifier sodium deoxycholate alleviates these problems by forming stable Janus core-shell emulsions through salinity-driven interfacial self-assembly. According to the interfacial behavior, dilational rheology, and molecular dynamics simulations, Janus-emulsion molecules are more closely arranged than traditional-emulsion molecules and generate an oil-water interfacial film that transforms into a gel film. In addition, at the same spray volume, the deposition area of the Janus emulsion increased by 37.70% compared with that of the traditional emulsion. Owing to the topology effect and deformation, the Janus emulsion adheres to rice micropapillae, achieving better flush resistance. Meanwhile, based on response of the Janus emulsion to stimulation by carbon dioxide (CO2), the emulsion lost to the soil can form a rigid shell for inhibiting the release of pesticides and metal ions from harming the soil. The pyraclostrobin release rate decreased by 50.89% at 4 h after the Janus emulsion was exposed to CO2. The Chao1 index of the Janus emulsion was increased by 12.49% as compared to coconut oil delivery in soil microbial community. The Janus emulsion ingested by harmful organisms can be effectively absorbed in the intestine to achieve better control effects. This study provides a simple and effective strategy, which turns waste into treasure, by combining metal ions in agrichemicals with natural amphiphilic molecules to prepare stable emulsions for enhancing agrichemical rainfastness and weakening environmental risk.
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Agroquímicos , Salinidade , Emulsões/química , Dióxido de Carbono , Íons , SoloRESUMO
Lithium thionyl chloride (Li-SOCl2) batteries are widely used due to their high energy density and long shelf life. However, the corrosive nature of SOCl2 poses a safety hazard, necessitating effective leak detection methods. We report an approach for real-time fluorescent detection of SOCl2 leakage in Li-SOCl2 batteries using a tetraphenylethene-based nanofilm. The nanofilms were prepared through the interfacial confined self-assembly method and exhibit excellent flexibility, homogeneity, tunable size and thickness, and adaptability to various substrates, enabling easy integration into sensor devices. They possess high photochemical stability and a photoluminescence quantum yield exceeding 25%, demonstrating their potential as high-performance fluorescent sensing material. The nanofilms also exhibit high sensitivity, good reproducibility, and selectivity toward SOCl2 detection. Upon exposure to SOCl2 vapor, the nanofilm shows a red-shifted and fluorescence quenching response, attributed to the protonation of the acylhydrazone bond in the nanofilm by the hydrolysis product of SOCl2, which disrupts the electronic structure of the nanofilm and leads to a decrease in the fluorescence intensity and a shift in the emission wavelength. A detection limit of â¼1.31 ppt and excellent repeatability over 300 cycles are demonstrated, highlighting their high sensitivity and reliability. This work paves the way for a highly sensitive and reliable leak detection system for Li-SOCl2 batteries, enhancing their safety and reliability in various applications.
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BACKGROUND: Protocell refers to the basic unit of life and synthetic molecular assembly with cell structure and function. The protocells have great applications in the field of biomedical technology. Simulating the morphology and function of cells is the key to the preparation of protocells. However, some organic solvents used in the preparation process of protocells would damage the function of the bioactive substance. Perfluorocarbon, which has no toxic effect on bioactive substances, is an ideal solvent for protocell preparation. However, perfluorocarbon cannot be emulsified with water because of its inertia. METHODS: Spheroids can be formed in nature even without emulsification, since liquid can reshape the morphology of the solid phase through the scouring action, even if there is no stable interface between the two phases. Inspired by the formation of natural spheroids such as pebbles, we developed non-interfacial self-assembly (NISA) of microdroplets as a step toward synthetic protocells, in which the inert perfluorocarbon was utilized to reshape the hydrogel through the scouring action. RESULTS: The synthetic protocells were successfully obtained by using NISA-based protocell techniques, with the morphology very similar to native cells. Then we simulated the cell transcription process in the synthetic protocell and used the protocell as an mRNA carrier to transfect 293T cells. The results showed that protocells delivered mRNAs, and successfully expressed proteins in 293T cells. Further, we used the NISA method to fabricate an artificial cell by extracting and reassembling the membrane, proteins, and genomes of ovarian cancer cells. The results showed that the recombination of tumor cells was successfully achieved with similar morphology as tumor cells. In addition, the synthetic protocell prepared by the NISA method was used to reverse cancer chemoresistance by restoring cellular calcium homeostasis, which verified the application value of the synthetic protocell as a drug carrier. CONCLUSION: This synthetic protocell fabricated by the NISA method simulates the occurrence and development process of primitive life, which has great potential application value in mRNA vaccine, cancer immunotherapy, and drug delivery.
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Complex coacervate microdroplets, which are formed via spontaneous liquid-liquid phase separation by mixing two oppositely charged polyelectrolytes in water, have emerged as a new paradigm in the fields of origin of life, membraneless subcellular compartmentalization, bioreactors, and drug delivery. However, how to further improve its stability and enhance its selectivity in one particular coacervate system remains a challenge. By generating a membrane-like layer at the surface of coacervate microdroplets via electrostatic interactions between oppositely charged surfactants and polyelectrolytes, we here achieve tunable permeability and enhanced stability of the coacervates at the same time. Depending on the surfactants used, membrane-like layer-coated coacervate microdroplets exhibit different selectivity over solute sequestration and can promote or inhibit DNA hybridization. Our approach provides a practical tool to engineer functional bioinspired microcompartments with potential applications in the fields of controlled drug release and microreactor technology.
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Surfactantes Pulmonares , Tensoativos , Polieletrólitos , Água , LipoproteínasRESUMO
Functional Pickering emulsions that depend on the interparticle interactions hold promise for building template materials. A novel coumarin-grafting alginate-based amphiphilic telechelic macromolecules (ATMs) undergoing photo-dimerization enhanced particle-particle interactions and changed the self-assembly behavior in solutions. The influence of self-organization of polymeric particles on the droplet size, microtopography, interfacial adsorption and viscoelasticity of Pickering emulsions were further determined by multi-scale methodology. Results showed that stronger attractive interparticle interactions of ATMs (post-UV) endowed Pickering emulsion with small droplet size (16.8 µm), low interfacial tension (9.31 mN/m), thick interfacial film, high interfacial viscoelasticity and adsorption mass, and well stability. The high yield stress, outstanding extrudability (n1 < 1), high structure maintainability, and well shape retention ability, makes them ideal inks for direct 3D printing without any additions. The ATMs provides an increased capacity to produce stable Pickering emulsions with tailoring their interfacial performances and, providing a platform for fabricating and developing alginate-based Pickering emulsion-templated materials.
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Interfacial nanofilms with nonlinear optical (NLO) properties were prepared via confined dynamic condensation of 4,4'-methylenedianiline (MDA) with the synthesized 2,3-bis(4-(bis(4-formylphenyl)amino)phenyl)fumaronitrile (BTFA). Investigated using the open-aperture Z-scan technique, BTFA showed reverse saturable absorption ascribed to the synergetic mechanisms of two-photon and excited-state absorption. In contrast, the as-prepared nanofilms demonstrated broadband saturable absorption within the spectral range of 720â¼1700 nm. The characteristics of nonlinear absorption coefficient (ß) decreased along with increasing the incident pulse intensity. Taking advantage of the flexibility and post-machinability properties, the folding layers of the nanofilms offered the feasibility to fine-tune the specific NLO responses. The optimal ß value was found to be -10.1 cm/MW for eight-layer nanofilm as well as the normalized transmittance increased up to 35-fold at 800 nm. Utilized as a conceptual saturable absorber, the representative modulation depth and saturation intensity were observed to be around 2.4% and 7.37 GW/cm2 at 800 nm, respectively, comparable to traditional two-dimensional (2D) materials. Aiming to clarify the possible underlying physical processes, a four-level model was employed to illustrate the fast relaxation of the excited states. Present work demonstrates that proper design of building blocks combined with interfacially confined dynamic condensation enables rational development of high-performance NLO materials.
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Fluorescent films have been widely recognized as one of the most powerful tools for trace analyte detection. However, their use has been limited due to the poor photochemical stability of fluorophores at a gas-solid interface and inefficient film mass transfer. Herein, novel fluorescent films were developed through self-assembly of amphiphilic BODIPY derivatives on micropatterned ionic liquid surfaces. Unlike solid-state films, the obtained monolayer films exhibit excellent photochemical stability, similar to that of a solution. Moreover, the interfacial assembly of amphiphilic fluorophores can avoid gas diffusion inside the microdroplets, significantly improving the sensing performance. The 1/1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) monolayer exhibits high sensitivity, high selectivity, and a fast response to detect diethylchlorophosphate (DCP) vapor. The detection limit was 226 ppt, with a response time to DCP of 2.0 s. Importantly, the 1/[BMIM]BF4 monolayer can be reused for at least 50 cycles with no obvious signal fading. This study is expected to benefit the development of new strategies for designing fluorescence sensing films and lay a solid foundation for the fabrication of multifunctional sensing devices with excellent photochemical stability and sensing performance.
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Allomelanin is a class of nitrogen-free melanin mostly found in fungi and, like all naturally occurring melanins, is hydrophilic. Herein, we develop a facile method to modify synthetic hydrophilic allomelanin to yield hydrophobic derivatives through post-synthetic modifications. Amine-functionalized molecules of various kinds can be conjugated to allomelanin nanoparticles under mild conditions with high loading efficiencies. Hydrophobicity is conferred by introducing amine-terminated alkyl groups with different chain lengths. We demonstrate that the resulting hydrophobic allomelanin nanoparticles undergo air/water interfacial self-assembly in a controlled fashion, which enables the generation of large-scale and uniform structural colors. This work provides an efficient and tunable surface chemistry modification strategy to broaden the scope of synthetic melanin structure and function beyond the known diversity found in nature.
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Melaninas , Nanopartículas , Melaninas/química , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas/química , Água/química , AminasRESUMO
Improving bioavailability of orally delivered drugs is still challenging, as conventional drug delivery systems suffer from non-specific drug delivery in the gastrointestinal (GI) tract and limited drug absorption efficiency. Gastric drug delivery is even more difficult due to the harsh microenvironment, short retention time, and physiologic barriers in the stomach. Here, an oral drug delivery microcapsule system was developed for gastric drug delivery, which consists of ionic liquid (IL) as the inner carrier and metal-phenolic network (MPN) as the microcapsule shell. The IL@MPN microcapsules are prepared by interfacial self-assembly of FeIII and quercetin at the interface of hydrophobic IL ([EMIM][NTf2]) and water. The formation of MPN shell could improve the stability of IL droplets in water and endow the system with pH-response drug release properties, while the encapsulated IL core could efficiently load the drug and enhance the drug tissue permeability. The IL@MPN microcapsules showed enhanced drug absorption in the stomach after oral administration in a rat model, where the microcapsules are disassembled in gastric acid, and the released IL could reduce the viscosity of mucus gel and increase the drug transport rate across endothelial cells. This work presents a simple yet efficient strategy for oral drug delivery to the stomach. Given the diversity and versatility of both MPN and IL, the proposed self-assembled microcapsules could expand the toolbox of drug delivery systems with enhanced oral drug bioavailability.
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Líquidos Iônicos , Administração Oral , Animais , Cápsulas , Células Endoteliais , Compostos Férricos , Absorção Gástrica , Fármacos Gastrointestinais , Metais , Quercetina , Ratos , ÁguaRESUMO
All-aqueous microdroplets produced by liquid-liquid phase separation have emerged as promising models of artificial cells, and offer new approaches for the solvent-free encapsulation of fragile solutes. Yet, the lack of a membrane on such droplets makes them intrinsically unstable against coarsening, and precludes a fine control over chemical localization, as solutes can freely diffuse through the interface. Herein, we report the construction of stable and impermeable water-in-water emulsions via the interfacial self-assembly of mixed sodium oleate/1-decanol bilayers on dextran-rich droplets produced by segregative liquid-liquid phase separation with poly(ethylene glycol). Lipids spontaneously self-assemble as multilamellar structures at the surface of the droplets as revealed by freeze-fracture transmission electron microscopy and small-angle X-ray scattering. We further demonstrate that the lipid-based membrane is impermeable to oligonucleotides and proteins, but also to a low molecular weight dye, so that a strict chemical encapsulation can be achieved by spontaneous partitioning within the droplets before membrane self-assembly. Taken together, our results highlight the ease of production of fatty acid-stabilized all-aqueous emulsions droplets able to encapsulate a range of solutes without the need of oil or organic solvents, paving the way to the construction of robust membrane-bounded, polymer-rich artificial cells.