Formation Of Interfacial Film Research Articles

Influence of synergistic/competitive interactions of nonionic emulsifiers and proteins on the foam stability of whole egg liquids: Based on air-water and oil-water dual interface perspectives

Nonionic emulsifiers (NE) are widely used in sponge cakes because they can effectively improve the foaming properties of whole egg liquids (WEL). The WEL are rich in protein, lipids and water, forming air-water and oil-water interface during whipping and foaming. However, different NE plays different roles in the interface. No systematic study has been conducted on the stabilization mechanism of WEL by NE. This study first investigated the effect of different NE on the foaming properties of WEL. It was found that WEL with sucrose ester-9 (SE-9) had the highest foam stability (FS) (92.52%), while that with Tween 80 had the lowest (75.55%). It was found that this was related to the higher interfacial protein substitution ability of Tween 80. Next, free triglyceride content and CLSM analysis confirmed that NE promoted the formation of more oil-water interfaces in the foam. Moreover, NE could improve FS by reducing droplet size and increasing viscosity. Finally, the higher surface activity of NE than proteins was demonstrated by interfacial adsorption kinetics and dilatation rheology. SE-9 interacted with proteins at the air-water interface to enhance interfacial rigidity, whereas adsorption of Tween 80 led to a decrease in the rearrangement rate. The results also showed that the formation of oil-water interfacial films was dominated by the adsorption of NE. This study illustrated how different NE stabilized air-water and oil-water interfaces, and the effect of synergistic/competitive interactions with proteins on the stability of the interfaces. This will provide new insights into the stability regulation of WEL foam.

Improving foam stability: Calcium addition, high hydrostatic pressure, and their combinations on soybean protein isolates

Various combinations of high hydrostatic pressure treatment (HHPT, 0.1 or 600 MPa), calcium addition (0, 0.50, or 0.75 mmol CaCl2/g protein), and protein content ([Prot.], 1, 5, or 10 g/L) were applied to soybean protein isolate (SPI) dispersions to analyze their effects on the formation and stability of foams. The significant interactions between these factors led to several combinations that improved foam stability via different mechanisms that involved different solubilities, aggregate sizes, and molecular structures of proteins. Thirty min after foam formation, calcium combined with HHPT improved volume of foam (VF30) and volume of liquid retained (VLr30), by the formation of strong interfacial films owing to the increased cross-linking ability of soluble and intermediate-sized aggregates. Calcium without HHPT had a greater effect on VLr30 than on VF30, which could be owing to the insoluble and large aggregates that blocked Plateau borders. HHPT without calcium led to small denatured aggregates that were soluble and improved the VLr30 when [Prot.] was lower. Industrial relevanceCalcium enriched plant proteins with good techno-functional properties is a prevailing need, considering the current cultural, economic and environmental changes that occur. The findings of this study could serve as an input for the incorporation of high biological value proteins and calcium into aerated foods, and would contribute to develop innovative products. Treatment with high hydrostatic pressure could be advantageous on account of modifying the protein structure and thereby improving the stability of the foams. Under certain conditions, such as those of aerosol whipping creams, high hydrostatic pressure would simultaneously improve techno-functional properties of proteins and pasteurize the dispersions, which would then have to be safely canned.

Preparation of oil-in-water type Pickering emulsions stabilized by partially deacetylated nanochitin and pH-triggered drug release

Partially deacetylated nanochitin (DAcNC) exhibits amphiphilicity owing to the hydrophilic protonated amino groups and hydrophobic surface planes of DAcNC. Although DAcNCs possess emulsifying abilities, their role and versatility as emulsifiers remain unclear. In this study, we investigated oil-in-water (O/W) type Pickering emulsions stabilized with DAcNCs. Stable emulsions were formed using a variety of oils such as vegetable oils, decane, and ether oils. Measurements of the interfacial tension and adsorption of DAcNC showed that formation of tolerant interfacial films stabilized the emulsions. Furthermore, the pH-triggered release of ibuprofen, an antipyretic drug, was demonstrated using the emulsion. Enhanced ibuprofen release was observed upon increasing the pH from 2.0 to 6.0. This phenomenon can be attributed to the deprotonation of ammonium moieties on the DAcNC, which induced the desorption of DAcNC from oil/water interfaces. The DAcNC emulsion can be useful for the oral administration of ibuprofen as an antipyretic agent, facilitating intestinal release.

Cysteines in β-lactoglobulin affects its interfacial adsorption and protein film stabilization

HypothesisDisulfide bonds in proteins are strong chemical bonds forming the secondary and tertiary structure like in the dairy protein β-lactoglobulin. We hypothesize that the partial or complete removal of disulfide bonds affects the structural rearrangement of proteins caused by intra- and intermolecular interactions that in turn define the interfacial activity of proteins at oil/water interfaces. The experimental and numerical investigations contribute to the mechanistic understanding of the structure-function relationship, especially for the interfacial adsorption behavior of proteins. Experimental and numericalSystematically, the 5 cysteines of β-lactoglobulin were recombinantly exchanged by alanine. First, the protein structure of the variants in bulk was analyzed with Fourier-transform-infrared-spectroscopy and molecular dynamic simulations. Second, the structural changes after adsorption to the interface have been also analyzed by molecular dynamic simulations. The adsorption behavior was investigated by pendant drop analysis and the interfacial film properties by dilatational rheology. FindingsThe structural flexibility of β-lactoglobulin with no cysteines encourages its unfolding at the interface, and accelerates the interfacial protein film formation that results in more visco-elastic films in comparison to the reference.

Effects of different solid particle sizes on oat protein isolate and pectin particle-stabilized Pickering emulsions and their use as delivery systems

Oat protein isolate (OPI)/high methoxyl pectin (HMP) complexes (OPP) were prepared to stabilized Pickering emulsions and applied as nutraceutical delivery systems. The different mass ratios and pH changed the interactions between OPI and HMP that caused the different size of OPP. Specifically, smaller particle size of OPP (125.7–297.6 nm) were formed when hydrophobic interactions along with electrostatic forces predominant in OPP (OPI:HMP = 3:1, pH 4, 5). Among these particles, OPP-2 could stabilize Pickering emulsion efficiently through formation of dense interfacial film, which exhibited the highest apparent viscosity and the smallest average droplet size (23.39 μm). Moreover, OPP-2 stabilized Pickering emulsions with superior stability not only exhibited higher encapsulation efficiency of 85.63%, but also could control curcumin release in simulated gastrointestinal fluids to improve curcumin's bioaccessibility. These results verified the possibility of OPP to be a Pickering emulsions stabilizer, and also identified its potential to be a stable delivery system for bioactive compounds.

Study of CO2 hydrate formation on the surface of residue shell from dissociated CH4 hydrate

The use of hydrates to store CO2 is considered an effective method that can be implemented. However, the problems of interfacial hydrate film formation and low mass transfer efficiency when forming CO2 hydrate under static conditions still need to be solved. This study compared the growth modes of CH4 hydrate and CO2 hydrate under static conditions and believed that the wall-climbing growth mode of CH4 hydrate can be used to generate CO2 hydrate. It is proposed to use the residual shell of CH4 hydrate as a water-absorbing medium to change the mode in which CO2 hydrate is preferentially generated in the main body of the liquid phase. In this method, CO2 hydrate shows a faster formation rate and almost no induction time, which is attributed to the larger gas-liquid contact area provided by the shell, the residual ring in decomposed water on the surface, and the crystal structure inside the shell. When sodium dodecanoate (SD) is used as a promotor for CH4 hydrate to regenerate CO2 hydrate, the observation of the hydrate growth morphology shows that CO2 hydrate can grow on the CH4 hydrate shell. It does not have the wall climbing height of CH4 hydrate but grows toward the center of the reactor. When SDS is combined with SD to regenerate CO2 hydrate as an accelerator in the CH4 hydrate generation process, filamentous growth of CO2 hydrate can be observed.

Investigating the interfacial and bulk rheological properties of emulsions containing dry bean powder

This study aimed to investigate the impact of varying proportions of dry bean powder on the rheological properties of oil-in-water emulsions. Emulsions were formulated utilizing xanthan gum or dry bean powder across a range of concentrations, including 1%, 3%, 5%, and 7%. Additionally, a control emulsion (CTR) was formulated using xanthan gum exclusively. The rheological properties of the resulting emulsions, both linear and nonlinear, were characterized. Moreover, the correlation between microstructural attributes and the interfacial rheological response within these emulsion systems was thoroughly examined. A prominent observation was the occurrence of shear thinning, characterized by a reduction in viscosity under applied shear stress. Notably, the control emulsion (CTR) displayed the lowest interfacial viscosity values, whereas emulsions incorporating increasing proportions of dry bean powder demonstrated a proportional rise in interfacial viscosity. The highest consistency coefficient and apparent viscosity was recorded in the 7%DB sample with a value of 3.23 Pa.sn and 0.56 Pa.s, respectively. This suggests that emulsions formulated with dry bean powder may yield a more resilient interfacial film, attributed to the protein content inherent in dry beans. The establishment of a viscoelastic interfacial layer facilitated by dry bean powder in appropriate concentrations significantly contributes to the long-term stability of the emulsion. Unraveling the intricate relationship between interfacial behaviors holds paramount importance in advocating for the utilization of dry bean powder as a plant-based protein source. In conclusion, the incorporation of dry bean powder enhances the formation of interfacial films in O/W emulsions.

Combining in-situ observation and interfacial rheology as a tool to investigate the possible mechanism for improved emulsifying performance of gliadin-based colloid particles

Interfacial deformation and interfacial rheology behaviour of prolamin particles are relevant factors affecting their emulsification performance but have not yet been paid considerable attention to. Based on the finding that CMC modification significantly improved the emulsifying property of gliadin colloid particles (GCPs), the present study combined in situ observation and interfacial rheology as a tool to investigate the effect of CMC on the structure characteristics, interfacial deformation and interfacial rheology behaviour of GCPs and their correlation with emulsifying performance. The results demonstrated that gliadin/CMC complex particles (GCCPs) presented looser core-shell structures than GCPs. The interfacial deformation of particles and the formation of smooth interfaces were observed for both GCPs and GCCPs, and GCCPs exhibited faster deformation behaviour, which should correlate to the looser structure. Although GCCPs showed lower surface pressure and viscoelasticity modulus, the existence of CMC promoted the initial adsorption of particles and accelerated the formation of viscoelastic interfacial films, which contributed to the improvement of emulsifying performance. In addition, CMC endowed the interfacial layers with moderate viscosity and fluidity to resist the destabilisation induced by oil droplet deformation. The present study should provide insights for intuitive understanding and fine regulation of the interfacial behaviour of protein particles.

Formation of interfacial molecular film and metal‐trapping function of azacalixarene‐containing copolymers having spherulite‐forming ability

AbstractThe interfacial molecular film behavior of a newly synthesized copolymer having spherulite‐forming ability and consisting of an azacalixarene moiety and a polyethylene glycol linker was investigated. Furthermore, the ability of the azacalixarene ring in the copolymer Langmuir monolayer to trap metals from the subphase was examined. The copolymer formed a monolayer at the air/water interface with high‐density packing. In addition, the corresponding copolymer formed a stable interfacial monolayer whose behavior did not change significantly as the temperature of the subphase changed. The monolayer morphology exhibited a dot‐like crystalline domain. When the subphase contained cadmium ions, the cyclic moiety showed the ability to trap the metal cations. In this case, the distortion angle of the cup‐shaped conformation of the cyclic moiety in the organized molecular film expanded after metal trapping.Highlights LB film of a copolymer containing azacalixarene and PEG units was prepared. The copolymer formed a dense packing in the LB film. Copolymer film formed a surface morphology containing crystalline grains. The copolymer trapped Cd ions in the azacalixarene ring from the subphase. Due to trapping of Cd ions, the distortion angle of the ring widened by 7°.

In-situ repairing quantum-dot-monolayer-film defects for laminated light-emitting diodes

Quantum dot (QD) light-emitting diodes (QLEDs) have become one of the primary development directions for next-generation display techniques due to their excellent optoelectronic and solution-processing properties. High-performance QLEDs rely on high-quality light-emitting layers that are mainly stacked QD films deposited by spin-coating (SC). However, preparing large-area and defect-free monolayer films, which is crucial for high-quality displays, is the inherent drawback of the SC technique and is still challenging. Herein, we propose an in-situ defect-repairing strategy to create defect-passivating monolayer QD films at a liquid/air interface by a simple injection assembly (IA) technique. The monolayer QD film was assembled and passivated by a simple n-butylamine injection into ethylene glycol (EG), prompting the IA-QLEDs to exhibit excellent electrical performance. The as-fabricated IA-QLEDs outperform conventional SC-QLEDs with EQEs exceeding 24 % and significantly extended lifetimes. Furthermore, our method demonstrated its scalability (a defect-free 7×5 cm2 monolayer is fabricated), enabling the fabrication of large-area QD films with uniform morphology through a straightforward expansion of the film-forming container. This work proposes a general strategy for interfacial film formation and defect repair of QD film and holds significant promise for the practical application of high-performance QLEDs.

Optimizing oil-water interfacial rheology for in-situ synthesis of nanoparticles and asphaltene control during oil production

Asphaltene precipitation and deposition lead to plugging of oil production tubulars and damage in near wellbore porous media. This study addresses this challenge by shedding light on optimization of in-situ synthesis conditions of Fe2O3 nanoparticles to enhance asphaltene adsorption. The approach involves utilizing dynamic interfacial tension (IFT) and interfacial elasticity as the key factors influencing the in-situ synthesis. Model oils were prepared by dissolution of a dead oil in different ratios of toluene/vacuum gasoil to control the aggregate size, hydrophilicity, and interfacial film formation capability of asphaltene. Emulsions of iron salt solution (brine) in the model oils were prepared for the in-situ synthesis. The iron cation molarity and the water content of the emulsions were adjusted by considering the oils-brine dynamic IFT and interfacial elasticity as well as the emulsions stability with temperature. The most stable emulsions were exposed to in-situ synthesis at reservoir-temperature. The texture and structure of the synthesized nanoparticles were characterized well and their asphaltene adsorption capacity was measured. Results indicate that, although the dynamic IFT is a footprint of the hydrophilicity and size distribution of the asphaltene aggregates in the interface, the interfacial elasticity shows the aggregates arrangement and thus interfacial film formation, leading to the emulsions stability and efficient synthesis. The in-situ synthesized nanoparticles are crystalline α-Fe2O3 with the size of smaller than 75 nm. The crystalline structure of the nanoparticles is further developed by increasing the synthesis time period and water content of the starting emulsion. The higher the water content, the more is the adsorbed carbonaceous species on the in-situ synthesized nanoparticles. Characterization data and thermogravimetric analysis confirm that the adsorbed species are mostly monolayer asphaltenes. Most of the adsorption takes place in early time of the synthesis, thereafter there is a marginal increase in the adsorption with time. Dynamic IFT and interfacial elasticity provide unique data for in-situ synthesis of nanoparticles for asphaltene adsorption and thus aggregation control.

Aggregate Size Modulates the Oil/Water Interfacial Behavior of Myofibrillar Proteins: Toward the Thicker Interface Film and Disulfide Bond.

Myofibrillar protein (MP) aggregate models have been established to elucidate the correlation between their aggregate sizes and interfacial properties. The interfacial layer thickness was measured by the polystyrene latex method and quartz crystal microbalance with dissipation measurement. Interfacial conformations were then characterized in situ (front-surface fluorescence spectroscopy) and ex situ (reactive sulfhydryl group and secondary structure measurement following MP displacement). The viscoelasticity of the interfacial film and its resistance to surfactant-induced competitive displacement were reflected by the dilatational rheology and dynamic interfacial tension with the bulk phase exchange. Finally, we compared the findings of competitive displacement before/after adding a sulfhydryl-blocking agent, N-ethylmaleimide, to highlight the role of S-S linkage on interfacial film formation and stability. We substantiated that the aggregate size of the MP governed their interfacial properties. Small-sized aggregates exhibited more ordered secondary structures on the oil-water interface, which was conducive to the adsorption ratio of the protein and the adsorption dynamics. Although larger aggregates lowered the diffusion rate during interfacial film formation, they allowed the thicker and more viscoelastic interfacial film to be constructed afterward through more disulfide bond formation, resulting in greater resistance to surfactant-induced competitive displacement.

A review of low-temperature lithium metal battery research

Rechargeable lithium metal batteries (LMBs) are one of the promising energy storage systems, which have the advantage of a high theoretical specific capacity of 3860 mAh/g and a low reduction potential of −3.04 V vs. SHE. With the development of society, the large use of batteries in low-temperature areas is inevitable. Typically, batteries fail at low temperatures, especially with temperatures below −20 °C, but the research on low-temperature behavior is limited. According to previous research on low-temperature lithium metal batteries, the main challenge is to suppress serious dendrite growth at low temperatures. Here, we reviewed the state-of-art progress of low-temperature LMBs, including protect layer, three-dimensional collector, and electrolyte. We found that most of the research works relate to electrolytes because a novel electrolyte can easily solvate, contribute to ion transportation, and be conducive to solid electrolyte interfacial (SEI) film formation, which can accelerate the kinetics at low temperatures, thus suppressing the serious dendrite growth at low temperatures. We propose that solid electrolytes can suppress the dendrite growth of LMBs at low temperatures effectively because solid electrolytes are not easy to be pierced.

Three-Phase Catassembly of 10 nm Au Nanoparticles for Sensitive and Stable Surface-Enhanced Raman Scattering Detection.

Interfacial self-assembly with the advantage of providing large-area, high-density plasmonic hot spots is conducive to achieving high sensitivity and stable surface-enhanced Raman scattering (SERS) sensing. However, rapid and simple assembly of highly repeatable large-scale multilayers with small nanoparticles remains a challenge. Here, we proposed a catassembly approach, where the "catassembly" means the increase in the rate and control of nanoparticle assembly dynamics. The catassembly approach was dropping heated Au sols onto oil chloroform (CHCl3), which triggers a rapid assembly of plasmonic multilayers within 15 s at the oil-water-air (O/W/A) interface. A mixture of heated sol and CHCl3 constructs a continuous liquid-air interfacial tension gradient; thus, the plasmonic multilayer film can form rapidly without adding functional ligands. Also, the dynamic assembly process of the three-phase catassembly ranging from cluster to interfacial film formation was observed through experimental characterization and COMSOL simulation. Importantly, the plasmonic multilayers of 10 nm Au NPs for SERS sensing demonstrated high sensitivity with the 1 nM level for crystal violet molecules and excellent stability with an RSD of about 10.0%, which is comparable to the detection level of 50 nm Au NPs with layer-by-layer assembly, as well as breaking the traditional and intrinsic understanding of small particles of plasmon properties. These plasmonic multilayers of 10 nm Au NPs through the three-phase catassembly method illustrate high SERS sensitivity and stability, paving the way for small-nanoparticle SERS sensing applications.

Study on the Stability Mechanism of Peanut OBs Extracted with the Aqueous Enzymatic Method.

In this study, the internal relationships among oil bodies (OBs), the protein-phospholipid interactions in aqueous phase, oil-water interface behavior, and the stability of reconstituted OBs were analyzed from the bulk phase, interface, and macro perspectives, and the stability mechanism of OBs was discussed. OB proteins and phospholipids were combined through hydrophobic and electrostatic interactions, resulting in the stretching of protein conformation. OB proteins and phospholipids act synergistically to increase interface pressure and the rate of increase in interface pressure with relatively stable elastic behavior, which is beneficial to the formation and stability of interfacial films. When OBs were reconstituted by an OB protein-phospholipid complex system, phospholipids bound to OB proteins through hydrophobic and electrostatic interactions. OB proteins and phospholipids uniformly covered the oil droplet surface of reconstituted OBs to form a stable interfacial film, which maintained the stability of OBs. The addition of phospholipids significantly reduced the particle size of OBs prepared by OB proteins in a dose-dependent manner, and particle size decreased with the increase in phospholipid content (p < 0.05). Phospholipids increased the net surface charge, enhanced electrostatic repulsion, and improved the physicochemical stability of reconstituted OBs. The stability mechanism elucidated in this study provides a theoretical basis for the demulsification of peanut OBs.

Analysis of polycarbonate degradation at melt/FeCr-alloy interfaces as a function of the alloy composition by means of combinatorial thin film chemistry

Interfacial reactions at the polycarbonate (PC)/FeCr-alloy interface during melt contact were studied as function of the Fe:Cr ratio within the alloy. Thin Fe/Cr films with lateral composition gradients were deposited by magnetron sputtering; the analysis of the films was done with microscopy and X-ray photoelectron spectroscopy (XPS). The local interfacial polymeric film formation could be therefore directly correlated with the Fe:Cr ratio. The local thickness and structure of the formed polycarbonate residue was analyzed by means of imaging ellipsometry, atomic force microscopy as well as Fourier-transform infrared spectroscopy under grazing incidence and XPS. Moreover, confocal fluorescence microscopy of the PC melt/alloy interface could reveal the formation of minor degradation products in the interphase region. The results show that already an Fe:Cr ratio of 2 : 1 leads to a strong inhibition of the thermal degradation in comparison to the unalloyed iron, and that in general, the enrichment of chromium in the passive film leads to an effective suppression of interfacial PC degradation. The data contributes to improving the mechanistic understanding of the role of iron during this process. Additionally, a critical concentration of chromium in the alloys used for PC processing can be deduced.

Effect of tannic acid modification on the interface and emulsification properties of zein colloidal particles.

Interface modification driven by supramolecular self-assembly has been accepted as a valuable strategy for emulsion stabilization enhancement. However, there has been a dearth of comparative research on the effect of simple complexation and assembly from the perspective of mechanism. This work selected zein and tannic acid (TA) as representative protein and polyphenol modules for self-assembly (coined as TA-modified zein particle and TA-zein complex particle) to explore the surface properties, interfacial behavior, as well as the stability of constructed Pickering emulsions to obtain the regulation law of different modification methods on the interfacial behavior of colloidal particles. The results demonstrated that TA-modified zein colloidal particles stood a chance of improving emulsifying properties. When the TA concentration was 3 mmol/L, the optimized TA-modified zein particle was nano-sized (109.83 nm) and had advantageous interfacial properties, including sharply reduced surface hydrophobicity, and low diffusion rate at the oil/water interface. As a result, the shelf life of Pickering emulsion containing 50% oil phase was extended to 90 days. Through multi-angled research on the properties of the interfacial membrane, improvement of emulsion stability was due to the formation of viscoelastic interfacial film which resulted from the decrease of absorption rate between particles and interface. Using refined regulation to study the role of different sample preparation methods from a mechanistic perspective. Overall, this study has provided a reference for TA to regulate the surface properties and interface behavior of zein colloidal particles, enriched the understanding of colloidal interface assembly, and provided a theoretical basis for the quality control of interface-oriented food systems. This article is protected by copyright. All rights reserved.

Research progress of organic liquid electrolyte for sodium ion battery.

Electrochemical energy storage technology has attracted widespread attention due to its low cost and high energy efficiency in recent years. Among the electrochemical energy storage technologies, sodium ion batteries have been widely focused due to the advantages of abundant sodium resources, low price and similar properties to lithium. In the basic structure of sodium ion battery, the electrolyte determines the electrochemical window and electrochemical performance of the battery, controls the properties of the electrode/electrolyte interface, and affects the safety of sodium ion batteries. Organic liquid electrolytes are widely used because of their low viscosity, high dielectric constant, and compatibility with common cathodes and anodes. However, there are problems such as low oxidation potential, high flammability and safety hazards. Therefore, the development of novel, low-cost, high-performance organic liquid electrolytes is essential for the commercial application of sodium ion batteries. In this paper, the basic requirements and main classifications of organic liquid electrolytes for sodium ion batteries have been introduced. The current research status of organic liquid electrolytes for sodium ion batteries has been highlighted, including compatibility with various types of electrodes and electrochemical properties such as multiplicative performance and cycling performance of electrode materials in electrolytes. The composition, formation mechanism and regulation strategies of interfacial films have been explained. Finally, the development trends of sodium ion battery electrolytes in terms of compatibility with materials, safety and stable interfacial film formation are pointed out in the future.

Dissipative Particle Dynamics-Based Simulation of the Effect of Asphaltene Structure on Oil-Water Interface Properties.

Asphaltenes are the main substances that stabilize emulsions during the production, processing, and transport of crude oil. The purpose of this research is to investigate the process of asphaltenes forming interfacial films at the oil-water interface by means of dissipative particle dynamics (DPD) and the effect of asphaltenes of different structures on the oil-water interface during the formation of interfacial film. It is demonstrated that the thickness of the interfacial film formed at the oil-water interface gradually increases as the asphaltene concentration rises and the amount of asphaltene adsorbed at the oil-water interface gradually multiplies. Both the number and type of heteroatoms in asphaltenes affect the interfacial behavior of asphaltenes. The interface activity of asphaltenes can be enhanced by increasing the number of heteroatoms in the asphaltene, and the type of heteroatom affects as well the interfacial activity of the asphaltene as it affects the aggregation behavior of the asphaltene in the system. As the number of asphaltene aromatic rings increases, the oil-water interfacial tension (IFT) trends down gradually, while the effect of alkyl side chains on the reduction of IFT of asphaltenes is different, and asphaltenes with medium length alkyl side chains can reduce IFT more efficiently.

Structuring liquids through solvent-assisted interfacial association of oppositely charged polyelectrolytes and amphiphiles

HypothesisSculpting liquids into different shapes is usually based on the interfacial interactions of functionalized nanoparticles or polymers with specific ligands, leading to exciting material properties due to the combination of the mobility of liquid components with the solid-like characteristic of the arrested liquid/liquid interface. There is an intense interest in novel structured liquids produced from simple compounds with versatile application potentials. Complexes of oppositely charged commercial polyelectrolytes and traditional aliphatic surfactants are good candidates for this goal since they reveal rich structural features and could adsorb at various interfaces. However, they have not been applied yet for structuring liquids. ExperimentsThe interfacial interactions and film formation between aqueous sodium poly(styrene) sulfonate solutions (NaPSS) and hexadecylamine (HDA) solutions in various alkanols were investigated by surface tension measurements and ATR-IR spectroscopy. 3D printing experiments also assessed the robustness of the formed films. FindingsArrested fatty alcohol/water interfaces were formed due to the interfacial association of NaPSS, HDA, and alkanol molecules, which also act as cosurfactants in the surface region. These solid films enable the synthesis of temperature-sensitive all-in-liquid constructs and offer alternatives to bulk polyion/mixed surfactant assemblies prepared earlier through numerous synthesis steps.