New Insights into the Effects of Thermal Treatment on the Catalytic Activity and Conformational Structure of Glucose Oxidase Studied by Electrochemistry, IR Spectroscopy, and Theoretical Calculation

Kinetics of homogenous hydrogenation of 1-heptene catalysed by rhodium(I) complexes prepared in situ from μ,μ'-dichloro-bis(cyclooctenerhodium) and phosphines of the type RP(C6H5)2 (R = -CH3, -(CH2)nSi(CH3)3; n = 1-4) have been studied. The substitution of the ligands by the trimethylsilyl group was found to increase significantly the catalytic activity of the complexes. The results are discussed in relation to the electron density on the phosphorus atom determined by 31P NMR spectroscopy and to its proton acceptor ability determined by IR spectroscopy.

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Versatile IR Spectroscopy Combined with Synchrotron XAS-XRD: Chemical, Electronic, and Structural Insights during Thermal Treatment of MOF Materials

European Journal of Inorganic Chemistry ◽

10.1002/ejic.201800140 ◽

2018 ◽

Vol 2018 (17) ◽

pp. 1847-1853 ◽

Cited By ~ 3

Author(s):

Satoshi Hinokuma ◽

Geir Wiker ◽

Takuya Suganuma ◽

Atul Bansode ◽

Dragos Stoian ◽

...

Keyword(s):

Thermal Treatment ◽

Ir Spectroscopy ◽

Structural Insights

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Synthesis of amine-epoxy based polymers and their potential application in the remediation of selected organic dyes from synthetic effluents

10.51415/10321/2655 ◽

2017 ◽

Author(s):

◽

Sharista Raghunath

Keyword(s):

Electron Microscopy ◽

Catalytic Activity ◽

Ir Spectroscopy ◽

1H Nmr Spectroscopy ◽

Organic Dyes ◽

Synthetic Dyes ◽

X Ray ◽

Dye Reduction ◽

Ft Ir ◽

Ft Ir Spectroscopy

The presence of dyes in effluent poses various environmental as well as health hazards for many organisms. Although various remediation strategies have been implemented to reduce their effect, dyes still manage to infiltrate into the environment and hence new strategies are required to address some of the problems. This study investigated the innovation of two cationic water-soluble polymers viz., Proline-Epichlorohydrin-Ethylenediamine Polymer (PEP) and Thiazolidine-Epichlorohydrin-Ethylenediamine Polymer (TEP) that were used to remediate selected synthetic dyes from synthetic effluent by adsorption and dye reduction. Both polymers were synthesized using monomers of a secondary amine, epichlorohydrin and ethylenediamine and were subsequently characterized and modified and their remediation potential studied. In the first study, PEP was synthesized and characterized by 1H-NMR Spectroscopy, FT-IR Spectroscopy, dynamic light scattering, and thermogravimetric analysis (TGA). Thereafter PEP was modified with bentonite clay, by simple mixing of the reactants, to form a Proline-Epichlorohydrin-Ethylenediamine Polymer-bentonite composite (PRO-BEN); it was characterized by FT-IR Spectroscopy, scanning electron microscopy (SEM)/ energy dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Adsorption studies were then undertaken with a synthetic effluent containing three textile dyes, viz., Reactive Blue 222 (RB 222), Reactive Red 195 (RR 195) and Reactive Yellow (RY 145). Various conditions were investigated including pH of the solution, temperature, sodium chloride concentration, initial dye concentration and the dosage of adsorbent used. The experimental data for all dyes followed a Langmuir isotherm. The adsorption process was found to be pseudo-second order. According to the thermodynamic parameters, the adsorption of the dyes was classified as physisorption and the reaction was spontaneous and exothermic. The data were also compared using studies with alumina as an adsorbent. Results showed that PRO-BEN exhibited better absorptivity and desorption than alumina making its use a better recyclable remediation strategy for the removal of organic dyes in wastewater treatment plants. In the second study, TEP was synthesized and then characterized by FT-IR Spectroscopy, 1H-NMR Spectroscopy, TGA and DLS. Thereafter, TEP was used to prepare TEP capped gold nanoparticles (TEP-AuNPs). Herein, two methods were investigated: the Turkevich method and an adaptation of the Turkevich method using bagasse extract. The TEP-AuNPs was characterized by FT-IR Spectroscopy, SEM, EDX, DLS and TEM. Thereafter the reduction of each of Allura Red, Congo Red and Methylene Blue was investigated with the TEP-AuNPs for its catalytic activity toward dye reduction. This study showed that the batch of AuNPs prepared by the Turkevich method had higher rates of dye reduction compared with AuNPs prepared using bagasse extract. Also the quantity of TEP used as capping agent greatly influenced the size, shape and surface charge of the nanoparticles as well as their catalytic performance: the Vroman effect explained this behavior of the TEP-AuNPs. It was finally concluded that whilst PRO-BEN, in the first study, showed excellent dye remediation properties, the second study on TEP-AuNPs showed good catalytic activity for the reduction of selected dyes, however, it was more effective at lower polymer concentration. Finally, both materials displayed good potential for the clean-up of selected synthetic dyes from synthetic effluents.

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Synthesis, structure and thermal expansion of the phosphates M0.5+x M′x Zr2−x (PO4)3 (M, M′–metals in oxidation state +2)

Pure and Applied Chemistry ◽

10.1515/pac-2016-1005 ◽

2017 ◽

Vol 89 (4) ◽

pp. 523-533 ◽

Cited By ~ 7

Author(s):

Elena Asabina ◽

Vladimir Pet’kov ◽

Pavel Mayorov ◽

Dmitriy Lavrenov ◽

Igor Schelokov ◽

...

Keyword(s):

Thermal Expansion ◽

Thermal Treatment ◽

Ir Spectroscopy ◽

Microprobe Analysis ◽

Electron Microprobe Analysis ◽

Sol Gel ◽

X Ray Diffraction ◽

X Ray ◽

Structural Types ◽

The Difference

AbstractThe phosphates M0.5+x M′x Zr2−x (PO4)3 (M–Ca, Mn, Co, Sr, Cd, Ba, Pb; M′–Mg, Mn, Co) were synthesized by sol-gel method with the following thermal treatment of reaction mixtures. X-ray diffraction, IR spectroscopy and electron microprobe analysis showed that the obtained phosphates crystallized in Sc2(WO4)3 (SW) and NaZr2(PO4)3 (NZP) structural types. Both types of crystal structures are based on a framework comprised of octahedra and tetrahedra, the difference between them is fragments orientation. Thermal expansion of the phosphates was studied in the temperature range 20–800°C. Some compounds were found to belong to low-expanding materials (αav ~2·10−6°C−1).

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ORIGINAL RESEARCH: An avidin-biotin immobilization approach for horseradish peroxidase and glucose oxidase on layered silicates with high catalytic activity retention and improved thermal behavior

Industrial Biotechnology ◽

10.1089/ind.2007.3.082 ◽

2007 ◽

Vol 3 (1) ◽

pp. 82-88 ◽

Cited By ~ 3

Author(s):

Nikolaos G. Chalkias ◽

Emmanuel P. Giannelis

Keyword(s):

Catalytic Activity ◽

Horseradish Peroxidase ◽

Thermal Behavior ◽

Glucose Oxidase ◽

Layered Silicates ◽

Original Research ◽

High Catalytic Activity

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Cu(II) and Fe(III) Complexes Derived from N-Acetylpyrazine-2-Carbohydrazide as Efficient Catalysts Towards Neat Microwave Assisted Oxidation of Alcohols

Catalysts ◽

10.3390/catal9121053 ◽

2019 ◽

Vol 9 (12) ◽

pp. 1053 ◽

Cited By ~ 7

Author(s):

Manas Sutradhar ◽

Tannistha Roy Barman ◽

Armando J. L. Pombeiro ◽

Luísa M. D. R. S. Martins

Keyword(s):

Catalytic Activity ◽

Ir Spectroscopy ◽

Maximum Yield ◽

Catalytic Efficiency ◽

Benzyl Alcohols ◽

X Ray ◽

X Ray Crystallography ◽

Microwave Assisted ◽

Tert Butyl Hydroperoxide ◽

Oxidation Of Alcohols

The mononuclear Cu(II) complex [Cu((kNN′O-HL)(H2O)2] (1) was synthesized using N-acetylpyrazine-2-carbohydrazide (H2L) and characterized by elemental analysis, IR spectroscopy, ESI-MS and single crystal X-ray crystallography. Two Fe(III) complexes derived from the same ligand viz, mononuclear [Fe((kNN′O-HL)Cl2] (2) and the binuclear [Fe(kNN′O-HL)Cl(μ-OMe)]2 (3) (synthesized as reported earlier), were also used in this study. The catalytic activity of these three complexes (1–3) was examined towards the oxidation of alcohols using tert-butyl hydroperoxide (TBHP) as oxidising agent under solvent-free microwave irradiation conditions. Primary and secondary benzyl alcohols (benzyl alcohol and 1-phenylethanol), and secondary aliphatic alcohols (cyclohexanol) were used as model substrates for this study. A comparison of their catalytic efficiency was performed. Complex 1 exhibited the highest activity in the presence of TEMPO as promoter for the oxidation of 1-phenylethanol with a maximum yield of 91.3% of acetophenone.

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Graphene Oxide and Oxidized Carbon Black as Catalyst for Crosslinking of Phenolic Resins

Polymers ◽

10.3390/polym11081330 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1330 ◽

Cited By ~ 2

Author(s):

Maria Rosaria Acocella ◽

Aniello Vittore ◽

Mario Maggio ◽

Gaetano Guerra ◽

Luca Giannini ◽

...

Keyword(s):

Differential Scanning Calorimetry ◽

Graphene Oxide ◽

Catalytic Activity ◽

Thermal Treatment ◽

Carbon Black ◽

Crosslinking Reaction ◽

Scanning Calorimetry ◽

Indirect Methods ◽

Phenolic Resins ◽

Oxidized Carbon

Influence of different graphite-based nanofillers on crosslinking reaction of resorcinol, as induced by hexa(methoxymethyl)melamine, is studied. Curing reactions leading from low molecular mass compounds to crosslinked insoluble networks are studied by indirect methods based on Differential Scanning Calorimetry. Reported results show a catalytic activity of graphene oxide (eGO) on this reaction, comparable to that one already described in the literature for curing of benzoxazine. For instance, for an eGO content of 2 wt %, the exothermic crosslinking DSC peak (upon heating at 10 °C/min) shifted 6 °C. More relevantly, oxidized carbon black (oCB) is much more effective as catalyst of the considered curing reaction. In fact, for an oCB content of 2 wt %, the crosslinking DSC peak can be shifted more than 30 °C and a nearly complete crosslinking is already achieved by thermal treatment at 120 °C. The possible origin of the higher catalytic activity of oCB with respect to eGO is discussed.

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Acid and base properties of molybdophosphoric acid supported on zirconia: Characterized by IR spectroscopy, TPD and catalytic activity

Fuel ◽

10.1016/j.fuel.2012.03.003 ◽

2012 ◽

Vol 100 ◽

pp. 144-151 ◽

Cited By ~ 6

Author(s):

J.G. Hernández-Cortez ◽

E. López-Salinas ◽

Ma. Manríquez ◽

J.A. Toledo ◽

M.A. Cortes-Jacome

Keyword(s):

Catalytic Activity ◽

Ir Spectroscopy ◽

Molybdophosphoric Acid ◽

Acid And Base ◽

Base Properties

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Multiple Mapping of Peptide Sequences Recognized by Various Monoclonal Anti-ADAMTS13 Antibodies with Functional or Nonfunctional Effects On the Catalytic Activity.

Blood ◽

10.1182/blood.v114.22.3182.3182 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3182-3182

Author(s):

Terumichi Nakagawa ◽

Takanori Moriki ◽

Yusuke Yamaguchi ◽

Atsuko Igari ◽

Kenji Soejima ◽

...

Keyword(s):

Amino Acids ◽

Catalytic Activity ◽

Molecular Conformation ◽

Conflicts Of Interest ◽

Surface Display ◽

Peptide Sequence ◽

Phage Library ◽

Conformational Structure ◽

Lambda Phage ◽

Cleavage Activity

Abstract Abstract 3182 Poster Board III-119 Fourteen mouse anti-ADAMTS13 monoclonal antibodies (MoAb#1∼#13, A10) were individually analyzed for their precise epitope peptide sequences in each domain using lambda phage surface display system. A phage library expressing random peptide fragments of ADAMTS13 on its surface was constructed, thereby selecting phage clones bound to each MoAbs immobilized on microtiter plates. Binding epitope sequences for eleven MoAbs were defined, although MoAb#3, #4 and #5 were not clarified. Among 11 epitope-determined MoAbs, epitopes were relatively short (6 to 23 amino acids) in MoAb#1, #2, #8, #11, #12 and #13, recognizing metallopretease, disintegrin-like, TSP1-4, TSP1-8, CUB1 and C-terminus domains, respectively. On the other hand, epitopes were relatively long (49 to 72 amino acids) in A10, MoAb#6, #7, #9 and #10, recognizing disintegrin-like, TSP1-2, TSP1-3, TSP1-5 and TSP1-7 domains, respectively. MoAb#1, #2 and A10 demonstrated inhibitory effects on the cleavage activity of ADAMTS13 evaluated by FRETS-VWF73 assay. MoAb#1 recognized Gln159 to Asp166 in the metalloprotease domain, and MoAb#2 and A10 recognized Asn308 to Glu327, Tyr305 to Glu376 in the disintegrin-like domain, respectively. From findings using C-terminal truncated mutants of ADAMTS13, MoAb#3 and #5 were supposed to recognize TSP1-1 and spacer domain, respectively, although only C-terminal tail peptide sequences were selected from both of the screening, suggesting the possibility of intramolecular association between the C-terminal region and TSP1-1/spacer domains. MoAb#4 was supposed to recognize disintegrin-like domain, although we could not obtain any significant ADAMTS13 peptide sequence from the screening. We speculate that these 3 epitope-undetermined MoAbs may recognize complex conformational structure of ADAMTS13. Alternatively, intact peptide structure of ADAMTS13 might not be expressed properly on the phage surface. In conclusion, we defined precise epitope sequences of 11 monoclonal anti-ADAMTS13 antibodies. Three of them, recognizing metalloprotease or disintegrin-like domains inhibited the cleavage activity of ADAMTS13. Analysis of the epitope sequences may elucidate the correlation between the molecular conformation and the catalytic activity. Disclosures No relevant conflicts of interest to declare.

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