Publications de Rüdiger Scheu

Hydration mediated interfacial transitions on mixed hydrophobic/hydrophilic nanodroplet interfaces

Sylvie Roke, Rüdiger Scheu, Nikolay Smolentsev, Filip Kovacik, Halil Ibrahim Okur

Interfacial phase transitions are of fundamental importance for climate, industry, and biological processes. In this work, we observe a hydration mediated surface transition in supercooled oil nanodroplets in aqueous solutions using second harmonic and sum ...

2018

Charge Asymmetry at Aqueous Hydrophobic Interfaces and Hydration Shells

Yixing Chen, Sylvie Roke, Kailash Chandra Jena, Rüdiger Scheu

The solvation of ions in a dielectric continuum is symmetric with respect to the sign of the ionic charge. Yet, many phenomena show indirect evidence that water may have a preference for negative charge: the vast majority of biological membrane interfaces ...

Wiley-Blackwell2014

Sum frequency spectroscopy of the hydrophobic nanodroplet/water interface: Absence of hydroxyl ion and dangling OH bond signatures

Sylvie Roke, Rüdiger Scheu, Nikolay Smolentsev

Vibrational sum frequency scattering measurements were performed on deuterated hexadecane oil nanodroplets dispersed in aqueous pH neutral and basic solutions. The predominant symmetry of the observed vibrational signatures was derived using nonlinear ligh ...

Elsevier2014

Toward Vibrational Dynamics at Liquid-Liquid and Nano-Interfaces: Time-Resolved Sum-Frequency Scattering

Sylvie Roke, Rüdiger Scheu

Interfacial molecular dynamics are key to understanding many phenomena in technology and life sciences. We demonstrate a first step toward accessing vibrational dynamics at liquid-liquid and nanoscopic (bio)-interfaces using time-resolved sum-frequency sca ...

American Chemical Society2014

Specific ion effects and the molecular structure of water, ions and amphiphiles on nanoscopic hydrophobic interfaces

Rüdiger Scheu

EPFL2014

Specific Ion Effects in Amphiphile Hydration and Interface Stabilization

Yixing Chen, Sylvie Roke, Rüdiger Scheu

Specific ion effects can influence many processes in aqueous solutions: protein folding, enzyme activity, self-assembly, and interface stabilization. Ionic amphiphiles are known to stabilize the oil/water interface, presumably by dipping their hydrophobic ...

Amer Chemical Soc2014

Stern Layer Formation Induced by Hydrophobic Interactions: A Molecular Level Study

Yixing Chen, Sylvie Roke, Rüdiger Scheu

The molecular ionic surface structure and charge of the electric double layer around a nanodroplet and its structural change induced by hydrophobic effects are measured using vibrational coherent surface scattering spectroscopy, second harmonic scattering, ...

Amer Chemical Soc2013

Analysis of Complex Spectra Using Fourier Filtering

Yixing Chen, Sylvie Roke, Rüdiger Scheu

We present a method to analyze complex spectral data, such as that obtained from vibrational sumfrequency generation (SFG), using Fourier filtering. The proposed filter locates the center frequency of all resonances in a complex data set. The analysis is u ...

Amer Chemical Soc2013

Surface Impurities Are Not Responsible For the Charge on the Oil/Water Interface: A Comment

Sylvie Roke, Kailash Chandra Jena, Rüdiger Scheu

A recent communication by Roger and Cabane[1] on the origin of negative charge on the interface between oil and water states that: "The basic assumption of all previous experimental and theoretical studies has been that these systems have "pristine" oil/wa ...

Wiley-VCH Verlag GmbH2012

Comparison of scattering and reflection SFG: a question of phase-matching

Sylvie Roke, Kailash Chandra Jena, Hilton Barbosa De Aguiar, Rüdiger Scheu

We present a comparison between sum frequency scattering (SFS) and reflection mode sum frequency generation (R-SFG). We have used scattering theory to describe both scattering experiments as well as reflection mode experiments. The interfacial vibrational ...

2012