Authors Schmaljohann, D. ; Nitschke, M. ; Beyerlein, D. ; Werner, C.
Title Thermo-reversible swelling of plasma immobilized hydrogel films
Date 01.04.2003
Number 10988
Abstract A series of plasma immobilized hydrogel films based on PNiPAAm-g-PEG or PDEAAm-g-PEG, resp., has been studied with respect to their swelling behavior. Plasma immobilization was confirmed to be a powerful tool for covalent attachment of a polymer film onto polymeric substrates. The films were studied with temperature-dependent ellipsometry. All films showed a thermo-reversible swelling behavior. Two time regimes of swelling were identified. The dynamic swelling occurs almost instantaneously and can be utilized for various biomedical applications. The swelling equilibrium can be at much higher swelling degrees. In general, the films show a slight shift in the transition temperatures towards lower values compared to the polymer solutions. Electrolytes present in buffer solutions or cell culture media further decrease the transition temperature. The main structural difference within this polymer series lays in the two different monomeric units NiPAAm and DEAAm. It is noteworthy that DEAAm causes a more gradual change in film thickness, whereas the transition in NiPAAm containing films is sharper. In all cases a hysteresis between heating and cooling was found.<br /><br />Polymeric Surface Modification: Biomedical Applications<br />The 225th ACS National Meeting, New Orleans, LA, March 23-27, 2003
Publisher Polymer Preprints
Citation Polymer Preprints 44 (2003) 196-197

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