Colloids and Interfaces

17 pages, 4099 KB

Open AccessArticle

Synthesis of Quaternary Ammonium Gemini Levelers and Their Action Mechanisms in Microvias Void-Free Copper Filling

by Tao Song, Jun-Yi Wang, Jiang-Peng Qiu, Jia-Qiang Yang, Zhao-Yun Wang, Yi Zhao, Xiao-Hui Yang, Ren Hu, Jun Cheng, Fang-Zu Yang, Lian-Huan Han and Dong-Ping Zhan

Colloids Interfaces 2025, 9(5), 62; https://doi.org/10.3390/colloids9050062 - 15 Sep 2025

Abstract

Developing a highly efficient leveler in acid copper electroplating solution is one of the primary tasks necessary for achieving superconformal filling of microvias and interconnections in printed circuit boards (PCBs). Two triethylenediamine-based Gemini levelers, both with terminal quaternary ammonium groups, are synthesized and [...] Read more.

Developing a highly efficient leveler in acid copper electroplating solution is one of the primary tasks necessary for achieving superconformal filling of microvias and interconnections in printed circuit boards (PCBs). Two triethylenediamine-based Gemini levelers, both with terminal quaternary ammonium groups, are synthesized and named as GL1 (C8) after reaction of triethylenediamine with 1,8-dichlorooctane and GL2 (C6 with two C–O linkages) after triethylenediamine with 1,2-bis(2-chloroethoxy) ethane. Electrochemical experiments indicate that at 100 rpm and 1000 rpm GL2 combines with a suppressor and accelerator to exhibit greater potential difference of 23 mV than GL1 in 9 mV for Cu²⁺ reduction, demonstrating that GL2 has a stronger synergistic convection-dependent adsorption (CDA) effect. Microvias copper electroplating experiments confirm that acid copper electroplating solution containing GL2 achieve more effective superconformal void-free filling as it results in FP = 96.1%, while the solution containing GL1 results in FP = 70%. Theoretical calculations indicate that adsorption energy of GL2 is −1037.54 kJ·mol⁻¹, which is lower than GL1 (−1019.06 kJ·mol⁻¹). GL2 displays lower electron density compared to GL1, which facilitates its displacement by accelerator at the bottom. The lower adsorption energy of GL2 suggests the weaker adsorption ability and the stronger CDA behavior. Full article

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18 pages, 670 KB

Open AccessReview

Recent Developments and Applications of Food-Based Emulsifiers from Plant and Animal Sources

by Yuqiao Jin and Achyut Adhikari

Colloids Interfaces 2025, 9(5), 61; https://doi.org/10.3390/colloids9050061 - 10 Sep 2025

Abstract

Food-based emulsifiers, derived from natural or edible sources such as soybeans, oats, eggs, milk, and fruits, have gained increasing attention in the food industry due to their clean label appeal, recognition as natural ingredients, and alignment with consumer demand for fewer synthetic additives. [...] Read more.

Food-based emulsifiers, derived from natural or edible sources such as soybeans, oats, eggs, milk, and fruits, have gained increasing attention in the food industry due to their clean label appeal, recognition as natural ingredients, and alignment with consumer demand for fewer synthetic additives. These emulsifiers are also valued for their biodegradability, environmental sustainability, and potential nutritional benefits. The food-based compounds have been extensively studied for their functional and physicochemical properties. This review provides a comprehensive overview of recent developments and applications of food-based emulsifiers, with a focus on protein-based, polysaccharide-based, and phospholipid-based emulsifying agents derived from plant and animal sources. The mechanisms, advantages, and disadvantages of the food-based emulsifiers are discussed. Plant-based emulsifiers offer sustainability, wide availability, and cost-efficiency, positioning them as a promising area for research. Combinations of food-based emulsifiers such as polysaccharides, proteins, and phospholipids can be utilized to enhance emulsion stability. This paper evaluates current literature and discusses future challenges and trends in the development of food-based emulsifiers. Full article

(This article belongs to the Special Issue Recent Advances on Emulsions and Applications: 3rd Edition)

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11 pages, 10408 KB

Open AccessCommunication

Leaving Glauber’s Salt Island: The Road to Stabilisation

by Poppy O’Neill, Anastasia Stamatiou and Ludger Fischer

Colloids Interfaces 2025, 9(5), 60; https://doi.org/10.3390/colloids9050060 - 9 Sep 2025

Abstract

Glauber’s salt is a promising phase change material for thermal energy storage due to its high latent heat capacity of 234 J/g and melting point of 34 °C, making it well-suited for low-temperature heating applications. However, its practical use has been limited by [...] Read more.

Glauber’s salt is a promising phase change material for thermal energy storage due to its high latent heat capacity of 234 J/g and melting point of 34 °C, making it well-suited for low-temperature heating applications. However, its practical use has been limited by phase separation and associated loss of performance during repeated thermal cycling. This study aimed to address this limitation through a novel stabilisation approach. The material was encapsulated within an emulsion matrix designed to physically constrain the salt and inhibit separation during melting and to form a phase change dispersion. The phase change dispersion was subjected to 100 controlled heating–cooling cycles whilst monitoring the latent heat capacity and phase transition plateaus. The phase change dispersion retained its thermal properties throughout testing, showing no measurable degradation in storage capacity nor shift in phase transition temperature. These results demonstrate that this encapsulation mechanism can effectively maintain the functional performance of Glauber’s salt under repeated thermal cycling. This approach may form the basis for more durable salt hydrate-based storage media and has potential relevance for applications in building heating, waste heat recovery and renewable energy integration. By improving stability, this method helps unlock the long-term operational viability of phase change materials. Full article

(This article belongs to the Special Issue Recent Advances on Emulsions and Applications: 3rd Edition)

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12 pages, 2456 KB

Open AccessArticle

Drying Molybdate/Iron Hydroxide Interface Leading to Both Inner- and Outer-Sphere Surface Complexes Depending on Initial Concentrations

by Romain Botella and Grégory Lefèvre

Colloids Interfaces 2025, 9(5), 59; https://doi.org/10.3390/colloids9050059 - 5 Sep 2025

Abstract

Drying is ubiquitous. However, its influence on surface speciation has been seldom studied. Through an in situ Attenuated Total Reflection–Infrared (ATR-IR) spectroscopy analysis of the drying of molybdate solutions on a lepidocrocite particle film, the change in surface speciation is followed. No formation [...] Read more.

Drying is ubiquitous. However, its influence on surface speciation has been seldom studied. Through an in situ Attenuated Total Reflection–Infrared (ATR-IR) spectroscopy analysis of the drying of molybdate solutions on a lepidocrocite particle film, the change in surface speciation is followed. No formation polymolybdates nor precipitate are observed upon drying at pH 8. An in situ washing of the dried solid/solution interface unveils the existence of surface outer-sphere and inner-sphere complexes. Decreasing the molybdate concentration highlights a saturation effect of the surface upon drying. Moreover, the careful analysis of substrate IR bands showed non-uniform drying which is an important insight to understand dehydration chemistry. The remaining molybdate ions at the surface as inner-sphere complexes are present as binuclear monodentate complexes stabilized by sodium. Full article

(This article belongs to the Special Issue Ten Years Without Nikola Kallay)

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17 pages, 5055 KB

Open AccessArticle

Removal of Copper (II) from Aqueous Solutions Using Silica Xerogel as Sorbent: Adsorption Properties and Mechanism

by Ammaeva Shanaz, Isaev Abdulgalim, Schubert Richard, Pankov Ilya and Talanov Valery

Colloids Interfaces 2025, 9(5), 58; https://doi.org/10.3390/colloids9050058 - 1 Sep 2025

Abstract

The contamination of water resources with heavy metals creates problems for using it as a source of drinking water. Adsorption is one of the most promising methods for heavy metal ion removal from natural and wastewater. The process of removing copper (II) from [...] Read more.

The contamination of water resources with heavy metals creates problems for using it as a source of drinking water. Adsorption is one of the most promising methods for heavy metal ion removal from natural and wastewater. The process of removing copper (II) from aqueous solutions using SiO₂ xerogel as an adsorbent has been studied. The xerogel was thoroughly characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and argon adsorption–desorption isotherms, revealing an amorphous structure with a high surface area (~347 m²/g) and uniform mesoporosity (2–14 nm pore size). The surface chemistry, dominated by silanol groups, was confirmed by XPS analysis. The adsorption process is influenced by electrostatic interactions between the positively charged Cu(II) ions and the negatively charged surface groups, with the optimal performance near neutral pH. Batch adsorption experiments demonstrated that the silica xerogel effectively removes Cu(II) ions from aqueous solutions, with removal efficiency exceeding 99% at pH values above 4.0. The maximum adsorption capacity of copper (II) ions on SiO₂ xerogel is 67.5 mg/L. Full article

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15 pages, 4888 KB

Open AccessFeature PaperArticle

Rapid Removal of Sizing Agent from Carbon Fiber Surface by Liquid-Phase Plasma Electrolysis

by Chiyuhao Huang, Qian Zhou, Maoyuan Li, Xiaolin Wei, Dongqin Li, Xin He and Weiwei Chen

Colloids Interfaces 2025, 9(5), 57; https://doi.org/10.3390/colloids9050057 - 1 Sep 2025

Abstract

In this study, liquid-phase plasma electrolysis (LPE) was successfully employed to remove the sizing agent from T800 carbon fiber surfaces. Through systematic investigation of varying arcing voltages (185–215 V) and electrode spacings (10–20 mm), we determined that an optimal combination of 200 V [...] Read more.

In this study, liquid-phase plasma electrolysis (LPE) was successfully employed to remove the sizing agent from T800 carbon fiber surfaces. Through systematic investigation of varying arcing voltages (185–215 V) and electrode spacings (10–20 mm), we determined that an optimal combination of 200 V and 10 mm spacing achieved near-complete sizing removal, as confirmed by SEM, TGA, and XPS analyses. Under this condition, plasma bombardment dominated the removal mechanism, eliminating sizing residues while exposing the underlying fiber grooves. TGA further demonstrated that in samples treated at a 10 mm interval, the weight loss of LPE samples before 300 °C was negligible, indicating that the sizing agent had been thoroughly removed. The results of XPS further confirmed the high efficiency of LPE in the removal of sizing agents (C-O bond content from 41.6% to 26.9%), and the retention of C-O also proved that LPE could maintain the surface activity of carbon fibers, confirming the effectiveness of LPE in decomposing the sizing agent. Meanwhile, based on the above test results, an attempt was made to explain the mechanism of LPE in removing sizing agents from the surface of carbon fibers. Full article

(This article belongs to the Special Issue State of the Art of Colloid and Interface Science in Asia)

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17 pages, 1931 KB

Open AccessArticle

Improvement in the Stability of Perilla Seed Oil Microemulsion and Its Role in Fat Accumulation Reduction in Caenorhabditis elegans

by Junwei Pan, Yunzhou Tang, Ziqing Liang, Yong Cao and Yunjiao Chen

Colloids Interfaces 2025, 9(5), 56; https://doi.org/10.3390/colloids9050056 - 30 Aug 2025

Abstract

Perilla seed oil (PSO) possesses various physiological functions, such as lowering blood lipids and preventing cancer; however, its poor water solubility, dispersibility, and oxidative stability severely limit its application scope. Epigallocatechin gallate (EGCG) is a natural antioxidant abundant in tea leaves. In this [...] Read more.

Perilla seed oil (PSO) possesses various physiological functions, such as lowering blood lipids and preventing cancer; however, its poor water solubility, dispersibility, and oxidative stability severely limit its application scope. Epigallocatechin gallate (EGCG) is a natural antioxidant abundant in tea leaves. In this study, PSO–casein–EGCG microemulsions were prepared, and their stability and lipid-lowering effects were evaluated. The results showed that the PSO microemulsion had a particle size of 361.23 ± 14.85 nm, a zeta potential of −20.77 ± 0.68 mV, a polydispersity index (PDI) of 0.17 ± 0.07, and an encapsulation efficiency of 94.3%. PSO microemulsions remained stable at room temperature for 5 days without droplet aggregation. The stability of the microemulsions was good when the NaCl concentration was between 0.1 and 1 mM and the pH was between 5 and 9. PSO microemulsions enhanced the oxidative stability of PSO. Additionally, PSO microemulsions significantly reduced triglyceride levels in Caenorhabditis elegans (77.50%, p < 0.005). Finally, it was found that the average lipid droplet size of ZXW618 mutant nematodes decreased by 41.23% after PSO microemulsion treatment. Therefore, PSO microemulsions may reduce fat accumulation in C. elegans by decreasing lipid droplet size. This provides new insights for advancing the application of PSO in the food processing industry. Full article

(This article belongs to the Special Issue Recent Advances on Emulsions and Applications: 3rd Edition)

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20 pages, 3265 KB

Open AccessArticle

Phytochemical-Assisted Fabrication of Biogenic Silver Nanoparticles from Vitex negundo: Structural Features, Antibacterial Activity, and Cytotoxicity Evaluation

by Mohit Yadav, Nisha Gaur, Nitin Wahi, Sandeep Singh, Krishan Kumar, Azadeh Amoozegar and Eti Sharma

Colloids Interfaces 2025, 9(5), 55; https://doi.org/10.3390/colloids9050055 - 28 Aug 2025

Abstract

Multidrug resistance (MDR) is an emerging global health concern worldwide, driving the need for innovative solutions. Herbal approaches are gaining attention and acceptance due to safer profiles and very few side effects. In this study, silver nanoparticles (VN-AgNPs) were synthesized using Vitex negundo [...] Read more.

Multidrug resistance (MDR) is an emerging global health concern worldwide, driving the need for innovative solutions. Herbal approaches are gaining attention and acceptance due to safer profiles and very few side effects. In this study, silver nanoparticles (VN-AgNPs) were synthesized using Vitex negundo, a medicinally valuable plant. A methanolic extract was prepared from Vitex negundo and the phytochemical evaluation confirmed the presence of flavonoids, alkaloids, and terpenoids, with quantitative analysis revealing high total phenolic content (TPC: 23.59 mg GAE/g) and total flavonoid content (TFC: 45.23 mg rutin/g), both maximized under microwave-assisted extraction (MAE). The antioxidant activity was also highest (18.77 mg AA/g). Characterization of the optimized extract by GC–MS identified various bioactive compounds. VN-AgNPs were synthesized using the aqueous leaf extract under specified conditions and were structurally characterized using many techniques and evaluated for antibacterial activity against four bacterial strains. VN-AgNPs exhibited significant antibacterial efficacy with inhibition zones measuring 16 ± 0.87 mm against Bacillus (Gram-positive), 15 ± 0.46 mm against E. coli (Gram-negative), 12 ± 0.64 mm against Pseudomonas (Gram-negative), and 11 ± 0.50 mm against Pectobacterium (Gram-negative plant pathogen). These findings highlight the efficacy of green-synthesized VN-AgNPs as a promising alternative to combat MDR pathogens, paving the way for sustainable and effective antimicrobial strategies. Full article

(This article belongs to the Special Issue Biocolloids and Biointerfaces: 2nd Edition)

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22 pages, 2212 KB

Open AccessArticle

Bemotrizinol-Loaded Lipid Nanoparticles for the Development of Sunscreen Emulsions

by Maria Grazia Sarpietro, Debora Santonocito, Giuliana Greco, Stefano Russo, Carmelo Puglia and Lucia Montenegro

Colloids Interfaces 2025, 9(5), 54; https://doi.org/10.3390/colloids9050054 - 26 Aug 2025

Abstract

In this work, bemotrizinol (BMTZ), a broad-spectrum UV-filter, was loaded into nanostructured lipid carriers (NLC) whose lipid matrix contained different oils (isopropyl myristate, decyl oleate, caprylic/capric triglyceride) to assess the effects of the lipid core composition on the properties of the resulting NLC. [...] Read more.

In this work, bemotrizinol (BMTZ), a broad-spectrum UV-filter, was loaded into nanostructured lipid carriers (NLC) whose lipid matrix contained different oils (isopropyl myristate, decyl oleate, caprylic/capric triglyceride) to assess the effects of the lipid core composition on the properties of the resulting NLC. Subsequently, the effects of incorporating different concentrations of optimized BMTZ-loaded NLC on the technological properties of O/W emulsions (pH, viscosity, spreadability, occlusion factor, in vitro BMTZ release, skin permeation, and in vitro sun protection factor) were assessed. The optimized BMTZ-loaded NLC contained 3.0% w/w of isopropyl myristate and showed mean size = 190.6 ± 9.8 nm, polydispersity index = 0.153 ± 0.013, ζ-potential = −10.6 ± 1.7 mV, and loading capacity = 8% w/w. The incorporation of increasing concentrations (5, 10, 20% w/w) of optimized BMTZ loaded into emulsions provided a slight increase in spreadability, lower viscosity, and no change in pH, occlusion factor, and BMTZ release compared to emulsions containing free BMTZ. No BMTZ skin permeation was observed from all formulations. About a 20% increase in sun protection factor values was obtained for vehicles containing BMTZ-loaded NLC compared with formulations incorporating the same amount of free BMTZ. Therefore, incorporating BMTZ-loaded NLC into emulsions could be a promising strategy to develop safer and more effective sunscreen formulations. Full article

(This article belongs to the Special Issue Recent Advances on Emulsions and Applications: 3rd Edition)

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27 pages, 1363 KB

Open AccessFeature PaperReview

Promising Nanotechnology-Based Strategies for Melanoma Treatment

by Letícia Sias-Fonseca, Paulo C. Costa, Lucília Saraiva, Ana Alves and Maria Helena Amaral

Colloids Interfaces 2025, 9(4), 53; https://doi.org/10.3390/colloids9040053 - 20 Aug 2025

Abstract

Melanoma is a type of skin cancer with high lethality and increasing incidence. Current treatments typically involve surgery as the first step, followed by adjuvant treatments, which are necessary in most cases. These adjuvant treatments may include radiotherapy, phototherapy, chemotherapy, immunotherapy, and combined [...] Read more.

Melanoma is a type of skin cancer with high lethality and increasing incidence. Current treatments typically involve surgery as the first step, followed by adjuvant treatments, which are necessary in most cases. These adjuvant treatments may include radiotherapy, phototherapy, chemotherapy, immunotherapy, and combined therapies. However, patients with melanoma still face great difficulties, such as the inefficiency of therapies and serious side effects, in addition to uncomfortable scars. Most of these problems are related to limitations of antitumor therapies, such as the low bioavailability of drugs, degradation in biological fluids, rapid clearance, difficulty in reaching the tumors, the low capacity for accumulation and infiltration in tumor cells, toxicity to healthy cells, and systemic action. Thus, antitumor therapy for melanoma remains a challenge. In this line, nanotechnology has brought new perspectives and has been the subject of intensive research on the use of nanoparticles (liposomes, lipid nanoparticles, polymeric nanoparticles, inorganic nanoparticles, carbon nanotubes, dendrimers, nanogels, and biomimetic nanoparticles, among others) as carriers for the controlled release of drugs and tumor diagnosis. This work outlines the main limitations of current melanoma therapies and explores how nanoparticle-based drug delivery systems can overcome these challenges, highlighting recent research and clinical developments. Full article

(This article belongs to the Special Issue Feature Reviews in Colloids and Interfaces)

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18 pages, 2249 KB

Open AccessFeature PaperArticle

An Innovative Approach for Assessing Foam Stability Based on Electrical Conductivity Measurements of Liquid Films

by Angelos T. Zamanis, Sotiris P. Evgenidis, Thodoris D. Karapantsios and Margaritis Kostoglou

Colloids Interfaces 2025, 9(4), 52; https://doi.org/10.3390/colloids9040052 - 18 Aug 2025

Abstract

Foam stability plays a critical role in a wide range of industrial and scientific applications. In this study, an innovative method is presented for assessing foam stability through electrical conductivity measurements of liquid films formed within a controlled experimental setup. A modified horizontal [...] Read more.

Foam stability plays a critical role in a wide range of industrial and scientific applications. In this study, an innovative method is presented for assessing foam stability through electrical conductivity measurements of liquid films formed within a controlled experimental setup. A modified horizontal glass capillary system with vertically aligned copper electrodes was developed, allowing the continuous monitoring of film drainage and rupture behavior under precise humidity (92% RH) and temperature (30 °C). Experiments were conducted using various concentrations of sodium dodecyl sulfate and Ethylan 1005, with and without NaCl addition. The results demonstrate that film stability increases with higher surfactant concentrations up to a point, beyond which the addition of salt can have either stabilizing or destabilizing effects depending on whether concentration levels are below or above the Critical Micelle Concentration (CMC). At sub-CMC levels, NaCl enhanced film stability by promoting surfactant adsorption and reducing electrostatic repulsion. Conversely, in super-CMC conditions, NaCl led to film destabilization, likely due to changes in interfacial structure and micellar behavior. This approach provides a simple, sensitive, and reproducible technique to quantitatively characterize foam film stability, offering key mechanistic insights and practical guidance for the formulation and optimization of foaming systems across diverse applications. Full article

(This article belongs to the Special Issue Exclusive Papers of the Editorial Board Members of Colloids and Interfaces 2024–2025)

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15 pages, 1643 KB

Open AccessFeature PaperArticle

Towards Building a Unified Adsorption Model for Goethite Based on Variable Crystal Face Contributions: III Carbonate Adsorption

by Mario Villalobos and América Xitlalli Cruz-Valladares

Colloids Interfaces 2025, 9(4), 51; https://doi.org/10.3390/colloids9040051 - 18 Aug 2025

Abstract

Goethite, a ubiquitous Fe(III) oxyhydroxide mineral, typically occurs in very small particle sizes whose interfacial properties critically influence the fate and transport of ionic species in natural systems. The surface site density of synthetic goethite increases with particle size, resulting in enhanced adsorption [...] Read more.

Goethite, a ubiquitous Fe(III) oxyhydroxide mineral, typically occurs in very small particle sizes whose interfacial properties critically influence the fate and transport of ionic species in natural systems. The surface site density of synthetic goethite increases with particle size, resulting in enhanced adsorption capacity per unit area. In the first two parts of this study, we modeled the adsorption of protons, nitrate, As(V), Pb(II), Zn(II), and phosphate on goethite as a function of particle size, adsorbate concentration, pH, and ionic strength, using unified parameters within the CD-MUSIC framework. Here, we extend this work to characterize the interfacial behavior of carbonate in goethite suspensions, using a comprehensive dataset generated previously under both closed and open CO₂ system conditions. Carbonate oxyanions, prevalent in geochemical environments, exhibit competitive and complexation interactions with other ions and mineral surfaces. Although a bidentate bridging surface carbonate complex has been successful in previous modeling efforts on goethite, we found that the size of the carbonate moiety is too small and would require extreme octahedron bending of the goethite’s singly coordinated sites to accommodate this type of binding. Here, we propose a novel complex configuration that considers structural, physicochemical, and spectroscopic evidence. Optimal unified affinity constants and charge distribution parameters for this complex simulated all experimental data successfully, providing further validation of the CD-MUSIC model for describing relevant goethite/aqueous interfacial reactions. Full article

(This article belongs to the Special Issue Ten Years Without Nikola Kallay)

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18 pages, 19925 KB

Open AccessFeature PaperArticle

The Precipitation of Calcium Carbonate in the Presence of Macromolecules Isolated from Corals

by Jasminka Kontrec, Nives Matijaković Mlinarić, Damir Kralj, Giuseppe Falini, Atiđa Selmani, Stefano Goffredo and Branka Njegić Džakula

Colloids Interfaces 2025, 9(4), 50; https://doi.org/10.3390/colloids9040050 - 15 Aug 2025

Abstract

This study investigated the CaCO₃ spontaneous precipitation in the presence of soluble organic macromolecules (SOMs) extracted from the skeleton of Mediterranean colonial coral species, symbiotic Cladocora caespitosa (SOM-CCA) and asymbiotic Astroides calycularis (SOM-ACL). This approach was used as a model to explore [...] Read more.

This study investigated the CaCO₃ spontaneous precipitation in the presence of soluble organic macromolecules (SOMs) extracted from the skeleton of Mediterranean colonial coral species, symbiotic Cladocora caespitosa (SOM-CCA) and asymbiotic Astroides calycularis (SOM-ACL). This approach was used as a model to explore biomineralization processes in marine organisms. The research was conducted in systems without or with the addition of Mg²⁺ (Mg/Ca molar ratio was 5:1) and/or SOMs (concentration range was 0.5–4 ppm). In the model system (system without Mg²⁺ or SOMs), only vaterite spherulites precipitated, while in the system with added Mg²⁺, only aragonite irregular aggregates were observed. Although the addition of SOMs did not influence the polymorphic composition of the CaCO₃ precipitates, it led to noticeable changes in induction time and morphology of CaCO₃ crystals, and these effects were stronger in the presence of SOM-ACL. By comparing systems containing both Mg²⁺ and SOM with the model system as well as with systems where Mg²⁺ or SOMs were added individually, the dominant role of Mg²⁺ in the aragonite formation was observed. However, the combined effect of Mg²⁺ and both SOMs enhanced the inhibition of CaCO₃ precipitation. This inhibitory effect was particularly enhanced in the system combining Mg²⁺ and SOM-ACL. Full article

(This article belongs to the Special Issue Ten Years Without Nikola Kallay)

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10 pages, 2398 KB

Open AccessArticle

APTES-Modified Interface Optimization in PbS Quantum Dot SWIR Photodetectors and Its Influence on Optoelectronic Properties

by Qian Lei, Lei Rao, Wencan Deng, Xiuqin Ao, Fan Fang, Wei Chen, Jiaji Cheng, Haodong Tang and Junjie Hao

Colloids Interfaces 2025, 9(4), 49; https://doi.org/10.3390/colloids9040049 - 22 Jul 2025

Abstract

Lead sulfide colloidal quantum dots (PbS QDs) have demonstrated great potential in short-wave infrared (SWIR) photodetectors due to their tunable bandgap, low cost, and broad spectral response. While significant progress has been made in surface ligand modification and defect state passivation, studies focusing [...] Read more.

Lead sulfide colloidal quantum dots (PbS QDs) have demonstrated great potential in short-wave infrared (SWIR) photodetectors due to their tunable bandgap, low cost, and broad spectral response. While significant progress has been made in surface ligand modification and defect state passivation, studies focusing on the interface between QDs and electrodes remain limited, which hinders further improvement in device performance. In this work, we propose an interface engineering strategy based on 3-aminopropyltriethoxysilane (APTES) to enhance the interfacial contact between PbS QD films and ITO interdigitated electrodes, thereby significantly boosting the overall performance of SWIR photodetectors. Experimental results demonstrate that the optimal 0.5 h APTES treatment duration significantly enhances responsivity by achieving balanced interface passivation and charge carrier transport. Moreover, The APTES-modified device exhibits a controllable dark current and faster photo-response under 1310 nm illumination. This interface engineering approach provides an effective pathway for the development of high-performance PbS QD-based SWIR photodetectors, with promising applications in infrared imaging, spectroscopy, and optical communication. Full article

(This article belongs to the Special Issue State of the Art of Colloid and Interface Science in Asia)

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17 pages, 6759 KB

Open AccessReview

Novel Structural Janus Hydrogels for Battery Applications: Structure Design, Properties, and Prospects

by Ping Li and Qiushi Wang

Colloids Interfaces 2025, 9(4), 48; https://doi.org/10.3390/colloids9040048 - 19 Jul 2025

Cited by 1

Abstract

Janus hydrogels, defined by their asymmetric architectures and bifunctional interfaces, have emerged as a transformative class of solid-state electrolytes in electrochemical energy storage. By integrating spatially distinct chemomechanical and ionic functionalities within a single matrix, they overcome the intrinsic limitations of conventional isotropic [...] Read more.

Janus hydrogels, defined by their asymmetric architectures and bifunctional interfaces, have emerged as a transformative class of solid-state electrolytes in electrochemical energy storage. By integrating spatially distinct chemomechanical and ionic functionalities within a single matrix, they overcome the intrinsic limitations of conventional isotropic hydrogels, offering enhanced interfacial stability, directional ion transport, and dendrite suppression in lithium- and zinc-based batteries. This mini-review systematically highlights recent breakthroughs in Janus hydrogel design, including interfacial polymerization and layer-by-layer assembly, which collectively enable precise modulation of crosslinking gradients and ion transport pathways. This review uniquely frames Janus hydrogels from a battery-centric and interface-engineering perspective. It elucidates key structure–function correlations, identifies current limitations in scalable fabrication and electrochemical longevity, and outlines future directions toward intelligent, multifunctional platforms for next-generation flexible and biointegrated energy systems. Full article

(This article belongs to the Special Issue State of the Art of Colloid and Interface Science in Asia)

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36 pages, 6346 KB

Open AccessArticle

Thermoresponsive Effects in Droplet Size Distribution, Chemical Composition, and Antibacterial Effectivity in a Palmarosa (Cymbopogon martini) O/W Nanoemulsion

by Erick Sánchez-Gaitán, Ramón Rivero-Aranda, Vianney González-López and Francisco Delgado

Colloids Interfaces 2025, 9(4), 47; https://doi.org/10.3390/colloids9040047 - 19 Jul 2025

Abstract

The design of emulsions at the nanoscale is a significant application of nanotechnology. For spherical droplets and a given volume of dispersed phase, the nanometre size of droplets inversely increases the total area,

A = \frac{3 V}{r}

, allowing greater contact with [...] Read more.

The design of emulsions at the nanoscale is a significant application of nanotechnology. For spherical droplets and a given volume of dispersed phase, the nanometre size of droplets inversely increases the total area,

A = \frac{3 V}{r}

, allowing greater contact with organic and inorganic materials during application. In topical applications, not only is cell contact increased, but also permeability in the cell membrane. Nanoemulsions typically achieve kinetic stability rather than thermodynamic stability, so their commercial application requires reasonable resistance to flocculation and coalescence, which can be affected by temperature changes. Therefore, their thermoresponsive characterisation becomes relevant. In this work, we analyse this response in an O/W nanoemulsion of Palmarosa for antibacterial purposes that has already shown stability for one year at controlled room temperature. We now study hysteresis processes and the behaviour of the statistical distribution in droplet size by Dynamic Light Scattering, obtaining remarkable stability under temperature changes up to 50 °C. This includes a maintained chemical composition observed using Fourier Transform Infrared Spectroscopy and the preservation of antibacterial properties analysed through optical density tests on cultures and the Spread-Plate technique for bacteria colony counting. We obtain practically closed hysteresis curves for some tracers of droplet size distributions through controlled thermal cycles between 10 °C and 50 °C, exhibiting a non-linear behaviour in their distribution. In general, the results show notable physical, chemical, and antibacterial stability, suitable for commercial applications. Full article

(This article belongs to the Special Issue Recent Advances on Emulsions and Applications: 3rd Edition)

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17 pages, 2732 KB

Open AccessFeature PaperArticle

Influence of Cellulose Nanocrystals and Surfactants on Catastrophic Phase Inversion and Stability of Emulsions

by Daniel Kim and Rajinder Pal

Colloids Interfaces 2025, 9(4), 46; https://doi.org/10.3390/colloids9040046 - 11 Jul 2025

Abstract

This study presents the first quantitative comparison of catastrophic phase inversion behavior of water-in-oil emulsions stabilized by nanocrystalline cellulose (NCC) and molecular surfactants with different headgroup charge types: anionic (sodium dodecyl sulfate referred to as SDS), cationic (octadecyltrimethylammonium chloride referred to as OTAC), [...] Read more.

This study presents the first quantitative comparison of catastrophic phase inversion behavior of water-in-oil emulsions stabilized by nanocrystalline cellulose (NCC) and molecular surfactants with different headgroup charge types: anionic (sodium dodecyl sulfate referred to as SDS), cationic (octadecyltrimethylammonium chloride referred to as OTAC), nonionic (C12–14 alcohol ethoxylate referred to as Alfonic), and zwitterionic (cetyl betaine referred to as Amphosol). By using conductivity measurements under controlled mixing and pendant drop tensiometry, this study shows that NCC markedly delays catastrophic phase inversion through interfacial jamming, whereas surfactant-stabilized systems exhibit concentration-dependent inversion driven by interfacial saturation. Specifically, NCC-stabilized emulsions exhibited a nonlinear increase in the critical aqueous phase volume fraction required for inversion, ranging from 0.253 (0 wt% NCC) to 0.545 (1.5 wt% NCC), consistent with enhanced resistance to inversion typically associated with the formation of rigid interfacial layers in Pickering emulsions. In contrast, surfactant-stabilized systems exhibited a concentration-dependent inversion trend with opposing effects. At low concentrations, limited interfacial coverage delayed inversion, while at higher concentrations, increased surfactant availability and interfacial saturation promoted earlier inversion and favored the formation of oil-in-water structures. Pendant drop tensiometry confirmed negligible surface activity for NCC, while all surfactants significantly lowered interfacial tension. Despite its weak surface activity, NCC imparted strong coalescence resistance above 0.2 wt%, attributed to steric stabilization. These findings establish distinct mechanisms for governing phase inversion in particle- versus surfactant-stabilized systems. To our knowledge, this is the first study to quantitively characterize the catastrophic phase inversion behavior of water-in-oil emulsions using NCC. This work supports the use of NCC as an effective stabilizer for emulsions with high internal phase volume. Full article

(This article belongs to the Special Issue Rheology of Complex Fluids and Interfaces: 2nd Edition)

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24 pages, 3309 KB

Open AccessArticle

Optical Investigation of the Combined Effect of pH and Temperature on the Interactions of BSA Protein with Iron Oxide Nanoparticles

by Elena A. Molkova, Ruslan M. Sarimov, Tatyana A. Matveeva, Alexander V. Simakin, Arthur G. Akopdzhanov, Dmitriy A. Serov, Maksim B. Rebezov, Maxim E. Astashev, Konstantin V. Sergienko, Mikhail A. Sevostyanov, Dmitriy O. Khort, Igor G. Smirnov, Alexey S. Dorokhov, Andrey Yu. Izmailov and Sergey V. Gudkov

Colloids Interfaces 2025, 9(4), 45; https://doi.org/10.3390/colloids9040045 - 7 Jul 2025

Abstract

The effect of pH and temperature on the interaction of sodium citrate-coated magnetic iron oxide nanoparticles (IONPs) with the BSA protein was studied using optical methods. The optical properties of aqueous colloids of BSA, IONPs, and BSA with IONPs were studied with pH [...] Read more.

The effect of pH and temperature on the interaction of sodium citrate-coated magnetic iron oxide nanoparticles (IONPs) with the BSA protein was studied using optical methods. The optical properties of aqueous colloids of BSA, IONPs, and BSA with IONPs were studied with pH changes in the range of 2–12 and temperature in the range of 25–85 °C. It was found that at pH 2.0, no significant changes in the optical properties were observed with increasing temperature in aqueous colloids containing a mixture of BSA with IONPs. Temperature affects the optical properties of BSA colloids with IONPs in the pH range from 5.0 to 8.0. Moreover, by increasing the temperature at these pH levels, it is possible to control the particle size in the colloids. In general, both temperature and pH have a significant effect on the properties of the aqueous colloid of BSA with IONPs and allow for the control of interactions between BSA and IONPs, namely, the processes of aggregation, particle reclustering, and protein denaturation. Full article

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30 pages, 4213 KB

Open AccessFeature PaperReview

The Effect of Adsorption Phenomena on the Transport in Complex Electrolytes

by Ioulia Chikina, Michel Beaughon, Pierre Burckel, Emmanuelle Dubois, Ivan T. Lucas, Sawako Nakamae, Ozlem Sel, Hubert Perrot, Régine Perzynski, Thomas J. Salez, Blanca E. Torres-Bautista and Andrey Varlamov

Colloids Interfaces 2025, 9(4), 44; https://doi.org/10.3390/colloids9040044 - 7 Jul 2025

Abstract

Over the last decade, numerous impedance studies of the conductivity of suspensions containing colloidal (dielectric, semiconducting or metallic) particles have often led to the conclusion that the well-known Maxwell theory is insufficient to quantitatively explain the properties of these systems. We review some [...] Read more.

Over the last decade, numerous impedance studies of the conductivity of suspensions containing colloidal (dielectric, semiconducting or metallic) particles have often led to the conclusion that the well-known Maxwell theory is insufficient to quantitatively explain the properties of these systems. We review some of the most characteristic results and show how the applicability of the Maxwell’s theory can be restored taking into account the adsorption phenomena occurring during AC impedance measurements in nanoparticle suspensions. The latter can drastically change the capacitance of the metal-electrolyte cell boundaries from the standard value, making it strongly dependent on the nanoparticle concentration. This factor significantly affects conductivity measurements through RC circuit characteristics. We present an analysis of available impedance measurement data of the dependence of conductivity on the nanoparticle concentration in this new paradigm. In order to emphasize the novelty and the acute sensitivity of ac-diagnosis to the presence of adsorption phenomena at the metal-electrolyte interface, direct adsorption determinations at such interfaces by using two modern experimental techniques are also presented. The main result of this work is the restoration of Maxwell’s theory, attributing the observed discrepancies to variations in cell conductance. Full article

(This article belongs to the Special Issue Feature Reviews in Colloids and Interfaces)

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