Electrochemically produced responsive hydrogel films: Influence of added salt on thickness and morphology

Bünsow, Johanna; Johannsmann, Diethelm

doi:10.1016/j.jcis.2008.07.009

Cited by 23 publications

(17 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For a discussion of the gelation kinetics and the small-scale morphology of the films produced by electrochemically triggered polymerization, see refs. [20,21]. Figure 2 shows a set of micrographs.…”

Section: Resultsmentioning

confidence: 99%

“…pNIPAm is soluble in pure water at room temperature, but precipitates in the presence of ammonium sulfate at the concentrations employed here. [21] The fact that the entire bubble surface is covered by a gel layer even for bubbles as large as 100 mm deserves a comment. Generally speaking, initiator decomposition occurs at the electrode surface only and polymerization is therefore limited to the near-surface range.…”

Section: Discussionmentioning

confidence: 99%

“…We reported on the formation and characterization of homogeneous poly(N-isopropylacrylamide) (pNIPAm) [19] hydrogel coatings on gold surfaces in refs. [20,21]. Here, we demonstrate a lithographic variant: one can use a small counter electrode to write patterns.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Patterned Hydrogel Layers Produced by Electrochemically Triggered Polymerization

Bünsow¹,

Johannsmann²

2009

Macromol. Rapid Commun.

Self Cite

View full text Add to dashboard Cite

We report on a lithographic mode of electrochemically triggered free radical polymerization. The polymerization is initiated by the reduction of an electrochemically active initiator. Hydrogel patterns can be written by employing a small insulated counter electrode. The investigations show that the "pen" actually is a small oxygen bubble between the counter electrode and the sample surface. The spot size corresponds to the size of the bubble produced between the counter electrode and the substrate. The gas/liquid interface traps the growing chains and guides the growth of a gel layer at the bubble surface. Since bubbles can be created and controlled in many different ways, this mechanism constitutes an easy route for the formation of structured, surface-bound polymer layers.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Patterned Hydrogel Layers Produced by Electrochemically Triggered Polymerization

Bünsow¹,

Johannsmann²

2009

Macromol. Rapid Commun.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Examples of electrochemically triggered insitu polymerizations are the electropolymerization of conducting polymers, [4] electrografting, [1,5,6] and electrochemically induced polymerizations where the initiating species is produced at anodic [7][8][9][10][11] or cathodic potentials. [12][13][14][15][16][17] In-situ polymerization is attractive because it does not require a high synthetic effort. However, it can not provide a good control over the polymer properties such as chain length, polydispersity, composition, or cross-linking density.…”

Section: Introductionmentioning

confidence: 99%

Electrodeposition of Amino‐Functionalized Particles in a pH Gradient: Quantitative Investigations Employing an Electrochemical Quartz Crystal Microbalance

Bünsow

Grabs

Schmidt‐Naake

et al. 2009

Macromolecular Symposia

Self Cite

View full text Add to dashboard Cite

Summary:The electrodeposition of amino-functionalized polystyrene and polybutylacrylate particles onto a gold electrode was investigated by an electrochemical quartz crystal microbalance (EQCM) and by AFM imaging. Particles with diameters in the range of 100 nm were prepared by miniemulsion polymerization. An electrochemical pH modulation in front of the electrode induced the neutralization of the amino groups and the particles readily precipitated onto the surface. The efficiency of the deposition was a function of the applied voltage, of the particles' softness, and of the amino content of the particles. Depending on the polymer composition, the coatings consisted of a dense array of individual miniemulsion particles or of a smooth polymer surface produced by coalescence.

show abstract

“…[18][19][20] This hydrogel film is swollen in a tetraethoxysilane (TEOS) solution. Application of a negative voltage shifts the pH to higher values, which induces the deposition of silica into the hydrogel film.…”

Section: Introductionmentioning

confidence: 99%

Preparation of Hydrogel‐Silica Composite Films by Electrochemically Triggered Deposition

Bünsow

Petri

Johannsmann

2009

Macromolecular Symposia

Self Cite

View full text Add to dashboard Cite

Summary:The electrochemical formation of hybrid films containing both a polymer and porous silica was performed in two different ways. In both cases, the deposition of the inorganic oxide was triggered by an electrochemical pH modulation in front of an electrode. Hydrolysis and condensation of the alkoxysilane precursors in the pH gradient yielded silica structures on the electrode surface. In the first route, an electrode was employed which had been previously coated with a polymer hydrogel. In this case, the silica readily precipitated into the hydrogel, forming rigid structures with thicknesses in the range of 100 nm. A second approach makes use of the deposition of an alkoxyvinylsilane precursor. Subsequent electrochemically induced polymerization of a polymer hydrogel inside these films is possible, but yields lower thicknesses than route I. This is explained by a blocking of the electrode by the vinylfunctionalized silica film.

show abstract

Electrochemically produced responsive hydrogel films: Influence of added salt on thickness and morphology

Cited by 23 publications

References 35 publications

Patterned Hydrogel Layers Produced by Electrochemically Triggered Polymerization

Patterned Hydrogel Layers Produced by Electrochemically Triggered Polymerization

Electrodeposition of Amino‐Functionalized Particles in a pH Gradient: Quantitative Investigations Employing an Electrochemical Quartz Crystal Microbalance

Preparation of Hydrogel‐Silica Composite Films by Electrochemically Triggered Deposition

Contact Info

Product

Resources

About