1
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Ogieglo W, Puspasari T, Ma X, Pinnau I. Sub-100 nm carbon molecular sieve membranes from a polymer of intrinsic microporosity precursor: Physical aging and near-equilibrium gas separation properties. J Memb Sci 2020. [DOI: 10.1016/j.memsci.2019.117752] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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2
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Swelling of 9 polymers commonly employed for solvent-resistant nanofiltration membranes: A comprehensive dataset. J Memb Sci 2019. [DOI: 10.1016/j.memsci.2018.09.059] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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3
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Kiran E, Hassler JC. High-Pressure Torsional Braid Analysis (HP-TBA): A new technique for assessment of thermal transitions and changes in moduli of polymers exposed to supercritical or compressed fluids. J Supercrit Fluids 2019. [DOI: 10.1016/j.supflu.2018.07.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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4
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Ogieglo W, Ghanem B, Ma X, Wessling M, Pinnau I. High-Pressure CO 2 Sorption in Polymers of Intrinsic Microporosity under Ultrathin Film Confinement. ACS APPLIED MATERIALS & INTERFACES 2018; 10:11369-11376. [PMID: 29528618 DOI: 10.1021/acsami.8b01402] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Ultrathin microporous polymer films are pertinent to the development and further spread of nanotechnology with very promising potential applications in molecular separations, sensors, catalysis, or batteries. Here, we report high-pressure CO2 sorption in ultrathin films of several chemically different polymers of intrinsic microporosity (PIMs), including the prototypical PIM-1. Films with thicknesses down to 7 nm were studied using interference-enhanced in situ spectroscopic ellipsometry. It was found that all PIMs swell much more than non-microporous polystyrene and other high-performance glassy polymers reported previously. Furthermore, chemical modifications of the parent PIM-1 strongly affected the swelling magnitude. By investigating the behavior of relative refractive index, nrel, it was possible to study the interplay between micropores filling and matrix expansion. Remarkably, all studied PIMs showed a maximum in nrel at swelling of 2-2.5% indicating a threshold point above which the dissolution in the dense matrix started to dominate over sorption in the micropores. At pressures above 25 bar, all PIMs significantly plasticized in compressed CO2 and for the ones with the highest affinity to the penetrant, a liquidlike mixing typical for rubbery polymers was observed. Reduction of film thickness below 100 nm revealed pronounced nanoconfinement effects and resulted in a large swelling enhancement and a quick loss of the ultrarigid character. On the basis of the partial molar volumes of the dissolved CO2, the effective reduction of the Tg was estimated to be ∼200 °C going from 128 to 7 nm films.
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Affiliation(s)
- Wojciech Ogieglo
- DWI Leibniz Institute for Interactive Materials , Forckenbeckstr. 50 , 52074 Aachen , Germany
- Functional Polymer Membranes Group, Advanced Membranes and Porous Materials Center, Division of Physical Sciences and Engineering , King Abdullah University of Science and Technology (KAUST) , Thuwal, Jeddah 23955-6900 , Kingdom of Saudi Arabia
| | - Bader Ghanem
- Functional Polymer Membranes Group, Advanced Membranes and Porous Materials Center, Division of Physical Sciences and Engineering , King Abdullah University of Science and Technology (KAUST) , Thuwal, Jeddah 23955-6900 , Kingdom of Saudi Arabia
| | - Xiaohua Ma
- Functional Polymer Membranes Group, Advanced Membranes and Porous Materials Center, Division of Physical Sciences and Engineering , King Abdullah University of Science and Technology (KAUST) , Thuwal, Jeddah 23955-6900 , Kingdom of Saudi Arabia
| | - Matthias Wessling
- DWI Leibniz Institute for Interactive Materials , Forckenbeckstr. 50 , 52074 Aachen , Germany
| | - Ingo Pinnau
- Functional Polymer Membranes Group, Advanced Membranes and Porous Materials Center, Division of Physical Sciences and Engineering , King Abdullah University of Science and Technology (KAUST) , Thuwal, Jeddah 23955-6900 , Kingdom of Saudi Arabia
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5
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Scherillo G, Loianno V, Pierleoni D, Esposito R, Brasiello A, Minelli M, Doghieri F, Mensitieri G. Modeling Retrograde Vitrification in the Polystyrene-Toluene System. J Phys Chem B 2018; 122:3015-3022. [PMID: 29499111 DOI: 10.1021/acs.jpcb.8b01766] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Atactic polystyrene, as reported in a recent contribution by our group, displays a marked change in glass transition when exposed to toluene vapor due to plasticization associated with vapor sorption within the polymer. The dependence of the glass transition temperature of the polymer-penetrant mixture on the pressure of toluene vapor is characterized by the so-called "retrograde vitrification" phenomenon, in that, at a constant pressure, a rubber to glass transition occurs by increasing the temperature. In this contribution, we have used a theoretical approach, based on the nonrandom lattice fluid thermodynamic model for the polymer-toluene mixture, to predict the state of this system, i.e., rubbery or glassy, as a function of fluid pressure and system temperature. The experimentally detectable glass transition is assumed to be a kinetically affected evidence of an underlying II order thermodynamic transition of the polymer mixture. On the basis of this hypothesis, the Gibbs-Di Marzio criterion, stating that equilibrium configurational entropy is zeroed at the glass transition, has been applied to locate the transition. The working set of equations consists of the expression of configurational entropy obtained from the adopted lattice fluid model equated to zero, coupled with the equation expressing the phase equilibrium between the polymer phase and the pure toluene vapor phase in contact and with the equations of state for the two phases. Theoretical predictions are in good qualitative and quantitative agreement with the experimental results previously obtained gravimetrically performing "dynamic" sorption experiments, which represent a neat example of the occurrence of so-called "type IV" glass transition temperature vs pressure behavior. The peculiar retrograde vitrification phenomenon and the glass transition temperature vs pressure envelope determined experimentally are well described by the proposed theoretical approach.
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Affiliation(s)
- Giuseppe Scherillo
- Department of Chemical, Materials and Production Engineering (DICMAPI) , University of Naples Federico II , Naples , Italy
| | - Valerio Loianno
- Department of Chemical, Materials and Production Engineering (DICMAPI) , University of Naples Federico II , Naples , Italy
| | - Davide Pierleoni
- Department of Civil, Chemical, Environmental and Materials Engineering (DICAM) , Alma Mater Studiorum University of Bologna , Bologna , Italy
| | - Rosario Esposito
- Department of Chemical, Materials and Production Engineering (DICMAPI) , University of Naples Federico II , Naples , Italy
| | - Antonio Brasiello
- Department of Industrial Engineering (DIIn) , Università degli Studi di Salerno , Fisciano ( Salerno ), Italy
| | - Matteo Minelli
- Department of Civil, Chemical, Environmental and Materials Engineering (DICAM) , Alma Mater Studiorum University of Bologna , Bologna , Italy
| | - Ferruccio Doghieri
- Department of Civil, Chemical, Environmental and Materials Engineering (DICAM) , Alma Mater Studiorum University of Bologna , Bologna , Italy
| | - Giuseppe Mensitieri
- Department of Chemical, Materials and Production Engineering (DICMAPI) , University of Naples Federico II , Naples , Italy
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6
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Pierleoni D, Minelli M, Scherillo G, Mensitieri G, Loianno V, Bonavolontà F, Doghieri F. Analysis of a Polystyrene-Toluene System through "Dynamic" Sorption Tests: Glass Transitions and Retrograde Vitrification. J Phys Chem B 2017; 121:9969-9981. [PMID: 28985470 DOI: 10.1021/acs.jpcb.7b08722] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Exposing a glassy polymer to a fluid phase (in gaseous or liquid state) containing a low molecular weight compound results in the sorption of the latter within the polymer, inducing, among other effects, the plasticization of the material which also promotes a change in the glass transition temperature. The amount of sorbed penetrant is often related in a complex fashion to the temperature and pressure of the fluid, thus determining that the locus of glass transition, when represented in pressure-temperature coordinates, may display as well rather complex patterns. This is an issue of particular importance in several applications of glassy polymers. In particular, we investigated the behavior of polystyrene in contact with toluene vapor by performing several modes of dynamic sorption experiments, in which the rate of change of the temperature of the system and/or of the pressure of the vapor phase are controlled with high accuracy, with the aim of creating a map of rubbery and glassy states of the polymer as a function of temperature and pressure of the toluene vapor. Isothermal tests were performed by changing the pressure at a controlled rate, isobaric tests were performed by changing the temperature at a controlled rate, and isoactivity tests were performed by concurrently changing, in a proper way, both temperature and pressure. A relevant feature resulting from these experiments is the presence of a discontinuity in the slope of the mass of toluene sorbed within polystyrene reported as a function of temperature and/or pressure. This discontinuity has been interpreted as the indication of the occurrence of a glass transition. The elaboration of the experimental results allowed identification of the pressure/temperature conditions at which rubbery or glassy states of the polymer mixture are established. Quite interestingly, the system displays the so- called "retrograde vitrification" phenomenon, which consists of the occurrence of a rubbery-to-glassy state transition as the temperature increases at a fixed pressure. The whole set of results has been successfully interpreted on the basis of thermodynamics of II order transitions accounting for the fact that experimental evidence of such transitions is significantly affected by the kinetics of polymer relaxation.
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Affiliation(s)
- Davide Pierleoni
- Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), ALMA MATER STUDIORUM University of Bologna , Bologna, Italy
| | - Matteo Minelli
- Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), ALMA MATER STUDIORUM University of Bologna , Bologna, Italy
| | - Giuseppe Scherillo
- Department of Chemical, Materials and Production Engineering (DICMAPI), University of Naples Federico II , Naples, Italy
| | - Giuseppe Mensitieri
- Department of Chemical, Materials and Production Engineering (DICMAPI), University of Naples Federico II , Naples, Italy
| | - Valerio Loianno
- Department of Chemical, Materials and Production Engineering (DICMAPI), University of Naples Federico II , Naples, Italy
| | - Francesco Bonavolontà
- Department of Electrical Engineering and Information Technology (DIETI), University of Naples Federico II , Naples, Italy
| | - Ferruccio Doghieri
- Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), ALMA MATER STUDIORUM University of Bologna , Bologna, Italy
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7
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Ogieglo W, Rahimi K, Rauer SB, Ghanem B, Ma X, Pinnau I, Wessling M. How Do Organic Vapors Swell Ultrathin Films of Polymer of Intrinsic Microporosity PIM-1? J Phys Chem B 2017; 121:7210-7220. [PMID: 28703006 DOI: 10.1021/acs.jpcb.7b03891] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dynamic sorption of ethanol and toluene vapor into ultrathin supported films of polymer of intrinsic microporosity PIM-1 down to a thickness of 6 nm are studied with a combination of in situ spectroscopic ellipsometry and in situ X-ray reflectivity. Both ethanol and toluene significantly swell the PIM-1 matrix and, at the same time, induce persistent structural relaxations of the frozen-in glassy PIM-1 morphology. For ethanol below 20 nm, three effects were identified. First, the swelling magnitude at high vapor pressures is reduced by about 30% as compared to that of thicker films. Second, at low penetrant activities (below 0.3p/p0), films below 20 nm are able to absorb slightly more penetrant as compared with thicker films despite a similar swelling magnitude. Third, for the ultrathin films, the onset of the dynamic penetrant-induced glass transition Pg has been found to shift to higher values, indicating higher resistance to plasticization. All of these effects are consistent with a view where immobilization of the superglassy PIM-1 at the substrate surface leads to an arrested, even more rigid, and plasticization-resistant, yet still very open, microporous structure. PIM-1 in contact with the larger and more condensable toluene shows very complex, heterogeneous swelling dynamics, and two distinct penetrant-induced relaxation phenomena, probably associated with the film outer surface and the bulk, are detected. Following the direction of the penetrant's diffusion, the surface seems to plasticize earlier than the bulk, and the two relaxations remain well separated down to 6 nm film thickness, where they remarkably merge to form just a single relaxation.
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Affiliation(s)
- Wojciech Ogieglo
- DWI - Leibniz Institute for Interactive Materials , Forckenbeckstrasse 50, 52074 Aachen, Germany
| | - Khosorov Rahimi
- DWI - Leibniz Institute for Interactive Materials , Forckenbeckstrasse 50, 52074 Aachen, Germany
| | - Sebastian Bernhard Rauer
- DWI - Leibniz Institute for Interactive Materials , Forckenbeckstrasse 50, 52074 Aachen, Germany
| | - Bader Ghanem
- Advanced Membranes and Porous Materials Center (AMPMC), King Abdullah University of Science and Technology (KAUST) , Al-Jazri Building 4, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Xiaohua Ma
- Advanced Membranes and Porous Materials Center (AMPMC), King Abdullah University of Science and Technology (KAUST) , Al-Jazri Building 4, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Ingo Pinnau
- Advanced Membranes and Porous Materials Center (AMPMC), King Abdullah University of Science and Technology (KAUST) , Al-Jazri Building 4, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Matthias Wessling
- DWI - Leibniz Institute for Interactive Materials , Forckenbeckstrasse 50, 52074 Aachen, Germany
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8
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Yang Q, Xu Q, Loos K. Enhanced Polystyrene Surface Mobility under Carbon Dioxide at Low Temperature for Nanoparticle Embedding Control. Macromolecules 2015. [DOI: 10.1021/ma5025686] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Qiuyan Yang
- Department of Polymer
Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Qun Xu
- College
of Material Science and Engineering, Zhengzhou University, Zhengzhou 450001, P. R. China
| | - Katja Loos
- Department of Polymer
Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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9
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Ogieglo W, Wormeester H, Eichhorn KJ, Wessling M, Benes NE. In situ ellipsometry studies on swelling of thin polymer films: A review. Prog Polym Sci 2015. [DOI: 10.1016/j.progpolymsci.2014.09.004] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Bal JK, Beuvier T, Chebil MS, Vignaud G, Grohens Y, Sanyal MK, Gibaud A. Relaxation of Ultrathin Polystyrene Films Hyperswollen in Supercritical Carbon Dioxide. Macromolecules 2014. [DOI: 10.1021/ma501281t] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. K. Bal
- LUNAM
Université, IMMM, Faculté de Sciences, Université du Maine, UMR 6283 CNRS, Le Mans Cedex 9, 72000, France
- Centre
for Research in Nanoscience and Nanotechnology, University of Calcutta, Technology Campus, Block JD2, Sector III, Saltlake City, Kolkata, 700098, India
| | - T. Beuvier
- LUNAM
Université, IMMM, Faculté de Sciences, Université du Maine, UMR 6283 CNRS, Le Mans Cedex 9, 72000, France
| | - M. S. Chebil
- LUNAM
Université, IMMM, Faculté de Sciences, Université du Maine, UMR 6283 CNRS, Le Mans Cedex 9, 72000, France
- Laboratoire
d’Ingénierie des MATériaux de Bretagne, Centre de Recherche, Rue de Saint Maudé, BP 92116, 56321 Lorient Cedex France
| | - G. Vignaud
- Laboratoire
d’Ingénierie des MATériaux de Bretagne, Centre de Recherche, Rue de Saint Maudé, BP 92116, 56321 Lorient Cedex France
| | - Y. Grohens
- Laboratoire
d’Ingénierie des MATériaux de Bretagne, Centre de Recherche, Rue de Saint Maudé, BP 92116, 56321 Lorient Cedex France
| | - M. K. Sanyal
- Surface
Physics and Material Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India
| | - A. Gibaud
- LUNAM
Université, IMMM, Faculté de Sciences, Université du Maine, UMR 6283 CNRS, Le Mans Cedex 9, 72000, France
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11
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Ogieglo W, Wessling M, Benes NE. Polymer Relaxations in Thin Films in the Vicinity of a Penetrant- or Temperature-Induced Glass Transition. Macromolecules 2014. [DOI: 10.1021/ma5002707] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Wojciech Ogieglo
- Membrane Science and Technology, MESA+ Institute, University of Twente, Enschede, The Netherlands
| | - Matthias Wessling
- Chemical Process
Engineering, RWTH Aachen University, Aachen, Germany
| | - Nieck E. Benes
- Inorganic
Membranes, MESA+ Institute, University of Twente, Enschede, The Netherlands
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12
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Ogieglo W, Wormeester H, Wessling M, Benes NE. Probing the Surface Swelling in Ultra-Thin Supported Polystyrene Films During Case II Diffusion of n-Hexane. MACROMOL CHEM PHYS 2013. [DOI: 10.1002/macp.201300371] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Wojciech Ogieglo
- Membrane Science and Technology, Mesa Institute for Nanotechnology; University of Twente; P.O. Box 217 7500 AE Enschede The Netherlands
| | - Herbert Wormeester
- Physics of Interfaces and Nanomaterials, Mesa Institute for Nanotechnology; University of Twente; P.O. Box 217 7500 AE Enschede The Netherlands
| | - Matthias Wessling
- RWTH Aachen University, Chemical Process Engineering; Turmstrasse 46 52064 Aachen Germany
| | - Nieck E. Benes
- Inorganic Membranes, Mesa Institute for Nanotechnology; University of Twente; P.O. Box 217 7500 AE Enschede The Netherlands
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13
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Chebil MS, Vignaud G, Grohens Y, Konovalov O, Sanyal MK, Beuvier T, Gibaud A. In Situ X-ray Reflectivity Study of Polystyrene Ultrathin Films Swollen in Carbon Dioxide. Macromolecules 2012. [DOI: 10.1021/ma301035f] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. Souheib Chebil
- LUNAM Université, IMMM, Faculté
de Sciences, Université du Maine, UMR 6283 CNRS, Le Mans Cedex 9, 72000, France
- Laboratoire d’Ingénierie des
MATériaux de Bretagne, Centre de Recherche, Rue de Saint Maudé, BP 92116, 56321 Lorient Cedex France
| | - G. Vignaud
- Laboratoire d’Ingénierie des
MATériaux de Bretagne, Centre de Recherche, Rue de Saint Maudé, BP 92116, 56321 Lorient Cedex France
| | - Y. Grohens
- Laboratoire d’Ingénierie des
MATériaux de Bretagne, Centre de Recherche, Rue de Saint Maudé, BP 92116, 56321 Lorient Cedex France
| | - O. Konovalov
- European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, BP 220, 38043
Grenoble, France
| | - M. K. Sanyal
- Surface
Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India
| | - T. Beuvier
- LUNAM Université, IMMM, Faculté
de Sciences, Université du Maine, UMR 6283 CNRS, Le Mans Cedex 9, 72000, France
| | - A. Gibaud
- LUNAM Université, IMMM, Faculté
de Sciences, Université du Maine, UMR 6283 CNRS, Le Mans Cedex 9, 72000, France
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14
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Ogieglo W, Wormeester H, Wessling M, Benes NE. Spectroscopic ellipsometry analysis of a thin film composite membrane consisting of polysulfone on a porous α-alumina support. ACS APPLIED MATERIALS & INTERFACES 2012; 4:935-943. [PMID: 22235899 DOI: 10.1021/am2015958] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Exposure of a thin polymer film to a fluid can affect properties of the film such as the density and thickness. In particular in membrane technology, these changes can have important implications for membrane performance. Spectroscopic ellipsometry is a convenient technique for in situ studies of thin films, because of its noninvasive character and very high precision. The applicability of spectroscopic ellipsometry is usually limited to samples with well-defined interfacial regions, whereas in typical composite membranes, often substantial and irregular intrusion of the thin film into the pores of a support exists. In this work, we provide a detailed characterization of a polished porous alumina membrane support, using variable-angle spectroscopic ellipsometry in combination with atomic force microscopy and mercury porosimetry. Two Spectroscopic ellipsometry optical models are presented that can adequately describe the surface roughness of the support. These models consider the surface roughness as a distinct layer in which the porosity gradually increases toward the outer ambient interface. The first model considers the porosity profile to be linear; the second model assumes an exponential profile. It is shown that the models can be extended to account for a composite membrane geometry, by deposition of a thin polysulfone film onto the support. The developed method facilitates practicability for in situ spectroscopic ellipsometry studies of nonequilibrium systems, i.e., membranes under actual permeation conditions.
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Affiliation(s)
- Wojciech Ogieglo
- Membrane Science and Technology, Department of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
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15
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Dutriez C, Satoh K, Kamigaito M, Yokoyama H. Nanocellular foaming of fluorine containing block copolymers in carbon dioxide: the role of glass transition in carbon dioxide. RSC Adv 2012. [DOI: 10.1039/c2ra01268e] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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16
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Lan Q, Yu J, Zhang J, He J. Enhanced Crystallization of Bisphenol A Polycarbonate in Thin and Ultrathin Films by Supercritical Carbon Dioxide. Macromolecules 2011. [DOI: 10.1021/ma102797r] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Qiaofeng Lan
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- Graduate University of Chinese Academy of Sciences, Beijing 100039, P. R. China
| | - Jian Yu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Jun Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Jiasong He
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
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17
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Lan Q, Yu J, He J, Maurer FHJ, Zhang J. Thermal Behavior of Poly(l-lactide) Having Low l-Isomer Content of 94% after Compressed CO2 Treatment. Macromolecules 2010. [DOI: 10.1021/ma101473r] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Qiaofeng Lan
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- Graduate School of Chinese Academy of Sciences, Beijing 100039, China
| | - Jian Yu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jiasong He
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Frans H. J. Maurer
- Department of Polymer & Materials Chemistry, Lund Institute of Technology, Lund University, SE-22100 Lund, Sweden
| | - Jun Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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18
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Li X, Barua S, Rege K, Vogt BD. Tuning stability of mesoporous silica films under biologically relevant conditions through processing with supercritical CO2. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:11935-11941. [PMID: 18795807 DOI: 10.1021/la801849n] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Mesoporous materials have been proposed for use in numerous biological environments such as substrates for cell culture and controlled release for drug delivery. Although mesoporous silica synthesis is facile, recent reports (Dunphy et al. Langmuir 2003, 19, 10403; Bass et al. Chem. Mater. 2007, 19, 4349) have demonstrated instability (dissolution) of pure mesoporous silica films under biologically relevant conditions. In this work, we demonstrate a simple processing handle (pressure) to control the dissolution of mesoporous silica films that are synthesized using preformed template films and supercritical CO 2. Spectroscopic ellipsometry is utilized to quantify changes in both the film thickness and porosity; these properties provide insight into the dissolution mechanism. The pore size increases as the films are exposed to phosphate-buffered saline (PBS) through preferential dissolution at the pore wall in comparison to the film surface; a mechanism reminiscent of bulk erosion of scaffolds for drug delivery. Thin mesoporous silica film lifetimes can be extended from several hours using traditional sol-gel approaches to days by using CO 2 processing for identical film thickness. Osteoblast attachment and viability on these films was found to correlate with their increased stability. This enhanced stability opens new possibilities for the utilization of mesoporous silica for biological applications, including drug delivery and tissue engineering.
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Affiliation(s)
- Xinxin Li
- Department of Chemical Engineering, Arizona State University, Tempe, Arizona 85284, USA
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19
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Li Y, Pham JQ, Johnston KP, Green PF. Contact angle of water on polystyrene thin films: effects of CO(2) environment and film thickness. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:9785-93. [PMID: 17685637 DOI: 10.1021/la0636311] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We examine the contact angle of water droplets on polystyrene (PS) thin films of varying thicknesses supported by silicon wafers under both air and pressurized carbon dioxide (CO2) environments. At 23 degrees C, the contact angle is found to increase upon increasing CO2 pressure in the vapor regime and then levels off in the liquid CO2 regime. A macroscopic model based on Young's equation and the geometric-mean method for interfacial tensions, and long-range van der Waals interactions, correctly predicts the trends and the magnitude of the contact angle dependence on pressure, although deviations occur at high CO2 activities. The contact angle was also found to depend on film thickness, h, when h was comparable to or smaller than 50 nm. Specifically, the contact angle decreases with decreasing PS film thickness. This behavior could be accounted for with the use of a model that incorporates the effects of film thickness, CO2 pressure, and the long-range van der Waals potential.
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Affiliation(s)
- Yuan Li
- Graduate Program in Materials Science and Engineering, Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
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Li Y, Park EJ, Lim KT, Johnston KP, Green PF. Role of interfacial interactions on the anomalous swelling of polymer thin films in supercritical carbon dioxide. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/polb.21159] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Li Y, Wang X, Sanchez IC, Johnston KP, Green PF. Ordering in Asymmetric Block Copolymer Films by a Compressible Fluid. J Phys Chem B 2006; 111:16-25. [PMID: 17201424 DOI: 10.1021/jp065987r] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We examine the morphological structures of asymmetric poly(ethylene oxide)-b-poly(1,1'-dihydroperflurooctyl methacrylate) (PEO-b-PFOMA) thin films upon annealing in a compressible fluid, supercritical CO2 (Sc-CO2). The strong affinity between PFOMA and CO2 is found to induce phase segregation when annealing PEO-b-PFOMA films at the same temperature as compared with vacuum. In vacuum, PEO-b-PFOMA films remain disordered from 80 to 180 degrees C, whereas, in Sc-CO2 at 13.9 MPa, an upper order-disorder transition (UODT) between 116 and 145 degrees C is found. In Sc-CO2, the observed ordered structure is layers of PEO spheres embedded in the matrix of PFOMA, followed by a brush layer, in which PEO wets the substrate. The swelling isotherms of PFOMA and PEO in CO2 are correlated with the Sanchez-Lacombe equation of state (SLEOS) to estimate the interaction parameters, XPFOMA-CO2 and XPEO-CO2. The phase segregation (order) induced by CO2 relative to vacuum at a given temperature is explained in terms of two factors: (1) copolymer volume fraction upon dilution with CO2, phi, and (2) the relative interaction parameter, DeltaX= XPEO-CO2 - XPFOMA-CO2. The latter factor favors order and is dominant at low temperatures over the phi factor, which always favors disorder. At high temperatures (above the T(ODT)), the preferential swelling of PFOMA by CO2 is less pronounced ( DeltaX decreases), and the copolymer is disordered.
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Affiliation(s)
- Yuan Li
- Graduate Program in Materials Science and Engineering and Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
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Li Y, Meli L, Lim KT, Johnston KP, Green PF. Structural Inversion of Micellar Block Copolymer Thin Films. Macromolecules 2006. [DOI: 10.1021/ma060960r] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuan Li
- Graduate Program in Materials Science and Engineering, Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, Department of Materials Science and Engineering, The University of Michigan, Ann Arbor, Michigan 48109, and Division of Image and Information Engineering, Pukyong National University, Pusan 608−739, South Korea
| | - Luciana Meli
- Graduate Program in Materials Science and Engineering, Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, Department of Materials Science and Engineering, The University of Michigan, Ann Arbor, Michigan 48109, and Division of Image and Information Engineering, Pukyong National University, Pusan 608−739, South Korea
| | - Kwon T. Lim
- Graduate Program in Materials Science and Engineering, Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, Department of Materials Science and Engineering, The University of Michigan, Ann Arbor, Michigan 48109, and Division of Image and Information Engineering, Pukyong National University, Pusan 608−739, South Korea
| | - Keith P. Johnston
- Graduate Program in Materials Science and Engineering, Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, Department of Materials Science and Engineering, The University of Michigan, Ann Arbor, Michigan 48109, and Division of Image and Information Engineering, Pukyong National University, Pusan 608−739, South Korea
| | - Peter F. Green
- Graduate Program in Materials Science and Engineering, Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, Department of Materials Science and Engineering, The University of Michigan, Ann Arbor, Michigan 48109, and Division of Image and Information Engineering, Pukyong National University, Pusan 608−739, South Korea
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Meli L, Pham JQ, Johnston KP, Green PF. Polystyrene thin films in CO(2). PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:051601. [PMID: 15244823 DOI: 10.1103/physreve.69.051601] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2003] [Revised: 01/28/2004] [Indexed: 05/24/2023]
Abstract
In air, or vacuum environments, liquid polystyrene (PS) thin films (thickness, h<100 nm ) supported by SiOx /Si substrates are structurally metastable or unstable, depending on film thickness. They rupture and eventually form droplets on the SiOx /Si substrates (dewet) due to the influence of destabilizing long-ranged van der Waals dispersion forces. We used scanning force microscopy to examine the structural stability of liquid PS films in the thickness range 5 nm<h<100 nm in liquid and in supercritical carbon dioxide ( CO2 ) environments. All films in this thickness range were metastable; holes developed throughout the films and over time these holes grew, impinged, and eventually formed droplets. The rate of destabilization is controlled by three factors: film thickness, temperature, and CO2 pressure (which dictates CO2 volume fraction in the films). Calculations of the effective interface potentials suggest that the energy barrier for nucleation and growth of holes in CO2 is larger than that in air, and in the limit of vanishingly low PS volume fraction the films should be stable.
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Affiliation(s)
- Luciana Meli
- Department of Chemical Engineering and Texas Material Institute, The University of Texas at Austin, Austin, Texas 78712, USA
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