To study the effects of genipin crosslinking on chitosan beads and their adsorption of copper and nickel ions

• Main Author: Oh, Jin Hao
• Other Authors: Chian Kerm Sin
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/141623
• Institution: Nanyang Technological University

Chitosan is a naturally found biopolymer that come in abundant, with its attractive properties such as biodegradable and metal ions removal had set many researchers in this researching direction. For this project, the chitosan beads are crosslinked with. The control parameter is time (in term of hours) while the other parameters are fixed. Crosslinking of chitosan were carried out in 1, 3 and 24 hours by immersing coagulated chitosan beads in genipin-ethanol solution. The crosslinked beads exhibit three major changes after crosslinking. Firstly, the colour change with respect to time, from translucent white to translucent brown. Secondly, the beads external surface hardness increases with respect to time, with the 24-hour crosslinked chitosan bead being the most brittle among other beads. Lastly, the beads’ size shrinks with respect to time, with the 24-hour crosslinked beads having the highest volume shrinkage. Both the uncrosslink and crosslinked beads are evaluated for their ability to adsorb heavy metal ions such as copper (Cu) and nickel (Ni) from aqueous solution. The 24-hour and 3-hour crosslinked beads have the highest Cu and Ni ions adsorption at 60 minutes respectively. The highest rate of adsorption occurred at the first 5 minutes of the test for all the beads, especially for Ni ion adsorption.