Scholarlink

<p>The utilization of carbon-based additives, generated from waste managed materials, to synthesize fly ash (FA)-based geopolymers with enhanced mechanical and electrical properties offers benefits in environmental protection and waste reduction. This study focused on preparing FA-based geopolymers at ambient conditions through alkali activation with a combination of NaOH-activated quartz (AQ) and water glass (Na<sub>2</sub>SiO<sub>3</sub> solution). The weight ratio of FA:AQ in the FA/AQ geopolymer was kept at 1:1 (wt:wt). Carbon-based additives, including carbon fibers (CFs) and thermally stabilized microcrystalline cellulose (SMCC), were separately mixed to FA/AQ geopolymer paste in two proportions (1% and 3% wt/wt) relative to FA. The formulated geopolymers were analyzed physically using Fourier transform infrared spectroscopy (FTIR), UV/Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and EDX. SEM analysis reveals the presence of voids and cavities in the neat FA geopolymer. However, integrating AQ into the FA-based geopolymer leads to significant matrix densification and reduced porosity, restricting ion mobility, resulting in high mechanical strength, and low electrical conductivity. Additionally, the enhanced compatibility of a higher percentage of CFs and SMCC (CFs(3%)@FA/AQ and SMCC(3%)@FA/AQ) with the geopolymer matrix forms dense, amorphous sodium aluminum silicate hydrate (N-A-S–H) links. This is confirmed by the increased compressive strength (11.1&#xa0;MPa and 18.1&#xa0;MPa) and higher intensities of SMCC’s XRD patterns. SMCC(3%)@FA/AQ demonstrates the lowest electric and dielectric properties (σ = 1.4 × 10<sup>–7</sup> S/cm and ε′ = 7 × 10<sup>4</sup>), indicating superior insulating properties. In contrast, the CFs(3%)@FA geopolymer matrix exhibits higher values (σ = 4.4 × 10<sup>–6</sup> S/cm and ε′ = 2.5 × 10<sup>6</sup>) compared to other matrices after shielding AQ that interrupt the conductive pathways.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Impact of reinforcement additives on physical and electrical properties of fly ash-based geopolymer materials

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年4月13日

查看全文
  • Khadiga M. Abas,
  • Rehab E. A. Ngida,
  • Somia M. Abbas

摘要

The utilization of carbon-based additives, generated from waste managed materials, to synthesize fly ash (FA)-based geopolymers with enhanced mechanical and electrical properties offers benefits in environmental protection and waste reduction. This study focused on preparing FA-based geopolymers at ambient conditions through alkali activation with a combination of NaOH-activated quartz (AQ) and water glass (Na2SiO3 solution). The weight ratio of FA:AQ in the FA/AQ geopolymer was kept at 1:1 (wt:wt). Carbon-based additives, including carbon fibers (CFs) and thermally stabilized microcrystalline cellulose (SMCC), were separately mixed to FA/AQ geopolymer paste in two proportions (1% and 3% wt/wt) relative to FA. The formulated geopolymers were analyzed physically using Fourier transform infrared spectroscopy (FTIR), UV/Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and EDX. SEM analysis reveals the presence of voids and cavities in the neat FA geopolymer. However, integrating AQ into the FA-based geopolymer leads to significant matrix densification and reduced porosity, restricting ion mobility, resulting in high mechanical strength, and low electrical conductivity. Additionally, the enhanced compatibility of a higher percentage of CFs and SMCC (CFs(3%)@FA/AQ and SMCC(3%)@FA/AQ) with the geopolymer matrix forms dense, amorphous sodium aluminum silicate hydrate (N-A-S–H) links. This is confirmed by the increased compressive strength (11.1 MPa and 18.1 MPa) and higher intensities of SMCC’s XRD patterns. SMCC(3%)@FA/AQ demonstrates the lowest electric and dielectric properties (σ = 1.4 × 10–7 S/cm and ε′ = 7 × 104), indicating superior insulating properties. In contrast, the CFs(3%)@FA geopolymer matrix exhibits higher values (σ = 4.4 × 10–6 S/cm and ε′ = 2.5 × 106) compared to other matrices after shielding AQ that interrupt the conductive pathways.