Solvent-free, ultrafast and ultrathin PDMS coating triggered by plasma for molecule separation and release

In this work, we developed a facile, ultrafast, and solvent-free polydimethylsiloxane (PDMS) coating method triggered by plasma for ultrathin coating on various nanostructured substrates at room temperature. During plasma treatment, the monomers in the bulk elastomer were excited and deposited on the surrounding substrates. The whole coating process can be completed within 15 s at room temperature, without the use of any solvent, demonstrating its green, energy-saving, and sustainable nature. The coated material and the underlying mechanism were investigated in detail by various characterization methods, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), mass spectrometry, and water static contact angle, fluorescence and electrochemical measurements, as well as simulation. The obtained PDMS coating was ultrathin, uniform, crack-free and quite stable, and was applied to the nanochannel membrane for molecular separation based on polarity. Thanks to the ultrasmall thickness and crack-free properties, a significant high flux as well as high selectivity was achieved. Furthermore, the ultrathin crack-free PDMS coating was also applied for the sealing of the nanochannel membrane for the controlled release of tripyridine ruthenium under acidic conditions. The developed green method would be potentially applied for coating of other polymers on various substrates and shows application in separation, sensing, surface modification, and protection.

Automated summary

An efficient and solvent-free PDMS coating method was developed with plasma treatment, enabling ultrathin coatings on nanostructured substrates within 15 seconds at room temperature. The method showed great potential for various applications in separation, controlled release, sensing, surface modification, and protection.