Gold Nanoparticles in Novel Green Deep Eutectic Solvents: Self-Limited Growth, Self-Assembly & Catalytic Implications

2015 ◽  
Vol 229 (1-2) ◽  
Author(s):  
Maeve O'Neill ◽  
Vikram Singh Raghuwanshi ◽  
Robert Wendt ◽  
Markus Wollgarten ◽  
Armin Hoell ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Self Assembly ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Reaction Rate Constant ◽  
Limited Growth ◽  
X Ray Scattering ◽  
Transmission Electron

AbstractIn this article, we are reporting the catalytic activity of gold nanoparticles (AuNPs) dispersed in a novel eco-friendly Deep Eutectic Solvent (DES; choline chloride and urea) at room temperature. A low energy sputter deposition method is employed to synthesize AuNPs on the DES surface. This is a simple, economical and clean method for producing monodisperse gold nanoparticles by a self-limited growth mechanism. Detailed Small Angle X-ray Scattering (SAXS), UV–Vis and Transmission Electron Microscopy (TEM) investigations show the formation of spherical AuNPs of 5 nm in diameter. Moreover, these particles have a strong tendency to self-assemble at the DES surface as well as into the bulk. This is a new addition to a novel generation of gold based catalysts. The catalytic activity of Au nanoparticles in DES is revealed quantitatively by analyzing the apparent conversion reaction rate constant

scholarly journals Morphological Transformation of SDS Aggregates in a Deep Eutectic Solvent Above the Fracto-eutectogel to Fluid Transition Temperature

2021 ◽  
Author(s):  
Lauren Matthews ◽  
Sarah E.S. Michel ◽  
Sarah E. Rogers ◽  
Paul Bartlett ◽  
Andrew J. Johnson ◽  
...  
Keyword(s):  
Self Assembly ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Polarized Light ◽  
Fluid Phase ◽  
Deep Eutectic Solvents ◽  
Isotropic Scattering ◽  
Morphological Transformation ◽  
Cylindrical Micelles ◽  
Potential Use

Understanding surfactant self-assembly in deep eutectic solvents (DES) is important to their potential use in industrial formulations. We have recently reported the formation of a fracto-eutectogel comprising SDS fractal aggregates at a concentration as low as 1.6 wt% in glyceline (a DES comprising glycerol and choline chloride) at room temperature. The building units of the fractals consisted of multilayers of self-assembled SDS lamellae arranged in a dendritic pattern. Here we report that this fractal phase transitions into a fluid phase above a critical gelation temperature, TCG ~ 45 oC, evident from polarized light microscopy (PLM) observations. Small-angle neutron scattering (SANS) reveals that this phase transition is underpinned by the nanoscopic morphological transformation of the SDS lamellae into cylindrical micelles at T > TGC. Fitting SANS profiles confirms that the morphology of the micelles is SDS-concentration (cSDS) dependent at T > TGC: cylindrical at cSDS > 0.6 wt% and spherical at cSDS = 0.6 wt%. At cSDS < 0.6 wt%, only isotropic scattering was observed in the SANS profiles. Such SDS self-assembly behaviors contrast with those we have previously observed in glycerol, which we attribute to the presence of ions (i.e. choline chloride) in glyceline. Our findings have general implications to surfactant self-assembly in DES, solvents that are rich in hydrogen bonding and ions.

scholarly journals Fracto-eutectogels: SDS dendritic fractals via counterion condensation in a deep eutectic solvent

2021 ◽  
Author(s):  
Lauren Matthews ◽  
Silvia Ruscigno ◽  
Sarah E. Rogers ◽  
Paul Bartlett ◽  
Andrew Johnson ◽  
...  
Keyword(s):  
Self Assembly ◽  
Molecular Mechanisms ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Industrial Applications ◽  
Nonaqueous Solvent ◽  
Counterion Condensation

Glyceline, a deep eutectic solvent comprising glycerol and choline chloride, is a green nonaqueous solvent with potential industrial applications. Molecular mechanisms of surfactant self-assembly in deep eutectic solvents are expected...

scholarly journals Growth mechanisms of self-assembled gold nanoparticles in Deep Eutectic Solvent

2014 ◽  
Vol 70 (a1) ◽  
pp. C891-C891
Author(s):  
Vikram Singh Raghuwanshi ◽  
Miguel Ochmann ◽  
Frank Polzer ◽  
Armin Hoell ◽  
Klaus Rademann
Keyword(s):  
Gold Nanoparticles ◽  
Self Assembly ◽  
Optical Switching ◽  
Bimetallic Nanoparticles ◽  
Volume Fraction ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
The Self ◽  
Gold Sputtering ◽  
Self Assembled

Self-assembled metallic nanoparticles are attractive candidates for plasmonic heating, non-linear optical switching [1], bio-analytical, chemical [2], catalytic , and surface enhanced RAMAN scattering (SERS) [3]. These applications are strongly dependent on the shape, size, composition, size distribution and volume fraction of nanoparticles. Here, self-assembly of gold nanoparticles (AuNPs) was obtained by low energy sputter deposition on Deep Eutectic Solvent (DES ; choline chloride and urea) surfaces and elucidated by Small Angle X-ray Scattering (SAXS), Cryogenic Transmission Electron Microscopy (Cryo-TEM) and UV-Vis. Data analysis shows the formation of spherically shaped AuNPs of 5 nm in diameter with narrow size distributions. Moreover, analysis reveals that prolongation of gold-sputtering time has no effect on the size of the particles and only the concentration of AuNPs increases linearly. The growth of the maxima in evaluated structure factor S(q) and the distance distribution function G(r) at higher concentrations of AuNPs is caused by the interference effects. Moreover, it indicates that the particles are not arranged in random but have a self-assembly in short-range order. Prolonged gold-sputtering time leads to increase in the ordering of the AuNPs with strong interactions. It is proposed that the self-assembly of AuNPs is due to the ionic liquid template effects of DES and the balancing physical forces. Moreover, a disulfide based stabilizer bis ((2-Mercaptoethyl) trimethylammonium) disulfide dichloride was applied to supress the self-assembly. The stabilizer even reverses the self-assembled or agglomerated AuNPs back to stable 5 nm individual particles. The templating effect of DES is compared with the non-templating solvent Castor oil. Our results will also pave a way to understand and control self-assembly of metallic and bimetallic nanoparticles.

scholarly journals Catalytic Activity of Beta-Cyclodextrin-Gold Nanoparticles Network in Hydrogen Evolution Reaction

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 118
Author(s):  
Qui Quach ◽  
Erik Biehler ◽  
Ahmed Elzamzami ◽  
Clay Huff ◽  
Julia M. Long ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Gold Catalyst ◽  
Hydrogen Gas ◽  
Hydrolysis Reaction ◽  
X Ray Diffraction ◽  
Beta Cyclodextrin ◽  
Transmission Electron ◽  
Production Of Hydrogen ◽  
Climate Crisis

The current climate crisis warrants investigation into alternative fuel sources. The hydrolysis reaction of an aqueous hydride precursor, and the subsequent production of hydrogen gas, prove to be a viable option. A network of beta-cyclodextrin capped gold nanoparticles (BCD-AuNP) was synthesized and subsequently characterized by Powder X-Ray Diffraction (P-XRD), Fourier Transform Infrared (FTIR), Transmission Electron Microscopy (TEM), and Ultraviolet-Visible Spectroscopy (UV-VIS) to confirm the presence of gold nanoparticles as well as their size of approximately 8 nm. The catalytic activity of the nanoparticles was tested in the hydrolysis reaction of sodium borohydride. The gold catalyst performed best at 303 K producing 1.377 mL min−1 mLcat−1 of hydrogen. The activation energy of the catalyst was calculated to be 54.7 kJ/mol. The catalyst resisted degradation in reusability trials, continuing to produce hydrogen gas in up to five trials.

Self-assembled luminescent cholate gels induced by a europium ion in deep eutectic solvents

Soft Matter ◽  
2021 ◽  
Author(s):  
Meng Sun ◽  
Qintang Li ◽  
Xiao Chen
Keyword(s):  
Self Assembly ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Sodium Cholate ◽  
The Self ◽  
Europium Ion ◽  
Self Assembled

Luminescent gels have been successfully fabricated through the self-assembly of sodium cholate and a europium ion in choline chloride-based deep eutectic solvents.

scholarly journals Alpha helical surfactant-like peptides self-assemble into pH-dependent nanostructures

Soft Matter ◽  
2021 ◽  
Vol 17 (11) ◽  
pp. 3096-3104
Author(s):  
Valeria Castelletto ◽  
Jani Seitsonen ◽  
Janne Ruokolainen ◽  
Ian W. Hamley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Small Angle ◽  
Self Assembly ◽  
X Ray ◽  
Cryogenic Transmission Electron Microscopy ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Ph Dependent ◽  
Ray Scattering

A designed surfactant-like peptide is shown, using a combination of cryogenic-transmission electron microscopy and small-angle X-ray scattering, to have remarkable pH-dependent self-assembly properties.

Toxico-metabolomics study of a deep eutectic solvent comprising choline chloride and urea suggests in vivo toxicity involving oxidative stress and ammonia stress

2021 ◽  
Vol 23 (3) ◽  
pp. 1300-1311 ◽  
Author(s):  
Dasom Jung ◽  
Jae Back Jung ◽  
Seulgi Kang ◽  
Ke Li ◽  
Inseon Hwang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
In Vivo Toxicity ◽  
Metabolomics Study ◽  
Ammonia Stress

The in vitro and in vivo studies suggest that choline chloride-based deep eutectic solvents may not be considered as pure, safe mixtures even if they consist of safe compounds.

scholarly journals Deep Eutectic Solvents Based Choline Chloride for Enzymatic Biodiesel Production from Degumming Palm Oil

2020 ◽  
Vol 32 (4) ◽  
pp. 733-738 ◽  
Author(s):  
R. Manurung ◽  
Taslim ◽  
A.G.A. Siregar
Keyword(s):  
Palm Oil ◽  
Raw Materials ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Biodiesel Production ◽  
Chloride Salt ◽  
Enzymatic Reactions ◽  
Potential Applications ◽  
Palm Oil Biodiesel

Deep eutectic solvents (DESs) have numerous potential applications as cosolvents. In this study, use of DES as organic solvents for enzymatic biodiesel production from degumming palm oil (DPO) was investigated. Deep eutectic solvent was synthesized using choline chloride salt (ChCl) compounds with glycerol and 1,2-propanediol. Deep eutectic solvent was characterized by viscosity, density, pH and freezing values, which were tested for effectiveness by enzymatic reactions for the production of palm biodiesel with raw materials DPO. Deep eutectic solvent of ChCl and glycerol produced the highest biodiesel yield (98.98%); weight of DES was only 0.5 % of that of the oil. In addition, the use of DES maintained the activity and stability of novozym enzymes, which was assessed as the yield until the 6th usage, which was 95.07 % biodiesel yield compared with the yield without using DES. Hence, using DES, glycerol in enzymatic biodiesel production had high potentiality as an organic solvent for palm oil biodiesel production

On the selective aerobic oxidation of benzyl alcohol with Pd/Au-nanoparticles in batch and flow

2014 ◽  
Vol 3 (1) ◽  
pp. 99-110 ◽  
Author(s):  
Hannes Alex ◽  
Norbert Steinfeldt ◽  
Klaus Jähnisch ◽  
Matthias Bauer ◽  
Sandra Hübner
Keyword(s):  
Catalytic Activity ◽  
Benzyl Alcohol ◽  
Aerobic Oxidation ◽  
X Ray ◽  
X Ray Scattering ◽  
Oxidation Of Benzyl Alcohol ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Selective Aerobic Oxidation

AbstractNanoparticles (NP) have specific catalytic properties, which are influenced by parameters like their size, shape, or composition. Bimetallic NPs, composed of two metal elements can show an improved catalytic activity compared to the monometallic NPs. We, herein, report on the selective aerobic oxidation of benzyl alcohol catalyzed by unsupported Pd/Au and Pd NPs at atmospheric pressure. NPs of varying compositions were synthesized and characterized by UV/Vis spectroscopy, transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS). The NPs were tested in the model reaction regarding their catalytic activity, stability, and recyclability in batch and continuous procedure. Additionally, in situ extended X-ray absorption fine structure (EXAFS) measurements were performed in order to get insight in the process during NP catalysis.

Deep eutectic solvent delignification: Impact of initial lignin

BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 7301-7310
Author(s):  
Veronika Majová ◽  
Silvia Horanová ◽  
Andrea Škulcová ◽  
Jozef Šima ◽  
Michal Jablonský
Keyword(s):  
Lactic Acid ◽  
Oxalic Acid ◽  
Lignin Content ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Kappa Number ◽  
Kraft Pulps ◽  
Oxygen Delignification ◽  
Detailed Understanding

This study aimed to resolve the issue of the lack of detailed understanding of the effect of initial lignin content in hardwood kraft pulps on pulp delignification by deep eutectic solvents. The authors used Kappa number of the concerned pulp, intrinsic viscosity, and selectivity and efficiency of delignification as the parameters of the effect. The pulp (50 g oven dry pulp) was treated with four different DESs systems based on choline chloride with lactic acid (1:9), oxalic acid (1:1), malic acid (1:1), and system alanine:lactic acid (1:9); the results were compared to those reached by oxygen delignification. The results showed that the pulp with a higher initial lignin content had a greater fraction of easily removed lignin fragments.

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