超音波輔助化學共沉法對提升水基磁性奈米流體磁性質之研究

Study on the enhanced magnetic properties of water-based magnetic nanofluids prepared by ultrasonic-assisted chemical co-precipitation

劉家瑞(Jia-Rui Liu)

指導教授 ： 翁輝竹

中原大學/工學院/機械工程研究所/碩士(2015年)

https://doi.org/10.6840/CYCU.2015.00397

摘要

本論文完成水基磁性奈米流體磁性質之分析。主要目的在探討超音波輔助化學共沉法對水基Fe3O4磁性奈米流體磁性質之提升。首先，藉由超音波技術輔助化學共沉法並透過改變不同鹼性溶液體積莫耳濃度、超音波振盪輸出功率及超音波振盪間歇時間以製備Fe3O4磁鐵礦奈米粒子。接著，透過溶膠凝膠法將穩定劑包覆於磁性奈米粒子上以製備出穩定之水基磁性奈米流體。最後，透過加速樣品測磁儀以分析水基磁性奈米流體之磁性質。
研究結果發現，改變鹼性溶液體積莫耳濃度時，透過使用超音波輔助化學共沉法，較單純使用化學共沉法時，流體磁性質可被提升。進一步結果發現，飽和磁化場強度及磁相粒子體積分率將隨著超音波振盪輸出功率增加而增加，達較高值後則稍稍減少，然而磁相粒子平均粒徑及流體初始磁化率則隨之增加而單調增加；並且，所有被分析之磁性質皆將隨著超音波振盪間歇時間增加而增加，且皆達較高值後漸趨減少。

關鍵字

水基磁性奈米流體, 超音波振盪技術, 化學共沉法, 磁性質

並列摘要

This thesis presents a study on the analysis of magnetic properties of water-based magnetic nanofluids. The main purpose is to study the enhancement of magnetic properties of water-based Fe3O4 magnetic nanofluids prepared by ultrasonic-assisted chemical co-precipitation method. First, magnetite nanoparticles (Fe3O4) are synthesized by chemical co-precipitation assisted by ultrasonic oscillation technology under different alkaline solution molarities, ultrasonic oscillation powers output, and ultrasonic oscillation intermittent times. Then, the sol-gel method is used for coating a stabilizer layer on each nanoparticle, so as to prepare stable water-based magnetic nanofluids. In the final step of this study, magnetic properties of water-based magnetic nanofluids are analyzed with the accelerating sample magnetometer (ASM).
Results show that, compared with the chemical co-precipitation method without the ultrasonic oscillation technology, the ultrasonic-assisted chemical co-precipitation method can enhance the magnetic properties of fluids by controlling alkaline solution molarity. It is further found that the saturation magnetization and magnetic-phase particle volume fraction increase with increasing ultrasonic oscillation power output and to greater values and then decrease slightly; however, the average magnetic-phase particle diameter and initial magnetic susceptibility monotonically increase with the power output. Moreover, all of analyzed magnetic properties increase with increasing ultrasonic oscillation intermittent time and to greater values and then decrease.

並列關鍵字

water-based magnetic nanofluids, ultrasonic oscillation technology, chemical co-precipitation method, magnetic properties

參考文獻

朱峙穎, 2014, 磁性奈米流體製備參數對流體磁性質之研究, 碩士論文, 機械工程學系, 中原大學.

蕭智文, 2013, 奈米流體應用於太陽能熱水器性能之研究, 碩士論文, 機械工程學系, 中原大學.

夏廣德, 2013, 奈米流體製備參數對流體內粒子懸浮性之研究, 碩士論文,機械工程學系, 中原大學.

姚壬謙, 2004, 化學共沉法製備Co2Z鐵氧磁體粉末之生成機構研究, 碩士論文, 資源工程所, 國立成功大學.

許學文, 2013, 磁性奈米流體應用於揚聲器音圈效能之研究, 碩士論文, 機械工程學系, 中原大學.