| 研究課題/領域番号 |
15F15722
|
|---|
| 研究機関 | 東京大学 |
|---|
研究代表者 |
田中 肇 東京大学, 生産技術研究所, 教授 (60159019)
|
|---|
| 研究分担者 |
THEURKAUFF ISAAC 東京大学, 生産技術研究所, 外国人特別研究員
|
|---|
| 研究期間 (年度) |
2015-04-24 – 2017-03-31
|
| キーワード | Statistical physics / Critical mixtures / Rheology / Casimir forces |
|---|
| 研究実績の概要 |
Our objective is to measure the mechanical properties of a binary fluid close to a demixion critical point. Following previous work done in the lab[P.Royall, Nature Physics, 2007 ] we have chosen a PMMA colloid - polystyrene polymer system, that undergoes demixion due to depletion forces. The goal is to measure the interaction force between large probe colloids due to the fluctuation of the critical medium surrounding them. The forces are Casimir-like and become dominant close to critical points.
Throughout our research, we`ve developed several original techniques: such as a chemistry of the binary fluid and a programming image analysis in Matlab and acquisition routines in Labview to systematize the experiment.
|
| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
We are introducing a phase controlled mirror in the optical path of the optical trap to control the dynamics of the optical trap, creating a force measurement system that is controlled both spatially, and in time. Creating for example a moving line trap; or two moving point traps. This implies reworking our optical setup as well as modifications of the Labview code. We are also programming a precision stage (Opto-Sigma), that allows Control of the sample position. For a static trap, it is another way of exerting a force on a colloidal probe.
|
| 今後の研究の推進方策 |
The force measurements will start soon. In the next weeks, we should be able to control probe trajectories and to measure forces acting on them. Once this is done, we will measure the rheological properties of the critical mixture, for different compositions. The fast confocal microscope will allow measurement of the fluid properties at the same time as the colloidal probes are observed. We will thus be able to observe in real space the deformation of domains in the critical mixture with shear.
By moving two probes close to each other, we will be able to measure the interaction potential in a critical mixture, and its out of equilibrium component. The fast confocal should allow us to observe the fluid fluctuations causing the Casimir-like part of the interaction.
|
