Correlation between the Molecular Structure and Photoresponse in Aliphatic Self-Assembled Monolayers with Azobenzene Tailgroups

Langmuir ◽  
2008 ◽  
Vol 24 (20) ◽  
pp. 11691-11700 ◽  
Author(s):  
Tobias Weidner ◽  
Frauke Bretthauer ◽  
Nirmalya Ballav ◽  
Hubert Motschmann ◽  
Horst Orendi ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled

Effect of molecular structure of self-assembled monolayers on their tribological behaviors in nano- and microscales

Wear ◽  
2003 ◽  
Vol 255 (7-12) ◽  
pp. 819-825 ◽  
Author(s):  
Hyo-Sok Ahn ◽  
Pham Duc Cuong ◽  
Sangkwon Park ◽  
Yong-Wook Kim ◽  
Jong-Choo Lim
Keyword(s):  
Molecular Structure ◽  
Self Assembled Monolayers ◽  
Tribological Behaviors ◽  
Assembled Monolayers ◽  
Self Assembled

Influence of Molecular Structure on Phase Transitions:  A Study of Self-Assembled Monolayers of 2-(Aryl)-ethane Thiols

2007 ◽  
Vol 111 (45) ◽  
pp. 16909-16919 ◽  
Author(s):  
Piotr Cyganik ◽  
Manfred Buck ◽  
Thomas Strunskus ◽  
Andrey Shaporenko ◽  
Gregor Witte ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Phase Transitions ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled

Dependence of deposition method on the molecular structure and stability of organosilanes revealed from degrafting by tetrabutylammonium fluoride

2020 ◽  
Vol 22 (2) ◽  
pp. 658-666
Author(s):  
Jason Miles ◽  
Yeongun Ko ◽  
Jan Genzer
Keyword(s):  
Molecular Structure ◽  
Vapor Deposition ◽  
Self Assembled Monolayers ◽  
Deposition Method ◽  
Structure And Stability ◽  
Tetrabutylammonium Fluoride ◽  
Assembled Monolayers ◽  
Self Assembled

We probe the structure of self-assembled monolayers comprising organosilanes on flat silica-based surfaces prepared by liquid and vapor deposition by removing the organosilane molecules gradually from the substrate via tetrabutylammonium fluoride.

Vibrational sum-frequency generation study of molecular structure, sterical constraints and nonlinear optical switching contrast of mixed alkyl-azobenzene self-assembled monolayers

2020 ◽  
Vol 234 (7-9) ◽  
pp. 1427-1452 ◽  
Author(s):  
Saira Riaz ◽  
Gernot Friedrichs
Keyword(s):  
Molecular Structure ◽  
Nonlinear Optical ◽  
Sum Frequency Generation ◽  
Self Assembled Monolayers ◽  
Sum Frequency ◽  
Nlo Response ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Frequency Generation ◽  
Insight Into

AbstractSelf-assembled monolayers (SAMs) of azobenzene (AB) functionalized alkyl thiols on gold diluted with simple alkyl thiols provide a straightforward way to photochromic surfaces with high and tunable photoswitching efficiency. Trans-cis isomerization of the AB molecule changes the physical properties of the surface, including the nonlinear optical (NLO) response. Vibrational sum-frequency generation (VSFG) spectroscopy as a nonlinear type of laser spectroscopy offers surface- and orientation-sensitive insight into the molecular structure of mixed SAMs. In this study, VSFG as well as ultraviolet-visible (UV/Vis) spectroscopy has been employed to investigate the morphology, molecular structure, and NLO response of mixed SAMs with systematically varied surface composition. Methylazobenzene (MeAB) has been used as the molecular switch with the methyl substituent serving as orientational VSFG marker. Both short-chain and long-chain alkyl thiol co-ligands have been used to gain insight into the interplay between SAM structure and sterical constraints that are known to limit the free switching volume. Underlining the dominating role of sterical effects for controlling photochromic properties, a strong inhibition of the photoswitching efficiency and NLO response has been observed for the SAMs with an alkyl thiol co-ligand long enough to spatially extend into the layer of the MeAB chromophore. Overall, with <12% signal change, the relative NLO switching contrasts remained low in all cases. VSFG spectral trends clearly revealed that the presumably higher photoswitching efficiency upon dilution with the co-ligand is counteracted by a loss of structural order of the chromophore.

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