Abstract
By employing small-angle neutron scattering (SANS), we investigated the microstructures of, poly(N-isopropylacrylamide) (PNIPA)-block-poly(ethylene glycol) (PEG) (NE) in deuterated water D 2O, as related to macroscopic behaviors of fluidity, turbidity and synerisis. SANS revealed following results: (i) microphase separation occurs at around above 17°C in a temperature range of transparent sol below 30°C. In the microdomain appeared in the transparent sol state, both block chains of PNIPA and PEG are swollen by water; (ii) for the NE solution of polymer concentration W p > 3.5% (w/v), corresponding to opaque gel above 30°C, a percolated structure, i.e., network-like domain is formed by NE as a result of macrophase separation due to dehydration of the PNIPA chains. As the temperature increases toward 40°C, the network domain is squeezed along a direction parallel to the NE interface, which leads to increase of the interfacial thickness given by swollen PEG chains and to the macroscopic synerisis behavior.
Original language | English |
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Pages (from-to) | 213-219 |
Number of pages | 7 |
Journal | Colloids and Surfaces B: Biointerfaces |
Volume | 38 |
Issue number | 3-4 SPEC. ISS. |
DOIs | |
Publication status | Published - Nov 15 2004 |
All Science Journal Classification (ASJC) codes
- Biotechnology
- Surfaces and Interfaces
- Physical and Theoretical Chemistry
- Colloid and Surface Chemistry