Mechanical Properties of Interfacial Films Formed by Lysozyme Self-Assembly at the Air−Water Interface

Langmuir ◽  
2006 ◽  
Vol 22 (21) ◽  
pp. 8897-8905 ◽  
Author(s):  
Andrew S. Malcolm ◽  
Annette F. Dexter ◽  
Anton P. J. Middelberg
Keyword(s):  
Mechanical Properties ◽  
Self Assembly ◽  
Water Interface ◽  
Air Water Interface ◽  
Interfacial Films

scholarly journals The interfacial structure and Young's modulus of peptide films having switchable mechanical properties

2007 ◽  
Vol 5 (18) ◽  
pp. 47-54 ◽  
Author(s):  
A.P.J Middelberg ◽  
L He ◽  
A.F Dexter ◽  
H.-H Shen ◽  
S.A Holt ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Self Assembly ◽  
Molecular Design ◽  
Foam Stability ◽  
Young's Modulus ◽  
Interfacial Structure ◽  
Water Interface ◽  
Air Water Interface ◽  
Peptide Dissociation

We report the structure and Young's modulus of switchable films formed by peptide self-assembly at the air–water interface. Peptide surfactant AM1 forms an interfacial film that can be switched, reversibly, from a high- to low-elasticity state, with rapid loss of emulsion and foam stability. Using neutron reflectometry, we find that the AM1 film comprises a thin (approx. 15 Å) layer of ordered peptide in both states, confirming that it is possible to drastically alter the mechanical properties of an interfacial ensemble without significantly altering its concentration or macromolecular organization. We also report the first experimentally determined Young's modulus of a peptide film self-assembled at the air–water interface ( E =80 MPa for AM1, switching to E <20 MPa). These findings suggest a fundamental link between E and the macroscopic stability of peptide-containing foam. Finally, we report studies of a designed peptide surfactant, Lac21E, which we find forms a stronger switchable film than AM1 ( E =335 MPa switching to E <4 MPa). In contrast to AM1, Lac21E switching is caused by peptide dissociation from the interface (i.e. by self-disassembly). This research confirms that small changes in molecular design can lead to similar macroscopic behaviour via surprisingly different mechanisms.

Light‐Triggered, Non‐Centrosymmetric Self‐Assembly of Aqueous Arylazopyrazoles at the Air‐Water Interface and SHG Switching

2020 ◽  
Author(s):  
Nobuo Kimizuka ◽  
Yuki Nagai ◽  
Keita Ishiba ◽  
Ryosuke Yamamoto ◽  
Teppei Yamada ◽  
...  
Keyword(s):  
Self Assembly ◽  
Water Interface ◽  
Air Water Interface

scholarly journals Nanoparticle interaction with model lung surfactant monolayers

2009 ◽  
Vol 7 (suppl_1) ◽  
Author(s):  
Rakesh Kumar Harishchandra ◽  
Mohammed Saleem ◽  
Hans-Joachim Galla
Keyword(s):  
Surface Properties ◽  
Self Assembly ◽  
Current Knowledge ◽  
Surface Film ◽  
Lung Surfactant ◽  
Hydrophobic Surface ◽  
Surface Pattern ◽  
Lipid Monolayers ◽  
Water Interface ◽  
Air Water Interface

One of the most important functions of the lung surfactant monolayer is to form the first line of defence against inhaled aerosols such as nanoparticles (NPs), which remains largely unexplored. We report here, for the first time, the interaction of polyorganosiloxane NPs (AmorSil20: 22 nm in diameter) with lipid monolayers characteristic of alveolar surfactant. To enable a better understanding, the current knowledge about an established model surface film that mimics the surface properties of the lung is reviewed and major results originating from our group are summarized. The pure lipid components dipalmitoylphosphatidylcholine and dipalmitoylphosphatidylglycerol have been used to study the biophysical behaviour of their monolayer films spread at the air–water interface in the presence of NPs. Film balance measurements combined with video-enhanced fluorescence microscopy have been used to investigate the formation of domain structures and the changes in the surface pattern induced by NPs. We are able to show that NPs are incorporated into lipid monolayers with a clear preference for defect structures at the fluid–crystalline interface leading to a considerable monolayer expansion and fluidization. NPs remain at the air–water interface probably by coating themselves with lipids in a self-assembly process, thereby exhibiting hydrophobic surface properties. We also show that the domain structure in lipid layers containing surfactant protein C, which is potentially responsible for the proper functioning of surfactant material, is considerably affected by NPs.

Effect of the Molecular Structure on the Hierarchical Self-Assembly of Semifluorinated Alkanes at the Air/Water Interface

Langmuir ◽  
2011 ◽  
Vol 27 (14) ◽  
pp. 8776-8786 ◽  
Author(s):  
Laurence de Viguerie ◽  
Rabea Keller ◽  
Ulrich Jonas ◽  
Rüdiger Berger ◽  
Christopher G. Clark ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Self Assembly ◽  
Water Interface ◽  
Semifluorinated Alkanes ◽  
Air Water Interface

scholarly journals A microrobotic platform actuated by thermocapillary flows for manipulation at the air-water interface

2021 ◽  
Vol 6 (52) ◽  
pp. eabd3557
Author(s):  
Franco N. Piñan Basualdo ◽  
A. Bolopion ◽  
M. Gauthier ◽  
P. Lambert
Keyword(s):  
Self Assembly ◽  
Thermocapillary Flow ◽  
Water Interface ◽  
Fluid Interface ◽  
Multiple Objects ◽  
Complex Objects ◽  
Stick Slip ◽  
Thermocapillary Flows ◽  
Simultaneous Control ◽  
Air Water Interface

Future developments in micromanufacturing will require advances in micromanipulation tools. Several robotic micromanipulation methods have been developed to position micro-objects mostly in air and in liquids. The air-water interface is a third medium where objects can be manipulated, offering a good compromise between the two previously mentioned ones. Objects at the interface are not subjected to stick-slip due to dry friction in air and profit from a reduced drag compared with those in water. Here, we present the ThermoBot, a microrobotic platform dedicated to the manipulation of objects placed at the air-water interface. For actuation, ThermoBot uses a laser-induced thermocapillary flow, which arises from the surface stress caused by the temperature gradient at the fluid interface. The actuated objects can reach velocities up to 10 times their body length per second without any on-board actuator. Moreover, the localized nature of the thermocapillary flow enables the simultaneous and independent control of multiple objects, thus paving the way for microassembly operations at the air-water interface. We demonstrate that our setup can be used to direct capillary-based self-assemblies at this interface. We illustrate the ThermoBot’s capabilities through three examples: simultaneous control of up to four spheres, control of complex objects in both position and orientation, and directed self-assembly of multiple pieces.

scholarly journals Extra Surfactant-Assisted Self-Assembly of Highly Ordered Monolayers of BaTiO3 Nanocubes at the Air—Water Interface

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 739 ◽  
Author(s):  
Hiroki Itasaka ◽  
Ken-Ichi Mimura ◽  
Kazumi Kato
Keyword(s):  
Self Assembly ◽  
Large Scale ◽  
Three Dimensional ◽  
Water Interface ◽  
Compression Pressure ◽  
Air Water Interface ◽  
Out Of Plane ◽  
Key Factor ◽  
Evaporation Induced Self Assembly ◽  
20 Nm

Assembly of nanocrystals into ordered two- or three-dimensional arrays is an essential technology to achieve their application in novel functional devices. Among a variety of assembly techniques, evaporation-induced self-assembly (EISA) is one of the prospective approaches because of its simplicity. Although EISA has shown its potential to form highly ordered nanocrystal arrays, the formation of uniform nanocrystal arrays over large areas remains a challenging subject. Here, we introduce a new EISA method and demonstrate the formation of large-scale highly ordered monolayers of barium titanate (BaTiO3, BT) nanocubes at the air-water interface. In our method, the addition of an extra surfactant to a water surface assists the EISA of BT nanocubes with a size of 15–20 nm into a highly ordered arrangement. We reveal that the compression pressure exerted by the extra surfactant on BT nanocubes during the solvent evaporation is a key factor in the self-assembly in our method. The BT nanocube monolayers transferred to substrates have sizes up to the millimeter scale and a high out-of-plane crystal orientation, containing almost no microcracks and voids.

scholarly journals Facile assembly of a graphitic carbon nitride film at an air/water interface for photoelectrochemical NADH regeneration

2020 ◽  
Vol 7 (13) ◽  
pp. 2434-2442 ◽  
Author(s):  
Changchao Jia ◽  
Wenjuan Hu ◽  
Yuanyuan Zhang ◽  
Chao Teng ◽  
Zupeng Chen ◽  
...  
Keyword(s):  
Self Assembly ◽  
Carbon Nitride ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Nitride Film ◽  
Water Interface ◽  
Film Electrode ◽  
Nadh Regeneration ◽  
Air Water Interface ◽  
Carbon Nitride Film

A graphitic carbon nitride film electrode could be assembled at an air/water interface from nanosheets which exhibits improved photoelectrochemical coenzyme regeneration by further coupling with graphene during the interfacial self-assembly.

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