実験報告書様式（一般利用課題・成果公開利用）

MLF Experimental Report

提出日 Date of Report
2017/8/2

課題番号 Project No.

装置責任者 Name of responsible person

2017A0075

Toshiya Otomo

実験課題名 Title of experiment

装置名 Name of Instrument/（BL No.）

The determination of mixing state of binary solution is confined

BL-21

spaces (4): immiscible small clusters

実施日 Date of Experiment

実験責任者名 Name of principal investigator2017.05.11 09:00 - 2017.05.13 09:00

Taku Iiyama
所属 Affiliation
Shinshu University
試料、実験方法、利用の結果得られた主なデータ、考察、結論等を、記述して下さい。（適宜、図表添付のこと）
Please report your samples, experimental method and results, discussion and conclusions. Please add figures andtables for better explanation.
1. 試料 Name of sample(s) and chemical formula, or compositions including physical form.
An original designed measurement cell which keeps a hermetically closed condition was used for BL21measurement. The ground activated carbon fiber A10 (Ad’all Co. Ltd.; pore width is 0.82 nm) was used asadsorbent.

We measured the ND of water-cyclohexane mixture on adsorbed states. The molar fractionof water w = 0 (pure cyclohexane), 0.25, 0.5, 0.75, 1.0 (pure water). The deuterium substitution samples,
C6D12 and D2O were used as adsorbate for reduction the recoil factor.

Adsorbed amounts on A10 werecontrolled at unity of fractional filling the pore ( = 0.9). The measurement time was 300 m for eachadsorbed condition.

2. 実験方法及び結果 （実験がうまくいかなかった場合、その理由を記述してください。）
Experimental method and results.

If you failed to conduct experiment as planned, please describe reasons.

In the proposal, we had a plan to measure the water –cyclohexane (D2O-C6D12) mixture as immiscible system
at low fractional filling ( = 0.5) in the micropore to investigate the small clusters. But we decide to change
the measurement about the saturated condition of the pore ( = 0.9), because the previous beam time used toother adsorption system (water-ethanol), and we need the data of saturated condition ( = 0.9) to comparewith the miscible system. The small cluster system will measure in next period.
For adsorbed condition samples, the carbon sample introduced in the cell of 10 mm diameter, and preheatedfor 8 h at 383 K and 1 mPa before the measurements. Then each adsorbate was introduced via vapor withthe adsorbed amount controlling. The sample cells were hermetically closed, and keep over 3 days for theequilibrium.

For bulk samples, cell of 6 mm diameter was used.

All data show the broad peak feature due to the liquid like structures of adsorbed phases even at low
fractional filling conditions. The subtraction of carbon peaks well done. It can be confirmed smooth profile
feature and continuous and systematic change of profiles with molar fraction of mixture.
12. 実験方法及び結果（つづき） Experimental method and results (continued)
Fig. 1 shows the structure
factors

ofadsorbed

water-cyclohexane

mixtureinthecarbon micropore with different
molar fractions.

These profiles

were obtained by subtracting thediffraction from carbon sample
itself after the data correcting.
The all profiles show the broadfeatures,

and

show

gradualchange with molar fraction. This
gradual change indicate that theboth of molecules introduce tothe pore even the immiscible

Fig.1 Comparing of structure factors of adsorbed
water-cyclohexane mixture with different molar fractions.

combination. We compared theexperimental profiles of middle
fractionandtheweighted

averages of pure water andcyclohexane profiles.

In thehigh Q region (Q > 40 nm-1), theexperiment profile and averaged
profile are similar. It indicatesthat the short range structuresuch as intramolecular structureof cyclohexane does not change
in the micropore.
aroundoftheHowever,firstsharp

Fig.2 The radial distribution functions of adsorbed
water-cyclohexane mixture with different molar fractions.

diffraction peak (FSDP) of micro-mixture profile does not coincide the average profile. It is indicate clearly,that the water and cyclohexane form a strange mixture in the carbon micropore.
Fig. 2 show the radial distribution functions of pure cyclohexane, water and these mixture in the micropore.
Unfortunately, we cannot find new peaks in the micro-mixture. The interatomic peak between different
molecules should be small or overlapped to the pure component peaks. The change of peak intensities of purecomponent, such as 0.40 nm for water, 0.61 nm for cyclohexane are not proportional to molar fraction. Theprofiles suggests the forming the micro-domain structure of each component in the micropore. However, thedomain size is not so large and is strongly affected the molar fraction.
We will combined XRD data of same systems and analysis the mixture by using reverse Monte Carlosimulation. By the using of both of ND and XRD profiles, the detailed structure included the domain size andshapes of water and cyclohexane mixture should be elucidated.
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