Glass formation and confined melting in sol–gel derived nano-ZnO aggregates
Source abstract
Abstract
Sol–gel processing of ZnO nanocolloids has been revisited to prepare various alkaline metal acetate (MAc: K, Na, Li-acetates) containing ZnO nanopowders. Using differential scanning calorimetry and X-ray diffraction investigations, several new relationships between the morphology and the thermodynamic behavior in the aforementioned particulate ZnO/MAc nanocomposites were noticed: (1) large MAc melting depression shifts −ΔTm ~ 80 °C due to salt confinement within porous ZnO aggregates, (2) corresponding MAc crystallization and re-crystallization temperature depression shifts, (3) presence of multimodal pore size distributions within nanoaggregates and (4) glass formation at temperatures Tg between −40 and 130 °C. We also note that the Tg value drops with rising alkaline metal size, increasing water content and decreasing ZnO particle size. In contrast, Tg rises in the case of co-doped Fe–LiAc/ZnO compositions.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Pigment Synthesis and Properties · ZnO doping and properties · Quantum Dots Synthesis And Properties
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References (12)
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