TY - JOUR
T1 - Single-molecule tracking measurement of PDMS layer during curing process
AU - Iwao, Ryo
AU - Yamaguchi, Hiroki
AU - Niimi, Tomohide
AU - Matsuda, Yu
N1 - Funding Information:
This work was partly supported by a JSPS, Japan Grant-in-Aid for Scientific Research (B), No. 16H04277 , 19H02086 and a research encouragement grants from the Asahi Glass Foundation, Japan .
Publisher Copyright:
© 2020 The Authors
PY - 2021/3/1
Y1 - 2021/3/1
N2 - The curing process of poly(dimethylsiloxane) (PDMS) was microscopically investigated by the single-molecule tracking method based on the diffusion motion of fluorescent dye molecules adding to the PDMS layer stored at a temperature of 308K. The PDMS layer was completely cured at 900 min after adding a curing agent. We compared the time- and ensemble-averaged mean square displacements (MSDs) of the tracked molecules at 90, 510, and 900 min after adding the curing agent into the PDMS layer. The discrepancies were observed between the time- and ensemble-averaged MSDs, indicating weak ergodicity breaking. The spatially averaged diffusion coefficient exhibited a two-step decrease: first step was rapid decrease suggesting the extent of crosslinking, and second step was slow one suggesting the increase of crosslink density. The single-molecule trajectory scale analysis revealed the heterogeneous distribution of the diffusion coefficient. By calculating the heat map from the slope of moment scaling spectrum (MSS) of each single-molecule trajectory, cluster structures were recognized. The spatial correlation of the slope of MSS decreased with the time elapsed. These results suggested the existence of the heterogeneous structure in the PDMS layer during the curing process.
AB - The curing process of poly(dimethylsiloxane) (PDMS) was microscopically investigated by the single-molecule tracking method based on the diffusion motion of fluorescent dye molecules adding to the PDMS layer stored at a temperature of 308K. The PDMS layer was completely cured at 900 min after adding a curing agent. We compared the time- and ensemble-averaged mean square displacements (MSDs) of the tracked molecules at 90, 510, and 900 min after adding the curing agent into the PDMS layer. The discrepancies were observed between the time- and ensemble-averaged MSDs, indicating weak ergodicity breaking. The spatially averaged diffusion coefficient exhibited a two-step decrease: first step was rapid decrease suggesting the extent of crosslinking, and second step was slow one suggesting the increase of crosslink density. The single-molecule trajectory scale analysis revealed the heterogeneous distribution of the diffusion coefficient. By calculating the heat map from the slope of moment scaling spectrum (MSS) of each single-molecule trajectory, cluster structures were recognized. The spatial correlation of the slope of MSS decreased with the time elapsed. These results suggested the existence of the heterogeneous structure in the PDMS layer during the curing process.
KW - Curing process
KW - Diffusion coefficient
KW - PDMS
KW - Single-molecule tracking
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U2 - 10.1016/j.physa.2020.125576
DO - 10.1016/j.physa.2020.125576
M3 - Article
AN - SCOPUS:85097199157
SN - 0378-4371
VL - 565
JO - Physica A: Statistical Mechanics and its Applications
JF - Physica A: Statistical Mechanics and its Applications
M1 - 125576
ER -