Influence of Polycation Composition on Electrochemical Film Formation

Schneider, Sabine; Janssen, Corinna; Klindtworth, Elisabeth; Mergel, Olga; Möller, Martin; Plamper, Felix A.

doi:10.3390/polym10040429

Cited by 8 publications

(23 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several previous studies on similar systems indicated the varying behavior of polymers in the presence of ferrocyanide ions or ferricyanide ions, according to their aggregation, [ 53,39 ] electrodeposition, [ 54,55 ] or interfacial activity. [ 10 ] These results confirmed the higher affinity between the block copolymers and ferricyanide ions amplifying the amphiphilicity of molecules in contrast to ferrocyanide ions.…”

Section: Resultsmentioning

confidence: 99%

Interfacial Rearrangements of Block Copolymer Micelles Toward Gelled Liquid–Liquid Interfaces with Adjustable Viscoelasticity

Prasser

Steinbach

Münch

et al. 2022

Small

Self Cite

View full text Add to dashboard Cite

modified by several types of additives such as low molecular weight surfactants and proteins, [3][4][5] particles, [6][7][8][9] or polymers. [10][11][12][13][14][15][16] Hereby, the adsorption of surface-active entities can occur by adsorption of unimers to form eventually more or less homogeneous monolayers. However, amphiphiles are often present in colloidal form as micelles. Since other colloidal particles, e.g., nanoparticles and microgels, can adsorb to interfaces in a pickeringlike fashion, intact micelles might also be prone to adsorb to the interface. [10,17,18] However, little is known on the fate of such interfacially attached micelles. In most cases, the kinetics of the rearrangements toward a monolayer are hard to capture.Generally, the interfacial tension is regarded as a primary indicator of adsorption processes, often deemed sufficient to trace changes at liquid interfaces. However, the involvement of certain substances or combinations can lead to complex interfaces with additional rheological properties, completely different to the ones of the pure interface. [1,19,20] Examples could involve, e.g., interfacial polymerization [21] (including classical nylon thread fabrication) or even interfacial crosslinking (bubble tea preparation). In some of these cases, the interfacial film is rather thick. However, also monolayers of amphiphiles can exhibit viscoelastic properties being essential for the properties of the whole system. Hence, Though amphiphiles are ubiquitously used for altering interfaces, interfacial reorganization processes are in many cases obscure. For example, adsorption of micelles to liquid-liquid interfaces is often accompanied by rapid reorganizations toward monolayers. Then, the involved time scales are too short to be followed accurately. A block copolymer system, which comprises poly(ethylene oxide) 110 -b-poly{[2-(methacryloyloxy)ethyl]diisopropylmethylammonium chloride} 170 (i.e., PEO 110 -b-qPDPAEMA 170 with quaternized poly(diisopropylaminoethyl methacrylate)) is presented. Its reorganization kinetics at the water/n-decane interface is slowed down by electrostatic interactions with ferricyanide ([Fe(CN) 6 ] 3-). This deceleration allows an observation of the restructuring of the adsorbed micelles not only by tracing the interfacial pressure, but also by analyzing the interfacial rheology and structure with help of atomic force microscopy. The observed micellar flattening and subsequent merging toward a physically interconnected monolayer lead to a viscoelastic interface well detectable by interfacial shear rheology (ISR). Furthermore, the "gelled" interface is redox-active, enabling a return to purely viscous interfaces and hence a manipulation of the rheological properties by redox reactions. Additionally, interfacial Prussian blue formation stiffens the interface. Such manipulation and in-depth knowledge of the rheology of complex interfaces can be beneficial for the development of emulsion formulations in industry or medicine, where colloidal stability or adapted permeabil...

show abstract

Section: Resultsmentioning

confidence: 99%

Interfacial Rearrangements of Block Copolymer Micelles Toward Gelled Liquid–Liquid Interfaces with Adjustable Viscoelasticity

Prasser

Steinbach

Münch

et al. 2022

Small

Self Cite

View full text Add to dashboard Cite

show abstract

“…This self-assembly process was reversible by electrochemical reduction of the ferricyanide . Amplified physical cross-linking of ferricyanides compared to that of ferrocyanides was found for other polycations as well. ,, …”

Section: Introductionmentioning

confidence: 88%

“…6 The insertion of specific groups or monomers leads to well-adaptable properties, i.e., the so-called stimuli-responsive or smart polymers and are defined by the reversible, large changes in their behavior due to small environmental changes . There is a large variety of external triggers causing changes in certain polymer systems . A well-known example of a temperature-sensitive polymer is poly( N -isopropyl acrylamide), which becomes insoluble in water above a certain temperature due to beneficial coil-to-globule transition. ,,− Furthermore, pH adjustment can influence the aggregation behavior of BCPs by the (de)protonation of different blocks. − Other triggers for smart polymers, which change the solution properties, are radiation, , magnetic stimuli, etc. ,, Intriguingly, complexation of different polymeric and/or supramolecular building blocks gives additional versatility by opening a modular approach.…”

Section: Introductionmentioning

confidence: 99%

“…However, triggering the aggregation behavior by electrochemistry was investigated in several studies before. ,− Here, an established concept is the quaternization of PDMAEMA blocks and their derivatives. The resulting hydrophilic poly{[2-(methacryloyloxy)ethyl]trimethylammonium chloride} (PMOTAC) blocks exhibited distinct interactions to certain oppositely charged counterions. ,,, Studies of miktoarm star polymers consisting of a poly(ethylene oxide) (PEO) block and 2.5 PMOTAC blocks on average addressed the complexation of hexacyanoferrates (HCFs). In situ oxidation from ferrocyanide ([Fe(CN) 6 ] 4− ) to ferricyanide ([Fe(CN) 6 ] 3− ) led to the formation of vesicles, where PMOTAC blocks assemble while water solvates the PEO blocks.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Electrochemical Stimulation of Water–Oil Interfaces by Nonionic–Cationic Block Copolymer Systems

et al. 2020

Self Cite

View full text Add to dashboard Cite

Variable interfacial tension could be desirable for many applications. Beyond classical stimuli like temperature, we introduce an electrochemical approach employing polymers. Hence, aqueous solutions of the nonionic–cationic block copolymer poly(ethylene oxide)114-b-poly{[2-(methacryloyloxy)ethyl]diisopropylmethylammonium chloride}171 (i.e., PEO114-b-PDPAEMA171 with a quaternized poly(diisopropylaminoethyl methacrylate) block) were investigated by emerging drop measurements and dynamic light scattering, analyzing the PEO114-b-qPDPAEMA171 impact on the interfacial tension between water and n-decane and its micellar formation in the aqueous bulk phase. Potassium hexacyanoferrates (HCFs) were used as electroactive complexants for the charged block, which convert the bishydrophilic copolymer into amphiphilic species. Interestingly, ferricyanides ([Fe(CN)6]3–) act as stronger complexants than ferrocyanides ([Fe(CN)6]4–), leading to an insoluble qPDPAEMA block in the presence of ferricyanides. Hence, bulk micellization was demonstrated by light scattering. Due to their addressability, in situ redox experiments were performed to trace the interfacial tension under electrochemical control, directly utilizing a drop shape analyzer. Here, the open-circuit potential (OCP) was changed by electrolysis to vary the ratio between ferricyanides and ferrocyanides in the aqueous solution. While a chemical oxidation/reduction is feasible, also an electrochemical oxidation leads to a significant change in the interfacial tension properties. In contrast, a corresponding electrochemical reduction showed only a slight response after converting ferricyanides to ferrocyanides. Atomic force microscopy (AFM) images of the liquid/liquid interface transferred to a solid substrate showed particles that are in accordance with the diameter from light scattering experiments of the bulk phase. In conclusion, the present results could be an important step toward economic switching of interfaces suitable, e.g., for emulsion breakage.

show abstract

“…electropolymerization), and in these cases, the resulting film is generally localized on the electrode surface. However, there are several indirect electron transfer mechanisms that generate diffusible species or gradients that act over longer distances (μm to mm from the electrode surface) to trigger thin film or hydrogel formation [117,[136][137][138]. In these cases, the electrochemical currents indirectly transduce the electrical inputs into the generation of macromolecular and macroscopic structures (note: such indirect mechanisms require redox reactions at the electrode surface and diffusible chemical species that shuttle electrons to/from the electrode).…”

Section: Electrical Current Quantifies Electrochemical Reactionsmentioning

confidence: 99%

Electrobiofabrication: electrically based fabrication with biologically derived materials

Kim

et al. 2019

Biofabrication

View full text Add to dashboard Cite

While conventional material fabrication methods focus on form and strength to achieve function, the fabrication of material systems for emerging life science applications will need to satisfy a more subtle set of requirements. A common goal for biofabrication is to recapitulate complex biological contexts (e.g. tissue) for applications that range from animal-on-a-chip to regenerative medicine. In these cases, the material systems will need to: (i) present appropriate surface functionalities over a hierarchy of length scales (e.g. molecular features that enable cell adhesion and topographical features that guide differentiation); (ii) provide a suite of mechanobiological cues that promote the emergence of native-like tissue form and function; and (iii) organize structure to control cellular ingress and molecular transport, to enable the development of an interconnected cellular community that is engaged in cell signaling. And these requirements are not likely to be static but will vary over time and space, which will require capabilities of the material systems to dynamically respond, adapt, heal and reconfigure. Here, we review recent advances in the use of electrically based fabrication methods to build material systems from biological macromolecules (e.g. chitosan, alginate, collagen and silk). Electrical signals are especially convenient for fabrication because they can be controllably imposed to promote the electrophoresis, alignment, self-assembly and functionalization of macromolecules to generate

show abstract

Influence of Polycation Composition on Electrochemical Film Formation

Cited by 8 publications

References 47 publications

Interfacial Rearrangements of Block Copolymer Micelles Toward Gelled Liquid–Liquid Interfaces with Adjustable Viscoelasticity

Interfacial Rearrangements of Block Copolymer Micelles Toward Gelled Liquid–Liquid Interfaces with Adjustable Viscoelasticity

Electrochemical Stimulation of Water–Oil Interfaces by Nonionic–Cationic Block Copolymer Systems

Electrobiofabrication: electrically based fabrication with biologically derived materials

Contact Info

Product

Resources

About