Cleavage mechanism and surface chemical characterization of phengitic Muscovite and Muscovite as constrained by X-Ray Photoelectron Spectroscopy

1998 ◽  
Vol 25 (2) ◽  
pp. 168-181 ◽  
Author(s):  
Giuseppe G. Biino ◽  
Pierangelo Gröning
1995 ◽  
Vol 414 ◽  
Author(s):  
S. Seal ◽  
S. Krezoski ◽  
T. L. Barr ◽  
D. H. Petering

AbstractSiliceous materials are the principal components of Earth's crust and also have become key ingredients of modem technology. Recently, we have expanded our chemical characterization of complex silicates (e.g., framework [1] and sheet types [2]) to include studies of their interaction with select biocells [3,4]. It is becoming apparent that the surface chemistry of these silicates, and perhaps that of silica itself, plays a key role in the oft resulting cell pathogenesis, thus enhancing the value of further investigations with X-ray photoelectron spectroscopy. The present research describes the unique growth of Ehrlich (murine or rat tumor) cells on Sio and SiO2 wafers, and also on select seaentine silicates (such as chrysotile asbestos). Tbese growth studies were followed by both cell/silicate separations and unique freeze drying [3,4]. XPS examination at select stages discovered cell induced alterations in the Si, O, Mg and particularly Fe chemistry of the silicon based systems as well as corresponding changes in the cell chemistry. Many of these features were confirmed by atomic absorption spectroscopy.


2020 ◽  
Vol 1 (1) ◽  
pp. 80-89
Author(s):  
Mohammadali Azadfar ◽  
Michael P. Wolcott

The surface chemical compositions of powdered cellulose have been characterized utilizing X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) techniques. Powdered cellulose was prepared by milling of bleached softwood pulp residues through a lab-scale planetary ball mill. Here we show how milling a mixture of the powdered cellulose with potassium hydroxide determines the surface chemical compositions of the obtained powdered cellulose, in a completely dry condition. The XPS analysis indicated the presence of new carbon and oxygen atoms as C4, C5, and O3. In turn, the FTIR analysis showed the stretching vibrations of the carbon–carbon double bond. The results suggest the formation of active oxygenated species on powdered cellulose surfaces.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 490
Author(s):  
María Montserrat Cruz-Benítez ◽  
Pablo Gónzalez-Morones ◽  
Ernesto Hernández-Hernández ◽  
José Roberto Villagómez-Ibarra ◽  
Javier Castro-Rosas ◽  
...  

In this work, we report the synthesis of graphene oxide (GO) nanohybrids with starch, fructose, and micro-cellulose molecules by sonication in an aqueous medium at 90 °C and a short reaction time (30 min). The final product was washed with solvents to extract the nanohybrids and separate them from the organic molecules not grafted onto the GO surface. Nanohybrids were chemically characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy and analyzed by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). These results indicate that the ultrasound energy promoted a chemical reaction between GO and the organic molecules in a short time (30 min). The chemical characterization of these nanohybrids confirms their covalent bond, obtaining a grafting percentage above 40% the weight in these nanohybrids. This hybridization creates nanometric and millimetric nanohybrid particles. In addition, the grafted organic molecules can be crystallized on GO films. Interference in the ultrasound waves of starch hybrids is due to the increase in viscosity, leading to a partial hybridization of GO with starch.


RSC Advances ◽  
2021 ◽  
Vol 11 (43) ◽  
pp. 27074-27083
Author(s):  
Patrizia Pagliara ◽  
Daniela Chirizzi ◽  
Maria Rachele Guascito

Red spherula cells from sea urchin coelomic fluid have attracted great interest for their specific and intriguing properties, such as antimicrobial activities and immune response, that probably tie in with their red characteristic pigments.


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