Effects of composition on the durability and weathering of flat glass

Abstract

Among the environmental factors affecting glass weathering are humidity, exposure time, temperature, and the presence of pollutants in the atmosphere. Notwithstanding that the weathering produced depends on numerous factors, the important weathering effect of high humidity may be specifically mitigated by using a good chemical composition for the glass. To evaluate this relationship, flat glass samples from three suppliers were studied. The chemical composition of the samples was determined and the variability in compositions was evaluated to verify to what extent these small differences can affect their chemical durability. The chemical durability of the samples was evaluated by determining the hydrolytic resistance of crushed glass powder and using a visual appearance evaluation of bulk samples. The results demonstrate that when the samples are frequently washed, the compositional differences found between the suppliers can cause a significant difference in durability. The samples possessing the highest molar concentrations of Al 2 O 3 , and alkaline earth oxides (MgO + CaO) exhibited the highest

Identification of the ancient glass analysis based on the logistics model and the SVM

“…Lead-barium glass developed from Chinese Chu culture has added lead ore as a flux in the firing process, and the content of lead oxide (PbO) and barium oxide (BaO) is relatively high [8,13]. Potassium glass is made of high potassium content substances such as plant ash as a flux, which is mainly popular in the south of China, Lingnan, Southeast Asia, India and other regions [2,4,11]. Glass can be divided into high-potassium glass and lead-barium glass [3,9].…”

Structural studies in aluminophosphosilicate glasses and in cold-pressurized borosilicate glasses by Nuclear Magnetic Resonance in the solid state

“…The addition of sodium in the system conspicuously affects the coefficient of thermal expansion by depolymerizing the network. 18,21,22 29 shows the coefficient of thermal expansion (in blue) increases as a function of the increase in sodium oxide concentration. This result is expected and represents the network being globally depolymerized by sodium ions.…”

“…38,[129][130][131] Some studies also indicate that chemical durability is affected not only by the chemical composition but also by the proportion of linkages that are susceptible to hydrolysis. 22,131,132 For instance, wellestablished studies showed that the addition of alumina to phosphate glasses can strengthen their chemical durability due to the formation of Al-O-P linkages. [33][34][35][36] Additionally, the weathering of a glass is commonly initiated by the interaction of network modifiers, such as Na + ion, with neutral water from the atmosphere.…”

“…The reactions of the Na + cation with H2O trigger the glass deterioration process. 22,130 Therefore, it is hypothesized that the observed non-linear trend might correlate with non-linear trends in the network connectivity and/or the local environment of the sodium ions.…”

“…The addition of sodium in the system can deeply affect properties as the coefficient of thermal expansion by depolymerizing the network and/or as hydrolytic stability by changing the dissolution rate. 16,18,[21][22][23][24] All these changes shed light on which kind of bond connections, in the network, would reflect the macroscopic and thermodynamic properties.…”