scholarly journals Nanoparticle-Induced Self-Assembly of Block Copolymers into Nanoporous Films at the Air–Water Interface

ACS Nano ◽  
2020 ◽  
Vol 14 (9) ◽  
pp. 12203-12209
Author(s):  
Seulki Kang ◽  
Du Yeol Ryu ◽  
Emilie Ringe ◽  
Robert J. Hickey ◽  
So-Jung Park

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Lin Zhu ◽  
Fang Chen ◽  
Xiaoyan Ma ◽  
Xiu Qiang ◽  
Zhiguang Li ◽  
...  

The aggregation behavior of three tadpole-shaped Polyhedral oligomeric silsesquioxane (POSS) based block copolymers using different blocks poly(methyl methacrylate) (PMMA) and poly(trifluoroethyl methacrylate) (PTFEMA) with different block sequence and ratio (POSS-PTFEMA161-b-PMMA236, POSS-PMMA277-b-PTFEMA130, and POSS-PMMA466-b-PTFEMA172) was investigated on the air-water interface. The interfacial rheology of three block copolymers was studied by surface pressure isotherm, compression modulus measurements, and compression and expansion hysteresis analysis on the Langmuir trough. The block sequence and ratio play a great role in self-assembly behavior at the interface. Based on surface pressure isotherm analysis, a thin film with low elasticity was achieved for the POSS-PTFEMA161-b-PMMA236. Moreover, for the block copolymer with same segment sequence (POSS-PMMA2-b-PTFEMA), the thin film compression capability is increased with increasing the PMMA ratio. The morphology of the deposited LB thin film was illustrated by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). We observed that a thin film was composed by crater-shaped quasi-2D micelles for POSS-PTFEMA-b-PMMA, while it was proved that only flaky texture was observed for both POSS-PMMA277-b-PTFEMA130 and POSS-PMMA466-b-PTFEMA172. The thickness and area of flaky aggregates were greatly related to PMMA ratio. The different interface self-assembly structure evolution was proposed based on the interfacial rheology and thin film morphology studies.





2020 ◽  
Author(s):  
Nobuo Kimizuka ◽  
Yuki Nagai ◽  
Keita Ishiba ◽  
Ryosuke Yamamoto ◽  
Teppei Yamada ◽  
...  


Langmuir ◽  
2020 ◽  
Author(s):  
Xin Li ◽  
Yijun Zhang ◽  
Mingxiao Li ◽  
Yang Zhao ◽  
Lingqian Zhang ◽  
...  


2009 ◽  
Vol 7 (suppl_1) ◽  
Author(s):  
Rakesh Kumar Harishchandra ◽  
Mohammed Saleem ◽  
Hans-Joachim Galla

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.



Langmuir ◽  
2011 ◽  
Vol 27 (14) ◽  
pp. 8776-8786 ◽  
Author(s):  
Laurence de Viguerie ◽  
Rabea Keller ◽  
Ulrich Jonas ◽  
Rüdiger Berger ◽  
Christopher G. Clark ◽  
...  


2021 ◽  
Vol 6 (52) ◽  
pp. eabd3557
Author(s):  
Franco N. Piñan Basualdo ◽  
A. Bolopion ◽  
M. Gauthier ◽  
P. Lambert

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.



2007 ◽  
Vol 5 (18) ◽  
pp. 47-54 ◽  
Author(s):  
A.P.J Middelberg ◽  
L He ◽  
A.F Dexter ◽  
H.-H Shen ◽  
S.A Holt ◽  
...  

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.



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