SEM observations of particle track membrane surfaces modificated using plasma treatment

Properties of poly(ethylene terephthalate) track membrane (PET TM) exposed to an allyl alcohol radiofrequency plasma after pre-activation its surface in an oxygen plasma were studied. The influence of plasma treatment conditions on basic membrane characteristics, i.e. pore size and shape, wettability, and water permeability, was studied. It has been shown that the plasma treatment of membrane can significantly improve its performance characteristics.

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Modification of Asymmetric Polysulfone Membrane Surfaces using Mixed Ar/O2 Plasma Technique

Walailak Journal of Science and Technology (WJST) ◽

10.48048/wjst.2019.4773 ◽

2018 ◽

Vol 16 (6) ◽

pp. 423-431

Author(s):

Chaiporn KAEW-ON ◽

Thawat CHITTRAKARN ◽

Soraya RUANGDIT ◽

Chalad YUENYAO ◽

Yutthana TIRAWANICHAKUL

Keyword(s):

Plasma Treatment ◽

Functional Groups ◽

Membrane Surface ◽

Glow Discharge Plasma ◽

Coagulation Bath ◽

Dense Layer ◽

Water Contact ◽

Polysulfone Membrane ◽

Membrane Surfaces ◽

Phase Inversion Technique

Asymmetric polysulfone (PSF) membranes for gas separation were prepared via dry-wet phase inversion technique at different conditions such as coagulation bath temperature (CBT) and evaporation time (ET). The thickness of the dense layer that plays an important role on gas selectivity has been investigated by adjusting CBT and ET. Additionally, membranes were treated with mixed Ar/O2 DC glow discharge plasma in order to modify membrane wettability, surface roughness, and functional groups on the membrane surface. Scanning electron microscopy (SEM) was used to illustrate a cross sectional structure of PSF membranes. Hydrophilic properties of the membrane surfaces were analyzed via water contact angle (WCA) and surface energy measurements. Morphological structures of membrane surfaces, roughness and creation of functional groups were analyzed both before and after plasma treatment by atomic force microscopy and Fourier transform infrared spectroscopy, respectively. Experimental results show that CBT and ET can change porous voids size of the supporting layer and the dense layer thickness underneath of the membrane surface, while a mixed Ar/O2 gas plasma treatment can enhance hydrophilic properties of the asymmetric PSF membrane surfaces.

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Stereo Electron Microscopy Applied to High Resolution Freeze-Etch Replicas

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100068527 ◽

1970 ◽

Vol 28 ◽

pp. 306-307

Author(s):

L. Andrew Staehelin

Keyword(s):

Electron Microscopy ◽

Plastic Deformation ◽

High Resolution ◽

Smooth Surfaces ◽

Small Particles ◽

Membrane Surfaces ◽

Wide Acceptance ◽

New Information ◽

Number Of Particles ◽

Small Holes

Freeze-etched membranes usually appear as relatively smooth surfaces covered with numerous small particles and a few small holes (Fig. 1). In 1966 Branton (1“) suggested that these surfaces represent split inner mem¬brane faces and not true external membrane surfaces. His theory has now gained wide acceptance partly due to new information obtained from double replicas of freeze-cleaved specimens (2,3) and from freeze-etch experi¬ments with surface labeled membranes (4). While theses studies have fur¬ther substantiated the basic idea of membrane splitting and have shown clearly which membrane faces are complementary to each other, they have left the question open, why the replicated membrane faces usually exhibit con¬siderably fewer holes than particles. According to Branton's theory the number of holes should on the average equal the number of particles. The absence of these holes can be explained in either of two ways: a) it is possible that no holes are formed during the cleaving process e.g. due to plastic deformation (5); b) holes may arise during the cleaving process but remain undetected because of inadequate replication and microscope techniques.

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