scholarly journals Anodic Electrodeposition of Chitosan–AgNP Composites Using In Situ Coordination with Copper Ions

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2754
Author(s):  
Dmitry S. Kharitonov ◽  
Aliaksandr A. Kasach ◽  
Agnieszka Gibala ◽  
Małgorzata Zimowska ◽  
Irina I. Kurilo ◽  
...  
Keyword(s):  
Cross Section ◽  
Staphylococcus Epidermidis ◽  
Biomedical Applications ◽  
Copper Ions ◽  
Surface Functional Groups ◽  
Novel Approach ◽  
Anodic Electrodeposition ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Chitosan is an attractive material for biomedical applications. A novel approach for the anodic electrodeposition of chitosan–AgNP composites using in situ coordination with copper ions is proposed in this work. The surface and cross-section morphology of the obtained coating with varying concentrations of AgNPs were evaluated by SEM, and surface functional groups were analyzed with FT-IR spectroscopy. The mechanism of the formation of the coating based on the chelation of Cu(II) ions with chitosan was discussed. The antibacterial activity of the coatings towards Staphylococcus epidermidis ATCC 35984/RP62A bacteria was analyzed using the live–dead approach. The presented results indicate that the obtained chitosan–AgNP-based films possess some limited anti-biofilm-forming properties and exhibit moderate antibacterial efficiency at high AgNP loads.

scholarly journals Fatty Acid Prediction in Bovine Milk by Attenuated Total Reflection Infrared Spectroscopy after Solvent-Free Lipid Separation

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1054
Author(s):  
Christopher Akhgar ◽  
Vanessa Nürnberger ◽  
Marlene Nadvornik ◽  
Margit Velik ◽  
Andreas Schwaighofer ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Milk Fat ◽  
Regression Models ◽  
Bovine Milk ◽  
Attenuated Total Reflection ◽  
Solvent Free ◽  
Novel Approach ◽  
Whole Milk ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

In the present study, a novel approach for mid-infrared (IR)-based prediction of bovine milk fatty acid composition is introduced. A rapid, solvent-free, two-step centrifugation method was applied in order to obtain representative milk fat fractions. IR spectra of pure milk lipids were recorded with attenuated total reflection Fourier-transform infrared (ATR-FT-IR) spectroscopy. Comparison to the IR transmission spectra of whole milk revealed a higher amount of significant spectral information for fatty acid analysis. Partial least squares (PLS) regression models were calculated to relate the IR spectra to gas chromatography/mass spectrometry (GC/MS) reference values, providing particularly good predictions for fatty acid sum parameters as well as for the following individual fatty acids: C10:0 (R2P = 0.99), C12:0 (R2P = 0.97), C14:0 (R2P = 0.88), C16:0 (R2P = 0.81), C18:0 (R2P = 0.93), and C18:1cis (R2P = 0.95). The IR wavenumber ranges for the individual regression models were optimized and validated by calculation of the PLS selectivity ratio. Based on a set of 45 milk samples, the obtained PLS figures of merit are significantly better than those reported in literature using whole milk transmission spectra and larger datasets. In this context, direct IR measurement of the milk fat fraction inherently eliminates covariation structures between fatty acids and total fat content, which poses a common problem in IR-based milk fat profiling. The combination of solvent-free lipid separation and ATR-FT-IR spectroscopy represents a novel approach for fast fatty acid prediction, with the potential for high-throughput application in routine lab operation.

Nano-Sized [60]Fullerene-Cyclodextrin Molecules

2001 ◽  
Vol 675 ◽  
Author(s):  
Jeong-Seo Park ◽  
Han-Chang Kang ◽  
Kurt E. Geckeler
Keyword(s):  
Biomedical Applications ◽  
Addition Reaction ◽  
Water Soluble ◽  
Separation And Purification ◽  
Subsequent Reaction ◽  
Fullerene Derivatives ◽  
Covalently Bonded ◽  
Scattering Measurements ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

ABSTRACTAs [60]fullerene is a very hydrophobic macromolecule, there have been a number of attempts to make it more hydrophilic for biomedical applications. By attaching hydrophilic moieties such as poly(oxyethylene)(POE) chains and cyclodextrin molecules to [60]fullerene, novel water-soluble and biocompatible materials have been successfully prepared [1,2].The synthesis of novel macrocyclic fullerene conjugates which are water-soluble is reported. The telechelic fullerene derivatives have been prepared via addition reaction of POE-based arms with covalently bonded β-cyclodextrin (CD) to [60]fullerene. To this end, a mono-tosylated CD derivative has been prepared in pyridine and then reacted with an amino-functional POE in the presence of triethylamine. The subsequent reaction of [60]fullerene with the hydrophilic POE-conjugated CD-derivative yielded the macrofullerene after separation and purification procedures.The macrocyclic [60]fullerene derivatives obtained were soluble in water and characterized by UV-VIS and FT-IR spectroscopy as well as light scattering measurements and thermogravimetric analysis.

scholarly journals Monitoring the Interfacial Polymerization of Piperazine and Trimesoyl Chloride with Hydrophilic Interlayer or Macromolecular Additive by in-situ FT-IR Spectroscopy

2019 ◽  
Author(s):  
Xi Yang
Keyword(s):  
Ir Spectroscopy ◽  
Reaction Rate ◽  
Interfacial Polymerization ◽  
Reaction System ◽  
Reaction Rates ◽  
Water Permeation ◽  
Ft Ir ◽  
Trimesoyl Chloride ◽  
Ft Ir Spectroscopy

The interfacial polymerization (IP) of piperazine (PIP) and trimesoyl chloride (TMC) has been extensively utilized to synthesize the nanofiltration (NF) membrane. However, it is still a huge challenge to monitor the IP reaction, because of the fast reaction rate and the formed ultra-thin film. Herein, two effective strategies are applied to reduce the IP reaction rate: (1) the introduction of hydrophilic interlayers between the porous substrate and the formed polyamide layer; (2) the addition of macromolecular additives in the aqueous solution of PIP. As a result, in-situ FT-IR spectroscopy was firstly used to monitor the IP reaction of PIP/TMC reaction system, with hydrophilic interlayers or macromolecular additives. Moreover, we study the formed polyamide layer growth on the substrate, in a real-time manner. The in-situ FT-IR experimental results confirm that the IP reaction rates are effectively suppressed and the formed polyamide thickness reduces from 138±24 nm to 46±2 nm. Furthermore, the optimized NF membrane with excellent performance are consequently obtained, which include the boosted water permeation flux about 141~238 (L·m2·h/MPa) and superior salt rejection of Na2SO4 > 98.4%.

A Novel Approach to Photoacoustic FT-IR Spectroscopy: Rheo-Photoacoustic Measurements

1989 ◽  
Vol 43 (8) ◽  
pp. 1387-1393 ◽  
Author(s):  
William F. McDonald ◽  
Hans Goeitler ◽  
Marek W. Urban
Keyword(s):  
Molecular Structure ◽  
Thin Films ◽  
Fourier Transform ◽  
Acoustic Waves ◽  
Polymeric Materials ◽  
Photoacoustic Signal ◽  
Novel Approach ◽  
Ft Ir ◽  
Property Changes ◽  
Ft Ir Spectroscopy

A new rheo-photoacoustic Fourier transform infrared cell has been developed to perform stress-strain studies on polymeric materials. The rheo-photoacoustic measurements lead to the enhancement of the photoacoustic signal and allow one to monitor the effect of elongational forces on the molecular structure of polymers. Propagating acoustic waves are detected as a result of the deformational changes and thermal property changes upon the applied stress. Applications of this technique to fibers, films, and adhesion of thin films are presented.

Synthesis of Biocompatible Magnetic Iron Oxide (γ-Fe2O3 and Fe3O4) Nanoparticles by a Modified Polyol Process for Biomedical Applications

2010 ◽  
Vol 1256 ◽  
Author(s):  
Georgia Basina ◽  
Ioannis Panagiotopoulos ◽  
Eamonn Devlin ◽  
George Hadjipanayis ◽  
Levent Colak ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Magnetic Particles ◽  
Polyol Process ◽  
X Rays ◽  
Colloidal Solutions ◽  
Heating Rates ◽  
Fast Heating ◽  
Ft Ir ◽  
Magnetite Phase ◽  
Ft Ir Spectroscopy

AbstractHighly crystalline superparamagnetic Fe3O4 nanoparticles coated by poly-vinylpyrrolidone (PVP) were prepared by simultaneous thermal decomposition of ferrous and ferric inorganic salts in polyethylene glycol (PEG) with molecular weight 200. The magnetic particles have a diameter in the range of 8-15 nm, and after exchange with citric acid diammonium salt, they transform into very stable super hydrophilic colloidal solutions. The presence of magnetite phase was confirmed using powder X-rays diffraction (XRD) and Mössbauer spectroscopy, while thermogravimetric analysis and FT-IR spectroscopy confirmed the presence of PVP or citrate anions on the nanoparticles surface. The magnetic properties revealed superparamagnetic behavior, with the composite material showing a saturation magnetization up to 57 emu/g. The Fe3O4 nanoparticles prepared by this modified polyol process are suitable for biomedical applications because of the biocompatibility of citrate anions. Magnetic hyperthermia experiments in neutral water solutions shows that the particles induce fast heating rates with specific absorption rate (SAR) values which reached 57.53 W/gFe, when the concentration of iron is 11.2 mgFe/ml.

Ethylene polymerization on a SiH4-modified Phillips catalyst: detection of in situ produced α-olefins by operando FT-IR spectroscopy

2012 ◽  
Vol 14 (7) ◽  
pp. 2239 ◽  
Author(s):  
Caterina Barzan ◽  
Elena Groppo ◽  
Elsje Alessandra Quadrelli ◽  
Vincent Monteil ◽  
Silvia Bordiga
Keyword(s):  
Ir Spectroscopy ◽  
Ethylene Polymerization ◽  
Phillips Catalyst ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

STRUCTURAL INVESTIGATIONS OF CuO–B2O3–Bi2O3 GLASSES BY MEANS OF EPR AND FT-IR SPECTROSCOPIES

2004 ◽  
Vol 18 (16) ◽  
pp. 803-810 ◽  
Author(s):  
I. ARDELEAN ◽  
SIMONA CORA ◽  
RALUCA CICEO-LUCACEL
Keyword(s):  
Local Structure ◽  
Copper Content ◽  
Copper Ions ◽  
Glass Structure ◽  
Mixed Valence ◽  
Structural Investigations ◽  
Valence States ◽  
Distorted Octahedral ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

EPR and FT-IR spectroscopy have been used to investigate the B 2 O 3– Bi 2 O 3 glass matrix containing CuO in order to obtain more information about the local structure of these glasses. The EPR absorption spectra revealed the presence in the glass structure of the Cu 2+ ions in axially distorted octahedral environments. No superexchange interaction of Cu 2+ was detected. In the samples with x≥5 mol%, mixed valence states of copper ions were revealed. The FT-IR measurements indicate the presence in the glass structure of the distorted [ BiO 6] polyhedra, tri- and tetra-borate units ( BO 3, BO 4) and its dependence by the copper content.

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