Molecular Orientation, Aggregation, and Order in Rhodamine Films at the Fused Silica/Air Interface

1999 ◽  
Vol 103 (7) ◽  
pp. 1124-1133 ◽  
Author(s):  
Tanya Kikteva ◽  
Dmitry Star ◽  
Zhihong Zhao ◽  
Tammy L. Baisley ◽  
Gary W. Leach
Keyword(s):  
Molecular Orientation ◽  
Fused Silica ◽  
Air Interface

A Molecular Architectural Approach to Self-Assembled Monolayers as NLO Materials

1995 ◽  
Vol 413 ◽  
Author(s):  
Xiaoguang Yang ◽  
Laura Smilowitz ◽  
C. Thomas Buscher ◽  
Duncan McBranch ◽  
Jeanne Robinson ◽  
...  
Keyword(s):  
Molecular Orientation ◽  
Surface Coverage ◽  
Second Harmonic ◽  
Fused Silica ◽  
Nonlinear Susceptibility ◽  
Self Assembled Monolayers ◽  
Fundamental Wavelength ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Derivatives Of

ABSTRACTSelf-assembled molecular architechtures of nonlinear optical (NLO) chromophores and their super-chromophores are discussed. The chromophores are derivatives of azobenzene sulfonates and the super chromophores are derivatives of calix[4]stilbazole and calix[4]stilbazolium. The studies of azobenzene sulfonates are aimed at understanding the surface coverage and molecular orientation in polar self-assembled monolayers (SAMs). The optimized molecular orientation was found to be 32±3 degree and the maximum surface coverage is approximately 2–4 molecules per nm2 depending on the molecular cross-section. The calixarene chromophores are macrocyclic compounds consisting of four simple D-π-A units bridged by methylene groups. These molecules were synthesized such that four D-π-A units of the calix[4]arene were aligned along the same direction with the calixarene in a cone conformation. Both simple and super-chromophores were subsequently fabricated into covalently bound selfassembled monolayers on the surfaces of fused silica and silicon. Spectroscopic second harmonic generation (SHG) measurements were carried out to determine the absolute value of the dominant element of the second-order nonlinear susceptibility, d33 = 60 pm/V at a fundamental wavelength of 890 nm. Furthermore, SHG imaging was employed to investigate the pattemed SAMs of NLO super chromophores.

Phase transition of molecular orientation at the liquid-air interface

1994 ◽  
Vol 50 (1) ◽  
pp. 614-617 ◽  
Author(s):  
Akihiko Sugimura ◽  
Mitsumasa Iwamoto ◽  
Ou-Yang Zhong-can
Keyword(s):  
Phase Transition ◽  
Molecular Orientation ◽  
Air Interface

scholarly journals The surface roughness, but not the water molecular orientation varies with temperature at the water–air interface

2015 ◽  
Vol 17 (36) ◽  
pp. 23559-23564 ◽  
Author(s):  
Yuki Nagata ◽  
Taisuke Hasegawa ◽  
Ellen H. G. Backus ◽  
Kota Usui ◽  
Seiji Yoshimune ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Surface Roughness ◽  
Temperature Dependence ◽  
Molecular Orientation ◽  
Sum Frequency Generation ◽  
Sum Frequency ◽  
Air Interface ◽  
Frequency Generation

We examine the temperature dependence of the interfacial molecular structure at the water–air interface by combining experimental and simulated sum-frequency generation (SFG) spectroscopy.

Biaxiality ordering of molecular orientation in a monolayer at the liquid-air interface

1996 ◽  
Vol 54 (6) ◽  
pp. 6537-6540 ◽  
Author(s):  
Mitsumasa Iwamoto ◽  
Akihiko Sugimura ◽  
Ou-Yang Zhong-can
Keyword(s):  
Molecular Orientation ◽  
Air Interface

Order To Disorder Transition at The Polymer-Air Interface for Hydrophobic Octadecyl Side Chain Copolymers

2000 ◽  
Vol 661 ◽  
Author(s):  
Keshav S. Gautam ◽  
Ali Dhinojwala
Keyword(s):  
Transition Temperature ◽  
Molecular Orientation ◽  
Crystalline State ◽  
Liquid Crystalline ◽  
Side Chain ◽  
Side Chains ◽  
Disorder Transition ◽  
Sum Frequency ◽  
Air Interface ◽  
Alkyl Side Chains

ABSTRACTMolecular orientation of octadecyl alkyl side chains at the poly (vinyl octadecyl carbamates-co-vinyl acetate) polymer-air interface has been studied using surface sensitive sum frequency generation (SFG) spectroscopy. At 280C, below the side chain crystalline transition temperature, the SFG spectra show strong methyl vibrations indicating ordered alkyl side chains at the polymer-air interface. In the liquid state (980C), the SFG spectra show higher contributions from the methylene vibrations indicating higher gauche defects at the interface. This surface order to disorder transition is gradual and spans over a broad temperature range (50-900C), where the bulk is in the smectic liquid crystalline state.

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