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 |
|---|---|
| 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 |
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All Science Journal Classification (ASJC) codes
- Biotechnology
- Surfaces and Interfaces
- Physical and Theoretical Chemistry
- Colloid and Surface Chemistry
Cite this
Small-angle neutron scattering study on microstructure of poly(N-isopropylacrylamide)-block-poly(ethylene glycol) in water. / Motokawa, Ryuhei; Masahiko, Annaka; Nakahira, Takayuki; Koizumi, Satoshi.
In: Colloids and Surfaces B: Biointerfaces, Vol. 38, No. 3-4 SPEC. ISS., 15.11.2004, p. 213-219.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Small-angle neutron scattering study on microstructure of poly(N-isopropylacrylamide)-block-poly(ethylene glycol) in water
AU - Motokawa, Ryuhei
AU - Masahiko, Annaka
AU - Nakahira, Takayuki
AU - Koizumi, Satoshi
PY - 2004/11/15
Y1 - 2004/11/15
N2 - 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.
AB - 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.
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U2 - 10.1016/j.colsurfb.2004.01.019
DO - 10.1016/j.colsurfb.2004.01.019
M3 - Article
VL - 38
SP - 213
EP - 219
JO - Colloids and Surfaces B: Biointerfaces
JF - Colloids and Surfaces B: Biointerfaces
SN - 0927-7765
IS - 3-4 SPEC. ISS.
ER -