In this work, FTIR spectroscopy in transmission mode has been used to study the water sorption and transport in poly--caprolactone (PCL). The characteristic spectrum of absorbed water was isolated data by using difference spectroscopy, to obtain a description of the water sorption mechanism at a molecular level. Moreover, spectroscopic data were coupled with gravimetric sorption measurements, to correlate the equilibrium absorbance with water concentration in PCL. The transient sorption stage was also analysed, allowing an estimation of water diffusion coefficient in PCL. The analysis of the spectral region of the (OH) stretching vibration of water revealed the presence of two species of absorbed water, i.e. water molecules directly interacting with carbonyl group of polymer backbone and dimers, corresponding to a second shell hydration layer. Finally, the experimental sorption isotherms were successfully interpreted using an equation of state thermodynamic approach grounded on a compressible lattice fluid framework accounting for self- and cross-hydrogen bond formation. Based on the evidences of the FTIR spectroscopy, in the implementation of the model, only one proton acceptor group (i.e. carbonyl) has been assumed to be present on the polymer backbone.

Water sorption thermodynamics and mass transport in PCL: interactional issues emerging from vibrational spectroscopy / P., Musto; M., Galizia; Scherillo, Giuseppe; Mensitieri, Giuseppe. - In: MACROMOLECULAR CHEMISTRY AND PHYSICS. - ISSN 1521-3935. - 214:(2013), pp. 1921-1930. [10.1002/macp.201300030]

Water sorption thermodynamics and mass transport in PCL: interactional issues emerging from vibrational spectroscopy

SCHERILLO, GIUSEPPE;MENSITIERI, GIUSEPPE
2013

Abstract

In this work, FTIR spectroscopy in transmission mode has been used to study the water sorption and transport in poly--caprolactone (PCL). The characteristic spectrum of absorbed water was isolated data by using difference spectroscopy, to obtain a description of the water sorption mechanism at a molecular level. Moreover, spectroscopic data were coupled with gravimetric sorption measurements, to correlate the equilibrium absorbance with water concentration in PCL. The transient sorption stage was also analysed, allowing an estimation of water diffusion coefficient in PCL. The analysis of the spectral region of the (OH) stretching vibration of water revealed the presence of two species of absorbed water, i.e. water molecules directly interacting with carbonyl group of polymer backbone and dimers, corresponding to a second shell hydration layer. Finally, the experimental sorption isotherms were successfully interpreted using an equation of state thermodynamic approach grounded on a compressible lattice fluid framework accounting for self- and cross-hydrogen bond formation. Based on the evidences of the FTIR spectroscopy, in the implementation of the model, only one proton acceptor group (i.e. carbonyl) has been assumed to be present on the polymer backbone.
2013
Water sorption thermodynamics and mass transport in PCL: interactional issues emerging from vibrational spectroscopy / P., Musto; M., Galizia; Scherillo, Giuseppe; Mensitieri, Giuseppe. - In: MACROMOLECULAR CHEMISTRY AND PHYSICS. - ISSN 1521-3935. - 214:(2013), pp. 1921-1930. [10.1002/macp.201300030]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/556439
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