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

課題番号 Project No.

装置責任者 Name of responsible person

2017B0034

Norifumi Yamada

実験課題名 Title of experiment

装置名 Name of Instrument/（BL No.）Interfacial structure and dynamics in stacked thin polymer films

BL No.16

実験責任者名 Name of principal investigator

実施日 Date of Experiment

Koji Fukao

2017.12.14-2017.12.17

所属 Affiliation
Ritsumeikan 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.
The polymer samples used in our measurements are atactic hydorated poly(methyl methacrylate) (h-PMMA)
and deuterated poly(methyl methacrylate) (d-PMMA) as follows: 1) h-PMMA-3: Mw=3.23x105, Mn=2.26x105 , 2)d-PMMA-5: Mw=7.63x103, Mn=7.00x103, 3) d-PMMA-6: Mw=2.63x105, Mn=2.29x105. All eight hydrogens are
replaced by deutrons for d-PMMA-5 and d-PMMA-6. The scattering length densities (SLD) of h-PMMA andd-PMMA are 1.0865 and 7.11, respectively.

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.

Two different types of 2-layered films of h-PMMA and d-PMMA (hd-PMMA-3 and -4) are prepared asfollows.

a) hd-PMMA-3:

A 35-nm-thick-film of blend of d-PMMA-6 andd-PMMA-5 with 4 different

ratios of 1.0:0, 0.9:0.1, 0.8:0.2, and 0.6:0.4 is stacked on the glass substrate, and then a 36-nm-thick-film ofh-PMMA-3 is stacked on the top of the d-PMMA layer. b) hd-PMMA-4:

A thin film of d-PMMA-6 withvarious thicknesses of 14.5 nm, 25.6 nm, 39.2 nm, 47.9 nm is stacked on the glass substrate, and then a
35-nm-thick-film of h-PMMA-3 is stacked on the top of d-PMMA layer. For the two sets of two-layered thinfilms (hd-PMMA-3 and hd-PMMA-4), we made neutron reflectivity measurements during the isothermal
annealing process at 409 K. From the neutron reflectivity as a function of scattering vector q, we evaluated thetime evolution of the thicknesses of d-PMMA and h-PMMA layers, the roughness at the interface between
d-PMMA and h-PMMA layers.
For hd-PMMA-3 samples, the glass transition temperature Tg of the d-PMMA layer decreases withincreasing fraction of d-PMMA-5, because Tg of d-PMMA-5 is lower than Tg of d-PMMA-6.
The glass transition temperature, Tg, of d-PMMA layer is higher than that of h-PMMA layer for hd-PMMA-2,
while Tg of d-PMMA layer is lower than that of h-PMMAlayer for hd-PMMA-1. Our previous neutron1reflectivity measurements suggest the possibility that the difference in Tg between the d-PMMA and h-PMMA
might induce the asymmetry of diffusion of polymer chains at the interface and hence the different time
evolution of the thickness of the d-PMMA layer and h-PMMA layer in the 2-layered thin films of d-PMMA and2. 実験方法及び結果（つづき） Experimental method and results (continued)
Figure 1 shows the annealing time dependence of the thicknesses of d-PMMA and h-PMMA layers for four
different ratios of d-PMMA-6 and d-PMMA-5. From this figure, we can see that the thickness of d-PMMAlayer increases and the thickness of h-PMMA layer decreases with increasing annealing time for hd-PMMA-3
with the fraction of 1.0:0, while the thickness of d-PMMA layer decreases and the thickness of h-PMMA layer
increases with increasing annealing time for hd-PMMA-3 with the fraction of 0.9:0.1, 0.8:0.2, and 0.6:0.4. This
result suggests that the decrease in Tg of d-PMMA layer, by blending d-PMMA-6 with d-PMMA-5, can bemonitored by the time evolution of the thicknesses of d-PMMA and h-PMMA layers.
Figure 2 shows the annealing time dependence of the thicknesses of d-PMMA and h-PMMA layers for four
different thicknesses of d-PMMA layers from 13 nm to 49 nm. During the annealing process at 409 K, thethickness of d-PMMA layer increases with increasing annealing time for the 35nm-thick-d-pMMA layer and49nm-thick-d-PMMA layer. For the 25nm-thick-d-PMMA layer, the thickness of d-PMMA layer decreases
with increasing annealing time. Furthermore, the decreasing rate for th 13nm-thick-d-PMMA is much larger
than that of the 25nm-thick-d-PMMA layer. Based on the observed results given in Figure 1, the observed
dependence of the time evolution of the thickness of the d-PMMA layer on the initial thickness of the d-PMMAlayer can be interpreted as follows. For 35nm- and 49nm-thick-d-PMMA layer, the glass transition
temperature is almost equal to that of the bulk d-PMMA, which is by a few degree larger than that of theh-PMMA layer. As the initial thickness of the d-PMMA layer decreases from 35nm to 25nm and then 13nm,
the Tg of the d-PMMA layer decreases and as a result, the Tg of d-PMMA layer is lower than that of theh-PMMA layer. If this interpretation is correct, the annealing time dependence of the thickness of the d-PMMA
layer in the two layered thin films of d-PMMA and h-PMMA can be used for monitor to evaluate the glasstransition temperature of the thin polymer layer.

Fig.1

Annealingtime

dependence

Fig.2

of

Annealingtime

dependenceofthickness of d-PMMA layer for 2-layered

thickness of d-PMMA layer for 2-layeredfilms of hd-PMMA-3 with various blending

films of hd-PMMA-4 with various initialfractions of d-PMMA-6 and d-PMMA-5.

thicknesses of d-PMMA-6.

2