A facile method towards rough morphology polymer brush for increased mobility of embedded nanoparticles

- A simple method to obtain polymer brush with rough nanoscale morphology is demonstrated.
- Roughness can be controlled by varying solvent qualities during the first and second round growths.
- Rough nanoscale morphology resulted in better mobility of incorporated gold nanoparticles.

The control of polymer brush morphology is important in determining its performance for various applications such as for anti-fouling coatings or as a host for polymer brush-nanoparticle nanocomposites. Herein we introduce a novel method to vary the surface roughness of polymer brushes by sequential growth in different solvent qualities. Poly(oligo ethylene glycol) methacrylate (POEGMA) was first grown homogeneously using a solvent of 20% water in methanol. A second round of synthesis was then performed with varying ratio of methanol-to-water and ethanol-to-water. We found that roughness generally increased with higher water content during the second round synthesis. Finally we observed, through incorporating as-prepared gold nanoparticles into POEGMA, that nanoparticle distribution and mobility could be improved by having a rougher surface morphology. These findings could be beneficial in designing localized surface plasmon resonance (LSPR)-based solid phase sensing platforms that rely on gold nanoparticle re-organization in polymer brushes.

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