1
|
Smith GN, Brok E, Schmiele M, Mortensen K, Bouwman WG, Duif CP, Hassenkam T, Alm M, Thomsen P, Arleth L. The microscopic distribution of hydrophilic polymers in interpenetrating polymer networks (IPNs) of medical grade silicone. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
2
|
Recent Trends in Noble Metal Nanoparticles for Colorimetric Chemical Sensing and Micro-Electronic Packaging Applications. METALS 2021. [DOI: 10.3390/met11020329] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Noble metal NPs are highly attractive candidates because of their unique combination of physical, chemical, mechanical, and structural properties. A lot of developments in this area are still fascinating the materials research community, and are broadly categorized in various sectors such as chemical sensors, biosensors, Förster resonance energy transfer (FRET), and microelectronic applications. The related function and properties of the noble metals in these areas can be further tailored by tuning their chemical, optical, and electronic properties that are influenced by their size, shape, and distribution. The most widely used Au and Ag NPs in dispersed phase below 100 nm exhibit strong color change in the visible range which alters upon aggregation of the NPs. The chemical sensing of the analyte is influenced by these NPs aggregates. In this article, we have summarized the uniqueness of noble metal NPs, their synthesis methods, nucleation and growth process, and their important applications in chemical sensing, microelectronic packaging, and Förster resonance energy transfer.
Collapse
|
3
|
Shafiq MD, Waggett F, Ismail NLM, Bartlett P. Electrostatic interactions of poly (methyl methacrylate) colloids: deposition patterns of evaporating non-aqueous colloidal droplets. Colloid Polym Sci 2021. [DOI: 10.1007/s00396-020-04769-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
4
|
Öztürk Er E, Dalgıç Bozyiğit G, Büyükpınar Ç, Bakırdere S. Magnetic Nanoparticles Based Solid Phase Extraction Methods for the Determination of Trace Elements. Crit Rev Anal Chem 2020; 52:231-249. [DOI: 10.1080/10408347.2020.1797465] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Elif Öztürk Er
- Chemical Engineering Department, Yıldız Technical University, İstanbul, Turkey
| | - Gamze Dalgıç Bozyiğit
- Faculty of Civil Engineering, Department of Environmental Engineering, Yıldız Technical University, İstanbul, Turkey
| | - Çağdaş Büyükpınar
- Department of Chemistry, Yıldız Technical University, İstanbul, Turkey
| | - Sezgin Bakırdere
- Department of Chemistry, Yıldız Technical University, İstanbul, Turkey
- Turkish Academy of Sciences (TÜBA), Ankara, Turkey
| |
Collapse
|
5
|
Parker B, Derry MJ, Ning Y, Armes SP. Exploring the Upper Size Limit for Sterically Stabilized Diblock Copolymer Nanoparticles Prepared by Polymerization-Induced Self-Assembly in Non-Polar Media. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:3730-3736. [PMID: 32216260 PMCID: PMC7161081 DOI: 10.1021/acs.langmuir.0c00211] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 03/26/2020] [Indexed: 06/10/2023]
Abstract
Reversible addition-fragmentation chain transfer (RAFT) dispersion polymerization of benzyl methacrylate is used to prepare a series of well-defined poly(stearyl methacrylate)-poly(benzyl methacrylate) (PSMA-PBzMA) diblock copolymer nanoparticles in mineral oil at 90 °C. A relatively long PSMA54 precursor acts as a steric stabilizer block and also ensures that only kinetically trapped spheres are obtained, regardless of the target degree of polymerization (DP) for the core-forming PBzMA block. This polymerization-induced self-assembly (PISA) formulation provides good control over the particle size distribution over a wide size range (24-459 nm diameter). 1H NMR spectroscopy studies confirm that high monomer conversions (≥96%) are obtained for all PISA syntheses while transmission electron microscopy and dynamic light scattering analyses show well-defined spheres with a power-law relationship between the target PBzMA DP and the mean particle diameter. Gel permeation chromatography studies indicate a gradual loss of control over the molecular weight distribution as higher DPs are targeted, but well-defined morphologies and narrow particle size distributions can be obtained for PBzMA DPs up to 3500, which corresponds to an upper particle size limit of 459 nm. Thus, these are among the largest well-defined spheres with reasonably narrow size distributions (standard deviation ≤20%) produced by any PISA formulation. Such large spheres serve as model sterically stabilized particles for analytical centrifugation studies.
Collapse
Affiliation(s)
- Bryony
R. Parker
- Dainton Building, Department
of Chemistry, University of Sheffield, Brook
Hill, Sheffield, South Yorkshire S3 7HF, United Kingdom
| | | | - Yin Ning
- Dainton Building, Department
of Chemistry, University of Sheffield, Brook
Hill, Sheffield, South Yorkshire S3 7HF, United Kingdom
| | - Steven P. Armes
- Dainton Building, Department
of Chemistry, University of Sheffield, Brook
Hill, Sheffield, South Yorkshire S3 7HF, United Kingdom
| |
Collapse
|
6
|
Sagisaka M, Saito T, Yoshizawa A, Rogers SE, Guittard F, Hill C, Eastoe J, Blesic M. Water-in-CO 2 Microemulsions Stabilized by Fluorinated Cation-Anion Surfactant Pairs. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:3445-3454. [PMID: 30739456 DOI: 10.1021/acs.langmuir.8b03942] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
High-water-content water-in-supercritical CO2 (W/CO2) microemulsions are considered to be green, universal solvents, having both polar and nonpolar domains. Unfortunately, these systems generally require environmentally unacceptable stabilizers like long and/or multifluorocarbon-tail surfactants. Here, a series of catanionic surfactants having more environmentally friendly fluorinated C4-C6 tails have been studied in terms of interfacial properties, aggregation behavior, and solubilizing power in water and/or CO2. Surface tensions and critical micelle concentrations of these catanionic surfactants are, respectively, lowered by ∼9 mN/m and 100 times than those of the constituent single fluorocarbon-tail surfactants. Disklike micelles in water were observed above the respective critical micelle concentrations, implying the catanionic surfactants have a high critical packing parameter, which should be suitable for the formation of reverse micelles. Based on visual observation of phase behavior and Fourier transform infrared spectroscopic and small-angle neutron scattering studies, one of the three catanionic surfactants tested was found to form transparent single-phase W/CO2 microemulsions with a water-to-surfactant molar ratio of up to ∼50. This is the first successful demonstration of the formation of W/CO2 microemulsions by synergistic ion-pairing of anionic and cationic single-tail surfactants. This indicates that catanionic surfactants offer a promising approach to generate high-water-content W/CO2 microemulsions.
Collapse
Affiliation(s)
- Masanobu Sagisaka
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology , Hirosaki University , 3 Bunkyo-cho , Hirosaki , Aomori 036-8561 , Japan
| | - Tatsuya Saito
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology , Hirosaki University , 3 Bunkyo-cho , Hirosaki , Aomori 036-8561 , Japan
| | - Atsushi Yoshizawa
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology , Hirosaki University , 3 Bunkyo-cho , Hirosaki , Aomori 036-8561 , Japan
| | - Sarah E Rogers
- ISIS-CCLRC, Rutherford Appleton Laboratory , Chilton OX11 0QX , Oxon , U.K
| | - Frédéric Guittard
- Univ. Cote d'Azur, NICE-Lab , 61-63 av. S. Viel , 06200 Nice , France
| | - Christopher Hill
- School of Chemistry , University of Bristol , Cantock's Close , Bristol BS8 1TS , U.K
| | - Julian Eastoe
- School of Chemistry , University of Bristol , Cantock's Close , Bristol BS8 1TS , U.K
| | - Marijana Blesic
- School of Chemistry and Chemical Engineering , Queen's University Belfast , University Road , Belfast BT7 1NN , U.K
| |
Collapse
|
7
|
Schreuer C, Vandewiele S, Strubbe F, Neyts K, Beunis F. Electric field induced charging of colloidal particles in a nonpolar liquid. J Colloid Interface Sci 2018; 515:248-254. [DOI: 10.1016/j.jcis.2018.01.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/09/2018] [Accepted: 01/10/2018] [Indexed: 10/18/2022]
|
8
|
Facal Marina PA, Delcheva I, Beattie DA. Multi-modal stabilisation of emulsions using a combination of hydrophilic particles and an amino acid. Colloids Surf A Physicochem Eng Asp 2018. [DOI: 10.1016/j.colsurfa.2017.11.074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
9
|
Chormey DS, Bakırdere S. Principles and Recent Advancements in Microextraction Techniques. FUNDAMENTALS OF QUORUM SENSING, ANALYTICAL METHODS AND APPLICATIONS IN MEMBRANE BIOREACTORS 2018. [DOI: 10.1016/bs.coac.2018.03.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
10
|
Smith GN, Ahualli S, Delgado ÁV, Gillespie DAJ, Kemp R, Peach J, Pegg JC, Rogers SE, Shebanova O, Smith N, Eastoe J. Charging Poly(methyl Methacrylate) Latexes in Nonpolar Solvents: Effect of Particle Concentration. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:13543-13553. [PMID: 29064706 DOI: 10.1021/acs.langmuir.7b02257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The electrophoresis of a well-established model system of charged colloids in nonpolar solvents has been studied as a function of particle volume fraction at constant surfactant concentration. Dispersions of poly(12-hydroxystearic acid)-stabilized poly(methyl methacrylate) (PMMA) latexes in dodecane were prepared with added Aerosol OT surfactant as the charging agent. The electrophoretic mobility (μ) of the PMMA latexes is found to decrease with particle concentration. The particles are charged by a small molecule charging agent (AOT) at finite concentration, and this makes the origin of this decrease in μ unclear. There are two suggested explanations. The decrease could either be due to the reservoir of available surfactant being exhausted at high particle concentrations or the interactions between the charged particles at high particle number concentrations. Contrast-variation small-angle neutron scattering measurements of PMMA latexes and deuterated AOT-d34 surfactant in latex core contrast-matched solvent were used to study the former, and electrokinetic modeling was used to study the latter. As the same amount of AOT-d34 is found to be incorporated with the latexes at all volume fractions, the solvodynamic and electrical interactions between particles are determined to be the explanation for the decrease in mobility. These measurements show that, for small latexes, there are interactions between the charged particles at all accessible particle volume fractions and that it is necessary to account for this to accurately determine the electrokinetic ζ potential.
Collapse
Affiliation(s)
- Gregory N Smith
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Silvia Ahualli
- Department of Applied Physics, School of Science, University of Granada , 18071 Granada, Spain
| | - Ángel V Delgado
- Department of Applied Physics, School of Science, University of Granada , 18071 Granada, Spain
| | - David A J Gillespie
- 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
| | - Jocelyn Peach
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, 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
| | - Olga Shebanova
- Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus , Chilton, Didcot OX11 0DE, United Kingdom
| | - Nathan Smith
- Merck Chemicals Ltd, University Parkway , Chilworth, Southampton SO16 7QD, United Kingdom
| | - Julian Eastoe
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| |
Collapse
|
11
|
Sagisaka M, Ogiwara S, Ono S, James C, Yoshizawa A, Mohamed A, Rogers SE, Heenan RK, Yan C, Peach JA, Eastoe J. New Class of Amphiphiles Designed for Use in Water-in-Supercritical CO 2 Microemulsions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:12413-12422. [PMID: 27448717 DOI: 10.1021/acs.langmuir.6b01670] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Water-in-supercritical CO2 microemulsions formed using the hybrid F-H surfactant sodium 1-oxo-1-[4-(perfluorohexyl)phenyl]hexane-2-sulfonate, FC6-HC4, have recently been shown to have the highest water-solubilizing power ever reported. FC6-HC4 demonstrated the ability to outperform not only other surfactants but also other FCm-HCn analogues containing different fluorocarbon and hydrocarbon chain lengths (Sagisaka, M. et al. Langmuir 2015, 31, 7479-7487). With the aim of clarifying the key structural features of this surfactant, this study examined the phase behavior and water/supercritical CO2 aggregate formation of 1-oxo-1-[4-(perfluorohexyl)phenyl]hexane (Nohead FC6-HC4), which is an FC6-HC4 analogue but now, interestingly, without the sulfonate headgroup. Surprisingly, Nohead FC6-HC4, which would not normally be identified as a classic surfactant, yielded transparent single-phase W/CO2 microemulsions with polar cores able to solubilize a water-soluble dye, even at pressures and temperatures so low as to approach the critical point of CO2 (e.g., ∼100 bar at 35 °C). High-pressure small-angle scattering (SANS) measurements revealed the transparent phases to consist of ellipsoidal nanodroplets of water. The morphology of these droplets was shown to be dependent on the pressure, Nohead FC6-HC4 concentration, and water-to-surfactant molar ratio. Despite having almost the same structure as Nohead FC6-HC4, analogues containing both shorter and longer hydrocarbons were unable to form W/CO2 microemulsion droplets. This shows the importance of the role of the hydrocarbon chain in the stabilization of W/CO2 microemulsions. A detailed examination of the mechanism of Nohead FC6-HC4 adsorption onto the water surface suggests that the hexanoyl group protrudes into the aqueous core, allowing for association between the carbonyl group and water.
Collapse
Affiliation(s)
- Masanobu Sagisaka
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Shunsuke Ogiwara
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Shinji Ono
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Craig James
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Atsushi Yoshizawa
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | | | - Sarah E Rogers
- ISIS-CCLRC, Rutherford Appleton Laboratory , Chilton, Oxon OX11 0QX, U.K
| | - Richard K Heenan
- ISIS-CCLRC, Rutherford Appleton Laboratory , Chilton, Oxon OX11 0QX, U.K
| | - Ci Yan
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
| | - Jocelyn Alice Peach
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
| | - Julian Eastoe
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
| |
Collapse
|
12
|
Smith GN, Finlayson SD, Gillespie DA, Peach J, Pegg JC, Rogers SE, Shebanova O, Terry AE, Armes SP, Bartlett P, Eastoe J. The internal structure of poly(methyl methacrylate) latexes in nonpolar solvents. J Colloid Interface Sci 2016; 479:234-243. [DOI: 10.1016/j.jcis.2016.06.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/08/2016] [Accepted: 06/08/2016] [Indexed: 11/26/2022]
|
13
|
Lee J, Zhou ZL, Behrens SH. Charging Mechanism for Polymer Particles in Nonpolar Surfactant Solutions: Influence of Polymer Type and Surface Functionality. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:4827-4836. [PMID: 27135950 DOI: 10.1021/acs.langmuir.6b00583] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Surface charging phenomena in nonpolar dispersions are exploited in a wide range of industrial applications, but their mechanistic understanding lags far behind. We investigate the surface charging of a variety of polymer particles with different surface functionality in alkane solutions of a custom-synthesized and purified polyisobutylene succinimide (PIBS) polyamine surfactant and a related commercial surfactant mixture commonly used to control particle charge. We find that the observed electrophoretic particle mobility cannot be explained exclusively by donor-acceptor interactions between surface functional groups and surfactant polar moieties. Our results instead suggest an interplay of multiple charging pathways, which likely include the competitive adsorption of ions generated among inverse micelles in the solution bulk. We discuss possible factors affecting the competitive adsorption of micellar ions, such as the chemical nature of the particle bulk material and the size asymmetry between inverse micelles of opposite charge.
Collapse
Affiliation(s)
- Joohyung Lee
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive Northwest, Atlanta, Georgia 30332, United States
| | - Zhang-Lin Zhou
- HP Incorporated, 16399 West Bernardo Drive, San Diego, California 92127, United States
| | - Sven Holger Behrens
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive Northwest, Atlanta, Georgia 30332, United States
| |
Collapse
|
14
|
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]
|
15
|
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
|
16
|
Lee J, Zhou ZL, Alas G, Behrens SH. Mechanisms of Particle Charging by Surfactants in Nonpolar Dispersions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:11989-11999. [PMID: 26484617 DOI: 10.1021/acs.langmuir.5b02875] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Electric charging of colloidal particles in nonpolar solvents plays a crucial role for many industrial applications and products, including rubbers, engine oils, toners, or electronic displays. Although disfavored by the low solvent permittivity, particle charging can be induced by added surfactants, even nonionic ones, but the underlying mechanism is poorly understood, and neither the magnitude nor the sign of charge can generally be predicted from the particle and surfactant properties. The conclusiveness of scientific studies has been limited partly by a traditional focus on few surfactant types with many differences in their chemical structure and often poorly defined composition. Here we investigate the surface charging of poly(methyl methacrylate) particles dispersed in hexane-based solutions of three purified polyisobutylene succinimide polyamine surfactants with "subtle" structural variations. We precisely vary the surfactant chemistry by replacing only a single electronegative atom located at a fixed position within the polar headgroup. Electrophoresis reveals that these small differences between the surfactants lead to qualitatively different particle charging. In the respective particle-free surfactant solutions we also find potentially telling differences in the size of the surfactant aggregates (inverse micelles), the residual water content, and the electric solution conductivity as well as indications for a significant size difference between oppositely charged inverse micelles of the most hygroscopic surfactant. An analysis that accounts for the acid/base properties of all constituents suggests that the observed particle charging is better described by asymmetric adsorption of charged inverse micelles from the liquid bulk than by charge creation at the particle surface. Intramicellar acid-base interaction and intermicellar surfactant exchange help rationalize the formation of micellar ions pairs with size asymmetry.
Collapse
Affiliation(s)
- Joohyung Lee
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Zhang-Lin Zhou
- Hewlett-Packard Company, 16399 W Bernardo Drive, San Diego, California 92127, United States
| | - Guillermo Alas
- School of Chemistry and Biochemistry, Georgia Institute of Technology , 901 Atlantic Drive NW, Atlanta, Georgia 30332, United States
| | - Sven Holger Behrens
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive NW, Atlanta, Georgia 30332, United States
| |
Collapse
|
17
|
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
|
18
|
Sagisaka M, Ono S, James C, Yoshizawa A, Mohamed A, Guittard F, Rogers SE, Heenan RK, Yan C, Eastoe J. Effect of Fluorocarbon and Hydrocarbon Chain Lengths in Hybrid Surfactants for Supercritical CO2. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:7479-87. [PMID: 26080002 DOI: 10.1021/acs.langmuir.5b01737] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Hybrid surfactants containing both fluorocarbon (FC) and hydrocarbon (HC) chains have recently been shown to solubilize water and form elongated reversed micelles in supercritical CO2. To clarify the most effective FC and HC chain lengths, the aggregation behavior and interfacial properties of hybrid surfactants FCm-HCn (FC length m/HC length n = 4/2, 4/4, 6/2, 6/4, 6/5, 6/6, and 6/8) were examined in W/CO2 mixtures as functions of pressure, temperature, and water-to-surfactant molar ratio (W0). The solubilizing power of hybrid surfactants for W/CO2 microemulsions was strongly affected by not only the FC length but also by that of the HC. Although the surfactants having short FC and/or HC tails (namely, m/n = 4/2, 4/4, and 6/2) did not dissolve in supercritical CO2 (even at ∼17 mM, ≤400 bar, temperature ≤ 75 °C, and W0 = 0-40), the other hybrid surfactants were able to yield transparent single-phase W/CO2 mixtures identified as microemulsions. The solubilizing power of FC6-HCm surfactants reached a maximum (W0 ∼ 80 at 45 °C and 350 bar) with a hydrocarbon length, m, of 4. The W0 value of 80 is the highest for a HC-FC hybrid surfactant, matching the highest value reported for a FC surfactant which contained more FC groups. High-pressure small-angle neutron scattering measurements from FCm-HCn/D2O/CO2 microemulsions were consistent with growth of the microemulsion droplets with increasing W0. In addition, not only spherical reversed micelles but also nonspherical assemblies (rodlike or ellipsoidal) were found for the systems with FC6-HCn (n = 4-6). At fixed surfactant concentration and W0 (17 mM and W0 = 20), the longest reversed micelles were obtained for FC6-HC6 where a mean aspect ratio of 6.3 was calculated for the aqueous cores.
Collapse
Affiliation(s)
- Masanobu Sagisaka
- †Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Shinji Ono
- †Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Craig James
- †Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Atsushi Yoshizawa
- †Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | | | - Frédéric Guittard
- ∥Univ. Nice Sophia-Antipolis, CNRS, Equipe Surfaces et Interfaces, Parc Valrose, 06100 Nice, France
| | - Sarah E Rogers
- ⊥ISIS-CCLRC, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX, United Kingdom
| | - Richard K Heenan
- ⊥ISIS-CCLRC, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX, United Kingdom
| | - Ci Yan
- #School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Julian Eastoe
- #School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| |
Collapse
|