Effect Of Rare Earth On Chemical Durability And Weathering Resistance Of ZnO-B₂O₃-SiO₂Glass

Borosilicate glass has developed rapidly in recent years, as a new glass material, borosilicate glass is widely used in photo-grey glasses, automotive glass, laser protection, window materials of spacecraft, new equipment switch, etc. with its high refractive, low dispersion, good chemical durability, weathering resistance and excellent optical properties. However，glass is vulnerable to external conditions in the using process that the surface gradually turns to be dim affecting the service life, thus improving the chemical durability and weathering resistance of glass is important problems in actual application.In view of the above problems, zinc borosilicate glass was chosen as the research object in this experiment, and zinc borosilicate glass doped with neodymium oxide, gadolinium oxide, yttrium oxide were prepared and then corroded in deionized water, acid, alkali solution and the atmosphere environment respectively. The scanning electron microscope (SEM) was used to observe the surface morphology after corrosion. The surface elements were analyzed by energy disperse spectrometer (EDS). Leaching of ions in the solution was tested by inductively coupled plasma emission spectrometer (ICP-AES). The ingredients of jelly in the acid were analyzed by XRD. The structure of the glass was analyzed by Fourier infrared spectroscopy (IR). Through the systemic research of zinc borosilicate glass doped with rare earth on the weathering resistance, chemical durability and the influence of the structure, the results show that:Humidity was the main environmental factor in weathering process of zinc borosilicate glass. The doping of rare earth can improve the weathering resistance of zinc borosilicate glass that yttrium oxide improves it the most obviously, and then it was gadolinium oxide, and neodymium oxide only had slight effect. Glass doped with1mol%Y2O3,0.75mol%Gd2O3showed the best weathering resistance. Zinc borosilicate glass doped with mixed yttrium oxide and gadolinium oxide had a better weathering resistance than glass doped with single rare earth oxide, and glass doped with0.5mol%Y2O3and0.5mol%Gd2O3had the best weathering resistance.Zinc borosilicate glass had the weakest acid resistance, the strongest water resistance, and the alkali resistance was between the middle. Doping rare earth oxide can improve the glass chemical durability, and the order is: Y2O3> Gd2O3> Nd2O3. The optimal doping amount was0.75mol%Gd2O3and1mol%Y2O3. The mix doping can improve glass chemical durability,0.5mol%Y2O3and0.5mol%Gd2O3mixed doped glass had the best chemical durability.It was found that part of the infrared absorption spectrum of zinc borosilicate glass doped with rare earth oxides moved to low wave number and the wave width got wider.This was mainly because the structure of B2O3changed in the glass that [BO3] structural unit partly transformed into [BO4] and the spatial structure of glass got compacted so the chemical stability of glass got enhanced.