scholarly journals Physical aging of glassy perfluoropolymers in thin film composite membranes. Part II. Glass transition temperature and the free volume model

2017 ◽  
Vol 525 ◽  
pp. 399-408 ◽  
Author(s):  
Milad Yavari ◽  
Sajjad Maruf ◽  
Yifu Ding ◽  
Haiqing Lin
Keyword(s):  
Thin Film ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Physical Aging ◽  
Composite Membranes ◽  
Film Composite ◽  
Volume Model ◽  
Thin Film Composite ◽  
Free Volume Model

scholarly journals Characteristics of Gas Permeation Behaviour in Multilayer Thin Film Composite Membranes for CO2 Separation

Membranes ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 22 ◽  
Author(s):  
Jelena Lillepärg ◽  
Sabrina Breitenkamp ◽  
Sergey Shishatskiy ◽  
Jan Pohlmann ◽  
Jan Wind ◽  
...  
Keyword(s):  
Thin Film ◽  
Mass Transfer ◽  
Time Lag ◽  
Composite Membranes ◽  
Gas Permeation ◽  
Porous Support ◽  
Film Composite ◽  
Thin Film Composite ◽  
Free Volume Model ◽  
The Individual

Porous, porous/gutter layer and porous/gutter layer/selective layer types of membranes were investigated for their gas transport properties in order to derive an improved description of the transport performance of thin film composite membranes (TFCM). A model describing the individual contributions of the different layers’ mass transfer resistances was developed. The proposed method allows for the prediction of permeation behaviour with standard deviations (SD) up to 10%. The porous support structures were described using the Dusty Gas Model (based on the Maxwell–Stefan multicomponent mass transfer approach) whilst the permeation in the dense gutter and separation layers was described by applicable models such as the Free-Volume model, using parameters derived from single gas time lag measurements. The model also accounts for the thermal expansion of the dense layers at pressure differences below 100 kPa. Using the model, the thickness of a silicone-based gutter layer was calculated from permeation measurements. The resulting value differed by a maximum of 30 nm to the thickness determined by scanning electron microscopy.

scholarly journals Physical Aging Behavior of a Glassy Polyether

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 954
Author(s):  
Xavier Monnier ◽  
Sara Marina ◽  
Xabier Lopez de Pariza ◽  
Haritz Sardón ◽  
Jaime Martin ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Physical Aging ◽  
Glassy State ◽  
Aging Behavior ◽  
Scanning Calorimetry ◽  
Narrow Temperature Range ◽  
Glass Forming ◽  
Fast Scanning Calorimetry

The present work aims to provide insights on recent findings indicating the presence of multiple equilibration mechanisms in physical aging of glasses. To this aim, we have investigated a glass forming polyether, poly(1-4 cyclohexane di-methanol) (PCDM), by following the evolution of the enthalpic state during physical aging by fast scanning calorimetry (FSC). The main results of our study indicate that physical aging persists at temperatures way below the glass transition temperature and, in a narrow temperature range, is characterized by a two steps evolution of the enthalpic state. Altogether, our results indicate that the simple old-standing view of physical aging as triggered by the α relaxation does not hold true when aging is carried out deep in the glassy state.

Tannin-based thin-film composite membranes integrated with nitrogen-doped graphene quantum dots for butanol dehydration through pervaporation

2021 ◽  
Vol 623 ◽  
pp. 119077
Author(s):  
Rumwald Leo G. Lecaros ◽  
Reincess E. Valbuena ◽  
Lemmuel L. Tayo ◽  
Wei-Song Hung ◽  
Chien-Chieh Hu ◽  
...  
Keyword(s):  
Thin Film ◽  
Quantum Dots ◽  
Graphene Quantum Dots ◽  
Composite Membranes ◽  
Film Composite ◽  
Nitrogen Doped ◽  
Thin Film Composite ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

scholarly journals Zwitterionic Triamine Monomer for the Fabrication of Thin-Film Composite Membranes

2020 ◽  
Author(s):  
Ngoc Lieu Le ◽  
Phuoc H.H. Duong ◽  
Bruno A. Pulido ◽  
Suzana P. Nunes
Keyword(s):  
Thin Film ◽  
Composite Membranes ◽  
Film Composite ◽  
Thin Film Composite
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