Interaction of a double hydrophilic block copolymer with lipid monolayers at the air–water interface

• Published in: Thin solid films Vol. 550; pp. 621 - 629
• Main Authors: Romão, Rute I.S., Martinho, José M.G., Gonçalves da Silva, Amélia M.P.S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.01.2014; Elsevier
• Subjects: Additives; Binary mixtures; Blocking; Condensed matter: structure, mechanical and thermal properties; Double hydrophilic block copolymer; Exact sciences and technology; Immersion; Langmuir monolayers; Langmuir-blodgett films; Lipids; Micro-segregation; Monolayers; Physics; Polymer – phospholipid interaction; Stearic acid; Surface pressure; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Micro-segregation; Double hydrophilic block copolymer; Langmuir monolayers; Polymer – phospholipid interaction; Gas liquid interface; Pressure effects; Segregation; Amides; Lipids; Phospholipids; Polymer - phospholipid interaction; Langmuir layer; Morphology; Low pressure; Monolayers; Phosphatidylcholine; Polymers; Sodium compounds; Block copolymer
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2013.10.120

The interaction of poly(N,N-dimethylacryl-amide)-b-poly(N,N-diethylacrylamide) (PDMA207-b-PDEA177), (DHBC), with 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), 1,2-dipalmitoyl-sn-glycero-3-phospho-(1′-rac-glycerol) (sodium salt) (DPPG) and stearic acid (SA), was investigated at the air–water interface. The π−A isotherms of DHBC/DPPC and DHBC/DPPG binary mixtures are nearly the sum of the contribution of components weighted by the molar composition, — the additive rule. The π−A curves of the mixtures show a plateau at ~7mNm−1, owing to the immersion of the hydrophilic block PDMA, and other at ~27mNm−1 attributed to the immersion of the less hydrophilic PDEA block. Differently, the binary mixtures of DHBC/SA and PDEA homopolymer/SA do not follow the additive rule of the components showing an expanding effect at low surface pressures. Brewster angle microscopy images show that both DHBC and PDEA polymers interact with lipid monolayers, strongly disturbing their morphology. •Hydrophilic polymer incorporates in the expanded regime of the lipid monolayers.•Polymer adsorbs underneath lipid condensed monolayers.•Double hydrophilic block copolymer interacts with monolayers of phospholipids.