Nanoscale structure of surfactant-induced nanoparticle monolayers at the oil–water interface

Calzolari, Davide C. E.; Pontoni, Diego; Deutsch, Moshe; Reichert, H.; Daillant, Jean

doi:10.1039/c2sm26520f

Cited by 64 publications

(69 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this case, the binding energy of a single particle is no longer sufficient to describe binding within a particle raft; instead, interactions between particles in the aggregates become relevant. 16 Here, we present a general method to quantify the adsorption energy of surface-active, soluble materials. First, we demonstrate measurements of the adsorption energy of surface-active polystyrene-b-poly(ethylene oxide) (PS−PEO) block copolymers and poly(ethylene oxide) (PEO) homopolymers spread on air−water surfaces, varying both molecular weight and bulk solvent conditions.…”

Section: * S Supporting Informationmentioning

confidence: 99%

Adsorption Energies of Poly(ethylene oxide)-Based Surfactants and Nanoparticles on an Air–Water Surface

et al. 2013

View full text Add to dashboard Cite

The self-assembly of polymer-based surfactants and nanoparticles on fluid–fluid interfaces is central to many applications, including dispersion stabilization, creation of novel 2D materials, and surface patterning. Very often these processes involve compressing interfacial monolayers of particles or polymers to obtain a desired material microstructure. At high surface pressures, however, even highly interfacially active objects can desorb from the interface. Methods of directly measuring the energy which keeps the polymer or particles bound to the interface (adsorption/desorption energies) are therefore of high interest for these processes. Moreover, though a geometric description linking adsorption energy and wetting properties through the definition of a contact angle can be established for rigid nano- or microparticles, such a description breaks down for deformable or aggregating objects. Here, we demonstrate a technique to quantify desorption energies directly, by comparing surface pressure–density compression measurements using a Wilhelmy plate and a custom-microfabricated deflection tensiometer. We focus on poly(ethylene oxide)-based polymers and nanoparticles. For PEO-based homo- and copolymers, the adsorption energy of PEO chains scales linearly with molecular weight and can be tuned by changing the subphase composition. Moreover, the desorption surface pressure of PEO-stabilized nanoparticles corresponds to the saturation surface pressure for spontaneously adsorbed monolayers, yielding trapping energies of ∼103 k B T.

show abstract

Section: * S Supporting Informationmentioning

confidence: 99%

Adsorption Energies of Poly(ethylene oxide)-Based Surfactants and Nanoparticles on an Air–Water Surface

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Structural investigations by grazing-incidence x-ray scattering have been employed to elucidate the structure of deposited Langmuir-Blodgett [9] and unsupported Langmuir monolayers [10]. In favorable cases, the contact angle of individual particles could be estimated by accurate modeling of the x-ray reflectivity curve [11,12].…”

Section: Introductionmentioning

confidence: 99%

Controlling the dynamics of a bidimensional gel above and below its percolation transition

et al. 2014

View full text Add to dashboard Cite

The morphology and the microscopic internal dynamics of a bidimensional gel formed by spontaneous aggregation of gold nanoparticles confined at the water surface are investigated by a suite of techniques, including grazing-incidence x-ray photon correlation spectroscopy (GI-XPCS). The range of concentrations studied spans across the percolation transition for the formation of the gel. The dynamical features observed by GI-XPCS are interpreted in view of the results of microscopic imaging; an intrinsic link between the mechanical modulus and internal dynamics is demonstrated for all the concentrations. Our work presents an example of a transition from a stretched to a compressed correlation function actively controlled by quasistatically varying the relevant thermodynamic variable. Moreover, by applying a model proposed some time ago by Duri and Cipelletti [Europhys. Lett. 76, 972 (2006)] we are able to build a master curve for the shape parameter, whose scaling factor allows us to quantify a "long-time displacement length." This characteristic length is shown to converge, as the concentration is increased, to the "short-time localization length" determined by pseudo-Debye-Waller analysis of the initial contrast. Finally, the intrinsic dynamics of the system is then compared with that induced by means of a delicate mechanical perturbation applied to the interface.

show abstract

“…[24][25][26] Mohwald et al 27 used X-ray reflectivity to characterize the adsorption layer of NPs at the air/water interface and to quantify the layer thickness on a Langmuir trough. Calzolari et al 28 used X-ray reflectivity to investigate the structure of NP monolayers in situ at water-hexane interface. In this work they had determined the immersion depth and contact angles of the NP (silica) core.…”

Section: Introductionmentioning

confidence: 99%

Contact angle and adsorption energies of nanoparticles at the air–liquid interface determined by neutron reflectivity and molecular dynamics

et al. 2015

View full text Add to dashboard Cite

Understanding how nanomaterials interact with interfaces is essential to control their self-assembly as well as their optical, electronic, and catalytic properties. We present here an experimental approach based on neutron reflectivity (NR) that allows the in situ measurement of the contact angles of nanoparticles adsorbed at fluid interfaces. Because our method provides a route to quantify the adsorption and interfacial energies of the nanoparticles in situ, it circumvents problems associated with existing indirect methods, which rely on the transport of the monolayers to substrates for further analysis. We illustrate the method by measuring the contact angle of hydrophilic and hydrophobic gold nanoparticles, coated with perdeuterated octanethiol (d-OT) and with a mixture of d-OT and mercaptohexanol (MHol), respectively.The contact angles were also calculated via atomistic molecular dynamics (MD) computations, showing excellent agreement with the experimental data. Our method opens the route to quantify the adsorption of complex nanoparticle structures adsorbed at fluid interfaces featuring different chemical compositions.

show abstract

Nanoscale structure of surfactant-induced nanoparticle monolayers at the oil–water interface

Cited by 64 publications

References 36 publications

Adsorption Energies of Poly(ethylene oxide)-Based Surfactants and Nanoparticles on an Air–Water Surface

Adsorption Energies of Poly(ethylene oxide)-Based Surfactants and Nanoparticles on an Air–Water Surface

Controlling the dynamics of a bidimensional gel above and below its percolation transition

Contact angle and adsorption energies of nanoparticles at the air–liquid interface determined by neutron reflectivity and molecular dynamics

Contact Info

Product

Resources

About