Structural investigation of V2O5–P2O5–K2O glass system with antibacterial potential

Abstract

The xV 2 O(1 − x)[0.8 P 2 O 5 • 0.2 K 2 O] glass system with 0 ≤ x ≤ 50 mol% was prepared and the structural changes induced in these glasses by increasing the vanadium oxide content were investigated by IR and ESR spectroscopies. The dual behaviour role of V 2 O 5 oxide, as network modifier (for x ≤ 10 mol%) and the network former (x ≥ 20 mol%), as a consequence of phosphate network depolymerization and P-O-V and V-O-V linkages appearance was also highlighted. The antibacterial effect of the glasses with x ≤ 20 mol% V 2 O 5 content was tested by optical density (OD) measurements. A linear correlation between the amount of vanadium and the antibacterial effect was evidenced.

Structural changes in V2O5-P2O5 glasses: non-constant force field molecular dynamics and IR spectroscopy

“…Increasing the intensity of this peak indicates the growth of connectivity of the phosphate network and the possible formation of this network with inclusions of vanadiumoxygen clusters. This suggestion is indirectly confirmed by the constancy of the peak near 980-990 cm -1 , whose appearance points up the existence of vanadium-oxygen clusters in the glass network [31].…”

“…As V 2 O 5 content grows, a redistribution of intensity is observed between the wavelength ranges of 400-650 and 850-1010 cm -1 . For the middle of the spectra (650-850 cm -1 ), no strong correlation between the glass composition and peak intensity is observed; however, its shape depends on the glass composition: when V , as well as various vibrations of phosphate glass network, for example, vibrations of O-P-O and O=P-O bonds [29][30][31]. Considering that the intensity of this peak increases as P 2 O 5 content grows, the main contribution might be assigned to the vibrations of PO 2 structural units [24,31].…”

“…, a gradual degeneration of the most intense peak is observed, and it shifts towards lower wavelengths (from 757 to 742 cm -1 for V 2 O 5 content of 95 and 75 mol %, respectively). The following vibrations can be excited in this spectrum area: stretching vibrations of P-O-P [24,31] and V-O-P [32] bonds and the vibrations of the vanadium-oxygen network such as asymmetric stretching vibrations of VO 2 groups in VO 4 tetrahedra [30,33]. Since the vibrations of phosphate and vanadate networks in this area are overlapped, it is complicated to unambiguously relate the peaks obtained by spectra deconvolution.…”

In Vitro Studies Demonstrate Antitumor Activity of Vanadium Ions from a CaO-P2O5-CaF2:V2O5 Glass System in Human Cancer Cell Lines A375, A2780, and Caco-2

“…For the glass system investigated in the present study, as shown in Figure 5 A,B, EPR spectra show a well-resolved hfs (hyperfine structure) for 0.25 ≤ x ≤ 4 mol %, with a structure based on 16 lines (8 in the parallel and 8 in the perpendicular band) attributed to the interaction of a 3d 1 spin electron with 51 V nuclear spin (I = 7/2). The spectral was generated based on a spin Hamiltonian appropriate for these spectra previously reported in [ 52 , 53 , 54 , 55 ]. EPR Hamiltonian parameters, MO coefficients, the Fermi contact coefficient ( K ), and the dipolar hyperfine coupling parameter (P) were calculated using the LCAO-MO model developed by Kivelson and Lee [ 56 ] for vanadyl ions.…”

Electrical Conductivity Enhancement of V2O5-P2O5-Bi2O3 Glasses by Nanocrystallization

“…10 In view of the fact that borophosphate glasses are known to be chemically more durable than pure phosphate and borate glasses they have attractive applications. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] In the present study, considering that V 2 O 5 is a glass network former, by using x-ray diffraction (XRD) and electrical properties of 60V 2 O 5 -xP 2 O 5 -(40-x) Bi 2 O 3 glasses and glass-ceramic nanocrystals were studied in the temperature range 300-500 K, these types of glasses and glass-ceramic nanocrystals have different applications.…”