磁性奈米流體製備參數對流體磁性質之研究

Study on the influence of preparation parameters on the magnetic properties of magnetic nanofluids

朱峙穎(Chin-Ying Chu)

指導教授 ： 翁輝竹

中原大學/工學院/機械工程研究所/碩士(2014年)

https://doi.org/10.6840/cycu201400581

摘要

本論文完成流體磁性質之分析，主要目的在探討不同製備參數對磁性奈米流體磁性質之影響。首先，我們藉由化學共沉法並透過改變不同體積莫耳濃度及攪拌速度以製備磁鐵礦奈米粒子。接著，藉由溶膠凝膠法並透過改變不同酸鹼值及工作溫度將穩定劑包覆於奈米粒子上以製備出穩定之水基磁性奈米流體。進一步，透過同軸套管密度計以估算流體內粒子殘存率。最後，透過加速樣品測磁儀以分析磁性奈米流體磁性質。
研究結果發現，在一般情形下，粒子殘存率隨體積莫耳濃度、攪拌速度、混合液酸鹼值及工作溫度增加而增加。然而隨著工作溫度持續增加，粒子殘存率至較大值後便下降。研究結果亦發現，在一般情形下，飽和磁化場強度隨著體積莫耳濃度增加而單調減少；隨著攪拌速度的增加則呈漸趨增加，但達一較高值後漸趨減少；隨著混合液酸鹼值增加而增加；隨著工作溫度增加則呈漸趨增加，但達一較高值後漸趨減少。

關鍵字

磁性奈米流體，奈米材料合成，化學共沉法，溶膠凝膠法，磁性質

並列摘要

This thesis presents a study on the analysis of magnetic properties of fluids. The main purpose is to study the influence of preparation parameters on magnetic properties of magnetic nanofluids. First, we prepare magnetite nanoparticles by the co-precipitation method with different molarities and stirring speeds. Then, we coat a stabilizer layer on each nanoparticle by the sol-gel method with different pH values and working temperatures, so as to prepare stable water-based magnetic nanofluids. Also, through the co-axial-tube density meter, we then estimate the residual ratio of particles in fluids. Finally, through the accelerating sample magnetometer (ASM), we then analyze the magnetic properties of magnetic nanofluids.
Results show that the residual ratio of particles in general increases with the increases in the molarity, stirring speed, pH value, and working temperature. However, when the working temperature increases further, the residual ratio would increase to a greater value and then decrease. It can also be found that in general the saturation magnetization monotonically decreases with the increasing molarity, increases with the increasing stirring speed and to a greater value and then decreases, increases with the increasing pH value and to a greater value and then decreases.

並列關鍵字

magnetic nanofluids ； nanomaterial synthesis ； chemical co-precipitation method ； sol-gel method ； magnetic properties

參考文獻

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