Polymerization of catechin catalyzed by Mn-, Fe- and Al-oxides

Chen, Yue Min; Tsao, Tsung-Ming; Liu, Cheng Chung; Huang, P. M.; Wang, Ming Kuang

doi:10.1016/j.colsurfb.2010.07.012

Cited by 53 publications

(20 citation statements)

References 34 publications

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“…Such residues are not new in the structures of condensed tannins, as already highlighted by Navarrete et al [10]. C-O stretching modes are assigned to the peak 1144 cm −1 for symmetric elongation of the C-O-C groups in the pyran ring of condensed tannins, consistent with the work reported by Chen et al [34]. The peaks 1030 cm , enable the distinction of procyanidins and prodelphinidins [35].…”

Section: Atr-ftmir Analysissupporting

confidence: 78%

Characterization of Tannin-Based Resins from the Barks of Ficus platyphylla and of Vitellaria paradoxa: Composites’ Performances and Applications

Ntenga¹,

Pagore²,

Pizzi³

et al. 2017

MSA

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This work investigates the physico-chemical and mechanical properties of tannins extracted from wood for composite materials manufacturing. Sustainable knowledge (in terms of physico-chemical properties and behaviours) of the material is needed to further enhance its applications. The condensed tannins extracted from the Bark of Ficus platyphylla (BFP) , as well as using CP MAS 13 C-NMR. It was found that, these two tannins are procyanidin/prodelphinidin and made up of catechin/epicatechin, gallocatechin/epigallocatechin units, fisetinidin, galloyl and carbohydrates residues. Furthermore, BFP and BVP tannin bonded particleboard densities lie in the range recommended by NF EN 326-1994 standard. The resins also yielded good internal bond strength results of the panels, above relevant international standard specifications minimum requirements for interior-grade panels. The Transmission Electron Microscopy with Energy Dispersive X-ray Spectroscopy Analysis (TEM/ EDXA) are showing the ultrastructure and reveal that most of the resin material appears to be in an amorphous phase mainly composed of carbon/oxygen with

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Section: Atr-ftmir Analysissupporting

confidence: 78%

Characterization of Tannin-Based Resins from the Barks of Ficus platyphylla and of Vitellaria paradoxa: Composites’ Performances and Applications

Ntenga¹,

Pagore²,

Pizzi³

et al. 2017

MSA

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“…Polycondensation of small organic molecules enhanced by metallic oxides such as Si, Al, Fe and Mn oxides has been well documented [5][6][7]. Natural minerals, such as birnessite, allophane and nontronite can enhance abiotic humification of organic matter, which has been validated by numerous studies [8][9][10].…”

Section: Introductionmentioning

confidence: 93%

Role of ferric oxide in abiotic humification enhancement of organic matter

Zhang

Yue

Lu³

et al. 2015

J Mater Cycles Waste Manag

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The significance of humification pathway as promoted by metallic oxides has previously been well investigated using a model system containing humus precursors. Metallic oxides, co-existing with organic matter in nature, are capable of promoting humification of organic matter to different degrees. This study is an investigation into the role of ferric oxide in the process of humification, based on the degree of darkening for humus precursors. Glucose (Glu), glycine (Gly) and catechol (Cat) were introduced as humification model precursors, and the role of ferric oxide in different periods of humification was discussed by characterizing humification degree in terms of dissolved organic carbon, ratio of Fulvic acids (FA) to Humic acids (HA), and E 600 . Valence changes of Fe were analyzed using X-ray photoelectron spectroscopy. The results showed that ferric oxide was effective on the conversion from FA to HA, and the effectiveness grew as the ferric oxide concentration increased. A higher pH value was more conducive to form dark substances. Amounts of Fe with various valences changed remarkably after humification, suggesting that ferric oxide was involved in the humification reaction.

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“…Wang and co-authors [24][25][26][27] have shown that the abiotic synthesis of fulvic and humic acids on the surface of clay minerals can proceed through heterogeneous catalysis (autooxidation and surface polymerization) of polyacids, gallic acid among them. Tombácz and coworkers synthesized fulvic acid on montmorillonite by heterogeneous catalysis of gallic acid with average molecular weight of 840 g/mol as determined by vapor pressure osmometry.…”

Section: Introductionmentioning

confidence: 99%

Mechanism of in Situ Surface Polymerization of Gallic Acid in an Environmental-Inspired Preparation of Carboxylated Core–Shell Magnetite Nanoparticles

et al. 2014

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Corresponding authorsM. Szekeres (szekeres@chem.u-szeged.hu) and E. Tombácz (tombacz@chem.u-szeged.hu) Graphical abstract AbstractMagnetite nanoparticles (MNPs) with biocompatible coatings are good candidates for MRI (magnetic resonance imaging) contrasting, magnetic hyperthermia treatments and drug delivery systems. The spontaneous surface induced polymerization of dissolved organic matter on environmental mineral particles inspired us to prepare carboxylated core-shell MNPs by using a ubiquitous polyphenolic precursor. Through the adsorption and in-situ surface polymerization of gallic acid (GA), a polygallate (PGA) coating is formed on the nanoparticles (PGA@MNP) with possible antioxidant capacity. The Polygallate on magnetite nanoparticles Humic matter on clays 2This is a PDF file of an unedited manuscript that has been accepted for publication. Final edited form is published in Langmuir, 2014, 30:15451−15461. http://dx.doi.org/10.1021/la5038102 present work explores the mechanism of polymerization with the help of potentiometric acid-base titration, dynamic light scattering (for particle size and zeta potential determination), UV-Vis (UVvisible light spectroscopy), FTIR-ATR (Fourier-transformed infrared spectroscopy by attenuated total reflection) and XPS (X-ray photoelectron spectroscopy) techniques. We observed the formation of ester and ether linkages between gallate monomers both in solution and in the adsorbed state. Higher polymers were formed in the course of several weeks both on the surface of nanoparticles and in the dispersion medium. The ratio of the absorbances of PGA supernatants at 400 and 600 nm (i.e., the E4/E6 ratio commonly used to characterize the degree of polymerization of humic materials) was determined to be 4.3, similar to that of humic acids. Combined XPS, dynamic light scattering and FTIR-ATR results revealed that prior to polymerization, the GA monomers became oxidized to polycarboxylic acids due to ring opening while Fe 3+ ions reduced to Fe 2+ . Our published results on the colloidal and chemical stability of PGA@MNPs are referenced thoroughly in the present work. Detailed studies on biocompatibility, antioxidant property and biomedical applicability of the particles will be published.

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Polymerization of catechin catalyzed by Mn-, Fe- and Al-oxides

Cited by 53 publications

References 34 publications

Characterization of Tannin-Based Resins from the Barks of <i>Ficus platyphylla</i> and of <i>Vitellaria paradoxa</i>: Composites’ Performances and Applications

Characterization of Tannin-Based Resins from the Barks of <i>Ficus platyphylla</i> and of <i>Vitellaria paradoxa</i>: Composites’ Performances and Applications

Role of ferric oxide in abiotic humification enhancement of organic matter

Mechanism of in Situ Surface Polymerization of Gallic Acid in an Environmental-Inspired Preparation of Carboxylated Core–Shell Magnetite Nanoparticles

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Polymerization of catechin catalyzed by Mn-, Fe- and Al-oxides

Cited by 53 publications

References 34 publications

Characterization of Tannin-Based Resins from the Barks of &lt;i&gt;Ficus platyphylla&lt;/i&gt; and of &lt;i&gt;Vitellaria paradoxa&lt;/i&gt;: Composites’ Performances and Applications

Characterization of Tannin-Based Resins from the Barks of &lt;i&gt;Ficus platyphylla&lt;/i&gt; and of &lt;i&gt;Vitellaria paradoxa&lt;/i&gt;: Composites’ Performances and Applications

Role of ferric oxide in abiotic humification enhancement of organic matter

Mechanism of in Situ Surface Polymerization of Gallic Acid in an Environmental-Inspired Preparation of Carboxylated Core–Shell Magnetite Nanoparticles

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Characterization of Tannin-Based Resins from the Barks of <i>Ficus platyphylla</i> and of <i>Vitellaria paradoxa</i>: Composites’ Performances and Applications

Characterization of Tannin-Based Resins from the Barks of <i>Ficus platyphylla</i> and of <i>Vitellaria paradoxa</i>: Composites’ Performances and Applications