Modeling the Structure of Complex Aluminosilicate Glasses: The Effect of Zinc Addition

Abstract

An empirical potential structure refinement of neutron and X-ray diffraction data combined with extended absorption fine structure evidence has been applied to the investigation of two distinct sets of complex aluminosilicate glasses containing different quantities of zinc. Data come from (i) neutron and X-ray total scattering experiments, which have been performed at the ISIS neutron spallation source (SANDALS beamline) and at the European Synchrotron Radiation Facility (ID11 beamline), and (ii) EXAFS experiments which have been performed at the European Synchrotron Radiation Facility (BM23 beamline). By careful examination of the modeled ensemble of atoms, a wide range of structural information has been extracted: coordination numbers, bond distances, cluster sizes, type of oxygen sharing, and the preference of large cations to adopt a charge-compensating role. The first series of glasses, which is characterized by a fixed network modifier element content (i.e., Na), shows how the introduction of Zn at the expense of Si and Al network forming elements does not significantly alter the polymerization degree, as a result of its dominant 4-fold coordination. In the case of the second series, which is characterized by fixed network forming element content (i.e., Si and Al), it is shown how the replacement of a network modifier element (i.e., Ca) with the introduction of Zn does not change the propensity of Zn to be mainly 4-fold coordinated by promoting the network. Where appropriate the experimental results have been compared with classical theoretical approaches such as stoichiometric models based on Zachariasen's rules and computational routines.

Comprehensive Study on Elastic Moduli Prediction and Correlation of Glass and Glass Ceramic Derived from Waste Rice Husk

“…Decrease in and of the samples is due to rise in amount of ZnO present in the samples which contains Zn 2+ ions where its zinc atom had higher atomic radius compared to Si atom therefore encouraging the transformation of BOs to NBOs in the system. Based on SiO 2 gradually reduced to 3 from 4 as the values of ZnO rise and this causes the structural units of SiO 4 to be converted to SiO 3 initiating the rise of NBOs [24][25][26]. Decrease in both and with the rise of ZnO also indicates that the ultrasonic wave encounters more resistance in the ZnO-SiO 2 samples as the amount of ZnO increases [27,28].…”

Multivalent network modifier upregulates bioactivity of multispecies biofilm-resistant polyalkenoate cement

“…While Al 3+ is a network intermediate, Zn 2+ is predominantly a network former with only a mild network modifying action. Thus, with its strong 4-fold coordination, Zn 2+ favors a more robust BO network, which resists interfacial exchange of inducerons and subsequently limits bioactivity [ 15 ].…”