Membrane surface modification and characterization by X-ray photoelectron spectroscopy, atomic force microscopy and contact angle measurements

Surface modification of microporous polypropylene membrane was performed by grafting polymerization of acrylamide.The morphological and microstructure changes of the membrane surface were confirmed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and atomic force microscopy. The results indicate that the pore size of the grafted membrane was reduced.

Download Full-text

Surface Modification of Polyethersulfone (PES) with UV Photo-Oxidation

Technologies ◽

10.3390/technologies9020036 ◽

2021 ◽

Vol 9 (2) ◽

pp. 36

Author(s):

Ibrahim Cisse ◽

Sarah Oakes ◽

Shreen Sachdev ◽

Marc Toro ◽

Shin Lutondo ◽

...

Keyword(s):

Surface Roughness ◽

Contact Angle ◽

Atomic Force Microscopy ◽

Photoelectron Spectroscopy ◽

Water Contact ◽

X Ray ◽

Force Microscopy ◽

Photo Oxidation ◽

Atomic Force ◽

Modified Surfaces

Polyethersulfone (PES) films are widely employed in the construction of membranes where there is a desire to make the surface more hydrophilic. Therefore, UV photo-oxidation was studied in order to oxidize the surface of PES and increase hydrophilicity. UV photo-oxidation using low pressure mercury lamps emitting both 253.7 and 184.9 nm radiation were compared with only 253.7 nm photons. The modified surfaces were characterized using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and water contact angle (WCA) measurements. Both sets of lamps gave similar results, showing an increase of the oxygen concentration up to a saturation level of ca. 29 at.% and a decrease in the WCA, i.e., an increase in hydrophilicity, down to ca. 40°. XPS detected a decrease of sp2 C-C aromatic group bonding and an increase in the formation of C-O, C=O, O=C-O, O=C-OH, O-(C=O)-O, and sulphonate and sulphate moieties. Since little change in surface roughness was observed by AFM, the oxidation of the surface caused the increase in hydrophilicity.

Download Full-text

Nanomechanical characterisation of a water-repelling terpolymer coating of cellulosic fibres

Cellulose ◽

10.1007/s10570-020-03675-9 ◽

2021 ◽

Author(s):

Julia Auernhammer ◽

Alena K. Bell ◽

Marcus Schulze ◽

Yue Du ◽

Lukas Stühn ◽

...

Keyword(s):

Contact Angle ◽

Raman Spectroscopy ◽

Atomic Force Microscopy ◽

Water Uptake ◽

Force Microscopy ◽

Angle Measurements ◽

Atomic Force ◽

Contact Angle Measurements ◽

Cellulosic Fibres ◽

Scanning Electron

Abstract Polymer coatings on cellulosic fibres are widely used to enhance the natural fibre properties by improving, for example, the hydrophobicity and wet strength. Here, we investigate the effects of a terpolymer P(S-co-MABP-co-PyMA) coating on cotton linters and eucalyptus fibres to improve the resistance of cellulose fibres against wetness. Coated and uncoated fibres were characterised by using scanning electron microscopy, contact angle measurements, Raman spectroscopy and atomic force microscopy with the objective of correlating macroscopic properties such as the hydrophobicity of the fleece with microscopic properties such as the coating distribution and local nanomechanics. The scanning electron and fluorescence microscopy results revealed the distribution of the coating on the paper fleeces and fibres. Contact angle measurements proved the hydrophobic character of the coated fleece, which was also confirmed by Raman spectroscopy measurements that investigated the water uptake in single fibres. The water uptake also induced a change in the local mechanical properties, as measured by atomic force microscopy. These results verify the basic functionality of the hydrophobic coating on fibres and paper fleeces but call into question the homogeneity of the coating. Graphic abstract

Download Full-text

Anisotropic Character of Talc Surfaces as Revealed by Streaming Potential Measurements, Atomic Force Microscopy, Molecular Dynamics Simulations and Contact Angle Measurements

Canadian Metallurgical Quarterly ◽

10.1179/cmq.2007.46.3.227 ◽

2007 ◽

Vol 46 (3) ◽

pp. 227-235 ◽

Cited By ~ 18

Author(s):

J. Nalaskowski ◽

B. Abdul ◽

H. Du ◽

J.D. Miller

Keyword(s):

Molecular Dynamics ◽

Contact Angle ◽

Atomic Force Microscopy ◽

Streaming Potential ◽

Force Microscopy ◽

Angle Measurements ◽

Atomic Force ◽

Contact Angle Measurements ◽

Anisotropic Character ◽

Dynamics Simulations

Download Full-text

The Effects of the Self-Assembly Time on the Preparation of Lanthanum-Based Thin Films on Sulfonated 3-Mercaptopropyl Trimethoxysilane

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.164.284 ◽

2012 ◽

Vol 164 ◽

pp. 284-288

Author(s):

Tao Bai ◽

Xian Hua Cheng

Keyword(s):

Thin Films ◽

Photoelectron Spectroscopy ◽

Self Assembly ◽

Self Assembled Monolayer ◽

X Ray ◽

Assembly Time ◽

Force Microscopy ◽

Angle Measurements ◽

Atomic Force ◽

Contact Angle Measurements

Lanthanum-based thin films are deposited on the oxidized 3-mercaptopropyl trimethoxysilane self-assembled monolayer (MPTS-SAM) based on the chemisorption of the sulfonic group. The surface energy, chemical composition, phase transformation and surface morphology of the films are analyzed by using contact angle measurements, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The experimental results indicate that the lanthanum-based thin films are absorbed on oxidized MPTS-SAM and lanthanum element with different oxidation states exists in the thin films deposited on the surface of self-assembly monolayers. The content of lanthanum on the oxidized MPTS-SAM increases with the extension of the assembly time and the rare earth reached saturation when the time was 6h.

Download Full-text