CERAMICS INTERNATIONAL, cilt.52, sa.5, ss.6771-6782, 2026 (SCI-Expanded, Scopus)
In this study, we demonstrate a sustainable mechanochemical route for transforming natural clinoptilolite-type zeolite into a quartz silica phase through prolonged low-energy planetary ball milling under ambient conditions, without thermal input or chemical additives. Structural and compositional analyses reveal a shear-induced phase transformation that initiates at similar to 16 h and becomes essentially complete by 32-48 h, accompanied by progressive particle refinement (to similar to 2-3 mu m), densification, preferential dealumination, and a marked increase in the Si/Al ratio, as corroborated by FE-SEM/EDS analyses conducted over multiple regions. Thermal analysis confirms continuous dehydration and a systematic rise in activation energy to similar to 95-101 kJ mol(-1) in the milled quartz phase, indicating enhanced structural stability. Beyond lattice reorganization, the transformation produces a pronounced shift in functional behavior: the pristine zeolite's high-loss, ion-dominated dielectric response is replaced by the highly resistive, low-permittivity, and low-loss characteristics of the quartz-like product, which remain stable from room temperature up to 700 K. This combined structural and dielectric evolution highlights the effectiveness of low-energy mechanochemistry in enabling shear-driven phase engineering and in tuning dielectric performance without thermal processing. Collectively, these findings provide new insight into environmentally benign and scalable routes for producing low-loss insulating materials and next-generation functional ceramics.