Onutai Sujitra, Osugi Takeshi, Sone Tomoyuki
Nuclear Fuel Cycle Engineering Laboratories, Japan Atomic Energy Agency, 4-33 Muramatsu, Tokai-mura, Naka-gun, Ibaraki 319-1194, Japan.
Materials (Basel). 2023 Jan 20;16(3):985. doi: 10.3390/ma16030985.
Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy was used to demonstrate the reaction mechanisms of alkali-activated materials (AAMs) and the early stage of structure formation in the materials. The effects of different types of alkali activator solutions on the structure formation and reaction mechanisms of AAMs were studied. The results revealed that the main peaks of the ATR-FTIR spectra of the AAMs in the 1300-650 cm range shifted to a low wavenumber with changing patterns, depending on the activator solution used, indicating that the dissolution and reorientation of metakaolin had occurred. Silica and alumina monomers were dissolved by the NaOH solution to produce crystalline zeolites. Although the reaction between metakaolin and NaSiO solution is slow, the condensation between the Al-OH from metakaolin and the Si-OH from NaSiO solution bonded the chain to be longer. Therefore, the NaSiO solution acted as a template-bonded monomer, formed long chains of Si-O-Si and Si-O-Al, and produced an amorphous AAM structure. In the mixed solution, when the NaOH in it dissolved the Si and Al monomers, the NaSiO in the solution also bonded with monomers and produced a complex structure. The different reaction that metakaolin had with different alkali activator solutions reflected the different phases, microstructures, and mechanical properties of the AAMs produced.
衰减全反射傅里叶变换红外光谱（ATR-FTIR）用于揭示碱激发材料（AAMs）的反应机理以及材料结构形成的早期阶段。研究了不同类型的碱激发剂溶液对AAMs结构形成和反应机理的影响。结果表明，在1300-650 cm范围内，AAMs的ATR-FTIR光谱主峰随着所用激发剂溶液的不同而发生不同模式的低波数位移，这表明偏高岭土发生了溶解和重新取向。二氧化硅和氧化铝单体被氢氧化钠溶液溶解以生成结晶沸石。尽管偏高岭土与硅酸钠溶液之间的反应较慢，但偏高岭土中的Al-OH与硅酸钠溶液中的Si-OH之间的缩合使链变长。因此，硅酸钠溶液作为模板键合单体，形成了Si-O-Si和Si-O-Al长链，并产生了无定形的AAM结构。在混合溶液中，当其中的氢氧化钠溶解硅和铝单体时，溶液中的硅酸钠也与单体结合并产生复杂结构。偏高岭土与不同碱激发剂溶液发生的不同反应反映了所制备的AAMs的不同相、微观结构和力学性能。
