Stimuli-Responsive, Hydrolyzable Poly(Vinyl Laurate-<i>co</i>-vinyl Acetate) Nanoparticle Platform for In Situ Release of Surfactants

Aldakkan, Bashayer; Hammami, Mohamed Amen; Qi, Genggeng; Kanj, Mazen Y.; Giannelis, Emmanuel P.

doi:10.1021/acsami.1c04977

Cited by 6 publications

(5 citation statements)

References 64 publications

(95 reference statements)

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“…Approximately 100 μL of the emulsion was poured onto a glass slide and covered with a coverslip. No addition of fluorescent dyes was necessary because of the autofluorescence of the oil …”

Section: Methodsmentioning

confidence: 99%

“…The assembly of nanoparticles at the oil–water interface has received widespread attention and has been extensively studied by numerous investigators. These studies include but are not limited to food processing and production, − drug encapsulation, , environmental remediation, − and enhanced oil recovery. − The interest stems from the fact that particle-laden interfaces offer a route to controlled interfacial properties, including the ultimate stability of an emulsion. − Oil droplets surrounded by particles result in improved viscoelastic properties of the interface. Hence, emulsion breakup, coalescence, or coarsening can be circumvented or slowed. ,− …”

Section: Introductionmentioning

confidence: 99%

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Probing the Interfacial Properties of Oil–Water Interfaces Decorated with Ionizable, pH Responsive Silica Nanoparticles

et al. 2023

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Particle-stabilized emulsions (Pickering emulsions) have recently attracted significant attention in scientific studies and for technological applications. The interest stems from the ease of directly assembling the particles at interfaces and modulating the interfacial properties. In this paper, we demonstrate the formation of stable, practical emulsions leveraging the assembly of ionizable, pH responsive silica nanoparticles, surface-functionalized by a mixture of silanes containing amine/ammonium groups, which renders them positively charged. Using pH as the trigger, the assembly and the behavior of the emulsion are controlled by modulating the charges of the functional groups of the nanoparticle and the oil (crude oil). In addition to their tunable charge, the particular combination of silane coupling agents leads to stable particle dispersions, which is critical for practical applications. Atomic force microscopy and interfacial tension (IFT) measurements are used to monitor the assembly, which is controlled by both the electrostatic interactions between the particles and oil and the interparticle interactions, both of which are modulated by pH. Under acidic conditions, when the surfaces of the oil and the nanoparticles (NPs) are positively charged, the NPs are not attracted at the interface and there is no significant reduction in the IFT. In contrast, under basic conditions in which the oil carries a high negative charge and the amine groups on the silica are deprotonated while still positively charged because of the ammonium groups, the NPs assemble at the interface in a closely packed configuration yielding a jammed state with a high dilatational modulus. As a result, two oil droplets do not coalesce even when pushed against each other and the emulsion stability improves significantly. The study provides new insights into the directed assembly of nanoparticles at fluid interfaces relevant to several applications, including environmental remediation, catalysis, drug delivery, food technology, and oil recovery.

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“…Approximately 100 μL of the emulsion was poured onto a glass slide and covered with a coverslip. No addition of fluorescent dyes was necessary because of the autofluorescence of the oil …”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Probing the Interfacial Properties of Oil–Water Interfaces Decorated with Ionizable, pH Responsive Silica Nanoparticles

et al. 2023

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“…Polymer brushes tethered onto various surfaces and/or interfaces with specific functionalities have resulted in advances not only in colloidal stabilization but also in drug delivery, surface coatings, implantable devices, soft robotics, surfactancy, , and sensing . By adopting multiple conformational states, the polymer brushes can be tuned to respond to specific changes, including the type of solvents, , ions, , pH, and temperature. , These different stimuli can trigger rapid transitions and can control the structure and properties of the polymer brushes, including entanglements, hydration, swelling, wetting, adhesion, and friction …”

Section: Introductionmentioning

confidence: 99%

Synthesis of Raspberry-like Nanoparticles via Surface Grafting of Positively Charged Polyelectrolyte Brushes: Colloidal Stability and Surface Properties

Aldakkan,

Chalmpes,

et al. 2024

Langmuir

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A method to synthesize stable, raspberry-like nanoparticles (NPs), using surface grafting of poly(glycidyl methacrylate) (PGMA) brushes on a polystyrene (PS) core with varying grafting densities, is reported. A twostep functionalization reaction of PGMA epoxide groups comprising an amination step first using ethylene diamine and then followed by a quaternization using glycidyltrimethylammonium chloride generates permanently and positively charged polyelectrolyte brushes, which result in both steric and electrostatic stabilization. The dispersion stability of the brush-bearing NPs is dramatically improved compared to that of the pristine PS core in salt solutions at ambient (25 °C) and elevated temperatures (60 °C). Additionally, the grafted polyelectrolyte chains undergo a reversible swelling in the presence of different ionic strength (IS) salts, which modulate the surface properties, including roughness, stiffness, and adhesion. An atomic force microscope under both dry and wet conditions was used to image conformational changes of the polyelectrolyte chains during the swelling and deswelling transitions as well as to probe the nanomechanical properties by analyzing the corresponding force−sample separation curves. The quaternized polyelectrolyte brushes undergo a conformational transition from a collapsed state to a swelled state in the osmotic brush (OB) regime triggered by the osmotic gradient of mobile ions to the interior of the polymer chain. At IS ∼ 1 M, the brushes contract and the globules reform (salted brush state) as evidenced by an increase in the surface roughness and a reduction in the adhesion of the brushes. Beyond IS ∼ 1 M, quartz crystal microbalance with dissipation monitoring measurements show that salt uptake continues to take place predominantly on the exterior surface of the brush since salt adsorption is not accompanied by a size increase as measured by dynamic light scattering. The study adds new insights into our understanding of the behavior of NPs bearing salt-responsive polyelectrolyte brushes with adaptive swelling thresholds that can ultimately modulate surface properties.

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“…Manipulating the properties of liquid–liquid interfaces and specifically oil–water interfaces using nanoparticles (so-called Pickering emulsions) has attracted widespread attention due to both scientific interest as well as use in practical applications. − Assembly of nanoparticles of various chemistries and dimensionalities at the oil–water interfaces stabilizes the emulsion and offers the possibility to synthesize materials with controlled behavior by fine-tuning interfacial properties. ,, By varying the chemistry and dimensionality of the nanoparticles, the adsorption energy and thus the interfacial properties can be modulated and controlled. , …”

Section: Introductionmentioning

confidence: 99%

Fine-Tuning the Surface and Interfacial Chemistry of Silica Nanoparticles to Control Stability in High Ionic Strength Electrolytes and Modulate Assembly at Oil–Water Interfaces

Alsmaeil,

Mohammed,

Aldakkan

et al. 2023

Chem. Mater.

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Controlling the interfacial chemistry is critical to the behavior of several material systems. In this report, we demonstrate how subtle changes in the surface chemistry of silica nanoparticles have a profound effect on their colloidal stability, as well as their ability to assemble at oil−water interfaces. The ability to direct the assembly by fine-tuning the surface chemistry of nanoparticles, NPs, allows for controlling the interfacial properties and the overall behavior of the resulting Pickering emulsions. We start by showing that the colloidal stability of silica nanoparticles functionalized by a mixture of silanes is dramatically improved compared to that of silica functionalized with either one. For example, NP suspensions synthesized using a 50:50 mixture of N1-(3-trimethoxysilylpropyl)diethylenetriamine and N-trimethoxysilylpropyl-N,N,Ntrimethylammonium in a complex brine containing a mixture of salts remain suspended when subjected to acceleration of 500 × g⃗ and temperatures as high as 60 °C. In contrast, particles functionalized with either one of the silanes are far less stable under the same conditions. The colloidal stability of the particles is correlated to the silane-grafted layers and surface roughness obtained by atomic force microscopy (AFM). We next studied the mechanism of the particles' assembly at oil−water interfaces and characterized the interfacial properties under various conditions. In all cases, the assembly is driven by electrostatic interactions between the positively charged particles and the negatively charged oil surface. Ultrasmall-/small-angle X-ray scattering measurements confirm the assembly of nanoparticles at the interface, and time-dependent scattering measurements reveal the presence of two steps in the assembly in brine, consistent with the interfacial tension dynamics. The assembled particles at the interface lead to a solid-like behavior or jamming, with the interface behaving like an elastic membrane with high dilatational and storage moduli. This study provides fundamental insights into the surface and interfacial properties of silane-grafted NPs and ways to fine-tune their assembly at oil−water interfaces while improving their colloidal stability under harsh environmental conditions.

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Stimuli-Responsive, Hydrolyzable Poly(Vinyl Laurate-co-vinyl Acetate) Nanoparticle Platform for In Situ Release of Surfactants

Cited by 6 publications

References 64 publications

Probing the Interfacial Properties of Oil–Water Interfaces Decorated with Ionizable, pH Responsive Silica Nanoparticles

Probing the Interfacial Properties of Oil–Water Interfaces Decorated with Ionizable, pH Responsive Silica Nanoparticles

Synthesis of Raspberry-like Nanoparticles via Surface Grafting of Positively Charged Polyelectrolyte Brushes: Colloidal Stability and Surface Properties

Fine-Tuning the Surface and Interfacial Chemistry of Silica Nanoparticles to Control Stability in High Ionic Strength Electrolytes and Modulate Assembly at Oil–Water Interfaces

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