Thesis Archive
Synthesis of Green Zero-valent Iron Using Polyphenols From Dried Green Tea Extract (2013-2014)
Madeline Anne S. Ngo
Cyrill C. Saranglao
Richard Paul M. Tiongco
Abstract:
-“In this study, green ZVI was synthesized using polyphenols obtained from green tea extract as the reducing agent and ferric chloride (FeCl3) as the iron precursor. This study aims to determine the most favorable conditions for the synthesis of green ZVI based on the yield, rate of oxidation and surface area of the metal product. The polyphenols were extracted through microwave-assisted extraction method from dried green tea with varying material to solvent ratio (1:18 – 1:22, g/ml). ZVI was then synthesized using the extracted polyphenols. Various experimental conditions, such as green tea extract flow rate (8-17, ml/min), and ferric chloride to green tea extract ratio (1:1-1:3, ml/ml), were investigated during synthesis. The resulting ZVI was analyzed through SEM-EDX and TEM. The conditions which gave the highest yield (89.53%) were the following: a green tea to solvent ratio of 1:20, a green tea extract flow rate of 8mL/min and a FeCl3 to green tea extract ratio of 1:2. On the other hand, the conditions which gave the smallest particle size (8.775 nm) were the following: a green tea to solvent ratio of 1:20, a green tea extract flow rate of 17 mL/min and a FeCl3 to green tea extract ratio of 1:3. The set of conditions: a green tea to solvent ratio of 1:20, a green tea extract flow rate 17 mL/min and a FeCl3 to green tea extract ratio of 1:1 gave the most uniform particle size distribution (9.70±2.168 nm). It was determined that the green tea extract flow rate was the only factor that significantly affected both the particle size and the yield. On the other hand, the green tea to solvent ratio was the sole factor that affected the rate of oxidation. Also, the rate of oxidation of the metal product was found to vary inversely with the polyphenol content.”
Adviser:
Dr. Josephine Q. Borja
Dr. Nathaniel P. Dugos
Dr. Erison C. Roque