The macroscopic volume shrinkage and swelling of poly (N-isopropylacrylamide) (PNIPA) gel induced by the compositional change in the methanol-water mixed solvent is correlated to the change in the nanoscopic free volume size and numerical concentration formed in the PNIPA gels. The free volume size
Volume phase transitions of poly(N-isopropylacrylamide) latex particles in mixed water-N,N-dimethylformamide solutions
β Scribed by Peng Wei Zhu; Donald H. Napper
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 425 KB
- Volume
- 256
- Category
- Article
- ISSN
- 0009-2614
No coin nor oath required. For personal study only.
β¦ Synopsis
Volume phase transitions of poly(N-isopropylacrylamide) (PNIPAM) latex particles in mixed water-N,N-dimethylformamide (DMF) solutions were studied at different temperatures and crosslink densities using dynamic light scattering. A collapse-swelling behaviour was observed on the addition of N,N-dimethylformamide to an aqueous dispersion medium. The degree of swelling was found to be dependent on the temperature and crosslink density. The transition between the collapsed state and the swollen state was continuous. The cononsolvency of water and DMF for PNIPAM latex particles has been interpreted in terms of the changes in the interactions between their components.
π SIMILAR VOLUMES
The effects of both anionic (sodium dodecyl sulfate, SDS) and cationic (dodecylpyridine bromide, DPB) surfactants on the phase transition of narrowly distributed poly(N-isopropylacrylamide) (PNIPAM) microgel particles were investigated by laser light scattering. The addition of SDS swells the partic