Browse
Submit Data
Databases
API
Help

Dataset Information

24 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Two-dimensional hyper-branched gold nanoparticles synthesized on a two-dimensional oil/water interface.

ABSTRACT: Two-dimensional (2D) gold nanoparticles can possess novel physical and chemical properties, which will greatly expand the utility of gold nanoparticles in a wide variety of applications ranging from catalysis to biomedicine. However, colloidal synthesis of such particles generally requires sophisticated synthetic techniques to carefully guide anisotropic growth. Here we report that 2D hyper-branched gold nanoparticles in the lateral size range of about 50 ~ 120?nm can be synthesized selectively on a 2D immiscible oil/water interface in a few minutes at room temperature without structure-directing agents. An oleic acid/water interface can provide diffusion-controlled growth conditions, leading to the structural evolution of a smaller gold nucleus to 2D nanodendrimer and nanourchin at the interface. Simulations based on the phase field crystal model match well with experimental observations on the 2D branching of the nucleus, which occurs at the early stage of growth. Branching results in higher surface area and stronger near-field enhancement of 2D gold nanoparticles. This interfacial synthesis can be scaled up by creating an emulsion and the recovery of oleic acid is also achievable by centrifugation.

SUBMITTER: Shin Y

PROVIDER: S-EPMC4143794 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Assembly and molecular order of two-dimensional peptoid nanosheets through the oil-water interface.

Project description:Peptoid nanosheets are a recently discovered class of 2D nanomaterial that form from the self-assembly of a sequence-specific peptoid polymer at an air-water interface. Nanosheet formation occurs first through the assembly of a peptoid monolayer and subsequent compression into a bilayer structure. These bilayer materials span hundreds of micrometers in lateral dimensions and have the potential to be used in a variety of applications, such as in molecular sensors, artificial membranes, and as catalysts. This paper reports that the oil-water interface provides another opportunity for growth of these unique and highly ordered peptoid sheets. The monolayers formed at this interface are found through surface spectroscopic measurements to be highly ordered and electrostatic interactions between the charged moieties, namely carboxylate and ammonium residues, of the peptoid are essential in the ability of these peptoids to form ordered nanosheets at the oil-water interface. Expanding the mechanism of peptoid nanosheet formation to the oil-water interface and understanding the crucial role of electrostatic interactions between peptoid residues in nanosheet formation is essential for increasing the complexity and functionality of these nanomaterials.

| S-EPMC4169914 | biostudies-literature

Formation of net-like patterns of gold nanoparticles in liquid crystal matrix at the air-water interface.

Project description:Controlled patterning and formation of nanostructures on surfaces based on self-assembly is a promising area in the field of "bottom-up" nanomaterial engineering. We report formation of net-like structures of gold nanoparticles (Au NPs) in a matrix of liquid crystalline amphiphile 4'-n-octyl-4-cyanobiphenyl at the air-water interface. After initial compression to at least 18 mN m(-1), decompression of a Langmuir film of a mixture containing both components results in formation of net-like structures. The average size of a unit cell of the net is easily adjustable by changing the surface pressure during the decompression of the film. The net-like patterns of different, desired average unit cell areas were transferred onto solid substrates (Langmuir-Blodgett method) and investigated with scanning electron microscopy and X-ray reflectivity (XRR). Uniform coverage over large areas was proved. XRR data revealed lifting of the Au NPs from the surface during the formation of the film. A molecular mechanism of formation of the net-like structures is discussed. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11051-012-0826-4) contains supplementary material, which is available to authorized users.

| S-EPMC3394235 | biostudies-literature

Langmuir films at the oil/water interface revisited.

Project description:We studied monomolecular layers at the oil/water interface (O/Wint) in a Langmuir interfacial trough using egg-yolk phosphatidylcholine (EPC) (the model phospholipid) and Vaseline (VAS) as oil phase. The temporal dynamics in the surface pressure (?) evolution depended on the method (spreading/adsorption) used for monolayers preparation and reflected the different distribution of EPC between all the system compartments (bulk phases and interfaces). We distinguished between EPC located either stable at the interface or hopping between the interface and bulk phases. The size order of the apparent mean molecular area, at constant ?, of EPC at different interfaces (EPCO/W?>?EPC/VAS0.02;A/W?>?EPCA/W), suggested that VAS molecules intercalated between the hydrocarbon chains of EPCO/W, at a molar fraction xVAS?>?0.02. However, EPC/VAS0.02;A/W showed the highest compressional free energy. This leaded us to study the EPC/VAS0.02 mixture at A/W by Brewster Angle Microscopy (BAM), finding that upon compression VAS segregated over the monolayer, forming non-coalescent lenses (as predicted by the spreading coefficient S?=?-13?mN/m) that remained after decompression and whose height changed (increase/decrease) accompanied the compression/decompression cycle. At the O/Wint, while some VAS molecules remained at the interface up to the collapse, others squeezed out towards the VAS bulk phase with an energy requirement lower than towards the air.

| S-EPMC6381208 | biostudies-literature

Ordered polyelectrolyte assembly at the oil-water interface.

Project description:Polyelectrolytes (PEs) are widely used in applications such as water purification, wastewater treatment, and mineral recovery. Although much has been learned in past decades about the behavior of PEs in bulk aqueous solutions, their molecular behavior at a surface, and particularly an oil-water interface where many of their applications are most relevant, is largely unknown. From these surface spectroscopic and thermodynamics studies we report the unique molecular characteristics that several common polyelectrolytes, poly(acrylic acid) and poly(methylacrylic acid), exhibit when they adsorb at a fluid interface between water and a simple insoluble organic oil. These PEs are found to adsorb to the interface from aqueous solution in a multistepped process with a very thin initial layer of oriented polymer followed by multiple layers of randomly oriented polymer. This additional layering is thwarted when the PE conformation is constrained. The adsorption/desorption process is highly pH dependent and distinctly different than what might be expected from bulk aqueous phase behavior.

| S-EPMC3295288 | biostudies-literature

Interaction of Surface-Modified Alumina Nanoparticles and Surfactants at an Oil/Water Interface: A Neutron Reflectometry, Scattering, and Enhanced Oil Recovery Study.

Project description:The evaluation of the mechanism of nanoparticle (NP)/surfactant complex adsorption at the critical oil/water interface was studied. A sophisticated technique (neutron reflectometry) was used to give a unique insight on NP/oil interactions in oil recovery systems. Herein, the adsorption of two modified alumina NPs with different degrees of hydrophobicity [hydrophilic = 2-[2-(2-methoxyethoxy)ethoxy]acetic acid and hydrophobic = octanoic acid (OCT)] stabilized with two different surfactants were studied at the oil/water interface. A thin layer of deuterated (D) and hydrogenated (H) hexadecane (contrast matching silicon substrate) oil was formed on a silicon block by a spin coating freeze process. The distribution of the NPs across the oil/water interface with the CTAB surfactant is similar between the two systems. NPs coated with CTAB have more affinity toward the oil/water interface, which explains the oil recovery increase by around 5% when flooding the core with the OCT-NP/CTAB system compared to the surfactant flooding alone. These results suggest that the NP/surfactant complexes can have potential usage in EOR recovery applications.

| S-EPMC9096789 | biostudies-literature

Droplet microfluidics for the highly controlled synthesis of branched gold nanoparticles.

Project description:The synthesis of anisotropic metallic nanoparticles (NPs) has been a field of intense and challenging research in the past decade. In this communication, we report on the reproducible and highly controllable synthesis of monodisperse branched gold nanoparticles in a droplet-based microfluidics platform. The process has been automated by adapting two different bulk synthetic strategies to microdroplets, acting as microreactors, for NP synthesis: a surfactant-free synthesis and a surfactant-assisted synthesis. Microdroplets were generated in two different microfluidic devices designed to accommodate the requirements of both bulk syntheses. The epitaxial growth of AuNSTs inside the microdroplets allowed for a fine control of reagent mixing and local concentrations during particle formation. This is the first time branched gold NPs have been synthesised in a microfluidics platform. The monodispersity of the product was comparable to the synthesis in bulk, proving the potential of this technology for the continuous synthesis of high quality anisotropic NPs with improved reproducibility.

| S-EPMC5799180 | biostudies-literature

Controlled synthesis of highly-branched plasmonic gold nanoparticles through peptoid engineering.

Project description:In nature, specific biomolecules interacting with mineral precursors are responsible for the precise production of nanostructured inorganic materials that exhibit complex morphologies and superior performance. Despite advances in developing biomimetic approaches, the design rules for creating sequence-defined molecules that lead to the synthesis of inorganic nanomaterials with predictable complex morphologies are unknown. Herein we report the design of sequence-defined peptoids for controlled synthesis of highly branched plasmonic gold particles. By engineering peptoid sequences and investigating the resulting particle formation mechanisms, we develop a rule of thumb for designing peptoids that predictively enabled the morphological evolution from spherical to coral-shaped nanoparticles. Through a combination of hyperspectral UV-Vis extinction microscopy and three-photon photoemission electron microscopy, we demonstrate that the individual coral-shaped gold nanoparticles exhibit a plasmonic enhancement as high as 105-fold. This research significantly advances our ultimate vision of predictive bio-inspired materials synthesis using sequence-defined synthetic molecules that mimic proteins and peptides.

| S-EPMC5998043 | biostudies-literature

Melamine Foams Decorated with In-Situ Synthesized Gold and Palladium Nanoparticles.

Project description:A versatile and straightforward route to produce polymer foams with functional surface through their decoration with gold and palladium nanoparticles is proposed. Melamine foams, used as polymeric porous substrates, are first covered with a uniform coating of polydimethylsiloxane, thin enough to assure the preservation of their original porous structure. The polydimethylsiloxane layer allows the facile in-situ formation of metallic Au and Pd nanoparticles with sizes of tens of nanometers directly on the surface of the struts of the foam by the direct immersion of the foams into gold or palladium precursor solutions. The effect of the gold and palladium precursor concentration, as well as the reaction time with the foams, to the amount and sizes of the nanoparticles synthesized on the foams, was studied and the ideal conditions for an optimized functionalization were defined. Gold and palladium contents of about 1 wt.% were achieved, while the nanoparticles were proven to be stably adhered to the foam, avoiding potential risks related to their accidental release.

| S-EPMC7240623 | biostudies-literature

Water Soluble Self-Aggregates Induced Green Emission of Biocompatible Citric Acid-PEG Hyper Branched Polymer.

Project description:An aliphatic citric acid-PEG hyper-branched polymer (CPHP) with a ?-bond on the polymer backbone was synthesized by a single- step melt reaction in which the polymerization and ?-bond formation occur simultaneously. The chemical structure of CPHP was confirmed by FTIR, 1H-NMR, 13C-NMR and MALDI-TOF mass spectral analyses. Aggregates are generally found to disperse in any solvent but the CPHP aggregates were soluble in water due to their hybrid nature. The ?-bond in the aconitate unit induces green emission by CH/? interaction while the PEG unit of CPHP increases its solubility in water. The soluble aggregates induced green emission (SAIE) of the CPHP was investigated by UV-Visible absorption and emission spectra, time- correlated single photon counting (TCSPC) and zeta potential measurements. The fluorescence life time (?f) increased from 4.93 to11.38?ns with an increase in CPHP concentration. The fluorescence quantum yield (?f) of CPHP can be altered by varying the concentration of CPHP.

| S-EPMC5704015 | biostudies-literature

Surface-Enhanced Hyper Raman Spectra of Aromatic Thiols on Gold and Silver Nanoparticles.

Project description:We report the two-photon excited nonresonant surface-enhanced hyper Raman scattering (SEHRS) spectra of six aromatic thiol molecules during their interaction with gold and silver nanostructures. SEHRS spectra were obtained from thiophenol, benzyl mercaptan, and phenylethyl mercaptan and from the three isomers 2-aminothiophenol (2-ATP), 3-aminothiophenol (3-ATP), and 4-aminothiophenol (4-ATP). All SEHRS spectra were excited off-resonance at a wavelength of 1064 nm and compared to surface-enhanced Raman scattering (SERS) spectra excited at 785 nm or at 633 nm. The SEHRS spectra show a different interaction of thiophenol, benzyl mercaptan, and phenylethyl mercaptan with silver and gold nanostructures. Density functional theory calculations were used to support band assignments, in particular, for the unknown SERS spectrum of 3-ATP, and identify a band of phenylethyl mercaptan as a vibrational mode unique to the SEHRS spectrum and very weak in the Raman and infrared spectra. 2-ATP, 3-ATP, and 4-ATP show a different interaction with gold nanostructures that was found to depend on pH. Bands in the SEHRS spectrum of 2-ATP could be assigned to 2,2'-dimercaptoazobenzene, suggested to be obtained in a plasmon-assisted reaction that occurred during the SEHRS experiment. The results provide the basis for a better characterization of organic thiols at surfaces in a variety of fields, including surface functionalization and plasmonic catalysis.

| S-EPMC7208179 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data