Vibrational Spectroscopic Observation of Acrylic Acid Coadsorbed in Dissociated and Molecular Forms on Oxidized Aluminum

Coast, R.; Pikus, Matthew; Henriksen, P. N.; Nitowski, Gary A.

doi:10.1021/jp961285y

Cited by 7 publications

(7 citation statements)

References 17 publications

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“…The main peaks at 1067, 1263, 1373, 1448, 1519, and 1637 cm -1 are consistent to those of acrylate reported previously. 23,24 At 300 °C, these peaks are still present. As compared to the 300 °C spectra of Figures 1 and 2, which lack the characteristic acrylate bands at 1263 (υ(C-C)), 1373 (δ(C-H)), and 1637 (υ(CdC)) cm -1 , it is concluded that thermal decomposition of lactic acid on TiO 2 is unlikely to proceed via acrylic acid or acrylate by a dehydration process.…”

Section: Adsorption Of Pyruvic Acid and Acrylicmentioning

confidence: 94%

Transmission FT-IR Study on the Adsorption and Reactions of Lactic Acid and Poly(lactic acid) on TiO₂

et al. 2010

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In situ Fourier transform infrared spectroscopy has been employed to investigate the adsorption and thermal decomposition of lactic acid and poly(lactic acid) on TiO2 with and without O2. Lactic acid dissociates primarily by deprotonation of COOH to form lactate (CH3CH(OH)COO) on TiO2 and by O−H (alcohol’s functional group) bond scission to form 2-oxy-propionic acid (CH3CH(O)COOH). As the surface temperature is raised higher than ∼250 °C in a vacuum, propionate is formed with minor acetate. In contrast, only acetate is formed with simultaneous CO2 evolution in the lactic acid decomposition in the presence of O2. No other products, such as acrylate from dehydration or pyruvate from oxidation of the OH group, are found. Poly(lactic acid) can dissociate by breaking the ester linkage, forming carboxylate species, on TiO2 at 30 °C. Poly(lactic acid) has the same high-temperature reaction products as those of lactic acid on TiO2. Besides, poly(lactic acid) on TiO2 irradiated at ∼320 nm in the presence of O2 is subjected to photodecomposition, generating CO2 and acetate. Possible mechanisms for decomposition of lactic acid and poly(lactic acid) on TiO2 are proposed.

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Section: Adsorption Of Pyruvic Acid and Acrylicmentioning

confidence: 94%

Transmission FT-IR Study on the Adsorption and Reactions of Lactic Acid and Poly(lactic acid) on TiO₂

et al. 2010

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“…29,30,62,102 Vibrational spectra were obtained using IETS and MRAIRS to study monolayers of pyruvic acid adsorbed on alumina incorporated in thin film Al/alumina/pyruvic acid/Pb samples. Spectra obtained using both techniques do not exhibit a carbonyl peak, however MRAIR spectra for similar samples without a Pb cover film do show the carbonyl stretch.…”

Section: Organic Compoundsmentioning

confidence: 99%

Inelastic Electron Tunneling Spectroscopy

Hipps

Mazur

2001

Handbook of Vibrational Spectroscopy

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The basic concepts of scanning tunneling microscopy (STM) are reviewed, with emphasis on instrumentation appropriate for spectroscopic applications. Applications of scanning tunneling spectroscopy to semiconductor and metal surfaces are discussed. Focus is then placed on the spectroscopy of single molecules adsorbed on surfaces. Examples of molecular images with sub‐molecular resolution are provided. Both inelastic electron tunneling spectroscopy (IETS) and orbital mediated tunneling spectroscopy (OMTS) are discussed. Molecular electronic spectra (OMTS) are displayed and contrasted with results from techniques requiring large (>10 9 ) numbers of molecules. Correlation between the nanoscale method of OMTS, and the microscale methods of ultraviolet photoelectron spectra (UPS) and electrochemical oxidation and reduction potentials will be made. Mapping of electron transport paths through a molecule and mapping of chemical components on a surface are both addressed.

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“…The mode of adsorption of carboxylic acids and their corresponding polymers onto mineral surfaces has been studied extensively using many spectroscopic techniques, including X-ray photoelectron, − inelastic electron tunneling, and Mössbauer spectroscopies. Infrared spectroscopic techniques such as diffuse reflectance (DRIFT) − and polarized grazing angle (PGA) have also been popular choices because the molecular vibrations associated with the carboxylate functionality offer considerable potential for identifying its binding mode.…”

Section: Introductionmentioning

confidence: 99%

In Situ FTIR-ATR Examination of Poly(acrylic acid) Adsorbed onto Hematite at Low pH

2003

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The adsorption of water-soluble polymers (e.g., flocculants, coagulants) onto mineral particles is typically characterized by “trains” of adsorbed polymer segments with “loops” and “tails” of unadsorbed polymer segments that extend into the solution. Ex situ spectroscopic studies carried out in the past have been complicated by the way in which the unadsorbed segments of the polymer interact with the surface of the substrate upon drying. In this study, an in situ Fourier transform infrared attenuated total reflection technique was used to examine the interaction of poly(acrylic acid) and hematite at pH 2. A hematite colloid was deposited onto a ZnSe crystal, and the poly(acrylic acid) solution was subsequently pumped across the coated crystal at a known rate. Polymer adsorption was irreversible and could be described by a Langmuir isotherm, the rate of curvature of which suggested that the adsorption was weak. The mode of adsorption was shown to be bidentate chelate complexation by the carboxylate functional group to a surface ferric ion. Pimelic acid, a simple model compound effectively representing a polymer consisting of only two monomer functionalities, adsorbed onto hematite in the same manner at pH 2 and gave no infrared spectral peaks associated with unadsorbed carboxylate groups, thereby supporting the proposed adsorption mechanism. The technique could also discriminate between the adsorbed and the unadsorbed segments of the adsorbed polymer molecule, however; the fraction of adsorbed segments was difficult to quantify. When a number of assumptions were made, it was found that at most 9% of the carboxylate functional groups of the polymer were adsorbed onto the hematite.

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Vibrational Spectroscopic Observation of Acrylic Acid Coadsorbed in Dissociated and Molecular Forms on Oxidized Aluminum

Cited by 7 publications

References 17 publications

Transmission FT-IR Study on the Adsorption and Reactions of Lactic Acid and Poly(lactic acid) on TiO₂

Transmission FT-IR Study on the Adsorption and Reactions of Lactic Acid and Poly(lactic acid) on TiO₂

Inelastic Electron Tunneling Spectroscopy

In Situ FTIR-ATR Examination of Poly(acrylic acid) Adsorbed onto Hematite at Low pH

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Vibrational Spectroscopic Observation of Acrylic Acid Coadsorbed in Dissociated and Molecular Forms on Oxidized Aluminum

Cited by 7 publications

References 17 publications

Transmission FT-IR Study on the Adsorption and Reactions of Lactic Acid and Poly(lactic acid) on TiO2

Transmission FT-IR Study on the Adsorption and Reactions of Lactic Acid and Poly(lactic acid) on TiO2

Inelastic Electron Tunneling Spectroscopy

In Situ FTIR-ATR Examination of Poly(acrylic acid) Adsorbed onto Hematite at Low pH

Contact Info

Product

Resources

About

Transmission FT-IR Study on the Adsorption and Reactions of Lactic Acid and Poly(lactic acid) on TiO₂

Transmission FT-IR Study on the Adsorption and Reactions of Lactic Acid and Poly(lactic acid) on TiO₂