Deposition of Thermoresponsive Plasma Polymer Films from N-Isopropylacrylamide Using Dielectric Barrier Discharge at Atmospheric Pressure

Abstract

Thermoresponsive polymers are of great interest as functional coatings in biomedical applications. Poly-N-isopropylacrylamide (NiPAAm) is a widely used compound that switches its surface properties from hydrophilic to hydrophobic by passing the lower critical solution temperature of 32°C. This study investigated plasma polymerization of NiPAAm (pp-NiPAAm) using a dielectric barrier discharge. The films' chemical composition, thermoresponsive behavior, and stability in water were analyzed. Small effects with regard to thermoresponsive behavior were observed for films with high retention of the monomer structure. Unfortunately, however, these films were not stable in water, so plasma copolymerization was performed to improve film stability. Two different monomers were chosen: vinyltrimethoxysilane and glycidyl methacrylate. Thin films of pp-NiPAAM-co-glycidyl methacrylate show thermoresponsive behavior. While stability in water was improved significantly, the responsive behavior was lost after storing these films in water. Future work to ensure the long-term stability of pp-NiPAAm films, particularly in an aqueous environment, has to be done.

Deposition of Plasma‐Polymerized Polyacrylic Acid Coatings by a Non‐Equilibrium Atmospheric Pressure Nanopulsed Plasma Jet

“…In recent years, many efforts have been dedicated to develop coating processes relying on non‐equilibrium plasma sources working at atmospheric pressure; as an example, the possibility to employ atmospheric pressure dielectric barrier discharges (AP‐DBD) to obtain functional surfaces with chemically reactive moieties such as amino or carboxylic groups was demonstrated. Solventless and environmentally friendly, like other PECVD methods, AP‐DBD operates at room temperature (RT) and does not require vacuum pumps, compared to the low pressure plasma processes.…”

Synthesis of Thermo-Sensitive Hydrogels from Free Radical Copolymerization of NIPAAm with MBA Initiated by Atmospheric Plasma Treatment

“…Although the use of low‐pressure plasma technology has proven successful in treatment of textiles or as previous surface activation for subsequent application of micro‐particulate hydrogel based on pNIPAAm and poly((1–4)‐2‐amino‐2‐deoxy‐ d ‐glucopyranose) or chitosan, a major breakthrough to the domain of synthesis of stimuli‐responsive hydrogels using plasma technology for functional finishing of textiles has not yet been accomplished. To date, only preliminary results aiming at deposition of pNIPAAm films using polymerization of NIPAAm in the vapour phase can be found in the literature …”

Insights into switchable thermoresponsive copolymer layers by atmospheric pressure plasma‐initiated chemical vapour deposition

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