Acetone

About: Acetone is a research topic. Over the lifetime, 9458 publications have been published within this topic receiving 120867 citations. The topic is also known as: propanone & dimethylketone.

Highly enhanced acetone sensing performance of porous C-doped WO3 hollow spheres by carbon spheres as templates

Abstract: WO3-based gas sensors have received considerable attention in breath acetone analysis for their great potential in the clinical diagnosis of diabetes. However, several key challenges, especially sensitivity, selectivity and stability, should be further addressed before WO3-based materials are capable of applying for acetone analysis. Herein, C-doped WO3 sensing materials were synthesized by coupling carbon sphere templates with post-heat treatment method. The resulting materials are composed mainly of e-WO3, a phase with high selectivity to acetone, and featured with porous hollow sphere structure. The as-fabricated sensors based on the C-doped WO3 materials show high sensitivity to acetone down to 0.2 ppm. By contrast, the sensors show substantially lower response to other gases including ethanol, methanol, toluene, NH3, NO and CO. In addition, the effect of the relative humidity (RH) on the sensing property was studied and it was found that the response distinction to acetone even at 90% RH was sufficient to separate diabetics from healthy people. More attractively, the e-phase WO3 could maintain its acetone sensing activity at 350 °C over 3 months, suggesting excellent long-term stability. The results gained herein may be useful for rational design of new types of highly selective and stable acetone sensing materials.

Atomic Force Microscopy and Molecular Dynamics Simulations for Study of Lignin Solution Self‐Assembly Mechanisms in Organic–Aqueous Solvent Mixtures

Abstract: Lignin-based nanomaterials fabricated by solution self-assembly in organic-aqueous solvent mixtures are among the most attractive biomass-derived products. To accurately control the structure, size, and properties of lignin-based nanomaterials, it is important to achieve fundamental understanding of its dissolution and aggregation mechanisms. In this work, atomic force microscopy (AFM) and molecular dynamics (MD) simulations are employed to explore the dissolution and aggregation behavior of enzymatic hydrolysis lignin (EHL) in different organic-aqueous solvent mixtures at molecular scale. EHL was found to dissolve well in appropriate organic-aqueous solvent mixtures, such as acetone-water mixture with a volume ratio of 7:3, whereas it aggregated in pure water, ethanol, acetone, and tetrahydrofuran. The interactions between the EHL-coated AFM probe and the substrate were 1.21±0.18 and 0.75±0.35 mN m-1 in water and acetone, respectively. In comparison, the interaction decreased to 0.15±0.08 mN m-1 in acetone-water mixture (7:3 v/v). MD simulations further indicate that the hydrophobic skeleton and hydrophilic groups of lignin could be solvated by acetone and water molecules, respectively, which significantly promoted its dissolution. Conversely, only the hydrophobic skeleton or the hydrophilic groups were solvated in organic solvent or water, respectively, inducing serious aggregation of lignin.

Measurements of Binary Diffusion Coefficients and Partition Ratios for Acetone, Phenol, α-Tocopherol, and β-Carotene in Supercritical Carbon Dioxide with a Poly(ethylene glycol)-Coated Capillary Column

Abstract: Binary diffusion coefficients, D 12 , and partition ratios, k, for the poly(ethylene glycol) (PEG) layer to supercritical carbon dioxide for acetone and some solid solutes such as phenol, α-tocopherol, and β-carotene were measured with a PEG-coated capillary column by a tracer response technique. The D 12 values for acetone with the PEG-coated column were consistent with those measured by the Taylor dispersion method in which an uncoated capillary column was employed. The D 12 and k values for all of the solutes decrease simply with increasing pressure, and the D 12 values were represented by the Schmidt number correlation.

New Pretreatment Methods Combining a Hot Water Treatment and Water/Acetone Extraction for Thermo-Chemical Conversion of Biomass

Abstract: New pretreatment methods were developed for separating hemicellulose, cellulose, and lignin from biomass for their efficient use in the thermo-chemical conversion of each component. One method is basically a two-step process. Biomass treated in hot water at 180 °C was extracted in a flowing stream of water/acetone mixture under 10 MPa at 230 °C. Through the hot water treatment, hemicellulose in biomass was successfully recovered as saccharides, leaving lignin and cellulose as a solid. Through the sequential extraction by the water/acetone solvent, lignin was depolymerized into the water/acetone-soluble compounds and the residual cellulose was partly dehydrated. The other method is a one-step process, in which biomass was directly extracted in 50% water/acetone solution at 200 °C using a batch reactor, and the residue was pure cellulose. The proposed methods were expected to be new routes for converting low-grade resources into valuable chemicals.

Salt effects in extraction of ethanol, 1‐butanol and acetone from aqueous solutions

Abstract: Experimental studies were performed to assess the effect of salt addition on the extraction of 1-butanol, ethanol and acetone from dilute aqueous solutions using cyclopentanol, n-valeraldehyde, tert-amyl alcohol, and Adol 85NF as extractants. The liquid-liquid partitioning was examined for a few strong electrolytes in a broad range of concentrations. Results demonstrate that the distribution coefficient and selectivity in systems with reduced water activity resulting from salt addition were markedly increased. These observations can be qualitatively explained on the basis of the hydration theory. It was also determined that strong electrolytes added to the aqueous feed reduced extractant solubility in the aqueous phase, thus contributing to lower solvent losses. The results showed that the extraction efficiency was not significantly affected by increasing salt content beyond a level that reduces the water activity to a value of 0.92.