PSI - Issue 70

R. Greesan et al. / Procedia Structural Integrity 70 (2025) 666–673

670

Yun-Ho Ahn et al. (2019) reported that the Ceno PCM support material contains visible voids and openings, forming a porous structure that effectively holds the Ceno-based PCM and prevents leakage. As illustrated in Fig. 3, the surface characteristics of the composite PCM change noticeably after impregnation. The previously vacant pores and cavities are completely filled with the Ceno-based PCM, and the rough, uneven surface of the matrix becomes uniformly smooth due to the PCM’s adherence. Following the immersion process, the microstructure of the composite is largely occupied by the PCM, a result influenced by capillary action and surface tension. These findings align with the observations made by Lisa Boussaba et al. (2018). 3.2. XRD The XRD diffractograms of Ceno PCM are shown in Fig. 2. According to the Ceno PCM patterns, it has a polycrystalline amorphous structure with certain crystalline phases (C, O, Al, and Si phases) at 43.58, 40.49, 7.42, and 8.52 weight percent, as well as amorphous quartz substance. The regular crystallization of Ceno PCM is confirmed by the XRD diffractogram,the amorphous phase of PCM shows three minor crystal peaks and single sharp crystal peak. In contrast, the XRD patterns of the Ceno – PCM composites reveal the presence of all characteristic diffraction peaks corresponding to their individual components. The slight angular deviations observed in these components are most likely caused by hydrogen bonding, in addition to the effects of capillary forces and surface tension interactions between Ceno and PCM molecules. Additionally, the decreased intensity of these peaks may be explained by the limited crystallinity of the components caused by their confinement within the pores of the Ceno spheres. Comparable findings have been documented for other PCMs, as reported by Lisa Boussaba et al. (2018).

Fig.2 X-ray Diffration of Ceno PCM

3.3. FTIR FT-IR analysis was performed to investigate the chemical structures of Cenosphere, Titanium Dioxide, and the PCM composite, as well as the prepared composite PCM, to confirm their chemical compatibility.FT-IR analysis was conducted to examine the structural changes in the Cenosphere, Titanium Dioxide, and PCM composite due to binder composition modifications. The FT-IR spectral curves (Figure 3) were recorded for the binders, showing a small peak at 1663 cm⁻¹ in the samples B -0 and B-8, which corresponds to the bending of molecularly coordinated water within the SiO₂ structure (Ahmet Sarı, 2019). The FT -IR spectra of the synthesized composite-PCM and the PCM based on cenospheres are presented in Figure 4. Two main absorption peaks at 2934 cm⁻¹ and 2864 cm⁻¹ in the FT-IR spectra of the Cenosphere-based PCM (M) correspond to the C-H stretching vibrations. The C=O stretching is indicated by peaks at 1639 cm⁻¹ and 1366 cm⁻¹, while the range from 625 cm⁻¹ to 138 cm⁻¹ is associated with C -H