TY - JOUR
T1 - Unexpected monolayer-to-bilayer transition of arylazopyrazole surfactants facilitates superior photo-control of fluid interfaces and colloids
AU - Honnigfort, Christian
AU - Campbell, Richard A.
AU - Droste, Jörn
AU - Gutfreund, Philipp
AU - Hansen, Michael Ryan
AU - Ravoo, Bart Jan
AU - Braunschweig, Björn
N1 - Funding Information:
The authors gratefully acknowledge funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (Grant Agreement 638278). We also thank Dana Glikman and Marco Schnurbus (University Münster) for their help with the neutron reectivity measurements. We thank the Deutsche For-schungsgemeinscha (SFB 858) for nancial support. The authors thank the ILL for the allocation of neutron beam time on FIGARO (DOI: 10.5291/ILL-DATA.9-12-540 and DOI: 10.5291/ ILL-DATA.9-10-1573) and Simon Wood for technical assistance during the experiments. Norbert Störkmann and Jürgen Kröninger are acknowledged for help with the irradiation setups.
Publisher Copyright:
This journal is © The Royal Society of Chemistry.
This journal is © The Royal Society of Chemistry 2020.
PY - 2020/2/28
Y1 - 2020/2/28
N2 - Interfaces that can change their chemistry on demand have huge potential for applications and are prerequisites for responsive or adaptive materials. We report on the performance of a newly designed n-butyl-arylazopyrazole butyl sulfonate (butyl-AAP-C
4S) surfactant that can change its structure at the air-water interface by E/Z photo-isomerization in an unprecedented way. Large and reversible changes in surface tension (Δγ = 27 mN m
-1) and surface excess (ΔΓ > 2.9 μmol m
-2) demonstrate superior performance of the butyl-AAP-C
4S amphiphile to that of existing ionic surfactants. Neutron reflectometry and vibrational sum-frequency generation spectroscopy reveal that these large changes are caused by an unexpected monolayer-to-bilayer transition. This exceptional behavior is further shown to have dramatic consequences at larger length scales as highlighted by applications like the light-triggered collapse of aqueous foam which is tuned from high (>1 h) to low (<10 min) stabilities and light-actuated particle motion via Marangoni flows.
AB - Interfaces that can change their chemistry on demand have huge potential for applications and are prerequisites for responsive or adaptive materials. We report on the performance of a newly designed n-butyl-arylazopyrazole butyl sulfonate (butyl-AAP-C
4S) surfactant that can change its structure at the air-water interface by E/Z photo-isomerization in an unprecedented way. Large and reversible changes in surface tension (Δγ = 27 mN m
-1) and surface excess (ΔΓ > 2.9 μmol m
-2) demonstrate superior performance of the butyl-AAP-C
4S amphiphile to that of existing ionic surfactants. Neutron reflectometry and vibrational sum-frequency generation spectroscopy reveal that these large changes are caused by an unexpected monolayer-to-bilayer transition. This exceptional behavior is further shown to have dramatic consequences at larger length scales as highlighted by applications like the light-triggered collapse of aqueous foam which is tuned from high (>1 h) to low (<10 min) stabilities and light-actuated particle motion via Marangoni flows.
UR - https://www.scopus.com/pages/publications/85080883316
UR - https://www.mendeley.com/catalogue/11ed5047-18b4-3298-b723-5161d6597f98/
UR - https://pureprojects.ppad.man.ac.uk/portal/en/publications/unexpected-monolayertobilayer-transition-of-arylazopyrazol-surfactants-facilitates-superior-photocontrol-of-fluid-interfaces-and-colloids(4eb5f9e7-a3a4-4e12-9601-c80530e39120).html
U2 - 10.1039/C9SC05490A
DO - 10.1039/C9SC05490A
M3 - Article
C2 - 32190275
SN - 2041-6520
VL - 11
SP - 2085
EP - 2092
JO - Chemical Science
JF - Chemical Science
IS - 8
ER -