^{1}, Hong Liu

^{2}, Zhong-Yuan Lu

^{2,a)}and Xue-Zhang Liang

^{1}

### Abstract

We focus on highly grafted binary polymer brushes with compatible components in the cases of different chain lengths. Layered structures parallel to the surface that indicating “phase separation” are observed in a series of dissipative particle dynamics simulations. The stretch parameters indicate that the short chains are suppressed in the lower layer of the film, whereas the longer chains are much stretched in the region dominated by the short chains (lower layer) but possess relaxed conformations in the upper layer. By slightly changing the solvent selectivity to prefer the short chains, we find a reversion of the layered structure. Such a sensitive switch of film property implies its potential application as tuning the wettability and adhesion of the surface in industry.

This work is supported by the National Science Foundation of China (Grant Nos. 20774036, 20974040, and 50930001) and Fok Ying Tung Education Foundation (114018).

I. INTRODUCTION

II. SIMULATION METHOD AND MODEL CONSTRUCTION

III. SIMULATION RESULTS AND DISCUSSION

IV. CONCLUSIONS

### Key Topics

- Polymers
- 29.0
- Solvents
- 27.0
- Entropy
- 9.0
- Surface finishing
- 7.0
- Phase separation
- 6.0

## Figures

The variation in the density difference profile of the two species along the direction as a function of in the systems with and for different graft densities. Five independent samples after equilibrium are chosen to calculate the mean value and the error bar. The error bars are not shown here for clarity.

The variation in the density difference profile of the two species along the direction as a function of in the systems with and for different graft densities. Five independent samples after equilibrium are chosen to calculate the mean value and the error bar. The error bars are not shown here for clarity.

The variation in the density difference profile of the two species along the direction as a function of in the systems with . Five independent samples after equilibrium are chosen to calculate the mean value and the error bar. The error bars are not shown here for clarity.

The variation in the density difference profile of the two species along the direction as a function of in the systems with . Five independent samples after equilibrium are chosen to calculate the mean value and the error bar. The error bars are not shown here for clarity.

The variation in the density difference profile of the two species along the direction as a function of in the systems with (a) and (b) . Five independent samples after equilibrium are chosen to calculate the mean value and the error bar. The error bars are not shown here for clarity.

The variation in the density difference profile of the two species along the direction as a function of in the systems with (a) and (b) . Five independent samples after equilibrium are chosen to calculate the mean value and the error bar. The error bars are not shown here for clarity.

A schematic illustration of different parts of B chain for the consideration of their stretch parameters in accordance with those in Fig. 5.

A schematic illustration of different parts of B chain for the consideration of their stretch parameters in accordance with those in Fig. 5.

The stretch parameters of the binary chains vs the variation in the chain lengths: (a) while increases from 50 to 100 and (b) while increases from 50 to 100. The solid circles stand for , the solid squares for , the lower part solid squares for , and the upper part solid squares for . Inset of (a): The variation of as a function of the chain length difference . Five independent samples after equilibrium are chosen to calculate the mean values and the error bars.

The stretch parameters of the binary chains vs the variation in the chain lengths: (a) while increases from 50 to 100 and (b) while increases from 50 to 100. The solid circles stand for , the solid squares for , the lower part solid squares for , and the upper part solid squares for . Inset of (a): The variation of as a function of the chain length difference . Five independent samples after equilibrium are chosen to calculate the mean values and the error bars.

The variation in the density difference profile of the two species along the z direction as a function of in the systems with and , where (a) the solvent is favoring A but neutral for B and (b) the solvent is “hating” B but neutral for A . Five independent samples after equilibrium are chosen to calculate the mean values and the error bars. The error bars are not shown for clarity.

The variation in the density difference profile of the two species along the z direction as a function of in the systems with and , where (a) the solvent is favoring A but neutral for B and (b) the solvent is “hating” B but neutral for A . Five independent samples after equilibrium are chosen to calculate the mean values and the error bars. The error bars are not shown for clarity.

Article metrics loading...

Full text loading...

Commenting has been disabled for this content