Hydrophilization and plasmonization of polystyrene substrate with Au nanoparticle organosol

A hydrophilization procedure of polystyrene substrate surfaces is proposed. Bis-(2-ethylhexyl) sulfosuccinate sodium (AOT) molecules are applied as a hydrophilizing agent. A feature of this procedure is the use of an Au nanoparticle organosol. The organosol allows one to form a hydrophilizing layer with high roughness on the substrate surface. The high roughness is due to the Au nanoparticles encapsulated in this layer. The hydro-philizing effect is greatly enhanced by the high roughness of the hydrophilizing layer. On the sixth day of the hydrophilization, the water contact angle decreases from 95 +/- 3 to 31 +/- 3. Meanwhile, the use of micellar solutions without nanoparticles does not make it possible to achieve such results (the angle decreases from 95 +/- 3 to 74 +/- 4 under similar conditions). The hydrophilization mechanism is described in detail. The polystyrene substrate is completely covered with the hydrophilizing layer during the first hydrophilization day. Then, the substrate wettability is improved only by increasing the roughness of this layer. It has been experimentally established that the proposed procedure is universal and allows one to obtain hydrophilic and superhydrophilic substrates from other materials (viz. Teflon, ITO glass and K glass). Note that the hydrophilized substrates exhibit a plasmon effect. This effect is due to the Au nanoparticles encapsulated in the hydrophilizing layer. The hydrophilizing agent contributes to the stabilization of plasmonic properties.

Automated summary

A method for hydrophilizing polystyrene substrate surfaces using gold nanoparticle organosol is proposed in this study, with detailed description of the hydrophilization process and mechanism. Experimental results demonstrate the universality of the method and the ability to obtain hydrophilic and superhydrophilic substrates from other materials.