The Synthesis And Investigation Of Polyelectrolyte Nanocomposite Hydrogels

The nanocomposite hydrogels were synthesized by in-situ solution polymerization in aqueous solution, in which anionic monomer and cationic monomer were selected as co-monomer and sodium montmorillonite (Na+-MMT) was employed as inorganic component. At the same time, the structures, performances and swelling behaviors of nanocomposite hydrogels with different ionic water-soluble monomers were investigated. This dissertation comprised six sections:Chapter 1: Introduction. In this section, the theories and the developments of research were introduced in detail.Chapter 2: The synthesis and investigation of polyampholyte hydrogels.P-AA, P-DAC,P(AA-DAC) hydrogels were synthesized by solution polymerization. APS and MBA were used as initiator and crossliking agent. The equilibrium swelling ratios (ESR) of ampholyte hydrogels in distilled water and sodium chloride solutions (0.9 wt%) were investigated. Various factors, including the solution pH, the various salt solution, and monomer feed ratio etc. were studied. The results showed that the P(AA-DAC)hydrogel presented antipolyelectrolyte effect. With the concentration of the salt solution increase, the hydrogels swelling increase. It showed potential salt tolerance. At the same time, the dynamic parameters of hydrogels were also calculated in salt solutions with different concentration and the results illuminated that the swelling process was solvent diffuse to hydrogels interior. The structure of hydrogel was characterized by FTIR and NMR. The result indicated the hydrogels were copolymerized by AA and DAC, and the hydrogels composition nearly accord with the feed ratio of reactant monomer.Chapter 3: The synthesis and investigation of polyampholyte nanocomposite hydrogels. In this section, the polyampholyte nanocomposite hydrogels were synthesized, and the gel strength of polyampholyte nanocomposite hydrogel could be improved to the great extent due to the introduction of MMT. The swelling behaviors of polyampholyte nanocomposite hydrogels were investigated and the result showed that the polyampholyte nanocomposite hydrogels presented antipolyelectrolyte effect. Meanwhile, the analysis of swelling kinetic of nanocomposite hydrogels illuminated that the swelling kinetic should be assigned to the first order swelling dynamic and the swelling process was controlled by the non-Fickian diffusion mechanism.Chapter 4. The synthesis and investigation of polyelectrolyte nanocomposite hydrogels. The nanocomposite hydrogels were synthesized by in-situ solution polymerization in aqueous solution, in which anionic monomer 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) and cationic monomer 1-vinylimidazole (VI) were selected as co-monomer and modified-Montmorillonite (OMMT) was employed as inorganic component. The results of performance of composite hydrogels illuminated that the water absorbency of composite hydrogels could be improved. The swelling behaviors of nanocomposite hydrogels were investigated and the results showed that the ionic nanocomposite hydrogels presented polyelectrolyte effect. Meanwhile, the analysis of swelling kinetic of nanocomposite hydrogels illuminated that the swelling kinetic should be assigned to the first order swelling dynamic and the swelling process was controlled by the non-Fickian diffusion mechanism. The hydrogels P(OMMT-AMPS-VI) showed a maximum retention capacity (MRC) value for Cu(II) at pH 5 of 183mg/g.