Charge density effects on polyelectrolyte dynamic rheology

Harrington, John C.

doi:10.1002/app.27405

Cited by 7 publications

(7 citation statements)

References 71 publications

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“…Experimental results for noncrosslinked polyelectrolytes with α ranging from 0.05 to 0.50 demonstrate a power law relationship G ′ ∼ α x , where x ranges from 0.35 to 0.70, and x decreases with increased concentration 27. It is noted that at an equivalent 2% concentration, x = 0.62, consistent with this study.…”

Section: Discussionsupporting

confidence: 88%

The effects of neutralization on the dynamic rheology of polyelectrolyte microgel mucilages

Harrington

2012

J of Applied Polymer Sci

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The dynamic rheological properties of a model poly(acrylic acid) microgel mucilage in the closepacked concentrated region (reduced concentration cQ > 1) were evaluated as a function of the degree of neutralization, a ¼ [NaOH]/[COOH]. As the parent microgel is neutralized, up to an order of magnitude increase is observed in the swelling ratio Q, dynamic modulus, and yield properties. Four regions were observed where the dynamic rheological properties exhibited a different power law dependence with increasing a. The dynamic yield strain does not change remarkably with increased neutralization, whereas the dynamic yield stress increases more than 10-fold. This supports a mechanism where the yield strain depends on geometric considerations, whereas the yield stress reflects the stress required to force microgels past adjacent microgels. A linearity observed between modulus and dynamic yield stress with increased neutralization suggests a concerted expansion and affect on the rheological properties with the microgel core and emanating polymer chains.

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Section: Discussionsupporting

confidence: 88%

The effects of neutralization on the dynamic rheology of polyelectrolyte microgel mucilages

Harrington

2012

J of Applied Polymer Sci

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“…SAXS is a powerful method for the structural characterization of polymers and nanoparticles. 39−41 Since the sample concentrations in this study are well above the typical overlap concentration of PAA solutions, 42,43 all samples enter the semi-dilute regime. Figure 8 shows SAXS intensity versus wavevector (q).…”

Section: ■ Results and Discussionmentioning

confidence: 95%

“…To better understand the neutralization impact, small-angle X-ray scattering (SAXS) was performed to characterize the binder solution samples. SAXS is a powerful method for the structural characterization of polymers and nanoparticles. − Since the sample concentrations in this study are well above the typical overlap concentration of PAA solutions, , all samples enter the semi-dilute regime. Figure shows SAXS intensity versus wavevector ( q ).…”

Section: Resultsmentioning

confidence: 99%

Restorable Neutralization of Poly(acrylic acid) Binders toward Balanced Processing Properties and Cycling Performance for Silicon Anodes in Lithium-Ion Batteries

Shi

Jiang

Robertson

et al. 2020

ACS Appl. Mater. Interfaces

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Neutralization of poly(acrylic acid) (PAA)-based binders using lithium hydroxide is a common strategy for fabricating silicon anode laminates, which improves rheological properties of slurries toward high-quality electrode laminates. However, the significantly increased basicity causes degradation of Si particles while the irreversible conversion of carboxylic acid groups to lithium carboxylates undermines the binding strength, collectively leading to adverse cycling performance of the fabricated Si anodes. Herein, a novel neutralization process for PAA binders is developed. A weak base, ammonia (NH 3 ), was discovered as a neutralizing agent that still promotes rheological response of binder solutions but results in a reduced pH increase. Interestingly, the resulting ammonium carboxylate groups may cleave during the drying process to restore the neutralized PAA (PAA-NH 3 ) binders to their pristine states. The best-performing composition of 50% neutralization (PAA-50%NH 3 ) provides comparable rheological response as a PAA-Li binder as well as much improved cycling performance. The half-cells using the PAA-50%NH 3 binder can deliver 60% capacity retention over 100 cycles at C/3 rate, affording a 23.8% increase compared to PAA-Li half-cells. This restorable neutralization process of PAA binders represents an innovative strategy of mitigating issues from slurry processing of Si particles to achieve concurrent improvements in high-quality lamination and cycling performance.

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“…In the last decades, these polymers have gained many interests due to their specific rheological properties and applications in different industrial areas such as: paints and/or coatings, 7–9 cosmetics, 10–12 drug delivery, 13–15 enhanced oil recovery, 13–19 for example. On the other hand, it is well known that several parameters could affect the rheological properties of associative polyelectrolytes in aqueous media which fundamentally depend on the fraction of ionic groups, 20–23 charge density, 24 the suitable solvent for dissolution of resultant polymer which affects the dynamic of the medium, 25 the dielectric constant, 26–29 the salt concentration, 30–34 and surfactant 35–38 . Seng et al 39 described the influence of the concentration of selected additives on the viscosity of polyelectrolytes.…”

Section: Introductionmentioning

confidence: 99%

Impact of additives on the rheological properties of associating water‐soluble multiblock polyelectrolytes

Muñoz-López¹,

Thomas

Garcı́a-Cerda³

et al. 2021

J of Applied Polymer Sci

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The impact of additives on the rheological behavior of four associating water‐soluble multiblock polyelectrolytes previously synthesized via reversible addition‐fragmentation chain transfer (RAFT) polymerization was described. These polyelectrolytes contained different number of blocks ranged from 1 to 7 divided into hydrophilic and hydrophobic. The rheological analyses of polymers were performed at 25°C at a given concentration (0.1–15 wt%) in the presence of sodium chloride (NaCl) 0.1–0.5 M, sodium dodecyl sulfate (SDS) 2–10 mM or a mixture of both. Data demonstrated an increase in the viscosity of macroRAFT (ɳ = 0.002–9 Pa·s) and triblock copolymer‐TBC (ɳ = 0.003–0.04 Pa·s) versus the concentration of NaCl. Meanwhile, the viscosity of penta and heptablock copolymer exhibited a diminution whatever the (NaCl) used. Results from the rheological analyses of the associative polyelectrolytes at different (SDS) revealed that the viscosity of macroRAFT and triblock copolymer was kept constant in spite of the increment of the (SDS) while the viscosity of PBC and HBC displayed a pronounced diminution at the lower (SDS). Finally, the results from the rheological analyses of these polyelectrolytes versus a mixture of NaCl‐SDS showed a diminution in the viscosity of these solutions at any concentration of additives.

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Charge density effects on polyelectrolyte dynamic rheology

Cited by 7 publications

References 71 publications

The effects of neutralization on the dynamic rheology of polyelectrolyte microgel mucilages

The effects of neutralization on the dynamic rheology of polyelectrolyte microgel mucilages

Restorable Neutralization of Poly(acrylic acid) Binders toward Balanced Processing Properties and Cycling Performance for Silicon Anodes in Lithium-Ion Batteries

Impact of additives on the rheological properties of associating water‐soluble multiblock polyelectrolytes

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