Thermo-responsive binary microgel system

• Main Author: Lin, Wensheng
• Other Authors: Hu Xiao
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Materials::Material testing and characterization
• Online Access: https://hdl.handle.net/10356/148319
• Institution: Nanyang Technological University

Temperature sensitive cationic and anionic microgels was successfully synthesized using surfactant-free emulsion polymerization using N-isopropylacrylamide (NIPAM) as the main monomer and Allyl-1H-imadazole-1-carboxylate (AIC), sodium acrylate (SA) and 1-vinyl imidazole (VIM) as the copolymer. Different cross-linkers and initiators were used depending on the copolymer used. Binary mixtures of microgel were obtained by mixing the cationic and anionic microgels together. The sizes, morphologies, phase behaviour and swelling behaviour of the microgels were investigated using scanning electron microscopy (SEM), dynamic light scattering (DLS) and differential scanning calorimetry (DSC). The PNA/PNIPAM-co-SA binary microgel system was found to be more stable due to the presence of excess negative charges. The binary mixture of microgel have been successfully deposited onto a membrane to form a thin film using vacuum filtration. The thin films were characterized using SEM, atomic force microscopy (AFM) to study the surface and morphology of the film. Contact angle test was conducted to test the wettability of the film to water and oil. The binary microgel film shows potential in oil/water separation test. However, further analysis is required to determine its effectiveness.