Cation exchange membranes by radiation-induced graft copolymerization of styrene onto PFA copolymer films. IV. Morphological investigations using X-ray photoelectron spectroscopy

2000 ◽  
Vol 77 (11) ◽  
pp. 2455-2463 ◽  
Author(s):  
Mohamed Mahmoud Nasef ◽  
Hamdani Saidi ◽  
Mohd Ambar ◽  
Yarmo
Keyword(s):  
Cation Exchange ◽  
Photoelectron Spectroscopy ◽  
Graft Copolymerization ◽  
X Ray ◽  
Copolymer Films ◽  
Radiation Induced ◽  
Morphological Investigations

scholarly journals Evaluation of the Antimicrobial Protection of Pharmaceutical Kaolin and Talc Modified with Copper and Zinc

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1173
Author(s):  
Fotini Martsouka ◽  
Konstantinos Papagiannopoulos ◽  
Sophia Hatziantoniou ◽  
Martin Barlog ◽  
Giorgos Lagiopoulos ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Photoelectron Spectroscopy ◽  
Antimicrobial Properties ◽  
Exchange Capacity ◽  
Elevated Concentration ◽  
Chemical Mapping ◽  
Exchange Method ◽  
X Ray ◽  
Copper And Zinc ◽  
Antimicrobial Protection

Six pharmaceutical pastes were prepared using chemically modified kaolin and talc powders. Tests were conducted to determine their structural and chemical characteristics as well as their antimicrobial protection, thus rendering them suitable for cosmetic and pharmaceutical uses. Kaolin and talc were treated chemically via the cation exchange method to load the clay particles with copper and zinc ions, two cations well known for their antimicrobial properties. Mineralogical analyses were conducted by using X-ray diffraction (XRD) before and after the modification, confirming the mineralogical purity of the samples. Scanning electron microscopy was also used in conjunction with energy dispersed spectroscopy (SEM-EDS) to obtain chemical mapping images, revealing the dispersion of the added metals upon the clay minerals surfaces. Moreover, chemical analysis has been performed (XRF) to validate the enrichment of the clays with each metal utilizing the cation exchange capacity. All modified samples showed the expected elevated concentration in copper or zinc in comparison to their unmodified versions. From the X-ray photoelectron spectroscopy (XPS), the chemical state of the samples’ surfaces was investigated, revealing the presence of salt compounds and indicating the oxidation state of adsorbed metals. Finally, the resistance of pastes in microbial growth when challenged with bacteria, molds, and yeasts was assessed. The evaluation is based on the European Pharmacopeia (EP) criteria.

scholarly journals Direct Conjugation of Resveratrol on Hydrophilic Gold Nanoparticles: Structural and Cytotoxic Studies for Biomedical Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1898
Author(s):  
Iole Venditti ◽  
Giovanna Iucci ◽  
Ilaria Fratoddi ◽  
Manuela Cipolletti ◽  
Emiliano Montalesi ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
X Ray ◽  
Conjugated Systems ◽  
Cell Vitality ◽  
Anticancer Effects ◽  
Radiation Induced ◽  
Ft Ir ◽  
Cytotoxic Studies ◽  
X Ray Absorption

Strongly hydrophilic gold nanoparticles (AuNPs), functionalized with citrate and L-cysteine, were synthetized and used as Resveratrol (RSV) vehicle to improve its bioavailability. Two different conjugation procedures were investigated: the first by adding RSV during AuNPs synthesis (1) and the second by adding RSV after AuNPs synthesis (2). The two different conjugated systems, namely AuNPs@RSV1 and AuNPs@RSV2 respectively, showed good loading efficiency (η%): η1 = 80 ± 5% for AuNPs@RSV1 and η2 = 20 ± 3% for AuNPs@RSV2. Both conjugated systems were investigated by means of Dynamic Light Scattering (DLS), confirming hydrophilic behavior and nanodimension (<2RH> 1 = 45 ± 12 nm and <2RH> 2 = 170 ± 30 nm). Fourier Transform Infrared Spectroscopy (FT-IR), Synchrotron Radiation induced X-Ray Photoelectron Spectroscopy (SR-XPS) and Near Edge X-ray Absorption Fine Structure (NEXAFS) techniques were applied to deeply understand the hooking mode of RSV on AuNPs surface in the two differently conjugated systems. Moreover, the biocompatibility of AuNPs and AuNPs@RSV1 was evaluated in the concentration range 1.0–45.5 µg/mL by assessing their effect on breast cancer cell vitality. The obtained data confirmed that, at the concentration used, AuNPs do not induce cell death, whereas AuNPs@RSV1 maintains the same anticancer effects as the unconjugated RSV.

The Influence of Structure on Ba and K Uptake by a Synthetic Phyllomanganate

Clay Minerals ◽  
1994 ◽  
Vol 29 (2) ◽  
pp. 215-222 ◽  
Author(s):  
E. Paterson ◽  
R. Swaffield ◽  
L. Clark
Keyword(s):  
Chemical Analysis ◽  
Cation Exchange ◽  
Exchange Reaction ◽  
Charge Distribution ◽  
Photoelectron Spectroscopy ◽  
Basal Spacing ◽  
K Uptake ◽  
Selective Uptake ◽  
X Ray ◽  
Bulk Chemical

AbstractThe uptake of Ba2+ and K+ by a synthetic Na-phyllomanganate has been studied by chemical analysis, X-ray diffractometry and X-ray photoelectron spectroscopy. The changes in basal spacing arising from cation exchange have been used to monitor the progress of the exchange reaction and confirm the selectivity measured by bulk chemical analysis. However, the selective uptake of Ba2+ over Ca2+ is much greater than that of K+ over Na+ and it is suggested that charge distribution in the interlayer is important. The results are discussed in the light of recent advances in our understanding of the phyllomanganate structure.

scholarly journals Introduction of Bifunctional Group onto MWNT by Radiation-Induced Graft Polymerization and Its Use as Biosensor-Supporting Materials

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Yu-Jin Lee ◽  
Da-Jung Chung ◽  
Sang-Hyub Oh ◽  
Seong-Ho Choi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Glycidyl Methacrylate ◽  
Redox Reactions ◽  
Graft Polymerization ◽  
Red Wine ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Transmission Electron ◽  
Radiation Induced ◽  
Supporting Materials

A biosensor comprisingtyrosinaseimmobilized on bifunctionalized multiwalled carbon nanotube (MWNT) supports was prepared for the detection of phenolic compounds in drinks such as red wine and juices. The MWNT supports were prepared by radiation-induced graft polymerization (RIGP) of epoxy-containing glycidyl methacrylate (GMA), to covalently immobilize thetyrosinase, and vinyl ferrocene (VF), which can act as an electron transfer mediator via redox reactions. The bifunctionalized MWNTs were characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). Electrodes prepared with the MWNTs showed increased current with increasing VF content. A biosensor comprisingtyrosinaseimmobilized on the bifunctionalized MWNTs could detect phenol at 0.1–20 mM. Phenolics in red wine and juices were determined using the biosensor after its calibration.

Fe-loaded zeolites as catalysts in the formation of humic substance-like darkcoloured polymers in polycondensation reactions of humic precursors

Clay Minerals ◽  
2012 ◽  
Vol 47 (3) ◽  
pp. 355-364 ◽  
Author(s):  
S. Fukuchi ◽  
M. Fukushima ◽  
R. Nishimoto ◽  
G. Qi ◽  
T. Sato
Keyword(s):  
Cation Exchange ◽  
Photoelectron Spectroscopy ◽  
Ionic Species ◽  
Exchange Capacity ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Catalytic Activities ◽  
Ion Exchange Reaction ◽  
Xrd Patterns

AbstractTo enhance the catalytic activities of zeolites for the polycondensation reactions of humic precursors, Fe was loaded into a zeolite via an ion-exchange reaction and the resulting product was subjected to calcination at 773 K. Two types iron-loaded zeolites were prepared using one equivalent (Fe-Z-1) and 10-equivalents (Fe-Z-10) of Fe2+ to the cation-exchange capacity of a natural zeolite from Niki town (Hokkaido, Japan). X-ray diffraction (XRD) patterns and X-ray photoelectron spectroscopy (XPS) spectra showed that the Fe(II) that was originally loaded into the cation-exchange sites in the zeolite became oxidized to a Fe(III) ionic species during the preparation. The catalytic activities of each zeolite were evaluated, based on the degree of darkening for reaction mixtures containing catechol, glycine and glucose as model humic precursors. The catalytic activities of Fe-Z-1 and Fe-Z-10 were higher than that for an untreated zeolite, and increased with the amount of Fe in the zeolite.

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