Reflectometry on curved interfaces

Früh, Johannes; Rühm, Adrian; Möhwald, Helmuth; Krastev, Rumen; Köhler, R.

doi:10.1016/j.physb.2014.08.030

Cited by 5 publications

(8 citation statements)

References 36 publications

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“…The surface energy of the silicon stamp is significantly higher than the one of the PDMS, therefore the PEM touching the silicon master transfers to the silicon stamp. The PEM not touching the silicon stamp during printing, will stay on the PDMS, if the line tension of the PEM is lower than the PDMS surface 30 energy.…”

Section: Methodsmentioning

confidence: 99%

“…Sample 5 uses PAA as the initial layer to compare the results with reference 15. The denominators behind the brackets of the sample structures symbolize repetitions of 30 bilayer groups.…”

Section: Methodsmentioning

confidence: 99%

“…These standard PEM samples had 16 bilayers of PSS and PDDA (produced by the same way as described above) 90 whereby the thickness was known from X-ray and neutron reflectometry (measured at V6 in the Helmholtz Berlin). 30,31 …”

Section: Methodsmentioning

confidence: 99%

“…The PEM printing, if one considers only the surface energies in two and one dimensions, depends on the PEM-substrate (PP) interaction, the PEM-stamp (PS) interaction and the PEM cohesion energy (L) (line tension, of the PEM line which needs to 30 be ripped for the printing pattern structure). The surface energy properties and used values are explained in detail below and in the supporting information.…”

Section: Theorymentioning

confidence: 99%

“…9 One of these bottom up approaches is microcontact printing (µCP). 1,10 Another bottom up technique is the layer-by-layer self- 30 assembly technique, which is used for e.g. the production of polyelectrolyte multilayer 11,12 (PEM) thin films.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Micro-contact printing of PEM thin films: effect of line tension and surface energies

et al. 2015

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5Polyelectrolyte multilayer (PEM) thin films are popular candidates for surface coating due to their versatility, tunability and simple production method. Often these films are used in a 2D structured manner for creating defined cell scaffolds or electronic applications. Although these films were successfully printed in the past, the conditions and energies necessary for a successful printing were only investigated as isolated parameters or as a function of the substrate but not the PEM surface energy and therefore the 10 dominating forces remained controversial. We hereby present a theory and method for microcontact printing of condensed polyelectrolyte multilayer thin films, based on surface energies and the line tension. The theory relies on the surface energy of the substrate, stamp and PEM as well as the PEM line tension ratios to create the desired pattern. The presented theory is able to predict the printability, quality and resolution limit of a chosen system and was evaluated with experiments. A reduction of the production 15 time from the beginning of PEM assembly to the final pattern from several hours down to 30 minutes was achieved while increasing reproducibility and resolution of the printed patterns at the same time. We would like to point out, that this approach can generally be used for any kind of adsorbed thin film on substrates.

show abstract

Section: Methodsmentioning

confidence: 99%

“…Sample 5 uses PAA as the initial layer to compare the results with reference 15. The denominators behind the brackets of the sample structures symbolize repetitions of 30 bilayer groups.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Theorymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Micro-contact printing of PEM thin films: effect of line tension and surface energies

et al. 2015

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Modification of the N-methyl-4,5-diazacarbazole D-π-A with a π-conjugated bridge to enhance excited-state properties for superior utilization in green energy applications: A theoretical approach

Sajid,

Kosar,

Al-Saadi

et al. 2024

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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Elastic to Plastic Deformation in Uniaxially Stressed Polylelectrolyte Multilayer Films

Frueh

Rühm

et al. 2018

Langmuir

Self Cite

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Polyelectrolyte multilayer (PEM) are thin polymeric films produced by alternating adsorption of positively and negatively charged polyelectrolytes (PE) on a substrate. These films are considered drug delivery agents as well as coating material for implants, due to their antibiofouling and biologically benign properties. For these reasons the film mechanical properties as well as response to mechanical stress are important measurement parameters. Especially intriguing is the correlation of the mechanical properties of PEM on macroscopic level with the structure of PEM on molecular level, which is addressed here for the first time. This study investigates PEM from PDADMA/PSS produced by spraying technique with neutron and X-ray reflectometry. Reflectometry technique provides precise information on thickness and density (i.e., electron density or scattering length density, respectively), and, this way, allows to conclude on changes in film composition. Thus, neutron and X-ray reflectometry technique is suitable to investigate the overall and the internal transformations, which PEM films might undergo upon exposure to mechanical load. During uniaxial elongation two regimes of PEM-deformation can be observed: An elastic regime at small elongations (below ca. 0.2%), which is characterized by a reversible change of film thickness, and a plastic regime with a permanent change above this limit. Both regimes have in common, that the mechanical load induces an increase of the film thickness, which is accompanied by an uptake of water from the surrounding atmosphere. The strain causes a molecular rearrangement within the PEM-structure of stratified layers, which, even in elastic regime, is permanent, although the thickness change remains reversible.

show abstract

Reflectometry on curved interfaces

Cited by 5 publications

References 36 publications

Micro-contact printing of PEM thin films: effect of line tension and surface energies

Micro-contact printing of PEM thin films: effect of line tension and surface energies

Modification of the N-methyl-4,5-diazacarbazole D-π-A with a π-conjugated bridge to enhance excited-state properties for superior utilization in green energy applications: A theoretical approach

Elastic to Plastic Deformation in Uniaxially Stressed Polylelectrolyte Multilayer Films

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