以攪拌變因進行奈米級銀粉放大生產最適化

Chang等(2007) 以實驗數據求得以甲醛當還原劑進行奈米銀微粒膠體的最適化製造條件(在恆溫的條件下，在250cc的錐形瓶中放入100cc反應混合物進行反應)。反應過程中，考慮的實驗變因有反應溫度T，[Formaldehyde]/[AgNO3]、[NaOH]/[AgNO3]、PVP/AgNO3的莫耳比，以及保護劑PVP (polyvinyl-pyrrolidone) 的分子量大小。製造奈米銀膠體程序是以銀粒之平均粒徑以及硝酸銀的轉化率為考量。Chang等(2007) 以44個經過安排的實驗，鑑別了一可靠模式，並據此模式提供了在不同目標函數下之最適化製造條件。在本研究中，我們評估僅改變攪拌器轉速但採用Chang等(2007) 提供之最適化製造條件進行放大生產(2L或更大)奈米銀膠體是否可達到同樣的目標函數值。從放大生產的七組實驗中，在攪拌轉速為616 rpm時，反應所得奈米銀膠體之平均粒徑為30.96nm、轉化率為38.4% (同樣目標函數下之小批量生產奈米銀膠體其平均粒徑為28.63nm而轉化率為47.94% (Chang等，2007)) 。以另一目標函數進行放大生產時在攪拌器轉速616 rpm時奈米銀膠體之平均粒徑以及轉化率分別為35.69 nm和85.3% (同樣目標函數下之小批量獲得奈米銀膠體之平均粒徑為32.66nm，轉化率為85%)。從本實驗研究中可發現經由提高攪拌器轉速可略為提高轉化率，而奈米銀膠體之平均粒徑却不太改變。

關鍵字

奈米銀

並列摘要

Optimization on the synthesis of nanosized silver particles (Chang et al. 2007) by chemical reduction using formaldehyde in aqueous solution was carried out based on the laboratory experimental data (loading 100 cc reacting mixtures in a 250 cc beaker and shaking in an isothermal shaker). Effects of the possible processing variables such as the reaction temperature T, the mole ratios of [Formaldehyde]/[AgNO3] and [NaOH]/[AgNO3], PVP/AgNO3, and the molecular weight of protective agent PVP (polyvinyl-pyrrolidone) were considered. The colloid dispersion products were mainly characterized for its mean particle size and conversion of silver nitrate. The identified model based on the 44 designed experiments can provide us the optimal conditions for achieving different targets (Chang et al. 2007). In this study, we evaluated the feasibility of achieving the same targets by applying the optimal conditions cited by Chang et al. (2007) to the scale-up production (2 liters or more) of nanosized silver particles but varying the rotational speed of the impeller. From the seven experiments carried out, the particle diameter size 30.96 nm with conversion 38.4% was achieved at the rotational speed of the impeller 616 rpm (adopting the optimal conditions for achieving the minimum mean particle size 28.63nm with conversion 47.94% cited in Chang et al. (2007)). Similarly, the particle diameter size 35.69 nm with conversion 85.3% was achieved at the rotational speed of the impeller 616 rpm (adopting the optimal conditions for achieving mean particle size, 32.66nm with a desired conversion, 85% cited in Chang et al. (2007)). In this case study, by an increased rotational speed of the impeller (700rpm), a higher conversion can be achieved without sacrificing the mean particle size of the product.

並列關鍵字

Nanosized Silver

參考文獻

Hu, T. C., ” Use of Design of Experiments to Optimize Scale-up Production of Nanosized Silver Particles” , Thesis for Master of Science, Department of Chemical Engineering Tatung University, July (2006).

Lee, Y. P., ”Synthesis Optimization of Nanosized Silver Particles Via Sequential Pseudo-Uniform Design Method”, Thesis for Master of Science, Department of Chemical Engineering Tatung University, July (2005)

Pillai, Z. S. and Kamat. P. V. J. Phys. Chem. B. 2004, 108, 945.

Sondi, I.; Goia, D. V. and Matijevic, E. Colloid and Interface Science. 2003, 260, 75.

Wang, C. R.; Chen, J. D.; Ke, L. S. Chemistry. 2004, 62, 569.

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以攪拌變因進行奈米級銀粉放大生產最適化

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