Nenadović Miloš, Knežević Sanja, Ivanović Marija, Nenadović Snežana, Kisić Danilo, Popović Maja, Potočnik Jelena
Department of Atomic Physic, Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, University of Belgrade, Mike Petrović Alasa 12-14, Vinča, 11000 Belgrade, Serbia.
Department of Materials, Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, University of Belgrade, Mike Petrović Alasa 12-14, Vinča, 11000 Belgrade, Serbia.
Gels. 2024 Jul 17;10(7):468. doi: 10.3390/gels10070468.
In this research, the influence of the thermal treatment of geopolymer gels at 300 °C, 600 °C and 900 °C when incorporated with 5% rare earth elements (REEs) in the form of (GP-Sm) SmO and (GP-Nd) NdO was investigated. Changes in the chemical and structural properties of the geopolymer gels during thermal treatment for 1 h were monitored. Physico-chemical characterization was performed using the following methods: diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), scanning electron microscopy with energy dispersive spectrometry (SEM-EDS), and X-ray photoelectron spectroscopy (XPS). Besides the characterization of the fundamental properties, some practical macroscopic properties were analyzed as well: sorptivity, open porosity, and Archimedean density. The stretching vibrations of Nd-O-Si and Sm-O-Si were confirmed at a value of around 680 cmand an Nd-O-Si absorption band at a higher value, together with the most dominant band of Si-O stretching vibration similar for all the samples. No significant chemical changes occurred. Structural analysis showed that for GP-Nd, the largest pore diameter was obtained at 900 °C, while for GP-Sm, the largest pore diameter was obtained at 600 °C. EDS confirmed the amount of dopant to be about 5%. X-ray photoelectron spectroscopy showed that for GP-Nd, the ratio of Si and Al changed the most, while for GP-Sm, the ratio of Si and Al decreased with increasing temperature. The contributions of both dopants in the GP-gel structure remained almost unchanged and stable at high temperatures. The atomic percentages obtained by XPS analysis were in accordance with the expected trend; the amount of Si increased with the temperature, while the amount of Al decreased with increasing temperature. The sorptivity and open porosity showed the highest values at 600 °C, while the density of both geopolymers decreased linearly with increasing temperature.
在本研究中，研究了在以（GP-Sm）SmO和（GP-Nd）NdO形式掺入5%稀土元素（REEs）时，地聚合物凝胶在300℃、600℃和900℃下进行热处理的影响。监测了地聚合物凝胶在1小时热处理过程中化学和结构性质的变化。使用以下方法进行物理化学表征：漫反射红外傅里叶变换光谱（DRIFTS）、带能谱的扫描电子显微镜（SEM-EDS）和X射线光电子能谱（XPS）。除了对基本性质进行表征外，还分析了一些实际的宏观性质：吸水性、开孔率和阿基米德密度。Nd-O-Si和Sm-O-Si的伸缩振动在约680 cm处得到证实，Nd-O-Si吸收带出现在更高的值处，同时所有样品的Si-O伸缩振动的最主要谱带相似。未发生显著的化学变化。结构分析表明，对于GP-Nd，在900℃时获得最大孔径，而对于GP-Sm，在600℃时获得最大孔径。EDS证实掺杂剂的量约为5%。X射线光电子能谱表明，对于GP-Nd，Si和Al的比例变化最大，而对于GP-Sm，Si和Al的比例随温度升高而降低。两种掺杂剂在地聚合物凝胶结构中的贡献在高温下几乎保持不变且稳定。通过XPS分析获得的原子百分比符合预期趋势；Si的量随温度增加，而Al的量随温度升高而降低。吸水性和开孔率在600℃时显示出最高值，而两种地聚合物的密度均随温度升高呈线性下降。
