Mixed Alkali-zinc Effects on Thermo-mechanical Properties in Borosilicate Glasses

A series of mixed alkali-zinc borosilicate glasses with various r values(r=molar ratio of[ZnO]/([R^(2)O]+[ZnO]))from 0.00 to 1.00 were fabricated to probe the mixed alkali-zinc effects on thermo-mechanical properties.The nonlinear evolution of glass transition temperature(T_(g))with the addition of ZnO is ascribed to the competition of two converse factors,i e,the T_(g)depression as one of the colligative properties for a solution,on the one hand,and the enhancement of T_(g)due to the higher field strength of zinc cations compared to that of alkali ions.However,the nonlinear evolution of elastic moduli and coefficients of thermal expansion with r is attributed to the variance of intermediate-range clusters,which is confirmed by infrared and Raman scattering spectra.These findings are very helpful in tailoring the performance of borosilicate glasses.

Mixed-Alkali Effect on Thermal Property and Elastic Behavior in Borosilicate Glasses

We investigated the mixed alkali effect on the thermal properties and elastic response to temperature in the borosilicate glasses system with the composition of 70.65Si O_(2)·21.09B_(2)O_(3)·1.88Al_(2)O_(3)·(6.38-x)Li_(2)O·x Na_(2)O glasses,where x=0.00,1.595,3.19,4.785,and 6.38.Except for the expected positive and negative deviations from linearity for the coefficients of thermal expansion,room temperature E and G,we observed a new mixed alkali efiect on the response of elastic moduli to temperature.Fourier transform infrared spectra were obtained to elucidate the possible structural origin of the mixed alkali efiects.This work provides a valuable insight into the structural and mechanical properties of mixed-alkali borosilicate glasses.

Preparation and Optical Properties of Er^(3+)-Doped Gadolinium Borosilicate Glasses

Er^(3+)-doped Gd_2O_3 -SiO_2 -B_2O_3 -Na_2O glasses were prepared, and formation range of glass of Gd_2O_3 -SiO_2 -B_2O_3 system was experimentally obtained. It is found that the glass phase can be formed only when the content of SiO_2 is 0～50%(molar fraction), Gd_2O_3 is 0～30%(molar fraction) and B_2O_3 is above 20%(molar fraction) in this glass system. The glass can also be obtained but becomes translucent at the contents of 60%(molar fraction) SiO_2 and 30% Gd_2O_3 , or at the contents of 60%(molar fraction) SiO_2 and 30%(molar fraction) B_2O_3. There is no glass phase formed in other glass components. Glass forming ability for Gd_2O_3 content of 10%, was characterized by the value of β, the parameter of crystallization tendency, which is 0.32～1.76, obtained from the differential thermal analysis. The absorption and emission cross section, the J-O parameters Ωt_((2,4,6)) and radiative transition probabilities were calculated by using the theory of McCumber and Judd-Ofelt. The emission properties at 1.5 μm of the samples are discussed with the product of full width at half maximum and stimulated emission cross section. It can be seen that the value of the FWHM×σ_e^(peak) product in the prepared glass is more than those of germanate, silicate and phosphate glasses. Furthermore, the maximum value of the product among these glasses reported in this work is close to that of oxyfluoride silicate glass. Therefore, the Er^(3+)-doped gadolinium borosilicate glass in this paper is a candidate for broadband erbium doped fiber amplifiers.

Effects of SnO on Structure and Propertiesof Borosilicate Glasses

Tin was found in the bottom of float borosilicate glasses. To simulate the enriched amounts of SnO found on the surface of the float borosilicate glasses, a series of glasses were produced in which the stannous concentration was varied from 0.1 wt% to 9.0 wt%, while the relative concentration of other components were held constant. Infrared spectra were obtained to probe the effect of increased amounts of SnO on the structure of the glass samples. The results show that SnO plays the role of an intermediate in glasses studied. When FO/SnO〉1.0, SnO takes the role of network-former. And when FO/SnO〈1.0, SnO can give the free oxygen as network-modifier. Besides, SnO has intensive effect on thermal performance of borosilicate glasses.

Up-conversion photoluminescence characteristics of Yb^(3+):Er^(3+):Tm^(3+) co-doped borosilicate glasses

Yb^3＋：Er^3＋：Tm^3＋co-doped borosilicate glasses are prepared. Their strong up-conversion photoluminescence spectra in a range from ultra-violet to near-infrared, which are excited by a 978-nm laser diode, are measured, and the mechanisms of energy transfer among Yb^3＋ Er^3＋ and Tm^3＋ ions are discussed. The results show that there is an unexpected wavelength at 900-nm emission from Yb^3＋ Stark splitting levels to pump Tm^3＋ ions and there exists an optimum pump power. The concentration of the Tm^3＋ dopant gives rise to a prominent effect on the intensity of visible and near-infrared emissions for the yb^3＋：Er^3＋：Tm^3＋ co-doped borosilicate glasses.

Morphological and Structural Investigations on Iron Borosilicate Glasses

Borosilicate glasses and glass ceramics in the system 30Na2O-2Al2O3-25SiO2-xFe2O3(43-x)B2O3 (x = 0 - 20 mol%) have been prepared and studied by distinguished techniques. X-ray diffraction (XRD), transmission electron microscope (TEM), electron diffraction pattern (EDP) and SEM experiments are applied to explore the induced structural changes. Nanometer-sized species of polycrystalline structure are formed particularly in low Fe2O3 containing glasses. The size of the crystallites is found to depend on Fe2O3 concentrations. It is ranged from 10 to 33 nanometers. Structurally, these materials are suggested to contain different components, crystalline component and an interfacial component which situated between the crystallized domains. Presence of these components affects the atomic arrangement without short- or long-range order. An intermediate range ordered structure is dominant in glass ceramics of Fe2O3 2O3 concentration, since more disordered structure of lower size is present. These structural changes are found to be connected with the role of Fe2O3 and Na2O in glasses. Na2O is the strong glass modifier in the studied composition region, while Fe2O3 is consumed also as a modifier in composition of 2O3 is mainly dominant in the composition region of higher iron oxide concentration (8 - 20 mol%).

Mechanism of Cluster Formation on Cerium Borosilicate Glasses Based on TEM-EDP and SEM-EDEX Investigations

Cerium oxide has a great capacity to remove nonbridging oxygen atoms (NBO) from the glass network and serves as glass former units. The well formed CeO4 units played the role of decreasing NBO from the silicate network and cause a reduction in the concentration of tetrahedral boron groups (N4). The highest content of NBO in glass of lower CeO2 (1 mol%) has a dominant role in constructing crystalline clusters in the glass. Higher CeO2 concentration leads to formation of an amorphous glass network as documented by XRD and TEM-EDP spectra. Coordination of cerium with oxygen atoms gives uniform units of spherical morphology in the pure CeO2 as well as in cerium rich glass. Clustered species has a great benefit in the field of application, used as a shielding material for ionized radiations.

Nuclear Magnetic Resonance and FTIR Structural Studies on Borosilicate Glasses Containing Iron Oxide

The structure of borosilicate glasses of composition 30Na2O-2Al2O3-25SiO2-xFe2O3 (43-x) B2O3 has been investigated in the composition range of 0.5 20 mol% Fe2O3. 27Al, 11B, 29 Si MAS NMR and FTIR spectroscopies have been used to measure the fraction of different structural species in the glasses. It is evidenced from NMR data that both sodium and Fe2O3 (in low region up to 7 mol%) are the main glass modifier. Structural determination for borosilicate glasses with a high content of (Fe2O3) was carried out by FTIR spectroscopy, where both 11B and 29Si MAS NMR are impossible because of the high quantities of paramagnetic iron (III) species present. NMR analysis was performed on borosilicate glasses containing up to 7 mol% Fe2O3 and the N4 values obtained by FTIR spectroscopy agree within error with the 11B NMR results of the same glass samples. Fe2O3 is a main glass modifier in the low-Fe2O3-content region (≤6 mol%). On other hand, it plays the role of glass former at higher content of Fe2O3. Increasing both N4 of boron tetrahedral units and chemical shift of silicon nuclei to reach maxima at 5 mol% Fe2O3 confirms the role of Fe2O3 as a glass modifier in the low composition region. On the other hand, fast decrease in N4 with further increasing Fe2O3 contents ≥6 mol%) is an evidence for iron oxide to inter the glass network as a network former.

Visible to deep ultraviolet range optical absorption of electron irradiated borosilicate glass

To study the room-temperature stable defects induced by electron irradiation, commercial borosilicate glasses were irradiated by 1.2 MeV electrons and then ultraviolet（UV） optical absorption（OA） spectra were measured. Two characteristic bands were revealed before irradiation, and they were attributed to silicon dangling bond（E＇-center） and Fe^3＋species,respectively. The existence of Fe3＋was confirmed by electron paramagnetic resonance（EPR） measurements. After irradiation, the absorption spectra revealed irradiation-induced changes, while the content of E＇-center did not change in the deep ultraviolet（DUV） region. The slightly reduced OA spectra at 4.9 eV was supposed to transform Fe3＋species to Fe^2＋species and this transformation leads to the appearance of 4.3 eV OA band. By calculating intensity variation, the transformation of Fe was estimated to be about 5% and the optical absorption cross section of Fe2＋species is calculated to be 2.2 times larger than that of Fe^3＋species. Peroxy linkage（POL, ≡Si–O–O–Si≡）, which results in a 3.7 eV OA band, is speculated not to be from Si–O bond break but from Si–O–B bond, Si–O–Al bond, or Si–O–Na bond break. The co-presence defect with POL is probably responsible for 2.9-eV OA band.

The Coordination State of B and Al of Borosilicate Glass by IR Spectra

The IR spectra of R2O-RO-B2O3-SiO2 and R2O-RO-B2O3-Al2O3-SiO2 glasses were tested for the study of coordination state of B, Al and their content. The results show that no matter Na2O/B2O3〉1, =1, or〈1, both [BO3] and destroyed Si-O bond exist in glass structure; the addition of Al2O3 to borosilicate glass reduced both the number of non-bridging oxygen in the silicate network and the number of [BO4] units.

Effect of SiO_2/B_2O_3 Ratio on the Property of Borosilicate Glass Applied in Parabolic Trough Solar Power Plant

This work aimed to analyze the glass material used for sealing the end of a thermal collector in a parabolic trough solar power plant. Based on matched sealing requirements and application performance of glass and Kovar alloy 4J29, one borosilicate glass material （GD480S）, whose expansion coefficient was similar to that of Kovar alloy 4J29, was studied. Moreover, the effect of the ratio of SiO2 to B203 on the glass properties was explored in detail by Fourier transform infrared spectroscopy. As the SiO2 to B203 ratio in the glass increased from 4.18 to 5.77, the expansion coefficient showed a decreasing trend from 4.95×10-6/℃ to 4.55℃ 10-6/℃. In addition, the water resistance performance improved, enabling the glass material to seal well with the alloy for application in a trough solar power plant. Thus, the increase in the SiO2 to B2O3 ratio made the glass structure more compact and improved the glass performance to meet the requirements of an industrial tubular receiver.

The Effect of Sm_2O_3 on the Chemical Stability of Borosilicate Glass and Glass Ceramics

Sm2O3 containing zinc-borosilicate glass and glass ceramics were prepared by melt quenching method, and the effect of Sm2O3 and micro-crystallization on the chemical stability of borosilicate glass was explored. DTA analysis showed that the endothermic peak and exothermic peak of basic glass changed from 635 ℃ and 834 ℃ to 630 ℃ and 828 ℃ respectively as a result of the doping of Sm2O3. XRD analysis showed the promoting effect of Sm2O3 on crystallization ability of this glass. The cumulative mass loss of base glass, Sm2O3 containing glass, glass ceramic and Sm2O3 containing glass ceramic was 0.289, 0.253, 0.329, 0.269 mg/mm2 respectively after 26 days corrosion in alkali solution, and 1.293, 1.290, 0.999, 1.040 mg/mm2 respectively in acidic erosion medium. Micro-crystallization decreased and improved the alkali and acid resistance of borosilicate glass respectively, the addition of Sm2O3 increased the alkali resistance of base glass and glass ceramics, and the slight effect of Sm2O3 on the acid resistance of borosilicate glass was also observed.

Thermal Analysis and Immobilisation of Spent Ion Exchange Resin in Borosilicate Glass

The underground disposal of waste arising from the nuclear industry needs constant evaluation in order to improve upon it through minimizing the volume and cost by reducing the amount of glass used without compromising the safety of any leakage from the radioactive waste form. The immobilization of the spent resin (NRW-40) in borosilicate glass was investigated to meet the acceptance criteria for disposal of nuclear waste. The organic mixed bed resin in granular form was used as a waste target. The analysis of surrogate resin doped with radioactive and non-radioactive cesium (Cs) and cobalt (Co) was carried out to investigate their thermal and chemical properties and their compatibility with an alkaline borosilicate glass. The thermal analysis indicates that the structural damage caused by 1 mSv gamma radiation to the radioactive resin has altered its properties in comparison with the non-radioactive resin, same amount of cesium (8.88 wt%) and cobalt (1.88 wt%) were used in both resins. The immobilization of residue shows that the excess sulfur in the residue caused phase crystallization in the final glass matrix. It was found that the volatilization of Cs-137 and Co-60 from the successful radioactive resin-glass matrix (HG-3-IER-500) were more than that in the non-radioactive resin-glass matrix (HG-3-IEX-500). The study demonstrates comprehensive experimental and analytical works and shows that it is possible to minimise the volume of the waste while keeping the required safety levels, however further research needs to be carried out in this area.

Effects of energy deposition on mechanical properties of sodium borosilicate glass irradiated by three heavy ions: P, Kr, and Xe

Sodium borosilicate glasses are candidate materials for high-level radioactive waste vitrification;therefore, understanding the irradiation effects in model borosilicate glass is crucial. Effects of electronic energy deposition and nuclear energy deposition induced by the impact of heavy ions on the hardness and Young’s modulus of sodium borosilicate glass were investigated. The work concentrates on sodium borosilicate glasses, henceforth termed NBS1 (60.0% SiO2, 15.0% B2O3, and 25.0% Na2O in mol%). The NBS1 glasses were irradiated by P, Kr, and Xe ions with 0.3 MeV, 4 MeV, and 5 MeV, respectively. The hardness and Young’s modulus of ion-irradiated NBS1 glasses were measured by nanoindentation tests. The relationships between the evolution of the hardness, the change in the Young’s modulus of the NBS1 glasses, and the energy deposition were investigated. With the increase in the nuclear energy deposition, both the hardness and Young’s modulus of NBS1 glasses dropped exponentially and then saturated. Regardless of the ion species, the nuclear energy depositions required for the saturation of hardness and Young’s modulus were apparent at approximately 1.2 × 10^20 keV/cm^3 and 1.8 × 10^20 keV/cm^3, respectively. The dose dependency of the hardness and Young’s modulus of NBS1 glasses was consistent with previous studies by Peuget et al. Moreover, the electronic energy loss is less than 4 keV/nm, and the electronic energy deposition is less than 3.0 × 10^22 keV/cm^3 in this work. Therefore, the evolution of hardness and Young’s modulus could have been primarily induced by nuclear energy deposition.

Studies of Preparation and Characteristics in Borosilicate Photosensitive Glass-Ceramics

Photosensitive glass-ceramics have been extensively studied in recent years in that it is an attractive high diffraction efficiency grating materials. It is based on Stookey’s mixed fluoride sodium glass system for us to adopt, design prescriptions on the basis of SiO2-Na2O-Al2O3-ZnO for the glass main component and a series of glass doped with CeO2, AgNO3 and NaF etc. melted at about 1450?C, and the glass have good optical property (homogeneity, without bubble and stripe, high transparency). The borosilicate glass was exposed by ultraviolet light, and then after the heat treatment of the sample, the measurement of ultraviolet-visible-near infrared absorption spectrum and the X ray diffraction of exposure part was performed.

Utilisation of Borosilicate Glass Waste as a Micro-Filler for Concrete

Glass from a light bulb is a waste product that cannot be utilised in a traditional way. This study looks into the possibilities of using lamp borosilicate glass powder as a cement replacing admixture in conventional concrete. Experimental work provides preparation of standard concrete samples and sample testing after seven and 28-day ageing periods in standard conditions. The following glass materials were used for cement replacement： rough ground glass powder, glass dust from filters （both materials were obtained from a glass treatment plant） and additionally ground glass powder. The effect of glass powder on cement setting time was studied. The experimental results indicate that replacement of cement by rough glass powder decreases the compressive strength. Fine glass particles make it possible to replace up to 20% of cement without the loss in strength characteristics. Fine glass powder offers a long-term hardening effect. The best compressive strength results were achieved by using the glass that was additionally ground for 60 minutes. Glass dust obtained from filters shows a less significant effect. Summarising the research findings it may be concluded that ground borosilicate lamp glass may be successfully applied as a micro-filler for concrete as cement replacing material.

Color-converted remote phosphor prototype of a multiwavelength excitable borosilicate glass for white light-emitting diodes

We report a unique red light-emitting Eu-doped borosilicate glass to convert color for warm white light-emitting diodes. This glass can be excited from 394 nm-peaked near ultraviolet light, 466 nm-peaked blue light, to 534 nm- peaked green light to emit the desired red light with an excellent transmission in the wavelength range of 400-700 nm which makes this glass suitable for color conversion without a great cost of luminous power loss. In particular, when assembling this glass for commercial white light-emitting diodes, the tested results show that the color rendering index is improved to 84 with a loss of luminous power by 12 percent at average, making this variety of glass promising for inorganic ＂remote-phosphor＂ color conversion.

药用棕色中硼硅玻璃安瓿与吸入用盐酸氨溴索溶液的相容性研究

目的考察药用棕色中硼硅玻璃安瓿与吸入用盐酸氨溴索溶液的相容性。方法采用SEM、ICP-MS等方法,通过模拟试验及迁移试验研究药物与包装材料的相互作用,并根据毒理学研究资料评价相容性。结果经加速稳定性试验放置6个月后,测得盐酸氨溴索溶液中Si、B等7种元素含量可见大于40%的上升率,但未超过每日最大允许摄入量,玻璃安瓿表面的侵蚀圆斑随加速放置时间延长而有所增多或增大;经长期稳定性试验放置24个月后,盐酸氨溴索溶液中元素含量、玻璃安瓿表面均未见明显变化。结论加速稳定性试验提示药用棕色中硼硅玻璃安瓿与盐酸氨溴索溶液间存在相互作用的趋势,提示本品有效期应尽量缩短,并密切关注相互作用情况。

硼硅酸盐生物活性玻璃的矿化及机理初探

目的探讨硼硅酸盐生物活性玻璃体外矿化成类骨层状结构的机理。方法模拟体内环境,将硅酸盐玻璃(0B)、硼硅酸盐玻璃(2B)和硼酸盐玻璃(3B)浸泡于SBF溶液和含有明胶的SBF溶液中1周;随后采用质量损失分析、SEM、EDS、XRD及FTIR等测试方法对多种生物活性玻璃的矿化产物进行系统分析与比较;采用固体核磁NMR对生物玻璃进行玻璃结构分析。结果浸泡1周后,SEM观察到硼硅酸盐玻璃(2B)和不含硅的硼酸盐玻璃(3B)表面产生层状矿化产物,而硅酸盐玻璃(0B)表面只有一层矿化产物层;XRD和FTIR结果显示3种玻璃的表面产物均为含有部分羟基磷灰石的钙磷化合物;固体核磁波谱(11B)测试结果表明硼硅酸盐玻璃(2B)和不含硅的硼酸盐玻璃(3B)都存在大量[BO_(3)]平面三角体。最后,当硼硅酸盐玻璃(2B)浸泡在含有明胶的SBF溶液后,其矿化产物仍能维持层状结构;通过EDS分析可知形成明胶有机层和含羟基磷灰石的无机层相互堆积的特殊层状结构。结论2B和3B玻璃内部存在大量[BO_(3)]平面三角体所构造的二维平面结构。矿化过程中,不溶性反应物沉积在二维平面结构上,从而使矿化产物呈现层状结构。在浸泡液中添加一定量的明胶后,其可以有效地与硼硅酸盐玻璃的层状矿化结构相互匹配结合,最终堆叠形成有机相层与无机层相互交错的特殊结构。