Compression Induced Chirality in Dense Molecular Films at the Air−Water Interface Probed by Second Harmonic Generation

Three different liquid interfaces, water/air, thiophene/air, and water/thiophene, were probed using the second harmonic generation (SHG) technique. Thiophene and water have been chosen because the hyperpolarizability of these molecules has already been measured or calculated and the different values can be found in literature. We have studied the microscopic structure of these interfaces by comparing the components of the second order susceptibility tensor determined from the SHG polarization curve analysis with those determined via a molecular dynamics (MD) simulation of these interfaces. We have indeed computed the structure and orientation of water and thiophene molecules at the liquid/air and liquid/liquid (L/L) interfaces as a function of the distance from the interface. The integrated susceptibility values calculated by MD simulations agree well with SHG results and validate the choice of force fields that should permit to quantify more complex L/L interfaces.

show abstract

“…49 These parameters are given in Table II. The SHG setup was built above the air/liquid or liquid/liquid interface.…”

Section: Shg Experimentsmentioning

confidence: 99%

Analysis of the second harmonic generation signal from a liquid/air and liquid/liquid interface

Pham

Jonchère

Dufrêche

et al. 2017

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…This effect is smaller with a base-pair/dye ratio of 1 instead of 2. This I s (γ) profile can be properly reproduced by using the following function 42 :…”

Section: Resultsmentioning

confidence: 99%

Ultrafast excited-state dynamics at interfaces: fluorescent DNA probes at the dodecane/water interface

Licari¹,

Vauthey²

2015

SPIE Proceedings

View full text Add to dashboard Cite

Although the interfaces between two isotropic media are of primary importance in many areas of science and technology, their properties are only partially understood. Our strategy to obtain an insight into these properties is to investigate the ultrafast excited-state dynamics of environment-sensitive molecular probes at liquid interfaces using time-resolved surface second harmonic generation, and to compare it with the dynamics of the same molecules in bulk solutions. Additionally, this approach gives rich information on how the chemical reactivity may change when going from the bulk phase to the interface. This is illustrated by an investigation performed with a series of fluorescent DNA probes at the dodecane/water interface without and with the presence of DNA in the aqueous phase. Substantial differences in the conformation of these cyanine dyes (aggregated or not) and in the excited-state dynamics are observed when going from bulk solutions to the interface. Moreover, the presence of double-stranded DNA in the aqueous phase induces some chirality at the interface.

show abstract

“…The detailed description of the SHG setup can be found elsewhere [16]. Briefly, in our configuration, a fundamental 780 nm incoming wave was impinging onto the film surface with a 70° angle with controlled linear polarization.…”

Section: Nonlinear Opticsmentioning

confidence: 99%

“…Briefly, in our configuration, a fundamental 780 nm incoming wave was impinging onto the film surface with a 70° angle with controlled linear polarization. The harmonic outgoing wave at 390 nm was then collected in specular reflection through a spectrometer and a CCD camera [16].…”

Section: Nonlinear Opticsmentioning

confidence: 99%

Quadratic nonlinear optics to assess the morphology of riboflavin doped chitosan for eco-friendly lithography

et al. 2018

View full text Add to dashboard Cite

We report the use of the Second Harmonic Generation response from a riboflavin doped chitosan film as a characterization method of the film morphology. This film is of particular interest in the development of new and bio-sourced material for eco-friendly UV lithography. The method allows us to determine how riboflavin is distributed as a function of film depth in the sample. This possibility is of importance in order to have a better understanding of the riboflavin influence in chitosan films during the lithography process. On the contrary, linear optical techniques provide no information beyond the mere confirmation of the riboflavin presence.

show abstract

Compression Induced Chirality in Dense Molecular Films at the Air−Water Interface Probed by Second Harmonic Generation

Cited by 37 publications

References 30 publications

Analysis of the second harmonic generation signal from a liquid/air and liquid/liquid interface

Analysis of the second harmonic generation signal from a liquid/air and liquid/liquid interface

Ultrafast excited-state dynamics at interfaces: fluorescent DNA probes at the dodecane/water interface

Quadratic nonlinear optics to assess the morphology of riboflavin doped chitosan for eco-friendly lithography

Contact Info

Product

Resources

About