1
|
Imamura S, Sawaki K, Molina JJ, Turner MS, Yamamoto R. Collective Motion of Quincke Rollers with Fully Resolved Hydrodynamics. ADVANCED THEORY AND SIMULATIONS 2023. [DOI: 10.1002/adts.202200683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Shun Imamura
- Department of Chemical Engineering Kyoto University Kyoto 615‐8510 Japan
| | - Kohei Sawaki
- Department of Chemical Engineering Kyoto University Kyoto 615‐8510 Japan
| | - John J. Molina
- Department of Chemical Engineering Kyoto University Kyoto 615‐8510 Japan
| | - Matthew S. Turner
- Department of Chemical Engineering Kyoto University Kyoto 615‐8510 Japan
- Department of Physics University of Warwick Coventry CV4 7AL UK
| | - Ryoichi Yamamoto
- Department of Chemical Engineering Kyoto University Kyoto 615‐8510 Japan
| |
Collapse
|
2
|
Shadloo A, Peyvandi K, Shojaeian A, Shariat S. Determination of the Second Critical Micelle Concentration of Aqueous Non-Ionic Surfactants: Measurement and Calculation of Various Physicochemical Properties above the First CMC Point. Ind Eng Chem Res 2023. [DOI: 10.1021/acs.iecr.2c02641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Azam Shadloo
- Faculty of Chemical, Gas and Petroleum Engineering, Semnan University, Semnan35196-45399, Iran
| | - Kiana Peyvandi
- Faculty of Chemical, Gas and Petroleum Engineering, Semnan University, Semnan35196-45399, Iran
| | - Abolfazl Shojaeian
- Department of Chemical Engineering, Hamedan University of Technology, Hamedan65169, Iran
| | - Sheida Shariat
- Department of Pharmacy, Damghan Branch, Islamic Azad University, Damghan36711, Iran
| |
Collapse
|
3
|
Mauleon-Amieva A, Mosayebi M, Hallett JE, Turci F, Liverpool TB, van Duijneveldt JS, Royall CP. Competing active and passive interactions drive amoebalike crystallites and ordered bands in active colloids. Phys Rev E 2020; 102:032609. [PMID: 33075940 DOI: 10.1103/physreve.102.032609] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
Swimmers and self-propelled particles are physical models for the collective behavior and motility of a wide variety of living systems, such as bacteria colonies, bird flocks, and fish schools. Such artificial active materials are amenable to physical models which reveal the microscopic mechanisms underlying the collective behavior. Here we study colloids in a dc electric field. Our quasi-two-dimensional system of electrically driven particles exhibits a rich and exotic phase behavior exhibiting passive crystallites, motile crystallites, an active gas, and banding. Amongst these are two mesophases, reminiscent of systems with competing interactions. At low field strengths activity suppresses demixing, leading to motile crystallites. Meanwhile, at high field strengths, activity drives partial demixing to traveling bands. We parametrize a particulate simulation model which reproduces the experimentally observed phases.
Collapse
Affiliation(s)
- Abraham Mauleon-Amieva
- H.H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL, United Kingdom
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
- Centre for Nanoscience and Quantum Information, Tyndall Avenue, Bristol BS8 1FD, United Kingdom
- Bristol Centre for Functional Nanomaterials, Tyndall Avenue, Bristol BS8 1FD, United Kingdom
| | - Majid Mosayebi
- School of Mathematics, University of Bristol, Bristol BS8 1TW, United Kingdom
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, United Kingdom
| | - James E Hallett
- H.H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL, United Kingdom
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
- Centre for Nanoscience and Quantum Information, Tyndall Avenue, Bristol BS8 1FD, United Kingdom
| | - Francesco Turci
- H.H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL, United Kingdom
| | - Tanniemola B Liverpool
- School of Mathematics, University of Bristol, Bristol BS8 1TW, United Kingdom
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, United Kingdom
| | | | - C Patrick Royall
- H.H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL, United Kingdom
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
- Centre for Nanoscience and Quantum Information, Tyndall Avenue, Bristol BS8 1FD, United Kingdom
| |
Collapse
|
4
|
Khademi M, Cheng SSY, Barz DPJ. Charge and Electrical Double Layer Formation in a Nonpolar Solvent Using a Nonionic Surfactant. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:5156-5164. [PMID: 32326706 DOI: 10.1021/acs.langmuir.0c00311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In this work, we study the charge formation and the characteristics of the electrical double layer in a nonpolar medium using electrical impedance spectroscopy. To stabilize the free ionic species, a nonionic surfactant is added to the system. The conductivity and permittivity of the medium are obtained from high- to medium-frequency impedance data. Based on the correlation between (viscosity-adjusted) conductivity and surfactant concentration, we conclude that charge formation occurs due to a disproportionation mechanism. We accordingly estimate the concentration of the charge carriers in the sample and the Debye length of the diffuse double layer. The capacitance of the electrical double layer can be extracted from the low-frequency impedance data. We use this data to calculate the electrode distance of an equivalent parallel-plate capacitor. It is found that this distance is on the order of magnitude of Angstroms, indicating that the measured electrical double-layer capacitance is in fact the Stern layer capacitance.
Collapse
Affiliation(s)
- Mahmoud Khademi
- Department of Chemical Engineering, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Sammi Sham Yin Cheng
- Department of Chemical Engineering, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Dominik P J Barz
- Department of Chemical Engineering, Queen's University, Kingston, ON K7L 3N6, Canada
| |
Collapse
|
5
|
Bulavchenko AI, Shaparenko NO, Kompan’kov NB, Popovetskiy PS, Demidova MG, Arymbaeva AT. The formation of free ions and electrophoretic mobility of Ag and Au nanoparticles in n-hexadecane–chloroform mixtures at low concentrations of AOT. Phys Chem Chem Phys 2020; 22:14671-14681. [DOI: 10.1039/d0cp02153a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The electrophoretic mobility of Ag and Au nanoparticles in n-hexadecane–chloroform mixtures was studied as a function of the chloroform content (from 0 to 100 vol%).
Collapse
Affiliation(s)
| | - Nikita O. Shaparenko
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
| | - Nikolay B. Kompan’kov
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
| | - Pavel S. Popovetskiy
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
| | - Marina G. Demidova
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
| | - Aida T. Arymbaeva
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
| |
Collapse
|
6
|
Strubbe F, Neyts K. Charge transport by inverse micelles in non-polar media. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:453003. [PMID: 28895874 DOI: 10.1088/1361-648x/aa8bf6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Charged inverse micelles play an important role in the electrical charging and the electrodynamics of nonpolar colloidal dispersions relevant for applications such as electronic ink displays and liquid toner printing. This review examines the properties and the behavior of charged inverse micelles in microscale devices in the absence of colloidal particles. It is discussed how charge in nonpolar liquids is stabilized in inverse micelles and how conductivity depends on the inverse micelle size, water content and ionic impurities. Frequently used nonpolar surfactant systems are investigated with emphasis on aerosol-OT (AOT) and poly-isobutylene succinimide (PIBS) in dodecane. Charge generation in the bulk by disproportionation is studied from measurements of conductivity as a function of surfactant concentration and from generation currents in quasi steady-state. When a potential difference is applied, the steady-state situation can show electric field screening or complete charge separation. Different regimes of charge transport are identified when a voltage step is applied. It is shown how the transient and steady-state currents depend on the rate of bulk generation, on insulating layers and on the sticking or non-sticking behavior of charged inverse micelles at interfaces. For the cases of AOT and PIBS in dodecane, the magnitude of the generation rate and the type of interaction at the interface are very different.
Collapse
Affiliation(s)
- Filip Strubbe
- Electronics and Information Systems Department and Center for Nano and Biophotonics, Ghent University, Technologiepark Zwijnaarde 15, 9052 Zwijnaarde, Belgium
| | | |
Collapse
|
7
|
Michor EL, Berg JC. The particle charging behavior of ion-exchanged surfactants in apolar media. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2016.10.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
8
|
Michor EL, Ponto BS, Berg JC. Effects of Reverse Micellar Structure on the Particle Charging Capabilities of the Span Surfactant Series. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10328-10333. [PMID: 27649769 DOI: 10.1021/acs.langmuir.6b02959] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This paper investigates the effects of reverse micellar core size on the particle charging behavior of a series of acidic surfactants in apolar media. A series of Span surfactants was dissolved in deuterated decane at concentrations above the critical micelle concentration. The structures of the reverse micelles were measured using small-angle neutron scattering. It was determined that as the tail length of the surfactant increased, the size of the polar reverse micellar core decreased. Tritailed surfactants formed reverse micelles with the smallest polar cores, with radii of ∼4 Å. The sizes of the polar cores were correlated with the particle charging behavior of the Span surfactant series, as measured in a previous study. It was found that reverse micelles with intermediate core sizes imparted the largest electrophoretic mobilities to the particles. Reverse micelles with very small cores did not offer a large enough polar environment to favor charge stabilization, while very large polar cores favored disproportionation reactions in the bulk, resulting in increased electrostatic screening.
Collapse
Affiliation(s)
- Edward L Michor
- Department of Chemical Engineering, University of Washington , Box 351750, Seattle, Washington 98195-1750, United States
| | - Benjamin S Ponto
- Department of Chemical Engineering, University of Washington , Box 351750, Seattle, Washington 98195-1750, United States
| | - John C Berg
- Department of Chemical Engineering, University of Washington , Box 351750, Seattle, Washington 98195-1750, United States
| |
Collapse
|
9
|
Determination of charge carrier concentration in doped nonpolar liquids by impedance spectroscopy in the presence of charge adsorption. J Colloid Interface Sci 2016; 469:325-337. [DOI: 10.1016/j.jcis.2016.02.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 12/23/2015] [Accepted: 02/03/2016] [Indexed: 11/22/2022]
|
10
|
Bilibin AY, Shcherbinina TM, Girbasova NV, Lebedev VT, Kulvelis YV, Molchanov VS, Zorin IM. Colloidal properties of polymerizable counterion surfmers solutions based on alkylamino 2-acrylamido-2-methylpropanesulfonates in different solvents. Des Monomers Polym 2016. [DOI: 10.1080/15685551.2016.1169371] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
11
|
The effects of counterion exchange on charge stabilization for anionic surfactants in nonpolar solvents. J Colloid Interface Sci 2016; 465:316-22. [DOI: 10.1016/j.jcis.2015.11.062] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 11/25/2015] [Accepted: 11/25/2015] [Indexed: 11/21/2022]
|
12
|
Smith GN, Kemp R, Pegg JC, Rogers SE, Eastoe J. Sulfosuccinate and Sulfocarballylate Surfactants As Charge Control Additives in Nonpolar Solvents. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:13690-13699. [PMID: 26609708 DOI: 10.1021/acs.langmuir.5b03876] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A series of eight sodium sulfonic acid surfactants with differently branched tails (four double-chain sulfosuccinates and four triple-chain sulfocarballylates) were studied as charging agents for sterically stabilized poly(methyl methacrylate) (PMMA) latexes in dodecane. Tail branching was found to have no significant effect on the electrophoretic mobility of the latexes, but the number of tails was found to influence the electrophoretic mobility. Triple-chain, sulfocarballylate surfactants were found to be more effective. Several possible origins of this observation were explored by comparing sodium dioctylsulfosuccinate (AOT1) and sodium trioctylsulfocarballylate (TC1) using identical approaches: the inverse micelle size, the propensity for ion dissociation, the electrical conductivity, the electrokinetic or ζ potential, and contrast-variation small-angle neutron scattering. The most likely origin of the increased ability of TC1 to charge PMMA latexes is a larger number of inverse micelles. These experiments demonstrate a small molecular variation that can be made to influence the ability of surfactants to charge particles in nonpolar solvents, and modifying molecular structure is a promising approach to developing more effective charging agents.
Collapse
Affiliation(s)
- Gregory N Smith
- School of Chemistry, University of Bristol , Cantock's Close, Bristol, BS8 1TS, United Kingdom
| | - Roger Kemp
- Merck Chemicals Ltd , University Parkway, Chilworth, Southampton, SO16 7QD, United Kingdom
| | - Jonathan C Pegg
- School of Chemistry, University of Bristol , Cantock's Close, Bristol, BS8 1TS, United Kingdom
| | - Sarah E Rogers
- ISIS-STFC, Rutherford Appleton Laboratory , Chilton, Oxon, OX11 0QX, United Kingdom
| | - Julian Eastoe
- School of Chemistry, University of Bristol , Cantock's Close, Bristol, BS8 1TS, United Kingdom
| |
Collapse
|
13
|
Smith GN, Hallett JE, Eastoe J. Celebrating Soft Matter's 10th Anniversary: Influencing the charge of poly(methyl methacrylate) latexes in nonpolar solvents. SOFT MATTER 2015; 11:8029-8041. [PMID: 26369696 DOI: 10.1039/c5sm01190f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Sterically-stabilized poly(methyl methacrylate) (PMMA) latexes dispersed in nonpolar solvents are a classic, well-studied system in colloid science. This is because they can easily be synthesized with a narrow size distribution and because they interact essentially as hard spheres. These PMMA latexes can be charged using several methods (by adding surfactants, incorporating ionizable groups, or dispersing in autoionizable solvents), and due to the low relative permittivity of the solvents (εr ≈ 2 for alkanes to εr ≈ 8 for halogenated solvents), the charges have long-range interactions. The number of studies of these PMMA particles as charged species has increased over the past ten years, after few studies immediately following their discovery. A large number of variations in both the physical and chemical properties of the system (size, concentration, surfactant type, or solvent, as a few examples) have been studied by many groups. By considering the literature on these particles as a whole, it is possible to determine the variables that have an effect on the charge of particles. An understanding of the process of charge formation will add to understanding how to control charge in nonaqueous solvents as well as make it possible to develop improved technologically relevant applications for charged polymer nanoparticles.
Collapse
Affiliation(s)
- Gregory N Smith
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
| | | | | |
Collapse
|
14
|
Michor EL, Berg JC. Temperature Effects on Micelle Formation and Particle Charging with Span Surfactants in Apolar Media. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:9602-9607. [PMID: 26301921 DOI: 10.1021/acs.langmuir.5b02711] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This paper examines the effects of temperature on the micellization and particle charging behavior of the Span surfactant series in an apolar environment. The critical micelle concentrations of each of six surfactants at five temperatures were measured by conductometric techniques. The thermodynamic properties of micellization were calculated using Gibbs-Helmholtz analysis. Magnesia particles were then dispersed in solutions of these surfactants, and their electrophoretic mobilities were measured at three temperatures. Preliminary small-angle neutron scattering (SANS) experiments were conducted to measure the size of aggregates (referred to as reverse micelles) of three of the surfactants. It was found that for all but one of the surfactants the critical micelle concentration (CMC) increased by as much as an order of magnitude across a 40 °C range of temperature. One of the surfactants exhibited a decrease in CMC upon increasing temperature, likely due to a decrystallization of the tails upon reverse micelle formation. The maximum particle mobilities decreased upon increasing temperature due to the increased electrostatic screening by charged reverse micelles at higher temperatures.
Collapse
Affiliation(s)
- Edward L Michor
- Department of Chemical Engineering, University of Washington , Box 351750, Seattle, Washington 98195-1750, United States
| | - John C Berg
- Department of Chemical Engineering, University of Washington , Box 351750, Seattle, Washington 98195-1750, United States
| |
Collapse
|
15
|
Yezer BA, Khair AS, Sides PJ, Prieve DC. Use of electrochemical impedance spectroscopy to determine double-layer capacitance in doped nonpolar liquids. J Colloid Interface Sci 2014; 449:2-12. [PMID: 25315405 DOI: 10.1016/j.jcis.2014.08.052] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 08/13/2014] [Accepted: 08/23/2014] [Indexed: 11/30/2022]
Abstract
Electrochemical impedance spectroscopy in a thin cell (10 μm) was used to infer conductivity, permittivity and the differential double-layer capacitance of solutions of dodecane doped with OLOA 11000 [poly(isobutylene) succinimide] for concentrations of dopant between 0.1% and 10% by weight. All spectra (frequencies between 1 Hz and 100 kHz) were well fit by an equivalent circuit having four elements including a constant-phase element representing the double-layer capacitance. Using Gouy-Chapman theory for small zeta potentials and assuming univalent charge carriers, the double-layer capacitances were converted into charge carrier concentration which was found to be directly proportional to the weight percent of dopant with a 1 wt% solution having 87 carriers/μm(3) (the concentration of either positive or negative charges). This is only 17 ppm of the total monomer concentration calculated from the average molecule weight of the dopant. Dividing the measured conductivities by the charge carrier concentration, we inferred the mobility and hydrodynamic diameters for the charged micelles. The hydrodynamic diameters of carriers were significantly larger than the average diameter of all micelles measured independently by dynamic light scattering. This suggests that only large micelles become charged.
Collapse
Affiliation(s)
- Benjamin A Yezer
- Center for Complex Fluids Engineering and Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States
| | - Aditya S Khair
- Center for Complex Fluids Engineering and Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States
| | - Paul J Sides
- Center for Complex Fluids Engineering and Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States
| | - Dennis C Prieve
- Center for Complex Fluids Engineering and Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States.
| |
Collapse
|
16
|
Smith GN, Alexander S, Brown P, Gillespie DAJ, Grillo I, Heenan RK, James C, Kemp R, Rogers SE, Eastoe J. Interaction between surfactants and colloidal latexes in nonpolar solvents studied using contrast-variation small-angle neutron scattering. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:3422-3431. [PMID: 24593803 DOI: 10.1021/la500331u] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The interaction between deuterium-labeled Aerosol OT surfactant (AOT-d34) and sterically stabilized poly(methyl methacrylate) (PMMA) latex particles dispersed in nonpolar solvents has been studied using contrast-variation small-angle neutron scattering (CV-SANS). The electrophoretic mobilities (μ) of the latexes have been measured by phase-analysis light scattering, indicating that μ is negative. Two analogues of the stabilizers for the particles have been studied as free polymers in the absence of PMMA latexes: poly(12-hydroxystearic acid) (PHSA) polyester and poly(methyl methacrylate)-graft-poly(12-hydroxystearic acid) (PMMA-graft-PHSA) stabilizer copolymer. The scattering from both PHSA in dodecane and PMMA-graft-PHSA in toluene is consistent with extended polymer chains in good solvents. In dodecane, PMMA-graft-PHSA forms polymer micelles, and SANS is consistent with ellipsoidal aggregates formed of around 50 polymer chains. CV-SANS measurements were performed by measuring SANS from systems of PHSA, PMMA-graft-PHSA, and PMMA latexes with 10 and 100 mM surfactant solutions of AOT-d34 in both polymer/particle and AOT contrast-matched solvent. No excess scattering above the polymer or surfactant was found for PHSA in dodecane or PMMA-graft-PHSA in dodecane and toluene. This indicates that AOT does not significantly interact with the free polymers. Excess scattering was observed for systems with AOT-d34 and PMMA latexes dispersed in particle contrast-matched dodecane, consistent with the penetration of AOT into the PMMA latexes. This indicates that AOT does not interact preferentially with the stabilizing layers but, rather, is present throughout the colloids. Previous research ( Langmuir 2010, 26, 6967-6976 ) suggests that AOT surfactant is located in the latex PHSA-stabilizer layer, but all the results in this study are consistent with AOT poorly interacting with alkyl-stabilizer polymers.
Collapse
Affiliation(s)
- Gregory N Smith
- School of Chemistry, University of Bristol , Cantock's Close, Bristol, BS8 1TS, United Kingdom
| | | | | | | | | | | | | | | | | | | |
Collapse
|