Effects of Shear Flow on the Structures of Lamellar Liquid Crystals and Slow Dynamics
| Project/Area Number |
15340140
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biophysics/Chemical physics
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| Research Institution | Tokyo Metropolitan University |
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Principal Investigator |
KATO Tadashi Tokyo Metropolitan University, Department of Chemistry, Professor, 都市教養学部理工学系, 教授 (30142003)
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| Co-Investigator(Kenkyū-buntansha) |
KOMURA Shigeyuki Tokyo Metropolitan University, Department of Chemistry, Associate Professor, 都市教養学部理工学系, 助教授 (90234715)
FUJII Masatoshi Tokyo Metropolitan University, Department of Chemistry, Assistant Professor, 都市教養学部理工学系, 助手 (60183927)
KAWABATA Youhei Tokyo Metropolitan University, Department of Chemistry, Assistant Professor, 都市教養学部理工学系, 助手 (50347267)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥15,000,000 (Direct Cost: ¥15,000,000)
Fiscal Year 2005: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2004: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2003: ¥8,000,000 (Direct Cost: ¥8,000,000)
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| Keywords | lamellar phase / shear flow / dynamics / surfactant / liquid crystal / small-angle X-ray scattering / small-angle light scattering / small-angle neuron scattering / 光散乱 |
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| Research Abstract |
In the past 10 years, much attention has been paid to the effects of shear flow on the structure of a lamellar phase. In the present study, we have measured small-angle neutron and X-ray scattering, small-angle light scattering, and shear stress on the lamellar phases of a nonionic surfactant C_nH_<2n+1>(OC_2H_4)_mOH (C_nE_m) in D_2O under shear flow. We have found discontinuous decrease in the lamellar spacing for the shear rate of 0.3-1 s^<-1> suggesting local phase separation into concentrated lamellar and water-rich regions. We have also tried to clarify the mechanism of the local phase separation. The results can be summarized as follows.
1. Construction of an apparatus
We have constructed an apparatus for small-angle light scattering and small-angle X-ray scattering measurements under shear flow to investigate structural change in μm scale and nm scale, respectively.
2. Time-resolved small-angle neutron scattering (SANS) and light scattering (SALS) under shear
Time evolutions of 2-di
… More
mensionl SANS and SALS patterns have been observed after applying shear flow with a constant shear rate. The SANS results indicate discontinuous decrease in the repeat distance a few hours after applying shear flow in the range of shear rate 0.3-3s^<-1>, suggesting some sort of transition. It has been found that the repeat distance in the steady state takes a minimum around 1s^<-1>. From the SALS measurements, on the other hand, structural change in μm scale occurs a few minutes after applying shear flow. The decrease in the repeat distance may be induced by such a structural change in μm scale. At the shear rate of 3s^<-1>, a scattering pattern suggesting formation of the onion phase has been observed.
3. Measurements of shear stress
Time evolution of the shear stress has been recorded after applying shear flow with a constant shear rate. In the lower range of shear rte, the shear stress in the steady state increases with increasing shear rate. As the shear rate exceeds about 1s^<-1>, the shear stress decreases with shear rate, supporting the SANS results. Less
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Report
(4 results)
Research Products
(15 results)
