Top‐down approach to attach liquid polyethylene glycol to solid surfaces by plasma interaction

Abstract

A novel top-down approach is presented to produce stable functional films from low vapor pressure liquids via plasma processing. Low-pressure plasma activation and deposition are examined to cross-link liquid polyethylene glycol (PEG-400) surfaces. After stabilizing the thus-obtained films on the liquid with a silicone backing layer, water contact angle measurements, Fourier-transform infrared spectroscopy and scanning electron microscopy imaging were used for characterization. The results show that PEG molecules are covalently bonded to the solid films providing high hydrophilicity. K E Y W O R D S immobilization of molecules, liquid substrates, plasma polymerization, plasma treatment, polyethylene glycol

Plasma Processing of Low Vapor Pressure Liquids to Generate Functional Surfaces

“…It has been reported that PDMS contains low-molecular-weight molecules that can easily diffuse through a 50 to 70 nm thick carbon coating within hours and restore hydrophobicity of a former hydrophilic surface [ 78 ]. Thus, this diffusion can be assumed to have taken place in our samples, since it can be inhibited but not completely prevented by the PPF with a thickness of 200 nm, and the partially cross-linked PEG layer, which had a thickness in the same range, as we reported earlier [ 50 ].…”

“…So far, the described approaches have aimed at depositing solid materials on liquids while using the liquid just as supporting substrate. Going a step further, we proposed a novel approach to use a plasma process to deposit free-standing, thin films on liquid polyethylene glycol (PEG) and to additionally functionalize these films by covalently attaching PEG molecules [ 50 ]. The process schematic is depicted in Figure 1 .…”

“…In this way, the formerly inaccessible PEG side could be turned upwards and was analyzed. We could verify an attachment of PEG resulting in highly hydrophilic surface properties [ 50 ].…”

“…By plasma processing using argon and oxygen, partial cross-linking due to impinging ions, radicals and UV radiation occurred at the liquid’s surface, forming a solid PEG film. By applying an ethylene plasma, we combined the cross-linking with the effect of plasma polymerization, leading to a thin (∼200 nm [ 50 ]) hydrocarbon film covering the liquid and being covalently bond to it. Results on the composition, structure and surface properties of these samples and mechanisms leading to stable functionalized surfaces are presented and discussed.…”

Investigation of the Impact of Cold Plasma Treatment on the Chemical Composition and Wettability of Medical Grade Polyvinylchloride

“…The plasma treatment creates a complex mixture of surface functionalities, which influence surface physical and chemical properties; this results in a dramatic increase in the surface energy and consequent change in the wetting behaviour of the surface [9][10][11][12]. It was demonstrated recently that the plasma treatment may result in cross-linking of polymer molecules [13]. It was reported that plasma treatment leads to the essential electrical charging of a polymer surface observed for both synthetic and biological polymers [14][15].…”