Semi-alicyclic polyimides as potential membrane oxygenators: Rheological implications on film processing, morphology and blood compatibility

Abstract

Two polyimide structures were prepared from an alicyclic dianhydride and aromatic diamines, containing or lacking fluorine, and were tested as potential membrane oxygenators. First, the solution rheological properties were investigated to evaluate their effect on film processing by tape casting. Velocity and shear rates profiles were simulated to determine the shearing conditions during tape casting and transfer them in the flow curves. Proper films were obtained at a viscosity corresponding to a concentration in entangled regime, where pseudoplastic behavior is still noticed at shear rates beneath the blade. Theoretical predictions of gas permeability indicated a good oxygen (O 2 ) exchange and carbon dioxide (CO 2 ) removal through the studied polymers. Atomic force microscopy (AFM) scans revealed a morphology characterized by an intrinsic porosity. The pore size, uniformity and size distribution was affected by the structure of the diamine moiety. The interactions of blood with polyimide films indicated no prevalent adhesion of cells or plasma proteins. The results showed that the examined samples have adequate properties for potential membrane oxygenator applications.

Poly(azomethine‐imide)s containing siloxane moities: Optical, thermal, mechanical, and morphological properties

“…The phase images of 134F were obtained with tapping mode at room temperature (Figure ). Figure showed that 134F has an irregular topography, and it consists of a small nodular structure in agreement with similar studies in the literature …”

“…Figure 8 showed that 134F has an irregular topography, and it consists of a small nodular structure in agreement with similar studies in the literature. 32 SEM Analysis. SEM analysis of the polymers is an efficient and versatile instrument to clarify the surface morphology of polymers and this analysis provides the details of surface morphology.…”

New Strategy for Inducing Surface Anisotropy in Polyimide Films for Nematics Orientation in Display Applications

“…Such a PI molecular design approach produces disruption of the CTC interactions and hence renders better solubility and transparency [14][15][16]. In recent works, we showed that the use of cycloaliphatic dianhydrides in the PI synthesis leads to transparent materials, with high glass transition temperature, good dimensional stability, and appropriate adhesion with the LCs [9,[17][18][19][20][21]. Moreover, such partially aliphatic PIs have a smooth surface and their morphology can be modified by dynamic plowing lithography [22], rubbing [9,11,23], or by imprinting the banded texture of a lyotropic polymer [24,25].…”

Alignment layers based on poly(oxadiazole‐naphthylimide)s: New aspects on tuning anisotropy of the surface morphology and adhesion via rubbing

“…Similar dependencies of rheological moduli on shear frequency were reported for other PI structures, revealing a transition from viscous to elastic flow. 32,33 The fc parameter is linked to the relaxation features of the studied polymer fluids, indicating the rate at which the macromolecular structure is changed as a result of the applied variable shearing.…”