The influence of alkali cations on mix design of geopolymers is essential for their mechanical, thermal, and electrical performance. This research investigated the influence of alkali cation type on microscale characteristics and mechanical, dielectric, and thermal properties of fly ash-based geopolymer matrices. The geopolymers were elaborated via class F fly ash from the thermal plant Jorf Lasfar, El Jadida (Morocco), and several alkaline solutions. Morphological, structural, mechanical, dielectric, and thermal characteristics of materials synthesized via fly ash with different proportions of KOH and NaOH aged 28 days were evaluated. The physicochemical properties of class F fly ash-based geopolymers were assessed using X-ray diffraction (XRD), Fourier-transform infrared spectrometry (FTIR), and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDX) analyses. Based on readings of the results obtained, XRD and FTIR analysis detected the creation of semicrystalline potassium/sodium aluminate-silicate hydrate (KASH/NASH) gel in the elaborated matrices after the geopolymerization reaction. The SEM analysis proved the formation of alkali alumina-silicate hydrate gel in the raw material particles after the polycondensation stage. Experimental compressive strength data indicated that the highest compressive strength (39 MPa) was produced by the alkaline activator (75% KOH/25% NaOH). The dielectric parameters values of the elaborated materials changed depending of the mass ratios KOH/NaOH. Dielectric findings demonstrated that geopolymers containing 100% NaOH have better dielectric performances. The fire resistance study revealed that the geopolymer binders induced by KOH are stable up to 600°C. Based on these results, it can be deduced that the formulated geopolymer concrete possesses good mechanical, dielectric, and fire resistance properties.

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碱性活化剂的性质和用量对粉煤灰基高分子聚合物理化性质的影响

碱阳离子对地质聚合物混合设计的影响对其机械，热和电性能至关重要。这项研究调查了碱性阳离子类型对粉煤灰基地质聚合物基体的微观特征以及机械，介电和热学性能的影响。地热聚合物是通过热电厂Jorf Lasfar，El Jadida（摩洛哥）的F级粉煤灰和几种碱性溶液制成的。评估了粉煤灰在28天后使用不​​同比例的KOH和NaOH合成的材料的形态，结构，机械，介电和热特性。使用X射线衍射（XRD），傅里叶变换红外光谱（FTIR），F级粉煤灰基地质聚合物的理化性质进行了评估，扫描电子显微镜和能量色散X射线光谱（SEM / EDX）分析。根据获得的结果的读数，XRD和FTIR分析检测到地聚反应后，在精细基质中形成了半结晶钾/铝酸钠-硅酸盐水合物（KASH / NASH）凝胶。SEM分析证明了缩聚阶段后在原料颗粒中形成了碱金属铝硅酸盐水合物凝胶。实验抗压强度数据表明，碱性活化剂（75％KOH / 25％NaOH）产生最高抗压强度（39 MPa）。精制材料的介电参数值根据质量比KOH / NaOH的不同而变化。介电结果表明，含100％NaOH的地质聚合物具有更好的介电性能。耐火性研究表明，由KOH诱导的地聚合物粘合剂在高达600°C的温度下都是稳定的。根据这些结果，可以推断出配制的地质聚合物混凝土具有良好的机械，介电和耐火性能。