Submit to Molecules Review for Molecules Propose a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Amphiphilic Molecules, Interfaces and Colloids

Special Issue Editors
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Related Special Issue
Published Papers

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Physical Chemistry".

Deadline for manuscript submissions: closed (31 October 2024) | Viewed by 9588

Share This Special Issue

Special Issue Editors

Dr. Khristo Khristov

E-Mail Website
Guest Editor

Institute of Physical Chemistry, Bulgarian Academy of Science, 1113 Sofia, Bulgaria
Interests: emulsion and foams; thin liquid films; interfacial and bulk rheology; heavy crude oil; petroleum emulsions; electrochemical impedance spectroscopy of thin film; self-assembly
Special Issues, Collections and Topics in MDPI journals

Dr. Plamen Tchoukov

E-Mail Website
Guest Editor

Institute of Physical Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
Interests: emulsion and foams; thin liquid films; interfacial and bulk rheology; heavy crude oil; petroleum emulsions; electrochemical impedance spectroscopy of thin film; self-assembly
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Colloids, such as emulsions, foams, sols, and gels, play an integral role in living organisms, the natural environment, resource extraction, pharmaceuticals, cleaning products, processing industries, and in almost all aspects of our everyday life. To a large extent, colloid stability and functionality are defined by the properties of interfaces between dispersed and continuous phases and by the surface forces acting at the micro- and nanoscale levels. It is the amphiphilic molecules that are capable of altering colloidal system properties, thus changing the overall system behavior. This is why a comprehensive understanding of amphiphile molecular structure and the respective interactions taking place at the interfaces ensures an effective control over colloidal system properties.

For this Special Issue, we welcome contributions which highlight the relation between amphiphile molecular structure, self-assembly in solutions, molecular arrangements at interfaces, specific interactions at micro- and nanoscale, and the properties displayed by the colloidal systems. Suitable research will span from fundamental studies on the physicochemical behavior of colloidal systems to the design of innovative solutions for practical applications.

Dr. Khristo Khristov
Dr. Plamen Tchoukov
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

emulsions
foams
sols
gels
amphiphilic molecules
self-assembled structures
phase behavior
surface forces
intermolecular forces
adsorption
rheology
design of functionalized colloids
thin liquid films

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Related Special Issue

Amphiphilic Molecules, Interfaces and Colloids: 2nd Edition in Molecules (1 article)

Published Papers (10 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

13 pages, 5498 KiB

Open AccessArticle

Stimuli-Responsive Vesicles and Hydrogels Formed by a Single-Tailed Dynamic Covalent Surfactant in Aqueous Solutions

by Chunlin Xu, Na Sun, Huaixiu Li, Xingchen Han, Ailing Zhang and Panpan Sun

Molecules 2024, 29(21), 4984; https://doi.org/10.3390/molecules29214984 - 22 Oct 2024

Viewed by 561

Abstract

Controlling the hierarchical self-assembly of surfactants in aqueous solutions has drawn much attention due to their broad range of applications, from targeted drug release, preparation of smart material, to biocatalysis. However, the synthetic procedures for surfactants with stimuli-responsive hydrophobic chains are complicated, which restricts the development of surfactants. Herein, a novel single-tailed responsive surfactant, 1-methyl-3-(2-(4-((tetradecylimino) methyl) phenoxy) ethyl)-3-imidazolium bromides (C₁₄PMimBr), was facilely fabricated in situ by simply mixing an aldehyde-functionalized imidazolium cation (3-(2-(4-formylphenoxy) ethyl)-1-methyl imidazolium bromide, BAMimBr) and aliphatic amine (tetradecylamine, TDA) through dynamic imine bonding. With increasing concentration, micelles, vesicles, and hydrogels were spontaneously formed by the hierarchical self-assembly of C₁₄PMimBr in aqueous solutions without any additives. The morphologies of vesicles and hydrogels were characterized by cryogenic transmission electron microscopy and scanning electron microscopy. The mechanical properties and microstructure information of hydrogels were demonstrated by rheological measurement, X-ray diffraction, and density functional theory calculation. In addition, the vesicles could be disassembled and reassembled with the breakage and reformation of imine bonds by adding acid/bubbling CO₂ and adding alkali. This work provides a simple method for constructing stimuli-responsive surfactant systems and shows great potential application in targeted drug release, drug delivery, and intelligent materials. Full article

(This article belongs to the Special Issue Amphiphilic Molecules, Interfaces and Colloids)

► Show Figures

Graphical abstract

16 pages, 2887 KiB

Open AccessArticle

Influence of Linear Diamine Counterions on the Self-Assembly of Glycine-, Alanine-, Valine-, and Leucine-Based Amphiphiles

by Margarita Angel Alvarez, Nathan Black, Saylor Estelle Blanco, Katelyn Ruth Reid, Eugene J. Billiot, Fereshteh H. Billiot and Kevin F. Morris

Molecules 2024, 29(18), 4436; https://doi.org/10.3390/molecules29184436 - 18 Sep 2024

Viewed by 497

Abstract

Electrical conductimetry and dynamic light scattering (DLS) were used to investigate the aggregation behaviors of four amino acid-based surfactants (AABSs; undecanoyl-glycine, undecanoyl-l-alanine, undecanoyl-l-valine, undecanoyl-l-leucine) in the presence of five linear diamine counterions (1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane). Electrical conductimetry was used to measure the CMCs for each system, which ranged from 5.1 to 22.5 mM. With respect to counterions, the obtained CMCs decreased with increases in the interamine spacer length; this was attributed to the improved torsional binding flexibility in longer counterions. Strong linear correlations (mean R² = 0.9443) were observed between the CMCs and predicted surfactant partition coefficients (logP; water/octanol), suggesting that micellization is primarily driven by the AABS’s hydrophobicity for these systems. However, significant deviations in this linear relationship were observed for systems containing 1,2-diaminoethane, 1,4-diaminobutane, and 1,6-diaminohexane (p = 0.0774), suggesting altered binding dynamics for these counterions. pH measurements during the CMC determination experiments indicated the full deprotonation of the AABSs but did not give clear insights into the counterion protonation states, thus yielding an inconclusive evaluation of their charge stabilization effects during binding. However, DLS measurements revealed that the micellar size remained largely independent of the counterion length for counterions longer than 1,2-diaminoethane, with hydrodynamic diameters ranging from 2.2 to 2.8 nm. This was explained by the formation of charge-stabilized noncovalent dimers, with each counterion bearing a full +2 charge. Conductimetry-based estimates of the degrees of counterion binding (β) and free energies of micellization (ΔG°_M) revealed that bulky AABSs exhibit preferential binding to counterions with an even number of methylene groups. It is proposed that when these counterions form noncovalent dimers, perturbations in their natural geometries result in the formation of a binding pocket that accommodates the AABS steric bulk. While the direct application of these systems remains to be seen, this study provides valuable insights into the structure–property relationships that govern AABS aggregation. Full article

(This article belongs to the Special Issue Amphiphilic Molecules, Interfaces and Colloids)

► Show Figures

Graphical abstract

14 pages, 4302 KiB

Open AccessArticle

Investigation of the Aggregation of Aβ Peptide (1-40) in the Presence of κ-Carrageenan-Stabilised Liposomes Loaded with Homotaurine

by Kamelia Kamburova, Ivaylo L. Dimitrov, Feyzim Hodzhaoglu and Viktoria Milkova

Molecules 2024, 29(15), 3460; https://doi.org/10.3390/molecules29153460 - 24 Jul 2024

Viewed by 692

Abstract

The kinetics of amyloid aggregation was studied indirectly by monitoring the changes in the polydispersity of mixed dispersion of amyloid β peptide (1-40) and composite liposomes. The liposomes were prepared from the 1,2-dioleoyl-sn-glicero-3-phoshocholine (DOPC) phospholipid and stabilised by the electrostatic adsorption of κ-carrageenan. The produced homotaurine-loaded and unloaded liposomes had a highly negative electrokinetic potential and remarkable stability in phosphate buffer (pH 4 and 7.4). For the first time, the appearance and evolution of the aggregation of Aβ were presented through the variation in the standard percentile readings (D10, D50, and D90) obtained from the particle size distribution analysis. The kinetic experiments indicated the appearance of the first aggregates almost 30 min after mixing the liposomes and peptide solution. It was observed that by adding unloaded liposomes, the size of 90% of the particles in the dispersion (D90) increased. In contrast, the addition of homotaurine-loaded liposomes had almost minimal impact on the size of the fractions of larger particles during the kinetic experiments. Despite the specific bioactivity of homotaurine in the presence of natural cell membranes, this study reported an additional inhibitory effect of the compound on the amyloid peptide aggregation due to the charge effects and ‘molecular crowding’. Full article

(This article belongs to the Special Issue Amphiphilic Molecules, Interfaces and Colloids)

► Show Figures

Figure 1

15 pages, 2733 KiB

Open AccessArticle

Capillarity in Interfacial Liquids and Marbles: Mechanisms, Properties, and Applications

by Yang Liu, Yuanfeng Wang and John H. Xin

Molecules 2024, 29(13), 2986; https://doi.org/10.3390/molecules29132986 - 23 Jun 2024

Viewed by 1178

Abstract

The mechanics of capillary force in biological systems have critical roles in the formation of the intra- and inter-cellular structures, which may mediate the organization, morphogenesis, and homeostasis of biomolecular condensates. Current techniques may not allow direct and precise measurements of the capillary forces at the intra- and inter-cellular scales. By preserving liquid droplets at the liquid–liquid interface, we have discovered and studied ideal models, i.e., interfacial liquids and marbles, for understanding general capillary mechanics that existed in liquid-in-liquid systems, e.g., biomolecular condensates. The unexpectedly long coalescence time of the interfacial liquids revealed that the Stokes equation does not hold as the radius of the liquid bridge approaches zero, evidencing the existence of a third inertially limited viscous regime. Moreover, liquid transport from a liquid droplet to a liquid reservoir can be prohibited by coating the droplet surface with hydrophobic or amphiphilic particles, forming interfacial liquid marbles. Unique characteristics, including high stability, transparency, gas permeability, and self-assembly, are observed for the interfacial liquid marbles. Phase transition and separation induced by the formation of nanostructured materials can be directly observed within the interfacial liquid marbles without the need for surfactants and agitation, making them useful tools to research the interfacial mechanics. Full article

(This article belongs to the Special Issue Amphiphilic Molecules, Interfaces and Colloids)

► Show Figures

Graphical abstract

19 pages, 2534 KiB

Open AccessArticle

Aggregation Behavior and Application Properties of Novel Glycosylamide Quaternary Ammonium Salts in Aqueous Solution

by Yunkai Wang, Zeyu Chen, Erzhuang Zhang, Lifei Zhi, Martino Di Serio, Guoyong Wang, Yan Wang, Xiaoming Li, Xudong Liu and Ying Huang

Molecules 2024, 29(12), 2749; https://doi.org/10.3390/molecules29122749 - 9 Jun 2024

Viewed by 883

Abstract

Amidation of lactobionic acid with N,N-dimethylaminopropyltriamine was conducted to obtain N-(3′-dimethylaminopropyl)-lactamido-3-aminopropane (DDLPD), which was quaternized with bromoalkanes of different carbon chain lengths to synthesize double-stranded lactosylamide quaternary ammonium salt N-[N′[3-(lactosylamide)]propyl-N′-alkyl] propyl-N,N-dimethyl-N-alkylammonium bromide (C_nDDLPB, n = 8, 10, 12, 14, 16). The surface activity and the adsorption and aggregation behaviors of the surfactants were investigated via equilibrium surface tension, dynamic light scattering, and cryo-electron microscopy measurements in an aqueous solution. The application properties of the products in terms of wettability, emulsification, foam properties, antistatic, salt resistance, and bacteriostatic properties were tested. C_nDDLPB exhibited a low equilibrium surface tension of 27.82 mN/m. With an increase in the carbon chain length, the critical micellar concentration of C_nDDLPBD decreased. Cryo-electron microscopy revealed that all products except C₈DDLPB formed stable monolayer, multi-layer, and multi-compartmental vesicle structures in an aqueous solution. C₁₄DDLPB has the best emulsification performance on soybean oil, with a time of 16.6 min; C₁₄DDLPB has good wetting and spreading properties on polytetrafluoroethylene (PTFE) when the length of carbon chain is from 8 to 14, and the contact angle can be lowered to 33°~40°; C_nDDLPB has low foam, which is typical of low-foaming products; C₈DDLPB and C₁₀DDLPB both show good antistatic properties. C₈DDLPB and C₁₄DDLPB have good salt resistance, and C₁₂DDLPB has the best antimicrobial property, with the inhibition rate of 99.29% and 95.28% for E. coli and Gluconococcus aureus, respectively, at a concentration of 350 ppm. Full article

(This article belongs to the Special Issue Amphiphilic Molecules, Interfaces and Colloids)

► Show Figures

Figure 1

14 pages, 2568 KiB

Open AccessArticle

Dispersive Solid Phase Extraction of Melatonin with Graphene/Clay Mixtures and Fluorescence Analysis in Surfactant Aqueous Solutions

by Lucía Gutiérrez-Fernández, Ana M. Díez-Pascual and María Paz San Andrés

Molecules 2024, 29(11), 2699; https://doi.org/10.3390/molecules29112699 - 6 Jun 2024

Viewed by 746

Abstract

In this work, the dispersive solid phase extraction (dSPE) of melatonin using graphene (G) mixtures with sepiolite (SEP) and bentonite (BEN) clays as sorbents combined with fluorescence detection has been investigated. The retention was found to be quantitative for both G/SEP and G/BEN 4/96 and 10/90 w/w mixtures. G/clay 4/96 w/w mixtures were selected to study the desorption process since the retention was weaker, thus leading to easier desorption. MeOH and aqueous solutions of the nonionic surfactant Brij L23 were tested as desorbents. For both clays and an initial sample volume of 25 mL, a percentage of melatonin recovery close to 100% was obtained using 10 or 25 mL of MeOH as desorbent. Further, using a G/SEP mixture, 25 mL as the initial sample volume and 5 mL of MeOH or 60 mM Brij L23 solution as the desorbent, recoveries of 98.3% and 90% were attained, respectively. The whole method was applied to herbal tea samples containing melatonin, and the percentage of agreement with the labeled value was 86.5%. It was also applied to herbal samples without melatonin by spiking them with two concentrations of this compound, leading to recoveries of 100 and 102%. Full article

(This article belongs to the Special Issue Amphiphilic Molecules, Interfaces and Colloids)

► Show Figures

Figure 1

15 pages, 6633 KiB

Open AccessArticle

A Fusion–Growth Protocell Model Based on Vesicle Interactions with Pyrite Particles

by Dong Guo, Ziyue Zhang, Jichao Sun, Hui Zhao, Wanguo Hou and Na Du

Molecules 2024, 29(11), 2664; https://doi.org/10.3390/molecules29112664 - 4 Jun 2024

Viewed by 819

Abstract

Protocell models play a pivotal role in the exploration of the origin of life. Vesicles are one type of protocell model that have attracted much attention. Simple single-chain amphiphiles (SACs) and organic small molecules (OSMs) possess primitive relevance and were most likely the building blocks of protocells on the early Earth. OSM@SAC vesicles have been considered to be plausible protocell models. Pyrite (FeS₂), a mineral with primitive relevance, is ubiquitous in nature and plays a crucial role in the exploration of the origin of life in the mineral–water interface scenario. “How do protocell models based on OSM@SAC vesicles interact with a mineral–water interface scenario that simulates a primitive Earth environment” remains an unresolved question. Hence, we select primitive relevant sodium monododecyl phosphate (SDP), isopentenol (IPN) and pyrite (FeS₂) mineral particles to build a protocell model. The model investigates the basic physical and chemical properties of FeS₂ particles and reveals the effects of the size, content and duration of interaction of FeS₂ particles on IPN@SDP vesicles. This deepens the understanding of protocell growth mechanisms in scenarios of mineral–water interfaces in primitive Earth environments and provides new information for the exploration of the origin of life. Full article

(This article belongs to the Special Issue Amphiphilic Molecules, Interfaces and Colloids)

► Show Figures

Figure 1

20 pages, 2457 KiB

Open AccessArticle

Sugar-Based Surfactants: Effects of Structural Features on the Physicochemical Properties of Sugar Esters and Their Comparison to Commercial Octyl Glycosides

by Huiling Lu, Gwladys Pourceau, Benoit Briou, Anne Wadouachi, Théophile Gaudin, Isabelle Pezron and Audrey Drelich

Molecules 2024, 29(10), 2338; https://doi.org/10.3390/molecules29102338 - 16 May 2024

Cited by 2 | Viewed by 1012

Abstract

Two series of sugar esters with alkyl chain lengths varying from 5 to 12 carbon atoms, and with a head group consisting of glucose or galactose moieties, were synthesized. Equilibrium surface tension isotherms were measured, yielding critical micellar concentration (CMC) surface tensions at CMC (γcmc) and minimum areas at the air–water interface (Amin). In addition, Krafft temperatures (Tks) were measured to characterize the ability of molecules to dissolve in water, which is essential in numerous applications. As a comparison to widely used commercial sugar-based surfactants, those measurements were also carried out for four octyl d-glycosides. Impacts of the linkages between polar and lipophilic moieties, alkyl chain lengths, and the nature of the sugar head group on the measured properties were highlighted. Higher Tk and, thus, lower dissolution ability, were found for methyl 6-O-acyl-d-glucopyranosides. CMC and γcmc decreased with the alkyl chain lengths in both cases, but Amin did not appear to be influenced. Both γcmc and Amin appeared independent of the ester group orientation. Notably, alkyl (methyl α-d-glucopyranosid)uronates were found to result in noticeably lower CMC, possibly due to a closer distance between the carbonyl function and the head group. Full article

(This article belongs to the Special Issue Amphiphilic Molecules, Interfaces and Colloids)

► Show Figures

Figure 1

16 pages, 5059 KiB

Open AccessArticle

Co-Assembled Supramolecular Organohydrogels of Amphiphilic Zwitterion and Polyoxometalate with Controlled Microstructures

by Peilin Wei, Yu Duan, Chen Wang, Panpan Sun and Na Sun

Molecules 2024, 29(10), 2286; https://doi.org/10.3390/molecules29102286 - 12 May 2024

Cited by 1 | Viewed by 1302

Abstract

The organization of modifiable and functional building components into various superstructures is of great interest due to their broad applications. Supramolecular self-assembly, based on rationally designed building blocks and appropriately utilized driving forces, is a promising and widely used strategy for constructing superstructures with well-defined nanostructures and diverse morphologies across multiple length scales. In this study, two homogeneous organohydrogels with distinct appearances were constructed by simply mixing polyoxometalate (phosphomolybdic acid, HPMo) and a double-tailed zwitterionic quaternary ammonium amphiphile in a binary solvent of water and dimethyl sulfoxide (DMSO). The delicate balance between electrostatic attraction and repulsion of anionic HPMo clusters and zwitterionic structures drove them to co-assemble into homogeneous organohydrogels with diverse microstructures. Notably, the morphologies of the organohydrogels, including unilamellar vesicles, onion-like vesicles, and spherical aggregates, can be controlled by adjusting the ionic interactions between the zwitterionic amphiphiles and phosphomolybdic acid clusters. Furthermore, we observed an organohydrogel fabricated with densely stacked onion-like structures (multilamellar vesicles) consisting of more than a dozen layers at certain proportions. Additionally, the relationships between the self-assembled architectures and the intermolecular interactions among the polyoxometalate, zwitterionic amphiphile, and solvent molecules were elucidated. This study offers valuable insights into the mechanisms of polyoxometalate-zwitterionic amphiphile co-assembly, which are essential for the development of materials with specific structures and emerging functionalities. Full article

(This article belongs to the Special Issue Amphiphilic Molecules, Interfaces and Colloids)

► Show Figures

Figure 1

11 pages, 514 KiB

Open AccessFeature PaperArticle

Quantifying the Hydrophobic Effect per CF₂ Moiety from Adsorption of Fluorinated Alcohols at the Water/Oil Interface

by Boyan Peychev, Dimitrinka Arabadzhieva, Ivan L. Minkov, Elena Mileva and Radomir I. Slavchov

Molecules 2024, 29(7), 1421; https://doi.org/10.3390/molecules29071421 - 22 Mar 2024

Viewed by 1104

Abstract

Amphiphilic fluorocarbon substances are a trending topic of research due to their wide range of applications accompanied by an alarming environmental and health impact. In order to predict their fate in the environment, use them more economically, develop new water treatment methods, etc., a better understanding of their physicochemical behavior is required. Their hydrophobicity in water/oil systems is particularly sensitive to one key thermodynamic parameter: the free energy of transfer of a perfluoromethylene group from oil to water. However, for the –CF₂– moiety, the transfer energy values reported in the literature vary by more than ±25%. Due to the exponential relationship between this energy and the adsorption constants or the partition coefficients, such an uncertainty can lead to orders of magnitude error in the predicted distribution of fluorinated species. We address this problem by presenting an experimental determination of the hydrophobic effect of a –CF₂– moiety with a greater certainty than currently available. The transfer energy is determined by measuring the interfacial tension of water|hexane for aqueous solutions of short-chained fluorotelomer alcohols. The obtained results for the free energy of transfer of a –CF₂– moiety from oil to water are

1.68 \pm 0.02 \times R T_{0}

1.75 \pm 0.02 \times R T_{0}

, and

1.88 \pm 0.02 \times R T_{0}

at 288.15 K, 293.15 K, and 303.15 K, respectively. Full article

(This article belongs to the Special Issue Amphiphilic Molecules, Interfaces and Colloids)

► Show Figures

Journal Menu

Journal Browser

Amphiphilic Molecules, Interfaces and Colloids

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Related Special Issue

Published Papers (10 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI