scholarly journals Phase behaviour of mixtures of polyethylene glycol and polypropylene glycol: Influence of hydrogen bond clusters on the phase diagram

2002 ◽  
Vol 4 (15) ◽  
pp. 3743-3749 ◽  
Author(s):  
Susanne Eckert ◽  
Gerhard Meier ◽  
Ingo Alig
Keyword(s):  
Phase Diagram ◽  
Hydrogen Bond ◽  
Polyethylene Glycol ◽  
Phase Behaviour ◽  
Polypropylene Glycol

scholarly journals Development of Antifouling Polysulfone Membranes by Synergistic Modification with Two Different Additives in Casting Solution and Coagulation Bath: Synperonic F108 and Polyacrylic Acid

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 359
Author(s):  
Katsiaryna S. Burts ◽  
Tatiana V. Plisko ◽  
Mikael Sjölin ◽  
Goncalo Rodrigues ◽  
Alexandr V. Bildyukevich ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Polyacrylic Acid ◽  
Process Water ◽  
Coagulation Bath ◽  
Interpolymer Complex ◽  
Polypropylene Glycol ◽  
Layer Surface ◽  
Membrane Modification ◽  
Selective Layer ◽  
Casting Solution

This study deals with the development of antifouling ultrafiltration membranes based on polysulfone (PSF) for wastewater treatment and the concentration and purification of hemicellulose and lignin in the pulp and paper industry. The efficient simple and reproducible technique of PSF membrane modification to increase antifouling performance by simultaneous addition of triblock copolymer polyethylene glycol-polypropylene glycol-polyethylene glycol (Synperonic F108, Mn =14 × 103 g mol−1) to the casting solution and addition of polyacrylic acid (PAA, Mn = 250 × 103 g mol−1) to the coagulation bath is proposed for the first time. The effect of the PAA concentration in the aqueous solution on the PSF/Synperonic F108 membrane structure, surface characteristics, performance, and antifouling stability was investigated. PAA concentrations were varied from 0.35 to 2.0 wt.%. Membrane composition, structure, and topology were investigated by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The addition of PAA into the coagulation bath was revealed to cause the formation of a thicker and denser selective layer with decreasing its pore size and porosity; according to the structural characterization, an interpolymer complex of the two additives was formed on the surface of the PSF membrane. Hydrophilicity of the membrane selective layer surface was shown to increase significantly. The selective layer surface charge was found to become more negative in comparison to the reference membrane. It was shown that PSF/Synperonic F108/PAA membranes are characterized by better antifouling performance in ultrafiltration of humic acid solution and thermomechanical pulp mill (ThMP) process water. Membrane modification with PAA results in higher ThMP process water flux, fouling recovery ratio, and hemicellulose and total lignin rejection compared to the reference PSF/Synperonic F108 membrane. This suggests the possibility of applying the developed membranes for hemicellulose concentration and purification.

Rheological and structural studies on heat-induced gelation of concentrated skim milk

1995 ◽  
Vol 62 (2) ◽  
pp. 257-267 ◽  
Author(s):  
Atsumi Tobitani ◽  
Haruyoshi Yamamoto ◽  
Toshiaki Shioya ◽  
Simon B. Ross-Murphy
Keyword(s):  
Phase Diagram ◽  
Laser Light ◽  
Skim Milk ◽  
Phase Region ◽  
Polymer Physics ◽  
Phase Behaviour ◽  
Two Phase ◽  
Effects Of Ph ◽  
Higher Temperature ◽  
Temperature Side

SUMMARYHeat-induced gelation of milk was studied using both rheological and structural techniques. The sample was a conventional skim milk, concentrated with an ultrafiltration membrane, which formed gels when heated at appropriate pH. We investigated some factors that are considered to affect the gelation, such as concentration, pH and rennet treatment. The gelation process was monitored with a high precision oscillatory shear rheometer and the structure of gels was evaluated with quasi-elastic laser light scattering. From these results the gelation and phase separation behaviour were determined. By combining the results for different concentrations a phase diagram was obtained, which indicated that skim milk had a two-phase region on the higher temperature side. The effects of pH and rennet treatment were also evaluated with the aid of this phase diagram. The results were discussed on the basis of concepts of the phase behaviour of polymers, which were successfully developed in polymer physics.

scholarly journals Molecular dynamics simulation of α-unsubstituted oligo-thiophenes: dependence of their high-temperature liquid-crystalline phase behaviour on molecular length

2019 ◽  
Vol 7 (32) ◽  
pp. 9984-9995 ◽  
Author(s):  
Flora D. Tsourtou ◽  
Stavros D. Peroukidis ◽  
Vlasis G. Mavrantzas
Keyword(s):  
Molecular Dynamics ◽  
Phase Diagram ◽  
High Temperature ◽  
Molecular Dynamics Simulation ◽  
Liquid Crystalline ◽  
Md Simulations ◽  
Phase Behaviour ◽  
Dynamics Simulation ◽  
Molecular Length ◽  
Temperature Liquid

Phase diagram of α-nT oligomers with n = 5–8 from the MD simulations.

scholarly journals Phase Diagram of Purified CNS Myelin Reveals Continuous Transformation between Expanded and Compacted Lamellar States

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 670
Author(s):  
Julio M. Pusterla ◽  
Emanuel Schneck ◽  
Rafael G. Oliveira
Keyword(s):  
Phase Diagram ◽  
Phase Separation ◽  
Isothermal Transformation ◽  
Phase Behaviour ◽  
Apparent Difference ◽  
X Ray Diffraction ◽  
Lateral Phase Separation ◽  
Diffraction Peaks ◽  
Low Ionic Strength ◽  
Detergent Resistant Membrane

Purified myelin membranes (PMMs) are the starting material for biochemical studies, from individual components up to the isolation of detergent-resistant membrane (DRM) fractions or detergent-insoluble glycosphingolipid (DIG) fractions, which are commonly believed to resemble physiological lipid rafts. The normal DIG isolation protocol involves the extraction of lipids under moderate cooling. The isolation of PMMs also involves the cooling of myelin as well as exposure to low ionic strength (IS). Here, we addressed the combined influence of cooling and IS on the structure of PMMs. The phase behaviour was investigated by small angle X-ray diffraction. Analysis of the diffraction peaks revealed the lamellar periodicity ( d ), the number of periodically correlated bilayers ( N ), and the relatives fractions of each phase. Departure from physiological conditions induced a phase separation in myelin. The effect of monovalent and divalent ions was also compared at equivalent IS, showing a differential effect, and phase diagrams for both ion types were established—Ca2+ induced the well-known over-compacted phase, but additionally we also found an expanded phase at low IS. Na+ promoted phase separation, and also induced over-compaction at sufficiently high IS. Finally, exploring the whole phase diagram, we found evidence for the direct isothermal transformation from the expanded to the compacted phase, suggesting that both phases could in fact originate from the identical primary lateral phase separation, whereas the apparent difference lies in the inter-bilayer interaction that is modulated by the ionic milieu.

The phase behaviour of the system He-N2 related to the phase diagram of pure N2

1988 ◽  
Vol 150 (5) ◽  
pp. 478-483 ◽  
Author(s):  
Luc C. van den Bergh ◽  
Jan A. Schouten
Keyword(s):  
Phase Diagram ◽  
Phase Behaviour

Polyethylene Glycol Adsorption on Silica:  From Bulk Phase Behavior to Surface Phase Diagram

Langmuir ◽  
2007 ◽  
Vol 23 (12) ◽  
pp. 6631-6637 ◽  
Author(s):  
Nawal Derkaoui ◽  
Sylvère Said ◽  
Yves Grohens ◽  
René Olier ◽  
Mireille Privat
Keyword(s):  
Phase Diagram ◽  
Polyethylene Glycol ◽  
Phase Behavior ◽  
Bulk Phase ◽  
Surface Phase
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