Localized Morphological Heterogeneities in Synthetic Zeolite Materials: Insights from Scanning Electron Microscopy

Jing Li; Wei Liu

doi:10.71222/z7c9fg91

Authors

Jing Li Henan Vocational University of Science and Technology, Zhengzhou, Henan, China Author
Wei Liu Henan Vocational University of Science and Technology, Zhengzhou, Henan, China Author

DOI:

https://doi.org/10.71222/z7c9fg91

Keywords:

zeolite, scanning electron microscopy, morphological heterogeneity, microstructure

Abstract

Zeolite materials are pivotal in various industrial applications, including catalysis, adsorption, and separation, owing to their unique porous structures and tunable physicochemical properties. The macroscopic performance of these materials is intricately linked to their microscopic morphology, particle size distribution, and structural homogeneity. While conventional characterization techniques often provide bulk-averaged information, understanding localized morphological variations within and across zeolite samples is crucial for optimizing synthesis protocols and ensuring consistent performance. This study employs Scanning Electron Microscopy (SEM) to systematically investigate the surface morphology and particle arrangement across three distinct batches of a synthetic zeolite material, aiming to elucidate the extent and nature of localized morphological heterogeneities. Our findings reveal a spectrum of morphological uniformity, ranging from highly homogeneous particle distributions in one batch (Batch A) to pronounced heterogeneities, including variations in particle size, shape, packing density, and the presence of micro-defects, in others (Batches B and C). Specifically, Batch A displayed tightly packed, uniformly sized [e.g., cubic/spherical] particles (~150 ± 20 nm), while Batch B showed a broader size distribution (~200 ± 50 nm) and some irregularly shaped particles. Batch C exhibited significant morphological variations, with particle sizes ranging widely (~100 nm to 800 nm) and extensive evidence of incomplete crystallization, aggregation, and macro-voids. These observations underscore the subtle influence of synthesis conditions on micro-morphology and highlight the necessity of detailed localized characterization. The identified heterogeneities carry significant implications for the materials’ functional properties, such as catalytic activity, diffusivity, and mechanical stability. This research emphasizes the value of high-resolution SEM in diagnosing synthesis inconsistencies and provides a foundation for rational design strategies to achieve tailored and homogeneous zeolite structures for specific applications.

References

1. A. Akbarpour, M. Mahdikhani, and R. Z. Moayed, "Effects of natural zeolite and sulfate ions on the mechanical properties and microstructure of plastic concrete," Front. Struct. Civ. Eng., vol. 16, no. 1, pp. 86–98, 2022, doi: 10.1007/s11709-021-0793-x.

2. A. Khajeh et al., "Assessing the effect of lime-zeolite on geotechnical properties and microstructure of reconstituted clay used as a subgrade soil," Phys. Chem. Earth, vol. 132, p. 103501, 2023, doi: 10.1016/j.pce.2023.103501.

3. Y. Liu et al., "Room-temperature synthesis of zeolite membranes toward optimized microstructure and enhanced butane isomer separation performance," J. Am. Chem. Soc., vol. 145, no. 14, pp. 7718–7723, 2023, doi: 10.1021/jacs.3c00009.

4. X. Lu et al., "Microstructural manipulation of MFI-type zeolite films/membranes: Current status and perspectives," J. Membr. Sci., vol. 662, p. 120931, 2022, doi: 10.1016/j.memsci.2022.120931.

5. A. Zolghadri, B. Ahmadi, and H. Taherkhani, "Influence of natural zeolite on fresh properties, compressive strength, flexural strength, abrasion resistance, Cantabro-loss and microstructure of self-consolidating concrete," Constr. Build. Mater., vol. 334, p. 127440, 2022, doi: 10.1016/j.conbuildmat.2022.127440.

6. M. Tayebi and M. Nematzadeh, "Post-fire flexural performance and microstructure of steel fiber-reinforced concrete with re-cycled nylon granules and zeolite substitution," Structures, vol. 33, 2021, doi: 10.1016/j.istruc.2021.05.080.

7. A. Gossard et al., "Effects of the zeolite concentration on the microstructure of high internal phase emulsions stabilized by surfactant-coated zeolite particles," Colloids Surf. A Physicochem. Eng. Asp., vol. 625, p. 126853, 2021, doi: 10.1016/j.colsurfa.2021.126853.

8. L. Zhang et al., "The effect and mechanism of Si/Al ratio on microstructure of zeolite modified ceramsite derived from industrial wastes," Microporous Mesoporous Mater., vol. 311, p. 110667, 2021, doi: 10.1016/j.micromeso.2020.110667.

9. E. Erdogmus et al., "Effect of molding pressure and firing temperature on the properties of ceramics from natural zeolite," Constr. Build. Mater., vol. 402, p. 132960, 2023, doi: 10.1016/j.conbuildmat.2023.132960.

10. A. V. Korkmaz, "Mechanical activation of diabase and its effect on the properties and microstructure of Portland cement," Case Stud. Constr. Mater., vol. 16, 2022, doi: 10.1016/j.cscm.2021.e00868.