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Title: Impact of solvents and supercritical CO{sub 2} drying on the morphology and structure of polymer-based biofilms

In the present work, two-dimensional systems based on biodegradable polymers such as poly(ε-caprolactone) (PCL), poly(ethylene oxide) (PEO) and polylactic acid (PLA) are fabricated by means of a sustainable approach which consists in inducing phase separation in solutions of such polymers and “green” solvents, namely ethyl lactate (EL) and ethyl acetate (EA). The extraction of the solvent is promoted by a controlled drying process, which is performed in either air or supercritical CO{sub 2}. The latter can indeed act as both an antisolvent, which favors the deposition of the polymer by forming a mixture with EL and EA, and a plasticizing agent, whose solvation and transport properties may considerably affect the microstructure and crystallinity of the polymer films. The morphological, topographical and crystalline properties of the films are tailored through a judicial selection of the materials and the processing conditions and assessed by means of thermal analyses, polarized optical microscopy, scanning electron microscopy and confocal interferometric microscopy. The results show that the morphological and crystalline properties of the films are strongly dependent on the choice of both the polymer/solvent system and the operating conditions during the drying step. In particular, the morphological, topographical and thermal properties of films prepared starting frommore » highly crystalline polymers, namely PCL and PEO, are greatly affected by the crystallization of the material. Conversely, the less crystalline PLA forms almost completely amorphous films.« less
Authors:
; ;  [1] ; ;  [2]
  1. Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Piazzale V. Tecchio, 80, 80125 Napoli (Italy)
  2. Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra (Spain)
Publication Date:
OSTI Identifier:
22280351
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1599; Journal Issue: 1; Conference: 7. international conference on times of polymers (TOP) and composites, Ischia (Italy), 22-26 Jun 2014; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; ACETATES; CARBON DIOXIDE; CRYSTALLIZATION; DEPOSITION; DRYING; LACTATES; MICROSTRUCTURE; MORPHOLOGY; OPTICAL MICROSCOPY; POLYETHYLENE GLYCOLS; SCANNING ELECTRON MICROSCOPY; SOLVENTS; THERMAL ANALYSIS; THERMODYNAMIC PROPERTIES; THIN FILMS