In the present Communication, a completely "green" synthetic method for producing silver nanoparticles is introduced. The process simple, environmentally benign, and quite efficient. By gentle heating of an aqueous starch solution containing nitrate glucose, we produce relatively monodisperse, starched nanoparticles. β-d-Glucose serves as green reducing agent, while stabilization agent.

Integration of "green chemistry" principles into nanotechnology is one the key issues in nanoscience research today. In this work, we report an environmentally benign method for preparation Au, Ag, and Au–Ag nanoparticles water, using glucose as reducing agent starch protecting agent. The alloy prepared way appears to be homogeneous their sizes are well within quantum size domain (<10 nm), where they more amenable size-dependent changes electronic properties.

Understanding the fundamental principles for design of CO(2)-philic materials is growing importance due to potential enabling "green" chemistry and technologies in liquid supercritical CO(2) as alternative solvent systems. Recently, there have been numerous efforts develop hydrocarbon-based CO(2)-philes containing carbonyl groups, which are known interact through a Lewis acid-Lewis base (LA-LB) interaction with molecules, thereby providing necessary solvation energy dissolution. In this...

Supercritical carbon dioxide (scCO(2)) is increasingly promoted as an environmentally benign alternative to conventional organic solvents. The supercritical state bridges the gap between liquid and gaseous states by offering gaslike diffusion rates liquidlike solvent densities, thereby enabling potential opportunities a reaction separation medium in chemical industry. Understanding behavior of scCO(2) critical importance enable design CO(2)-philic molecular systems expand use these wider...

Acetylation of carbohydrates is proposed as a method for the synthesis inexpensive CO2-philes that can easily be modified wide variety green chemistry applications in liquid and supercritical CO2. The deliquescence peracetylated sugars contact with CO2 reported this communication well unparalleled solubility these compounds

It is well-known that, in general, fluorocarbons are highly soluble liquid and supercritical CO2 fluorine substitution has been widely utilized as a method to make otherwise insoluble organic compounds more CO2-philic. In this work, we investigate the CO2-philicity of fluorinated with varying numbers atoms system by using simple quantum chemical calculations. We explore fundamental nature fluorocarbon hydrocarbon interactions examining effects stepwise fluorination on methane correlated ab...

In carbonyl compounds having a hydrogen atom attached to the α-carbon or directly carbon, our recent ab initio and solvation studies have predicted presence of weak C−H···O interaction with CO2. This intermolecular acts cooperatively Lewis acid−Lewis base that exists between CO2 group. communication provides first experimental evidence for this cooperative in acetaldehyde−CO2 complex using Raman spectroscopy at 25.0 °C gas phase. The implications these interactions carbonyl-based CO2-philes...

X-ray absorption fine structure (XAFS) measurements and analyses are presented for Rb+ in supercritical water solutions. The of the first hydration shell at ambient conditions is compared to that region a temperature 424 °C pressures from 382 633 bar. For all reported studies, RbBr concentration 0.5 molal was used. XAFS results show there well-defined around cation even but these high temperatures extent Rb reduced by about 40%. A slight contraction this distance 0.10 Å also observed under...

X-ray absorption fine structure (XAFS) measurements and molecular dynamics simulations(MD) are used to explore the extent of Br- ion hydration in supercritical water solutions. The first shell under ambient conditions is compared that region spanning a temperature range from 25 475 °C pressures 1 650 bar. RbBr salt concentration was varied 0.02 1.5 molal. wide studied allowed detailed examination effect temperature, density, on conditions. present results provide important new insights into...

The hydrogen bond structure of liquid methanol was investigated as a function pressure and temperature up to 2.8 kbar from 297 413 K. Chemical shifts the CH3 OH groups were monitored throughout this regime, chemical shift difference between these two used describe changes network in methanol. equilibrium using molecular dynamics simulations phenomenological model describing clustering Results are presented concerning size distribution hydrogen-bonded clusters temperature. results indicate...

The ion pairing structure of Ni(Br)2 solutions (0.2 and 0.4 molal) under supercritical conditions was determined using x-ray absorption fine (XAFS) spectroscopy. These first measurements the average bulk show that approximately one Br− counterion is associated with each Ni2+. Ni2+-to-Br− distance 2.40 Å very accurately strength this interaction, as indicated by Debye–Waller factor (σ2=0.009 Å2), shows bromine anion tightly bound to nickel cation these conditions. In addition onset...

Acetylated carbohydrates have extremely high solubilities and miscibilities in CO2 form the basis of a new approach toward development renewable CO2-philes. Ab initio computational studies relevant to this system indicate that complexes with simple, model carbonyl compounds Lewis acid−Lewis base interaction between carbon atom oxygen is accompanied by cooperative, intermolecular C−H···O solute's hydrogen atom. The results show may provide an additional stabilization mechanism for solvation...

The quartz crystal microbalance (QCM) technique has been developed into a powerful tool for the study of solid-fluid interfaces. This focuses on applications QCM in high-pressure carbon dioxide (CO2) systems. Frequency responses six crystals with different electrode materials (silver or gold) and roughness values were determined helium, nitrogen, at 35-40 degrees C elevated pressures up to 3200 psi. goal is experimentally examine applicability traditional theory systems determine adsorption...

The emergence of new SARS-CoV-2 variants made the COVID-19 infection pandemic and/or endemic more severe and life-threatening due to ease transmission, rapid infection, high mortality, capacity neutralize therapeutic ability developed vaccines. These consequences raise questions on established management strategies based nano-assisted approaches, including diagnostics, therapeutics, efficient trapping virus eradication through stimuli-assisted masks filters composed nanosystems. Considering...

The equilibrium between the keto and enol tautomers of acetylacetone, trifluoroacetylacetone hexafluoroacetylacetone in neat liquid state dissolved supercritical fluid carbon dioxide have been studied, as a function pressure temperature, by 1 H NMR. This allows determination thermodynamic parameters, ΔH ΔS, for keto–enol equilibrium. observed trends are well correlated with extraction results this class compounds.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTConfinement Effects on the Dynamics of Liquid Carbon DisulfideS. L. Wallen, Nikiel, J. Yi, and JonasCite this: Phys. Chem. 1995, 99, 42, 15421–15427Publication Date (Print):October 1, 1995Publication History Published online1 May 2002Published inissue 1 October 1995https://pubs.acs.org/doi/10.1021/j100042a014https://doi.org/10.1021/j100042a014research-articleACS PublicationsRequest reuse permissionsArticle Views122Altmetric-Citations47LEARN ABOUT...

The solution structure of tert-butyl alcohol was investigated as a function pressure and temperature using high-resolution nuclear magnetic resonance (NMR) spectroscopy. Simulations the were undertaken molecular dynamics simple phenomenological model describing clustering in liquid alcohol. Chemical shifts, relaxation times (T1), line widths (fwhm) CH3 OH groups monitored over range up to ∼1.0 kbar from 297 423 K, respectively. demonstrated cyclic tetramer dominant liquid, with having...

Sugar acetates, recognized as attractive CO2-philic compounds, have potential uses pharmaceutical excipients, controlled release agents, and surfactants for microemulsion systems in CO2-based processes. This study focuses on the quantitative examination of absorption high pressure CO2 into these sugar derivatives using quartz crystal microbalance (QCM) a detector. In addition to measurement, QCM is initially found be able detect CO2-induced deliquescence at which happens depends several...

Nuclear magnetic resonance (NMR) offers researchers unique, highly localized molecular information. The importance of this technique is well established in studies using chemical shift, spin coupling, and relaxation times providing detailed structural information, determining equilibria kinetics, understanding dynamic processes. However, the widespread application NMR spectroscopy to high-pressure liquids supercritical fluids has been limited due complexity necessary instrumentation. One...

Supercritical fluid solvents allow continuous tuning of solvent density and therefore control the number distance solvent−solute interactions. Such interactions exert torque on molecules in solution thereby influence way which rotational orientation a solute molecule varies with time. In this work, we examine relaxation D2O two supercritical solvents: Xe CO2. former case, there are no electrostatic between solvent. Since nonelectrostatic very nearly centrosymmetric about center mass, is...