Electrochemistry of Surfactants

Schulz, Eduardo Nicolás; Schulz, Erica P.; CarlosSchulz, Pablo

doi:10.5772/67975

Cited by 7 publications

(5 citation statements)

References 83 publications

(112 reference statements)

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“…As repeatedly reported, − ionic surfactants tend to adsorb by their charged head rather than their hydrophobic tail onto a hydrophilic electrode. In terms of layer configuration, if the charge of the surfactant head group is opposite that of the electrode charge, bilayer adsorption occurs on the electrode, , which could be due to the additional electrostatic forces making the first adsorbed layer relatively stable. If the charge of the surfactant head group is the same as the electrode charge, despite the electrostatic repulsion, minor adsorption of the surfactant on the electrode is still observed experimentally. − In the case of EMAR with high concentrations of the supporting electrolyte salt, surfactants with the same charge as the electrode are likely adsorbed on a layer of ions with an opposite charge formed on the electrode, for example, Na + on the cathode, that screens the surfactant/electrode charge interactions (Figure ).…”

Section: Results and Discussionmentioning

confidence: 99%

“…The charge transfer resistance of the solution was impacted less by DTAB than that by SDS. On the negatively charged cathode, the surface electric field is reduced in the presence of adsorbed DTAB as a result of local charge neutralization, , which potentially causes an increase in the charge transfer resistance; the electrocatalytic effect to reduce the charge transfer is offset significantly by the local charge neutralization effect. These observations can be used to interpret the differences in charge transfer resistance between the samples observed in the EIS measurements (Figure D).…”

Section: Results and Discussionmentioning

confidence: 99%

“…As repeatedly reported, 33−35 ionic surfactants tend to adsorb by their charged head rather than their hydrophobic tail onto a hydrophilic electrode. In terms of layer configuration, if the charge of the surfactant head group is opposite that of the electrode charge, bilayer adsorption occurs on the electrode, 36,37 which could be due to the additional electrostatic forces making the first adsorbed layer relatively stable. If the charge of the surfactant head group is the same as the electrode charge, despite the electrostatic repulsion, minor adsorption of the surfactant on the electrode is still observed experimentally.…”

Section: ■ Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Improved CO₂ Capture Performance of Electrochemically Mediated Amine Regeneration Processes with Ionic Surfactant Additives

Rahimi

Zucchelli

Puccini

et al. 2020

ACS Appl. Energy Mater.

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For the effective reduction of global CO 2 emissions, it is essential to develop and deploy efficient and cost-effective technologies for CO 2 capture, especially from large point sources. We recently developed an electrochemically mediated amine regeneration (EMAR) system to replace traditional thermal desorption for the capture of CO 2 from post-combustion flue gases. Despite EMAR effectiveness on a laboratory scale, concerns regarding the high gas-to-liquid ratio in the electrochemical cell and longterm instability of the electrodes need to be addressed before further scale-up of the process to a pilot plant and beyond can be entertained. Accordingly, we investigated the effect of using sodium dodecyl sulfate (SDS) as an anionic surfactant and dodecyltrimethylammonium bromide (DTAB) as a cationic surfactant on the process operation. It was found that it is advantageous to use an anionic surfactant for a system such as EMAR that contains hydrophilic electrodes and a positively charged electrochemically active species. The overall cell resistance was notably reduced when SDS anionic surfactant was used. The precipitation of copper particles observed in the anode outlet when no surfactant was used was effectively avoided when SDS was added to the electrolyte, resulting in electrode stability. In addition, smaller gas bubbles were produced in the presence of the SDS surfactant, which resulted in less blockage of the electrode by the gas with a resultant lower cell potential under constant current conditions, driving more efficient CO 2 desorption. This led to an ∼25% reduction in the electrochemical energy requirement, the lowest ever achieved experimentally for the EMAR process. Overall, the addition of a very low concentration of SDS resulted in the successful circumvention of the important problems faced by the EMAR system regarding further scale-up.

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Section: Results and Discussionmentioning

confidence: 99%

Section: Results and Discussionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Improved CO₂ Capture Performance of Electrochemically Mediated Amine Regeneration Processes with Ionic Surfactant Additives

Rahimi

Zucchelli

Puccini

et al. 2020

ACS Appl. Energy Mater.

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“…Instead, it occurs when barriers that hinder learning are identified and removed. The organizational learning process also requires changes in organizational knowledge (Schulz, 2017). Revisions are needed in practices and ways of thinking that impact the performance of the organization (Chiva et al, 2014).…”

Section: Introduction Do Cybersecurity Exercises Benefit An Individua...mentioning

confidence: 99%

Learn to Train Like You Fight

Karjalainen¹,

Ojala²,

Vatanen³

et al. 2023

International Journal of Adult Education and Technology

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This qualitative study includes nine semi-structured interviews with cybersecurity experts from different security-related organizations who are familiar with cybersecurity exercises. Its contribution to cybersecurity workforce development focuses on organizational learning rather than individual skills development and relevant competencies. It was found that the utilization of thematic analysis methods develop individual readiness and expertise. It also enhances the maturity of an organization's processes, roles, communication, and exercise capabilities. Moreover, the exercises increase social trust between individuals and organizations through business-to-business cooperation. However, there were several barriers and challenges in utilizing learned skills and competencies within an organization, including a need to increase the capacity of staff members who participate in the exercise.

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“…14 We use it here as a model cationic therapeutic peptide that stands to benefit from controlled-release formulations that will modulate its dose-limiting nephrotoxic character. 15,16,17 In this work, PMB was complexed with hydrophobic counterions with different head groups, tail lengths and geometries, and log P values (Table 1). Nanocarrier formation and encapsulation efficiency were determined.…”

Section: ■ Introductionmentioning

confidence: 99%

Chemistry and Geometry of Counterions Used in Hydrophobic Ion Pairing Control Internal Liquid Crystal Phase Behavior and Thereby Drug Release

et al. 2021

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The combination of Flash NanoPrecipitation and hydrophobic ion pairing (HIP) is a valuable approach for generating nanocarrier formulations of ionic water-soluble drugs with controllable release properties dictated by liquid crystalline structuring of the ion pairs. However, there are few examples of this in practice in the literature. This work aims to decipher the influence of the nature of the hydrophobic counterion used in HIP and its consequent impact on liquid crystalline structuring and drug release. The hypothesis of this study was that hydrophobic counterions with different head and tail groups used for FNP with HIP would give rise to different liquid crystalline structures, which in turn would result in different drug release behavior. A cationic, watersoluble antibiotic, polymixin B, was complexed with eight different hydrophobic counterions with varying head and tail groups and encapsulated into nanocarriers 100−400 nm in size prepared using FNP. Sixteen formulations were assessed for internal structure by synchrotron small-angle X-ray scattering, and drug release was measured in vitro in physiological conditions. The liquid crystalline phases formed depended on the counterion head group and tail geometry, drug:counterion charge ratio, and the ionic strength and pH of the release medium. Drug release occurred more rapidly when no liquid crystalline phases were present and more slowly when higher-ordered phases existed. Specific findings include that phosphonic acid counterions lead to the formation of lamellar structures that persisted at pH 2.0 but were not present at pH 7.3. In contrast, sulfonic acids lead to lamellar or hexagonal phases that persisted at both pH 7.3 and 2.0, while hydrophobic counterions without alkyl tails did not form internal structures. It was also clear that the lipophilicity of the counterion does not dictate drug release. These findings confirm that the liquid crystalline phase behavior of the drug:counterion complex dictates drug release and significantly improves our understanding of the types of controlled release formulations that are possible using FNP with HIP.

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Electrochemistry of Surfactants

Abstract: The application of different electrochemical techniques to surfactant systems, namely polarography and cyclic voltammetry, differential capacitance, chronocoulometry and electrochemical impedance spectroscopy, is reviewed.

Cited by 7 publications

References 83 publications

Improved CO₂ Capture Performance of Electrochemically Mediated Amine Regeneration Processes with Ionic Surfactant Additives

Improved CO₂ Capture Performance of Electrochemically Mediated Amine Regeneration Processes with Ionic Surfactant Additives

Learn to Train Like You Fight

Chemistry and Geometry of Counterions Used in Hydrophobic Ion Pairing Control Internal Liquid Crystal Phase Behavior and Thereby Drug Release

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Electrochemistry of Surfactants

Abstract: The application of different electrochemical techniques to surfactant systems, namely polarography and cyclic voltammetry, differential capacitance, chronocoulometry and electrochemical impedance spectroscopy, is reviewed.

Cited by 7 publications

References 83 publications

Improved CO2 Capture Performance of Electrochemically Mediated Amine Regeneration Processes with Ionic Surfactant Additives

Improved CO2 Capture Performance of Electrochemically Mediated Amine Regeneration Processes with Ionic Surfactant Additives

Learn to Train Like You Fight

Chemistry and Geometry of Counterions Used in Hydrophobic Ion Pairing Control Internal Liquid Crystal Phase Behavior and Thereby Drug Release

Contact Info

Product

Resources

About

Improved CO₂ Capture Performance of Electrochemically Mediated Amine Regeneration Processes with Ionic Surfactant Additives

Improved CO₂ Capture Performance of Electrochemically Mediated Amine Regeneration Processes with Ionic Surfactant Additives