Effects of ionic strength and ion-specificity on the interface behavior of PDMAEMA-b-PLMA-b-POEGMA triblock terpolymer

He, Guanying; Wen, Gangyao; Skandalis, Athanasios; Pispas, Stergios; Liu, Dongxue

doi:10.1016/j.colsurfa.2022.130659

Cited by 3 publications

(5 citation statements)

References 38 publications

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“…After waiting 20 min at 2 or 20 mN m −1 , the substrate was withdrawn vertically through the monolayer at 2 mm min −1 . The transfer ratios of the above LB films were 1.3–2.0 which are higher than those of small amphiphiles (~1.0) but similar to those of amphiphilic block copolymers due to the good compressibility of hydrophilic blocks 40 . Furthermore, the initial LB films were also prepared without monolayer compression.…”

Section: Methodsmentioning

confidence: 84%

“…The transfer ratios of the above LB films were 1.3-2.0 which are higher than those of small amphiphiles ($1.0) but similar to those of amphiphilic block copolymers due to the good compressibility of hydrophilic blocks. 40 Furthermore, the initial LB films were also prepared without monolayer compression. To remove the deposited salt particles, each LB film was further immersed in ultrapure water for 2 min and then withdrawn both at 10 mm min À1 , which was repeated twice 30 and should have no destruction on its structure due to the good adsorption of the monolayer on the silicon wafer.…”

Section: Preparation and Afm Characterization Of Lb Filmsmentioning

confidence: 99%

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Ionic strength and anion‐specificity effects on the interfacial behavior of double hydrophilic block copolymer PNIPAM‐b‐POEGA

Pan,

Wen,

Giaouzi

et al. 2024

J of Applied Polymer Sci

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In our prior paper, surface micelles with the core‐shell‐petal structure of the double hydrophilic block copolymer poly(N‐isopropylacrylamide)‐block‐poly[oligo(ethylene glycol) acrylate] (PNIPAM‐b‐POEGA) were successfully evaluated. In this work, ionic strength (under acidic conditions) and anion‐specificity effects (under neutral conditions) on the aggregation behavior of PNIPAM‐b‐POEGA at the air/water interface and the morphologies of its Langmuir–Blodgett (LB) films were systematically studied. Under acidic conditions, the salting‐out effect prevails over the electrostatic shielding effect, and the amide group shells with a slight protonation degree are covered up by the large POEGA petals. Under neutral conditions, the stretching degrees of POEGA blocks at low/moderate salt concentrations are close. At high salt concentrations, the isotherms gradually shift to large molecular areas in the order of the NaCl, Na2SO4, NaNO3, and NaSCN cases. The hysteresis degrees of the monolayers increase with the increase of salt concentrations due to the gradually increased interfacial stretching degree and compression‐induced underwater solubility of POEGA blocks. All the initial LB films of PNIPAM‐b‐POEGA exhibit isolated circular micelles with small cores. Upon compression, the LB films exhibit slightly large micelles because of the possible coalescence of some neighboring cores.

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Section: Methodsmentioning

confidence: 84%

Section: Preparation and Afm Characterization Of Lb Filmsmentioning

confidence: 99%

Ionic strength and anion‐specificity effects on the interfacial behavior of double hydrophilic block copolymer PNIPAM‐b‐POEGA

Pan,

Wen,

Giaouzi

et al. 2024

J of Applied Polymer Sci

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“…This has been reported previously by He et al., where they describe this behavior as a “crowding effect”. [ 40 ]…”

Section: Resultsmentioning

confidence: 99%

“…This has been reported previously by He et al, where they describe this behavior as a "crowding effect". [40] Second, the experimental confirmation: to validate the results, Run 6 was performed and replicated. The NaCl concentration for Run 6 was selected to create an ionic strength midpoint between Run 1 and Run 2 to confirm the observed r AAm increase.…”

Section: Effects Of Ionic Strengthmentioning

confidence: 99%

Impact of Ionic Strength (Sodium Chloride Concentration) on Homopolymerization and Copolymerization Kinetics of Acrylamide and 2‐Acrylamido‐2‐Methylpropane Sulfonic Acid

Conrod,

Topcuoglu,

Penlidis

et al. 2024

Macro Reaction Engineering

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Anionic polyelectrolytes can be used for a variety of applications, including flocculation and enhanced oil recovery. While it is widely recognized that polyelectrolyte synthesis is impacted by the pre‐polymer formulation and polymerization conditions, the specific relationships between these factors and the subsequent polymer properties are not well understood. Therefore, the current work intends to improve understanding of ionic strength (IS) effects during the copolymerization of 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS) and acrylamide (AAm). The aims of the study were (i) to use in situ H1 NMR to study copolymerization kinetics, and (ii) to determine how increasing IS impacts copolymerization kinetics (and, by extension copolymer microstructure). It was found that altering IS prior to copolymerization had significant impacts on the reactivity ratios, and therefore impacted the microstructure through multiple mechanisms. Increasing IS caused a crowding effect, where the propagating chain developed a random coil conformation and caused steric hindrance of the large AMPS monomer, decreasing the likelihood of AMPS propagation. When the IS was increased further, the ionic shielding effect was more impactful, increasing the likelihood of AMPS propagation. Ultimately, this work will make it possible to manipulate IS to synthesize AMPS/AAm copolymers with specific desirable properties for target applications.This article is protected by copyright. All rights reserved

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“…Many researchers have demonstrated the ability of amphiphilic block copolymers to self-assemble into various monolayers at the air–water interface, − and the formation of nanoaggregates can be primarily controlled by modifying the polymer composition. Some common linear copolymers, such as polystyrene- block -poly(ethylene oxide) (PS- b -PEO), − polystyrene- block -poly(methyl methacrylate) (PS- b -PMMA), − and polystyrene- block -poly(2-vinylpyridine) (PS- b -P2VP), , have been comprehensively studied.…”

Section: Introductionmentioning

confidence: 99%

Closely Packed Core–Shell Micelle Structures of Double Hydrophilic Miktoarm Star Copolymers at the Air–Water Interface

Zhang,

Wen,

Giaouzi

et al. 2024

Langmuir

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The aggregation behavior of amphiphilic block copolymers at the air−water interface has been extensively studied, but less attention was given to that of star copolymers. In this work, we studied the interfacial aggregation behavior of two double hydrophilic pH-and temperatureresponsive miktoarm star copolymers of poly[di(ethylene glycol) methyl ether methacrylate]-poly [2-(dimethylamino)ethyl methacrylate] (PDEG-MA 3 -PDMAEMA 3 and PDEGMA 4 -PDMAEMA 7 , the subscripts denote arm numbers) with different molecular weights. The effects of subphase pH and temperature on the monolayer isotherms and hysteresis curves of the two star copolymers and the morphologies of their Langmuir−Blodgett (LB) films were studied by the Langmuir film balance technique and atomic force microscopy, respectively. At the air−water interface, the two star copolymers tend to form closely packed micelles. These micelles exhibit a core−shell structure, where the small hydrophobic core consists of cross-linker of ethylene glycol dimethacrylate (EGDMA) and the carbon backbones of PDEGMA and PDMAEMA arms and the short hydrophilic shell is composed of di(ethylene glycol) and tertiary amine side groups. With increasing subphase pH, the surface pressure versus molecular area isotherms shift toward larger mean molecular areas as a result of the enhanced interface adsorption of nonprotonated tertiary amine groups. The isotherm shift of PDEGMA 3 -PDMAEMA 3 monolayers is primarily attributed to high density of tertiary amine groups in the shells, while that of PDEGMA 4 -PDMAEMA 7 is mainly attributed to high density of di(ethylene glycol) groups in the shells. The hysteresis degrees in the monolayers of the two copolymers under alkaline and neutral conditions are greater than those under acidic conditions due to the decreased protonation degree of the tertiary amine groups. At 10 °C, the mobility of the shells is poor and the isotherms are located on the right. Above the lower critical solution temperature, di(ethylene glycol) groups contract, which causes a slight shift of the isotherms toward smaller mean molecular areas.

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Effects of ionic strength and ion-specificity on the interface behavior of PDMAEMA-b-PLMA-b-POEGMA triblock terpolymer

Cited by 3 publications

References 38 publications

Ionic strength and anion‐specificity effects on the interfacial behavior of double hydrophilic block copolymer PNIPAM‐b‐POEGA

Ionic strength and anion‐specificity effects on the interfacial behavior of double hydrophilic block copolymer PNIPAM‐b‐POEGA

Impact of Ionic Strength (Sodium Chloride Concentration) on Homopolymerization and Copolymerization Kinetics of Acrylamide and 2‐Acrylamido‐2‐Methylpropane Sulfonic Acid

Closely Packed Core–Shell Micelle Structures of Double Hydrophilic Miktoarm Star Copolymers at the Air–Water Interface

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