The Importance of Interactions at the Molecular Level: A Spectroscopic Study of a New Composite Sorber Material

2017 ◽  
Vol 71 (10) ◽  
pp. 2278-2285 ◽  
Author(s):  
Valentina Crocellà ◽  
Elena Groppo ◽  
Alessandro Dani ◽  
Alberto Castellero ◽  
Silvia Bordiga ◽  
...  

The functional properties of a new composite material having water vapor getter properties have been investigated by a large arsenal of characterization techniques. The composite system is originated by combining two constituents having very different chemical natures, a magnesium perchlorate (Mg(ClO4)2) salt and a polymeric acrylic matrix. In particular, Fourier transform infrared (FT-IR) and Raman spectroscopy have been fundamental to understand the type of interactions between the salt and the matrix in different hydration conditions. It was found that in the anhydrous composite system the dispersed Mg(ClO4)2 salt retains its molecular structure, because Mg2+ cations are still surrounded by their [ClO4]– counter-anions; at the same time, the salt and the polymeric matrix chemically interact each other at the molecular level. These interactions gradually vanish in the presence of water, and disappear in the fully hydrated composite system, where the Mg2+ cations are completely solvated by the water molecules.

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
I Mamarelis ◽  
V Mamareli ◽  
M Kyriakidou ◽  
O Tanis ◽  
C Mamareli ◽  
...  

Abstract Background The atherosclerotic ascending aorta could represent a potential source of emboli or could be an indicator of atherosclerosis in general with high mortality. The mechanism of aneurysm formation and atherosclerosis of the ascending aorta at the molecular level has not yet been clarified. To approach the mechanism of ascending aortic lesions and mineralization at a molecular level, we used the non-destructive FT-IR, Raman spectroscopy, SEM and Hypermicroscope. Methods Six ascending aorta biopsies were obtained from patients who underwent aortic valve replacement (AVR) cardiac surgery. CytoViva (einst inc) hyperspectral microscope was used to obtain the images of ascending aorta. The samples were dissolved in hexane on a microscope glass plate. The FT-IR and Raman spectra were recorded with Nicolet 6700 thermoshintific and micro-Raman Reinshaw (785nm, 145 mwatt), respectively. The architecture of ascending aorta biopsies was obtained by using scanning electron microscope (SEM of Fei Co) without any coating. Results FT-IR and Raman spectra showed changes arising from the increasing of lipophilic environment and aggregate formation (Fig. 1). The band at 1744 cm–1 is attributed to aldehyde CHO mode due to oxidation of lipids. The shifts of the bands of the amide I and amide II bands to lower are associated with protein damage, in agreement with SEM data. The bands at about 1170–1000 cm–1 resulted from the C-O-C of advanced glycation products as result of connecting tissues fragmentations and polymerization. The spectroscopic data were analogous with the lesions observed with SEM and hypermicroscopic images. Conclusions The present innovate molecular structure analysis showed that upon ascending aorta aneurysm development an excess of lipophilic aggregate formation and protein lesions, changing the elasticity of the aorta's wall. The released Ca2+ interacted mostly with carbonate-terminal of cellular protein chains accelerated the ascending aorta calcifications. Figure 1. FT-IR and Raman spectra Funding Acknowledgement Type of funding source: None


Author(s):  
K. Antonova ◽  
P. Byshewski ◽  
G. Zhizhin ◽  
J. Piechota ◽  
M. Marhevka

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
E. Zumelzu ◽  
M. J. Wehrhahn ◽  
F. Rull ◽  
H. Pesenti ◽  
O. Muñoz ◽  
...  

The material employed in this study is an ecoefficient, environmentally friendly, chromium (VI)-free (noncarcinogenic) metal polymer. The originality of the research lies in the study of the effect of new production procedures of salmon on metal packaging with multilayer polyethylene terephthalate (PET) polymer coatings. Our hypothesis states that the adhesion of postmortem salmon muscles to the PET polymer coating produces surface and structural changes that affect the functionality and limit the useful life of metal containers, compromising therefore their recycling capacity as ecomaterials. This work is focused on studying the effects of the biochemical changes of postmortem salmon on the PET coating and how muscle degradation favors adhesion to the container. The experimental design considered a series of laboratory tests of containers simulating the conditions of canned salmon, chemical and physical tests of food-contact canning to evaluate the adhesion, and characterization of changes in the multilayer PET polymer by electron microscopy, ATR, FT-IR, and Raman spectroscopy analyses. The analyses determined the effect of heat treatment of containers on the loss of freshness of canned fish and the increased adhesion to the container wall, and the limited capability of the urea treatment to remove salmon muscle from the container for recycling purposes.


2012 ◽  
Vol 626 ◽  
pp. 11-15
Author(s):  
Wan Ming Hua ◽  
Poh Sum Wong ◽  
Rosli Hussin ◽  
Zuhairi Ibrahim

This paper reported on the structural properties of Lithium-Barium borophosphate glasses. The glasses were prepared through melt quenching technique and studied in the compositional series which was 25Li2O:25BaO:(x)B2O3:(50-x)P2O5where 0x50 mol% .The aims of this work were to investigate the vibration mode about the local order around phosphorus tetrahedral structures and the boron coordination changed from trigonal to tetrahedral structures. Their basic properties were determined and their structure was studied by Fourier Transform Infrared (FT-IR) and Raman spectroscopy. Both spectroscopy analysis of the sample revealed vibration mode related to the characteristic phosphate bonds and borate bonds especially P-O-P, O-P-O ,P-O-B, BO3and BO4. Structural studies were devoted to the investigation of changes in boron coordination in the dependence on changes in B2O3or P2O5ratio in the borophosphate glasses. The decrease in the strength of the vibrations of the non-bridging PO2groups seems to indicate a progressive increase in the connectivity of the glass with increasing B2O3content. It was likely that this connectivity was due to the formation of P-O-B links at 890 cm-1, which replaced the vibration mode P-O-P. The increasing of B2O3content and decreasing the P2O5content causes the boron coordination changes from trigonal to tetrahedral and the basic units change from BO3to BO4. Overall, the high frequency bands corresponding to stretching vibration become broader, less distinct and overlap each other with an increasing B2O3content and decreasing P2O5content.


2014 ◽  
Vol 70 (7) ◽  
pp. 726-731 ◽  
Author(s):  
Alexander D. Burns ◽  
Brian O. Patrick ◽  
Anita E. Lam ◽  
David Dreisinger

Two new solid-state uranium(IV) sulfatex-hydrate complexes (wherexis the total number of coordinated plus solvent waters), namelycatena-poly[[pentaaquauranium(IV)]-di-μ-sulfato-κ4O:O′] monohydrate], {[U(SO4)2(H2O)5]·H2O}n, and hexaaquabis(sulfato-κ2O,O′)uranium(IV) dihydrate, [U(SO4)2(H2O)6]·2H2O, have been synthesized, structurally characterized by single-crystal X-ray diffraction and analyzed by vibrational (IR and Raman) spectroscopy. By comparing these structures with those of four other known uranium(IV) sulfatex-hydrates, the effect of additional coordinated water molecules on their structures has been elucidated. As the number of coordinated water molecules increases, the sulfate bonds are displaced, thus changing the binding mode of the sulfate ligands to the uranium centre. As a result, uranium(IV) sulfatex-hydrate changes from being fully crosslinked in three dimensions in the anhydrous compound, through sheet and chain linking in the tetra- and hexahydrates, to fully unlinked molecules in the octa- and nonahydrates. It can be concluded that coordinated waters play an important role in determining the structure and connectivity of UIVsulfate complexes.


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