Thickness Dependence of Macrovoid Evolution in Wet Phase-Inversion Asymmetric Membranes

2004 ◽  
Vol 43 (6) ◽  
pp. 1553-1556 ◽  
Author(s):  
Dongfei Li ◽  
Tai-Shung Chung ◽  
Jizhong Ren ◽  
Rong Wang
2012 ◽  
Vol 326-328 ◽  
pp. 422-427 ◽  
Author(s):  
Priscila Anadão ◽  
Rafael Rezende Montes ◽  
Henrique Souza de Santis ◽  
Hélio Wiebeck

Asymmetric polysulfone membranes were prepared by wet-phase inversion method from casting solutions consisting of PSf/NMP and water as non-solvent. The effects of polymer concentration and molar mass were investigated by rheological studies. Moreover, membranes were characterized by scanning electron microscope (SEM). It was found that polymer solutions containing between 22 and 25 wt% PSf/NMP originated microfiltration membranes. The use of a higher mass molar polysulfone has been shown to reduce diameter pore and to maintain morphology. All the results were interrelated into a discussion of the skin formation of asymmetric membranes.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 183
Author(s):  
Mariana F. P. Graça ◽  
Duarte de Melo-Diogo ◽  
Ilídio J. Correia ◽  
André F. Moreira

Despite all the efforts that have been done up to now, the currently available wound dressings are still unable to fully re-establish all the structural and functional properties of the native skin. To overcome this situation, researchers from the tissue engineering area have been developing new wound dressings (hydrogels, films, sponges, membranes) aiming to mimic all the features of native skin. Among them, asymmetric membranes emerged as a promising solution since they reproduce both epidermal and dermal skin layers. Wet or dry/wet phase inversion, scCO2-assisted phase inversion, and electrospinning have been the most used techniques to produce such a type of membranes. Among them, the electrospinning technique, due to its versatility, allows the development of multifunctional dressings, using natural and/or synthetic polymers, which resemble the extracellular matrix of native skin as well as address the specific requirements of each skin layer. Moreover, various therapeutic or antimicrobial agents have been loaded within nanofibers to further improve the wound healing performance of these membranes. This review article provides an overview of the application of asymmetric electrospun membranes as wound dressings displaying antibacterial activity and as delivery systems of biomolecules that act as wound healing enhancers.


2012 ◽  
Vol 128 (1) ◽  
pp. 750-753 ◽  
Author(s):  
Congran Guo ◽  
Stephen M. Budy ◽  
Douglas A. Loy

2021 ◽  
Vol 11 (4) ◽  
pp. 1815
Author(s):  
Michał Młotek ◽  
Agnieszka Gadomska-Gajadhur ◽  
Aleksandra Sobczak ◽  
Aleksandra Kruk ◽  
Michalina Perron ◽  
...  

Materials used for medical applications (e.g., the cellular scaffold) should have not only the specific chemical composition, but the surface layer properties as well. For this reason, a method which enables an increase in the number of pores, wettability of the surface, and improvement the conditions of nutrient transportation into the membrane is being studied. The plasma of a dielectric barrier discharge was applied for the surface modification of polylactide obtained by dry or wet phase inversion. The plasma-modified surface was analyzed by contact angle measurements with water and diiodomethane. The surface free energy (SFE) was calculated by the Owens–Wendt method. The highest SFE and its polar component (67.6 mJ/m2 and 39.5 mJ/m2, respectively) were received when the process was conducted in an Ar + CO2 gas mixture with a discharge power of 20 W. The purpose of this research was to increase the wettability and porosity of the membrane’s surface. It can be concluded that the dielectric barrier discharge can effectively change the surface of the polylactide membranes, and that the structure of the modified membranes was not damaged during modification. The process of modification was easier for the membranes made by dry phase inversion. These materials had higher SFE values after the modification.


2022 ◽  
Vol 641 ◽  
pp. 119924
Author(s):  
Sajjad Mohsenpour ◽  
Sebastian Leaper ◽  
Javad Shokri ◽  
Monica Alberto ◽  
Patricia Gorgojo

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