Acetaldehyde In Aqueous Solution Research Articles

Poly(vinyl alcohol)-based thin films for optical humidity sensing

The optical and humidity-sensing properties are studied of hydrophobically modified PVA, namely poly(vinyl alcohol-co-vinyl acetal)s of varied copolymer composition. Copolymers are synthesized by reacting PVA with acetaldehyde in aqueous solution, thus introducing cyclic acetal functionalities in the polymer chain. Thin polymer films are deposited by spin-coating and their optical properties are studied as a function of the copolymer composition, i.e., degree of acetalization. Reflectance measurements at different relative humidities in the range 5 – 95 % RH are conducted in order to probe the sensing behavior. The comparison with neat PVA thin films confirms the influence of the copolymer’s acetal fraction on the optical and sensing properties and degree of hysteresis. The feasibility of applying poly(vinyl alcohol-co-vinyl acetal) thin films for optical sensing of humidity is demonstrated and discussed.

SERS-based chip for discrimination of formaldehyde and acetaldehyde in aqueous solution using silver reduction.

A method is described for surface-enhanced Raman scattering (SERS) discrimination of formaldehyde (FA) and acetaldehyde (AA) in aqueous sample solutions. It is based on the use of a paper strip containing 4-aminothiophenol (Atp)-modified reduced graphene oxide (rGO)/[Ag(NH3)2]+ (rGO/[Ag(NH3)2]+/Atp). The addition of FA or AA induces the conversion of [Ag(NH3)2]+ complex to silver nanoparticles (AgNPs) because of aldehyde-induced silver reduction reaction. The AgNPs possess strong SERS activity. The average interparticle gaps between the AgNPs can be fine-tuned by controlling the experimental conditions, this leading to the formation of optimized SERS hot spots. It is also found that the changes in the spectral shapes and the relative intensity ratio of the bands at 1143 and 1072cm-1 result from the difference in the pH value of the surrounding solution. This effect enables the selective discrimination of FA and AA. The paper strip can be used as a SERS dipstick and swab for on-site determination of FA or AA in wine and human urine via the differences in the intensity of the SERS peaks. The assay works over a wide range of concentrations (0.45ng·L-1 to 480μg·L-1) for FA and AA, and the respective detection limits are 0.15 and 1.3ng·L-1. Graphical abstract Schematic presentation of the preparation procedure of 4-aminothiophenol (Atp)-modified reduced graphene oxide (rGO)/[Ag(NH3)2]+ hybrid paper and its surface-enhanced Raman scattering discrimination of formaldehyde and acetaldehyde based on silver reduction.

Fast and highly selective detection of acetaldehyde in liquor and spirits by forming aggregation-induced emission luminogen

Acetaldehyde is one of the most important flavor constituents in liquor and spirits, which is the major origination of its spicy taste. However, as a human carcinogen, excessive intake of acetaldehyde is harmful to health. In this work, a fluorescence sensor of 5-methoxycarbonylsalicylaldehyde hydrazone (1) was developed to achieve a fast and highly selective response for acetaldehyde. Mechanism study showed that when 1 combined with acetaldehyde in aqueous solution at neutral pH, an aggregation-induced emission luminogen (AIEgen) was produced, resulting in a “turn-on” fluorescence response. Compared to gas chromatography, the traditional detective method for acetaldehyde in liquor and spirits, fluorometry using 1 has a number of advantages including simplicity, quick response and capability of real-time detection. More important, the detections of acetaldehyde in real liquor and spirits samples were successfully achieved.

Isotopic separation of acetaldehyde and methanol from their deuterated isotopologues on a porous layer open tubular column allows quantification by stable isotope dilution without mass spectrometric detection

An isotopic separation of acetaldehyde and acetaldehyde-2,2,2-d3 was achieved in a temperature programmed run on a porous layer open tubular (PLOT) capillary column coated with particles of divinylbenzene ethylene glycol/dimethylacrylate (Rt®-U-BOND). This is the prerequisite for the development of quantitative analytical methods based on a stable isotope dilution assay (SIDA) without a mass spectrometric detection (non-MS SIDA). For routine analysis a flame ionization detector (FID) can thus be applied as a robust and low-cost alternative. In a preliminary study, static headspace extraction and gas chromatographic separation (HS-GC-FID) of acetaldehyde in aqueous solutions was shown as an application. Good linearity was obtained in a calibration range from 0.4 to 40mgL−1, with peak integration benefitting from the inverse isotope effect encountered on the specific porous polymer. Furthermore, separation of methanol and deuterated methanol (d3) could also be achieved under the same chromatographic conditions. The achieved isotopic separation of these important volatile compounds now allows non-MS SIDA-based methods that are still to be developed.

Modeling, simulation and analysis of a process for the production of crotonaldehyde

Crotonaldehyde is an important intermediate in the chemical industry and usually produced from acetaldehyde in aqueous solution. Recently, new results on the reactions which yield crotonaldehyde from acetaldehyde have become available. It was shown that the formation of aldoxane from acetaldehyde and acetaldol, as well as the oligomer formation in the system acetaldehyde and water have to be taken into account. In the present paper, the established process for the production of crotonaldehyde is analyzed based on that new information. A model for the physico-chemical properties of the relevant mixtures is developed as well as an equilibrium stage based process model. The models are implemented in a steady state process simulation tool which is used for numerical studies of the process. The results provide unexpected insights in the process which contains distillations in which complex reactions occur. A conceptual process design is carried out applying a structured approach. The performance of the process is analyzed and potential for its optimization is discussed.

Conical intersections in solution: formulation, algorithm, and implementation with combined quantum mechanics/molecular mechanics method.

The significance of conical intersections in photophysics, photochemistry, and photodissociation of polyatomic molecules in gas phase has been demonstrated by numerous experimental and theoretical studies. Optimization of conical intersections of small- and medium-size molecules in gas phase has currently become a routine optimization process, as it has been implemented in many electronic structure packages. However, optimization of conical intersections of small- and medium-size molecules in solution or macromolecules remains inefficient, even poorly defined, due to large number of degrees of freedom and costly evaluations of gradient difference and nonadiabatic coupling vectors. In this work, based on the sequential quantum mechanics and molecular mechanics (QM/MM) and QM/MM-minimum free energy path methods, we have designed two conical intersection optimization methods for small- and medium-size molecules in solution or macromolecules. The first one is sequential QM conical intersection optimization and MM minimization for potential energy surfaces; the second one is sequential QM conical intersection optimization and MM sampling for potential of mean force surfaces, i.e., free energy surfaces. In such methods, the region where electronic structures change remarkably is placed into the QM subsystem, while the rest of the system is placed into the MM subsystem; thus, dimensionalities of gradient difference and nonadiabatic coupling vectors are decreased due to the relatively small QM subsystem. Furthermore, in comparison with the concurrent optimization scheme, sequential QM conical intersection optimization and MM minimization or sampling reduce the number of evaluations of gradient difference and nonadiabatic coupling vectors because these vectors need to be calculated only when the QM subsystem moves, independent of the MM minimization or sampling. Taken together, costly evaluations of gradient difference and nonadiabatic coupling vectors in solution or macromolecules can be reduced significantly. Test optimizations of conical intersections of cyclopropanone and acetaldehyde in aqueous solution have been carried out successfully.

Enhancement in photocatalytic activity for acetaldehyde removal by embedding ZnO nano particles on multiwall carbon nanotubes

Multi-walled carbon nanotube/zinc oxide (MWCNT/ZnO) composites were synthesized by thermal hydrolysis method. The composites were prepared using multi-walled carbon nanotubes (MWCNTs) as a starting material, and zinc nitrate as a precursor. For characterization and morphological studies, different techniques such as FE-SEM, HRTEM, XRD, UV and FT-IR were applied. The photo catalytic activity of the prepared composite was evaluated by measuring the degradation of acetaldehyde in aqueous solution under UV laser irradiation. Almost 50% enhancement in photocatalytic activity for removal of acetaldehyde was recorded by embedding ZnO nanoparticles on the surface of MWCNTs.

Application of Sulfonated Carbon-Based Catalyst for Reactive Extraction of 1,3-Propanediol from Model Fermentation Mixture

This study deals with the possibility of the application of a low-cost sulfonated carbon-based catalyst for reactive extraction to separate 1,3-propanediol (1,3-PDO) from a model solution of 1,3-PDO biologically derived from glycerol. The catalyst was synthesized by incomplete carbonization of naphthalene in sulfuric acid, and was demonstrated to be active for the acetalization of 1,3-PDO with acetaldehyde in aqueous solution. The performance of the reactive extraction process by using a sulfonated carbon-based catalyst was proven to be excellent based on the percent recovery rate of 1,3-PDO. These results along with those on the catalyst reactivity demonstrate that the carbon-based catalyst can be used to replace expensive commercial catalysts currently used such as Dowex 50-WX4-200 and Amberlite IR120.

Photografting of methacrylic acid onto HDPE initiated by acetaldehyde in aqueous solutions

Acetaldehyde could act as a very effective photoinitiator for water-borne photografting. The photografting of methacrylic acid (MAA) onto polyethylene initiated by acetaldehyde in aqueous solutions was reported. Acetaldehyde had higher photoinitiation efficiency than acetone and formaldehyde. The extent of grafting varied with the acetaldehyde content in the solution and it showed the maximum when the content of acetaldehyde was about 10 w/w %. The extent of grafting firstly increased with the increase of monomer concentration till 2 mol/L and then kept constant or slightly decreased. ATR-FTIR characterizations of the grafted samples proved the successful grafting of MAA onto PE, and the calculated carbonyl indexes were in accord with the results obtained by the gravimetric method. The water absorbency of the grafted samples increased almost linearly with the extent of grafting. The difference in the photoinitiation efficiencies of acetaldehyde, acetone and formaldehyde was discussed through their differences in the n-π* transitions in water and the photoinitiation process. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Abiotic CC bond formation under environmental conditions: Kinetics of the aldol condensation of acetaldehyde in water catalyzed by carbonate ions (CO3 2− )

The role of CC bond-forming reactions such as aldol condensation in the degradation of organic matter in natural environments is receiving a renewed interest because naturally occurring ions, ammonium ions, NH+4, and carbonate ions, CO32−, have recently been reported to catalyze these reactions. While the catalysis of aldol condensation by OH− has been widely studied, the catalytic properties of carbonate ions, CO32−, have been little studied, especially under environmental conditions. This work presents a study of the catalysis of the aldol condensation of acetaldehyde in aqueous solutions of sodium carbonate (0.1–50 mM) at T = 295 ± 2 K. By monitoring the absorbance of the main product, crotonaldehyde, instead of that of acetaldehyde, interferences from other reaction products and from side reactions, in particular a known Cannizzaro reaction, were avoided. The rate constant was found to be first order in acetaldehyde in the presence of both CO32− and OH−, suggesting that previous studies reporting a second order for this base-catalyzed reaction were flawed. Comparisons between the rate constants in carbonate solutions and in sodium hydroxide solutions ([NaOH] = 0.3–50 mM) showed that, among the three bases present in carbonate solutions, CO32−, HCO3−, and OH−, OH− was the main catalyst for pH ≤ 11. CO32− became the main catalyst at higher pH, whereas the catalytic contribution of HCO3− was negligible over the range of conditions studied (pH 10.3–11.3). Carbonate-catalyzed condensation reactions could contribute significantly to the degradation of organic matter in hyperalkaline natural environments (pH ≥ 11) and be at the origin of the macromolecular matter found in these environments. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 676–686, 2010

Synthesis, characterization and photocatalytic activity of N-doped TiO 2 modified by platinum chloride

Structures and photocatalytic performance of N-doped TiO 2 modified by platinum chloride (PtCl x /N-TiO 2) was investigated. It was found that the PtCl x /N-TiO 2 forms anatase structure of TiO 2 involving nitrogen, chloride species and platinum ions (+IV) as major species, and it exhibits higher photocatalytic activity than either N-TiO 2 or PtCl x /TiO 2 for the decomposition of acetic acid or acetaldehyde in aqueous solutions under visible light irradiation ( λ > 420 nm). An enhancement of the photocatalytic activity on PtCl x /N-TiO 2 has been proposed as a Z-scheme mechanism for charge separation between platinum chloride and N-TiO 2.

The rapid hydration of the acetyl radical. A pulse radiolysis study of acetaldehyde in aqueous solution.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe rapid hydration of the acetyl radical. A pulse radiolysis study of acetaldehyde in aqueous solution.Man Nien. Schuchmann and Clemens. Von SonntagCite this: J. Am. Chem. Soc. 1988, 110, 17, 5698–5701Publication Date (Print):August 1, 1988Publication History Published online1 May 2002Published inissue 1 August 1988https://doi.org/10.1021/ja00225a019RIGHTS & PERMISSIONSArticle Views455Altmetric-Citations86LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (488 KB) Get e-Alerts Get e-Alerts

Spectrophotometric determination of acetaldehyde in aqueous solution with diazotized orthanilic acid

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSpectrophotometric determination of acetaldehyde in aqueous solution with diazotized orthanilic acidS. Flamerz and W. A. BashirCite this: Anal. Chem. 1982, 54, 11, 1734–1735Publication Date (Print):September 1, 1982Publication History Published online1 May 2002Published inissue 1 September 1982https://doi.org/10.1021/ac00248a018RIGHTS & PERMISSIONSArticle Views345Altmetric-Citations4LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (263 KB) Get e-Alerts Get e-Alerts

Reactivity of coordinated ligands in some cobalt(III) dipeptide complexes

In the reaction of [Co(glygly)NO 2en] (glygly-H 2 = glycylglycine, en = ethylenediamine) with acetaldehyde in aqueous solution at pH 11 four condensation products have been obtained. Their separation has been performed by means of adsorption chromatography on a cationic exchanger, in hydrogen form. On the basis of data obtained from electronic, 1H and 13C n.m.r. spectra, and also from the results of elemental analysis and paper chromatography, the reaction products obtained have been identified as: a) a mixture of[Co(threogly)NO 2 en] (threogly H 2 = threonylglycine) and [Co(allothreogly)NO 2 en] (allothreoglyH 2 = allothreonylglycine); b) [Co(glygly)-NO 2(CH 3CH=en)] (CH 3CH=en = N-ethylideneethylenediamine) and c) [Co(CH 3CH=glygly)NO 2en] (CH 3CH=glygly H 2 = N-ethylideneglycylglycine).

A Modified Simon-Lewin Reaction: N-Nitrosamines as Intermediates in the Reaction of Secondary Amines With Nitroprusside and Acetaldehyde

Abstract Secondary aliphatic amines give a blue color with sodium nitroprusside and acetaldehyde in aqueous solution at pH 10. A closely analogous reaction of N-nitrosamines has been discovered. Aliphatic N-nitrosamines can give a similar blue color with a secondary aliphatic amine, sodium pentacyanoaquoferrate (II) and acetaldehyde at pH 10. This suggests strongly that N-nitrosamines are intermediates in the corresponding nitroprusside reaction. The new reaction may also have some value as a color test for N-nitrosamines.

The Photochemical Decomposition of Acetaldehyde in Aqueous Solutions of Allyl Alcohol at 2537 Å.1

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Photochemical Decomposition of Acetaldehyde in Aqueous Solutions of Allyl Alcohol at 2537 Å.1June C. Chen and David H. VolmanCite this: J. Am. Chem. Soc. 1961, 83, 5, 1047–1049Publication Date (Print):March 1, 1961Publication History Published online1 May 2002Published inissue 1 March 1961https://doi.org/10.1021/ja01466a008RIGHTS & PERMISSIONSArticle Views92Altmetric-Citations3LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (297 KB) Get e-Alerts Get e-Alerts

The hydration of acetaldehyde in aqueous solution

The hydration of acetaldehyde in aqueous solution