- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Study of thermal conductivity of synthesized Al2O3-water nanofluid by pulsed laser ablation in liquid
摘要： In the present study, Aluminum oxide (Al2O3) nanoparticles dispersed water based nanofluids were prepared via laser ablation in liquid method. Al2O3 nanoparticles were synthesized in deionized water using a nanosecond Nd-YAG pulsed laser operating at 1064 nm. The structural, optical and morphological characterizations of the produced nanofluids were performed. Thermal properties of the prepared samples were evaluated through thermal conductivity measurements which were carried out at various nanoparticles concentration and at temperatures ranging from 25 °C to 45 °C. Morphological analysis by transmission electron microscopy revealed spherically shaped Al2O3 nanoparticles with an average size of 9 nm. Moreover, the results indicated that the thermal conductivity of Al2O3-water nanofluid was improved as compared to the pure water. The increase in temperature and nanoparticles concentration leads to higher thermal conductivity of nanofluids. It was found that the thermal conductivity enhancement was around 8.6% at nanoparticles volume fraction of 0.7 vol.% and temperature of 45°C. This work proved the possibilities of fabricating Al2O3-water nanofluid with enhanced thermal conductivity via laser ablation in liquid medium without the use of hazardous chemicals and vacuum conditions. Therefore, the synthesized nanofluids have great potential to be applied in medium temperature applications.
关键词： thermal conductivity,nanofluids,temperature,Al2O3 nanoparticles,laser ablation
更新于2025-09-23 15:19:57
-
Non-destructive and rapid interrogation of biochemical response of the leaves of wheat seedlings towards Al2O3 nanoparticles stress using attenuated total reflectance Fourier transform infrared spectroscopy
摘要： There has been tremendous development in the field of nanotechnology and consequently the release of nanoparticles in the environment and its interaction with the biotic components is inevitable. However, knowledge concerning nanomaterial biosafety, adverse effects, fate, and acquired biological reactivity is still at infancy and requires further scientific efforts to assess their possible nano-agricultural risks. Therefore, the present study aims to reveal the molecular alterations in the leaves of the wheat seedlings caused by direct exposure of Al2O3 NPs in non-destructive and rapid manner using attenuated total reflectance Fourier transform infrared spectroscopy. For this, the seedlings of wheat have been grown in sand matrix under controlled growth conditions and the toxicity of Al2O3 NPs has been introduced to the seedlings at different concentrations (0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4 and 1.6 mM). For determining the biochemical alterations, the infrared spectra of the leaves of control and Al2O3 NPs treated seedlings have been recorded in the wavenumber range 4000-400 cm-1. The principle component analyses of the preprocessed spectra indicate significant discrimination between the spectral signatures of control and Al2O3 NPs treated seedlings. The treatment of Al2O3 NPs enhances the spectral features of cellulose, hemicelluloses, lignin and pectin in the leaves of wheat seedlings. The treatment also increases the area of mehtylene bands of lipids, carboxyl and amine groups of amino acids and protein. Enhancement is also observed in carbonyl fingerprint region. The increase in the area of these molecules indicates the physiological significance of these molecules in the modulation of Al2O3 NPs stress in the wheat seedlings. The study adds substantive spectral data base to the existing elusive knowledge of nanotoxicity especially Al2O3 NPs to the plants and provides a molecular mechanism that defines the occurrence of biochemical changes and defense strategy of plants towards Al2O3 NPs toxicity.
关键词： biochemical analysis,ATR-FTIR,Al2O3 nanoparticles,wheat seedlings,nanotoxicity
更新于2025-09-11 14:15:04