1
|
Xu M, Tsona NT, Li J, Du L. Atmospheric chemical processes of microcystin-LR at the interface of sea spray aerosol. CHEMOSPHERE 2022; 294:133726. [PMID: 35085608 DOI: 10.1016/j.chemosphere.2022.133726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/06/2022] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
Microcystins are the most toxic toxins released by cyanobacteria and they have adverse effects on aquatic ecosystems and even human health. Although the removal and detoxification of microcystins in various water bodies have been extensively studied, the interaction mechanism and reaction process of microcystins once they enter the atmosphere are largely unknown, especially at the organic-enriched sea spray aerosol (SSA) interface. Herein, using the surface technique of Langmuir trough coupled in-situ infrared reflection-absorption spectra, we studied the interfacial behavior of microcystin-LR (MC-LR) in artificial seawater containing humic acid and typical surfactants in the presence or absence of UV-irradiation. Zwitterionic 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and anionic stearic acid (SA) were chosen as typical film-forming species, results obtained from the surface pressure-area isotherms showed that MC-LR caused greater expansion of the DSPC monolayer. The comparable results of MC-LR in DSPC/SA-containing systems indicated that the interaction ability was closely related to the monolayer molecular structure and was regulated by electrostatic interaction. Furthermore, the presence of humic acid (HA) could enhance the interaction between microcystin and monolayer molecules. UV-irradiation experiments showed that the photosensitized reaction greatly promoted the removal of microcystin embedded in the SSA surface compared with the direct photolysis effect in the absence of HA. These findings highlight that the toxic effects of microcystins after entering the atmosphere may be weakened by photochemical reactions.
Collapse
Affiliation(s)
- Minglan Xu
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao, 266237, China
| | - Narcisse T Tsona
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao, 266237, China
| | - Jianlong Li
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao, 266237, China
| | - Lin Du
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao, 266237, China.
| |
Collapse
|
2
|
Abstract
AbstractThe presence of water-immiscible organic liquids—commonly called non-aqueous phase liquids or NAPLs—in soils and groundwater, is a worldwide environmental problem. Typical examples of NAPLs include: petroleum products, organic solvents and organic liquid waste from laboratories and industry. The molecular components of NAPLs present in soils, rocks and groundwater are readily transferred to the vapour and aqueous phases. The extent to which they do this is determined by their solubility (which is quite limited) and vapour pressure (which can be quite high). These molecular components, once dispersed in the vapour phase or dissolved in the aqueous phase, can provide a long-term source of harm to biotic receptors. The object of this lecture text is to examine how we can assess the degree of harm using quantitative risk assessment and how NAPL contaminated environments can be restored through the use of chemical, biological and physical remediation technologies.
Graphical abstract
Collapse
|
3
|
Dupuy R, Richter C, Winter B, Meijer G, Schlögl R, Bluhm H. Core level photoelectron spectroscopy of heterogeneous reactions at liquid-vapor interfaces: Current status, challenges, and prospects. J Chem Phys 2021; 154:060901. [PMID: 33588531 DOI: 10.1063/5.0036178] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Liquid-vapor interfaces, particularly those between aqueous solutions and air, drive numerous important chemical and physical processes in the atmosphere and in the environment. X-ray photoelectron spectroscopy is an excellent method for the investigation of these interfaces due to its surface sensitivity, elemental and chemical specificity, and the possibility to obtain information on the depth distribution of solute and solvent species in the interfacial region. In this Perspective, we review the progress that was made in this field over the past decades and discuss the challenges that need to be overcome for investigations of heterogeneous reactions at liquid-vapor interfaces under close-to-realistic environmental conditions. We close with an outlook on where some of the most exciting and promising developments might lie in this field.
Collapse
Affiliation(s)
- Rémi Dupuy
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Clemens Richter
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Bernd Winter
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Gerard Meijer
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Robert Schlögl
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Hendrik Bluhm
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, D-14195 Berlin, Germany
| |
Collapse
|
4
|
Huo J, Wang Z, Chen H, He R. Impacts of Low Atmospheric Pressure on Properties of Cement Concrete in Plateau Areas: A Literature Review. MATERIALS 2019; 12:ma12091384. [PMID: 31035426 PMCID: PMC6539586 DOI: 10.3390/ma12091384] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 04/03/2019] [Accepted: 04/23/2019] [Indexed: 11/16/2022]
Abstract
Low atmospheric pressure (LAP) can enormously affect properties of cement concrete in plateau areas. There are fewer studies and attendances on this issue than those of cement concrete in normal atmospheric pressure (AP), because of the limitations of both environmental conditions and instruments. In order to improve properties of cement concrete under LAP, influences of LAP on properties of cement concrete were reviewed in this work. The influence rules and mechanism on properties of cement concrete were summarized. The corresponding mechanism and techniques were put forward for enhancing the properties of cement concrete. The results of researchers show that LAP can significantly reduce the air entraining ability of the air entraining agent (AEA). Air content in concrete linearly decreases with the decrease of AP when other conditions are constant. If the initial air content is high, the decrease rate of air content increases with the decrease of AP. When the initial air content in cement concretes is similar, the greater the slump of cement concrete, the stronger its resistance to the decrease of air content caused by the decrease of AP. In addition, the condition of the bubble characteristics of hardened cement concrete under LAP is worse than that under normal AP. Therefore, the change of concrete properties under LAP is mainly attributed to these bubble characteristics, such as air content, bubble spacing coefficient, bubble radius and bubble specific surface area. In this work, nano-silica (negative charges) with cationic oligomeric surfactants is recommended as a new type of AEA to optimize the bubble characteristics under LAP in plateau areas.
Collapse
Affiliation(s)
- Jinyang Huo
- School of Materials Science and Engineering, Chang'an University, Xi'an 710061, China.
| | - Zhenjun Wang
- School of Materials Science and Engineering, Chang'an University, Xi'an 710061, China.
- Engineering Research Center of Pavement Materials, Ministry of Education of P.R. China, Chang'an University, Xi'an 710064, China.
| | - Huaxin Chen
- School of Materials Science and Engineering, Chang'an University, Xi'an 710061, China.
- Engineering Research Center of Pavement Materials, Ministry of Education of P.R. China, Chang'an University, Xi'an 710064, China.
| | - Rui He
- School of Materials Science and Engineering, Chang'an University, Xi'an 710061, China.
- Engineering Research Center of Pavement Materials, Ministry of Education of P.R. China, Chang'an University, Xi'an 710064, China.
| |
Collapse
|
5
|
Link KA, Hsieh CY, Tuladhar A, Chase Z, Wang Z, Wang H, Walker RA. Vibrational studies of saccharide-induced lipid film reorganization at aqueous/air interfaces. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.02.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|
6
|
Lalgee LJ, Cox L, Fairman RA, Grierson L. DPPC monolayer response to non-spanning cobalt-cage metallosurfactants: Electrostatic complex formation. Chem Phys Lipids 2018; 213:1-12. [PMID: 29499181 DOI: 10.1016/j.chemphyslip.2018.02.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 02/23/2018] [Accepted: 02/26/2018] [Indexed: 01/08/2023]
Abstract
A novel series of amphiphilic cobalt-cage derivatives (ACCD), bearing a diaza-crown bridge and varying alkyl chains, facilitate ion transport across biomembrane models via self-aggregation. In this study, compression isotherm analyses and atomic force microscopy (AFM) were used to assess the interactions of these amphiphiles with Langmuir monolayers of dipalmitoylphosphatidylcholine (DPPC) in order to elucidate electrostatic and steric contributions to ion transport. The stability and compressibility of DPPC monolayers are disrupted by ACCD molecules with short (C12) alkyl chains. These top-heavy amphiphiles (large cone angles) create voids at the interface of the hydrophobic/aqueous layer leading to monolayer expansion and packing efficiency of the aliphatic chains is disrupted. Long-tailed analogues (C16, C18) are cohesively integrated into DPPC monolayers due to their smaller cone angles at the interfacial region and increased hydrocarbon compatibility in the hydrophobic region. Thermodynamic data indicate the formation of electrostatic complexes between DPPC and longer-tailed amphiphiles consistent with AFM observations of aggregate structures at the corresponding concentrations.
Collapse
Affiliation(s)
- Lorale J Lalgee
- The Department of Chemistry, Faculty of Science and Technology, The University of the West Indies, St. Augustine, Trinidad and Tobago.
| | - Leonette Cox
- The Department of Chemistry, Faculty of Science and Technology, The University of the West Indies, St. Augustine, Trinidad and Tobago.
| | - Richard A Fairman
- The Department of Chemistry, Faculty of Science and Technology, The University of the West Indies, St. Augustine, Trinidad and Tobago.
| | - Lebert Grierson
- The Department of Chemistry, Faculty of Science and Technology, The University of the West Indies, St. Augustine, Trinidad and Tobago.
| |
Collapse
|
7
|
Cationic oligomeric surfactants as novel air entraining agents for concrete. Colloids Surf A Physicochem Eng Asp 2018. [DOI: 10.1016/j.colsurfa.2017.11.065] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
8
|
Skoda MWA, Thomas B, Hagreen M, Sebastiani F, Pfrang C. Simultaneous neutron reflectometry and infrared reflection absorption spectroscopy (IRRAS) study of mixed monolayer reactions at the air–water interface. RSC Adv 2017. [DOI: 10.1039/c7ra04900e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Simultaneous neutron reflectometry and infrared spectroscopy can follow the oxidation of complex, realistic surfactant mixtures relevant for atmospheric chemistry.
Collapse
Affiliation(s)
- Maximilian W. A. Skoda
- ISIS Pulsed Neutron and Muon Source
- Science and Technology Facilities Council
- Rutherford Appleton Laboratory
- Harwell
- UK
| | - Benjamin Thomas
- ISIS Pulsed Neutron and Muon Source
- Science and Technology Facilities Council
- Rutherford Appleton Laboratory
- Harwell
- UK
| | | | | | | |
Collapse
|
9
|
Lodi A, Momicchioli F, Caselli M, Giancane G, Ponterini G. A comparative study of two amphiphilic merocyanines: from monomers to aggregates in Langmuir and Langmuir–Blodgett mixed films. RSC Adv 2013. [DOI: 10.1039/c2ra22962e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
10
|
Tang CY, Huang Z, Allen HC. Interfacial Water Structure and Effects of Mg2+ and Ca2+ Binding to the COOH Headgroup of a Palmitic Acid Monolayer Studied by Sum Frequency Spectroscopy. J Phys Chem B 2010; 115:34-40. [PMID: 21158425 DOI: 10.1021/jp1062447] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Cheng Y. Tang
- The Ohio State University, Department of Chemistry, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Zishuai Huang
- The Ohio State University, Department of Chemistry, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Heather C. Allen
- The Ohio State University, Department of Chemistry, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| |
Collapse
|
11
|
Tang CY, Huang Z, Allen HC. Binding of Mg2+ and Ca2+ to Palmitic Acid and Deprotonation of the COOH Headgroup Studied by Vibrational Sum Frequency Generation Spectroscopy. J Phys Chem B 2010; 114:17068-76. [PMID: 21062085 DOI: 10.1021/jp105472e] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Cheng Y. Tang
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Zishuai Huang
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Heather C. Allen
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| |
Collapse
|
12
|
Zhou T, Zhao J, You Y. Effect of the Interionic Distance on the Interfacial Behavior of Double-Chain Zwitterionic Amphiphiles. J DISPER SCI TECHNOL 2009. [DOI: 10.1080/01932690802701556] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
13
|
Belman N, Acharya S, Konovalov O, Vorobiev A, Israelachvili J, Efrima S, Golan Y. Hierarchical assembly of ultranarrow alkylamine-coated ZnS nanorods: a synchrotron surface X-ray diffraction study. NANO LETTERS 2008; 8:3858-3864. [PMID: 18823147 DOI: 10.1021/nl802287h] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The packing of anisotropic ultranarrow nanoparticles ( r <or= 0.5 nm) in Langmuir films was investigated for two types of nanoparticles: short ZnS wires coated with tetradecylamine and ZnS rods coated with octadecylamine. In situ grazing incidence small-angle X-ray scattering (GISAXS) revealed the formation, even under zero pressure, of ordered superstructures on the water surface consisting of alternating nanoparticles. A hierarchical "packing model" is proposed, based on GISAXS, transmission electron microscopy, thermogravimetric analysis, and grazing incidence X-ray diffraction of pure surfactant Langmuir films.
Collapse
Affiliation(s)
- Nataly Belman
- Department of Materials Engineering, Ilse Katz Institute of Nanotechnology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | | | | | | | | | | | | |
Collapse
|
14
|
Shankar BV, Patnaik A. J-aggregates in matrix stabilized two-dimensional azobenzene derivatives. J Colloid Interface Sci 2006; 302:259-66. [PMID: 16844137 DOI: 10.1016/j.jcis.2006.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Revised: 04/30/2006] [Accepted: 06/02/2006] [Indexed: 11/25/2022]
Abstract
A two-component film technique at the air-water interface has been used for fabricating matrix stabilized azobenzene J-aggregates. Langmuir monolayers of (E)-1-(3-chloro-4-(alkyloxy)phenyl)-2-phenyldiazene (CnCD, n=8,10,12) have been prepared with stearic acid (STA) as the two-dimensional matrix. Miscibility studies at a molecular level, explored from the monolayer pressure-area isotherms revealed a phase separation of the CnCD from the stearic acid matrix at a compression pressure of 10 mN/m. A 43-nm strong red shift in the 350 nm pi-pi * absorption feature implied formation of highly ordered J-aggregates of CnCDs in conformity with atomic force microscopy and micro-Raman spectral characteristics. While a one-component CnCD failed to form a 2D monolayer, the STA supported CnCD binary system crossed a mixed monolayer phase followed by compression, leading to the formation of matrix stabilized CnCD J-aggregates.
Collapse
Affiliation(s)
- B Vijai Shankar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India
| | | |
Collapse
|
15
|
Wiegart L, Struth B, Tolan M, Terech P. Thermodynamic and structural properties of phospholipid langmuir monolayers on hydrosol surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:7349-57. [PMID: 16042465 DOI: 10.1021/la050478m] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Measurements of Langmuir pressure/area isotherms, rheology, grazing incidence X-ray diffraction (GIXD), and grazing incidence diffuse X-ray scattering out of the specular plane (GIXOS) have been used to investigate the influence of a hydrosol containing charged mineral nanoparticles on the thermodynamic and structural properties of a DPPC monolayer. The mineral adsorption layer that is formed via electrostatic interaction underneath the lipid layer alters the thermodynamic properties of the phospholipid monolayer in terms of maximal achievable compression, compressibility, and phase behavior. Modifications appear in the latter case as a coolinglike effect. Rheology measurements of the bulk viscoelastic properties revealed a stabilizing effect of the transient bulk network on the surfactant layer. The lipid chain lattice is found to be reorganized and adapted to the internal atomic structure of the mineral particles. A model for the superposition of Bragg rods from the lipid chains and the minerals is applied to separate these scattering contributions. In the vicinity of the mineral particles, the (2) reflection for DPPC on a liquid substrate was found, indicating strongly suppressed fluctuations at the surface. An estimation of the Debye-Waller factor associated with the lipid layer organization is used to quantify the damping of fluctuations within the lipid matrix due to the rigidifying and stabilizing effect of the mineral particles.
Collapse
Affiliation(s)
- Lutz Wiegart
- European Synchrotron Radiation Facility (ESRF), B.P. 220, 38043 Grenoble Cédex 09, France
| | | | | | | |
Collapse
|
16
|
Müller PU, Akpo CC, Stöckelhuber KW, Weber E. Novel amphiphiles with preorganized functionalities-formation of Langmuir-films and efficiency in mineral flotation. Adv Colloid Interface Sci 2005; 114-115:291-302. [PMID: 15936297 DOI: 10.1016/j.cis.2004.07.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2004] [Accepted: 07/12/2004] [Indexed: 11/30/2022]
Abstract
Based on the principle of supramolecular preorganization, three different types of new oligofunctional surfactants have been designed and prepared differing in both the degree of conformational flexibility and the hydrophilic-lipophilic balance of their structures due to the chosen building blocks including rather rigid and shape-persistent backbones or a dendritic subunit. Surface-active properties of the oligofunctional surfactants involving critical micellization concentration, surface tension at cmc, effectiveness of surface tension reduction, and the efficiency of adsorption were determined by use of the surface tension isotherms, respectively. In particular the amino-acid-based amphiphiles show remarkable surface-active properties with the adsorption at the air/water interface and also the aggregation to micelles starting at very low concentration. By analysis of the surface pressure-surface area isotherms interesting information on the packing behavior and orientation of the amphiphilic molecules in relation to the molecular structure could be obtained. Moreover, limiting area and collapse pressure of the Langmuir-films were determined. Morphological observation of the dynamic process of monolayer compression at the air/water interface was carried out by Brewster angle microscopy illustrating several phase states visualized as snap shots. Furthermore, the effectiveness of the new surfactants acting as collecting agents in the process of flotation using the model mineral fluorite was studied. A surprisingly high recovery of the mineral was obtained for the surfactants with constricted flexibility. The flotation plots clearly manifest that bundling of surfactant subunits by tethering to an aromatic core or by dendritic branching is profitable, indicating that effects of preorganization of the oligofunctional surfactant molecules are important.
Collapse
Affiliation(s)
- P U Müller
- Institute of Organic Chemistry, Freiberg University of Mining and Technology, Freiberg/Saxony, Germany
| | | | | | | |
Collapse
|
17
|
Löwik DWPM, Linhardt JG, Adams PJHM, van Hest JCM. Non-covalent stabilization of a beta-hairpin peptide into liposomes. Org Biomol Chem 2003; 1:1827-9. [PMID: 12945757 DOI: 10.1039/b303749e] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
An oligopeptide modified on both the N- and C-termini with hydrophobic moieties was prepared on a solid phase and anchored into a liposome, stabilizing the fold of the peptide into a beta-hairpin, which would otherwise be a random coil.
Collapse
Affiliation(s)
- Dennis W P M Löwik
- Department of Organic Chemistry University of Nijmegen, Toernooiveld 1-U177, 6525 ED Nijmegen, The Netherlands.
| | | | | | | |
Collapse
|
18
|
Abstract
A gemini surfactant is an amphiphile possessing (in sequence) the following: hydrocarbon tail/polar group/spacer/polar group/hydrocarbon tail. Widespread interest in geminis has emerged recently from both industrial and academic laboratories. In the present contribution, two related families of geminis have been synthesized, both with trehalose, a disaccharide, as a polar spacer. One family, Series-A, is nonionic and has amide groups separating the long chains from the trehalose spacer. The other family, Series-B, has quaternary ammonium ions connecting the long chains to the trehalose spacer. It was found that Series-A geminis are water insoluble despite the two amides and multiple hydroxyls. When hydrated or extruded, these geminis form microscopically visible vesicular and tubular structures above their transition temperatures (which were determined calorimetrically). Insoluble monomolecular films, constructed from these geminis, have interfacial areas that are dominated by the sugar spacer although intermolecular chain/chain interactions seem to stabilize the films. Thus, the behavior of Series-A geminis in many ways parallels that of phospholipids and simple double-chain surfactants. It is as if the trehalose is less of a spacer than a large but conventional headgroup. In contrast, cationic Series-B geminis are water soluble and form micelles with critical micelle concentrations an order of magnitude lower than that of corresponding conventional surfactants. Molecular modeling using the Amber force field explains the difference in properties between the two families of geminis. Series-A are tubular in shape and thus prefer bilayer packing as do other amphiphiles in which the headgroups are similar in width to the sum of the tail diameters. Series-B geminis are conical-shaped and pack more readily into spherical micelles. This work entails synthesis, tensiometry, conductance, microscopy, surface balance studies, calorimetry, light scattering, and molecular modeling. In colloid chemistry, a balanced perspective cannot be achieved by one methodology alone but only through the pursuit of consilience among multiple approaches.
Collapse
Affiliation(s)
- F M Menger
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | | |
Collapse
|
19
|
Villamagna F, Whitehead M. Molecular modelling of surfactants in monolayers and Langmuir trough experiments. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0166-1280(95)04336-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
20
|
Enderle T, Meixner AJ, Zschokke‐Gränacher I. Phase transitions in mixed Langmuir films of 8CB and stearic acid. J Chem Phys 1994. [DOI: 10.1063/1.467487] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|