Stability and Performance Study of Polyethersulfone Membranes Modified Using Polyelectrolytes

2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Law Yong Ng ◽  
Abdul Wahab Mohammad ◽  
Ching Yin Ng ◽  
Nur Hanis Hayati Hairom

In this research work, porous PES membranes were initially pre-heated for certain duration of time and then surface-modified to reject the MgSO4 salt solutions through self-adsorption of polyelectrolytes. From the experimental work, higher membrane salt rejection capability can be obtained when the number of polyelectrolyte bilayers is increased. The images of the cross-sectional morphology of modified and non-modified membranes were obtained using field emission scanning electron microscopy (FESEM). All modified membranes showed relatively lower contact angle values.

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2174
Author(s):  
Diana Gregor-Svetec ◽  
Mirjam Leskovšek ◽  
Blaž Leskovar ◽  
Urška Stanković Elesini ◽  
Urška Vrabič-Brodnjak

Polylactic acid (PLA) is one of the most suitable materials for 3D printing. Blending with nanoparticles improves some of its properties, broadening its application possibilities. The article presents a study of composite PLA matrix filaments with added unmodified and lignin/polymerised lignin surface-modified nanofibrillated cellulose (NFC). The influence of untreated and surface-modified NFC on morphological, mechanical, technological, infrared spectroscopic, and dynamic mechanical properties was evaluated for different groups of samples. As determined by the stereo and scanning electron microscopy, the unmodified and surface-modified NFCs with lignin and polymerised lignin were present in the form of plate-shaped agglomerates. The addition of NFC slightly reduced the filaments’ tensile strength, stretchability, and ability to absorb energy, while in contrast, the initial modulus slightly improved. By adding NFC to the PLA matrix, the bending storage modulus (E’) decreased slightly at lower temperatures, especially in the PLA samples with 3 wt% and 5 wt% NFC. When NFC was modified with lignin and polymerised lignin, an increase in E’ was noticed, especially in the glassy state.


2001 ◽  
Vol 707 ◽  
Author(s):  
Ian C. Bache ◽  
Catherine M. Ramsdale ◽  
D. Steve Thomas ◽  
Ana-Claudia Arias ◽  
J. Devin MacKenzie ◽  
...  

ABSTRACTCharacterising the morphology of thin films for use in device applications requires the ability to study both the structure within the plane of the film, and also through its thickness. Environmental scanning electron microscopy has proved to be a fruitful technique for the study of such films both because contrast can be seen within the film without the need for staining (as is conventionally done for electron microscopy), and because cross-sectional images can be obtained without charging artefacts. The application of ESEM to a particular blend of relevance to photovoltaics is described.


2010 ◽  
Vol 44 (21) ◽  
pp. 2461-2472 ◽  
Author(s):  
Hui-Juan Zhang ◽  
Zhao-Zhu Zhang ◽  
Fang Guo ◽  
Wei Jiang ◽  
Kun Wang

Oleic acid-modified CuS nanoparticles were chemically synthesized. The tribological properties of surface modified and unmodified CuS nanoparticles as additives in the hybrid polytetrafluoroethylene (PTFE)/Kevlar fabric/phenolic composite were investigated in detail. The experimental results indicated that the incorporation of modified CuS nanoparticles improved the antiwear ability of the fabric/phenolic composite at varied loads and environmental temperatures. The reasons for the enhanced wear properties of the fabric/phenolic composite filled with surface-modified CuS nanoparticles were discussed based on the results of scanning electron microscopy and Fourier transform infrared spectroscopy.


2019 ◽  
Vol 10 (4) ◽  
pp. 301-309
Author(s):  
Maryam Omidvar ◽  
Zahra Hejri ◽  
Ahmad Moarefian

Abstract The present study used modified nanofiltration (NF) membranes to remove the emerging contaminant of amoxicillin (AMX) from synthetic wastewater. For this purpose, Merpol surfactant and polyvinylpyrrolidone were added to the casting solutions to prepare flat sheet asymmetric polyethersulfone (PES) NF membranes through phase inversion process. Then, the effect of adding Merpol surfactant at different concentrations on the morphology, hydrophilicity, and pure water flux (PWF) of the membranes, as well as the separation of AMX from aqueous solutions was investigated. The characteristics of the prepared membranes were studied by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), contact angle (CA) measurement and performance tests. The obtained results approved the improved hydrophilicity of the PES membranes after adding Merpol surfactant to the casting solution. The findings also revealed a gradual increase in the average size of the membrane pores in sub-layer and thinner top layer, proportional to the increase of surfactant content in the solution. The results also confirmed the increase of PWF under the influence of surfactant increase. As a result, for the membrane containing 8 wt% Merpol additive, the lowest CA (52.08°), the highest PWF (76.31 L/m2 h), and maximum AMX excretion (97%) were achieved.


Author(s):  
H. S. Borovetz ◽  
R. K. Matta ◽  
K. J. Goitein ◽  
T.-K. Hung ◽  
M. H. Weissman ◽  
...  

The need for systemic heparin anticoagulation during extended cardiopulmonary bypass (CPB) remains a serious impediment to clinical CPB support of circulatory and respiratory failures, especially in the newborn. Recent development of thromboresistive substrates which can be used to treat extracorporeal surfaces in contact with blood offers the potential for elimination of systemic blood heparinization. The present paper describes a scanning electron microscopy study of the attachment of one such substrate, tridodecyl- methylammonium chloride (TDMAC), to a novel micro-membrane oxygenator.Figure 1 shows a cross-sectional image of the alternating pattern of microchannel conduits for blood flow through the oxygenator. The micro-channels were fabricated on thin metal sheets with an approximate semi-circular shape (150 + 25 microns in radius). The gas exchange to the blood flow in the channels was accomplished through a micro-porous membrane which was placed across the diametric plane of the channels (1).


2016 ◽  
Vol 16 (4) ◽  
pp. 3383-3387 ◽  
Author(s):  
Toichiro Goto ◽  
Nahoko Kasai ◽  
Rick Lu ◽  
Roxana Filip ◽  
Koji Sumitomo

Interfaces between single neurons and conductive substrates were investigated using focused ion beam (FIB) milling and subsequent scanning electron microscopy (SEM) observation. The interfaces play an important role in controlling neuronal growth when we fabricate neuron-nanostructure integrated devices. Cross sectional images of cultivated neurons obtained with an FIB/SEM dual system show the clear affinity of the neurons for the substrates. Very few neurons attached themselves to indium tin oxide (ITO) and this repulsion yielded a wide interspace at the neuron-ITO interface. A neuron-gold interface exhibited partial adhesion. On the other hand, a neuron-titanium interface showed good adhesion and small interspaces were observed. These results are consistent with an assessment made using fluorescence microscopy. We expect the much higher spatial resolution of SEM images to provide us with more detailed information. Our study shows that the interface between a single neuron and a substrate offers useful information as regards improving surface properties and establishing neuron-nanostructure integrated devices.


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