Influence of nanoparticle processing and additives on PES casting solution viscosity and cast membrane characteristics

Polymer ◽  
2016 ◽  
Vol 103 ◽  
pp. 498-508 ◽  
Author(s):  
Lauren F. Greenlee ◽  
Nikki S. Rentz
Keyword(s):  
Solution Viscosity ◽  
Casting Solution ◽  
Nanoparticle Processing

scholarly journals Effect of Temperature Exposition of Casting Solution on Properties of Polysulfone Hollow Fiber Membranes

Fibers ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 110 ◽  
Author(s):  
Ilya Borisov ◽  
Vladimir Vasilevsky ◽  
Dmitry Matveev ◽  
Anna Ovcharova ◽  
Alexey Volkov ◽  
...  
Keyword(s):  
Phase Separation ◽  
Thermal Treatment ◽  
Transport Properties ◽  
Hollow Fiber ◽  
Treatment Time ◽  
Solution Viscosity ◽  
Oxidative Destruction ◽  
Hollow Fiber Membranes ◽  
Selective Layer ◽  
Casting Solution

It was shown for the first time that the conditions of thermal treatment of the casting solution significantly affect the morphology and transport properties of porous, flat, and hollow fiber polysulfone (PSf) membranes. It is ascertained that the main solution components that are subjected to thermo-oxidative destruction are the pore-forming agent polyethylene glycol (PEG) and solvent N-methyl-2-pyrrolidone (NMP). It is proved that hydroxyl groups of PEG actively react in the process of the casting solution thermo-oxidative destruction. It is shown that despite the chemical conversion taking place in the casting solution, their stability towards coagulation virtually does not change. The differences in the membrane morphology associated with the increase of thermal treatment time at 120 °C are not connected to the thermodynamic properties of the casting solutions, but with the kinetics of the phase separation. It is revealed that the change of morphology and transport properties of membranes is connected with the increase of the casting solution viscosity. The rise of solution viscosity resulted in the slowdown of the phase separation and formation of a more densely packed membrane structure with less pronounced macropores. It is determined experimentally that with the increase of casting solution thermal treatment time, the membrane selective layer thickness increases. This leads to the decrease of gas permeance and the rise of the He/CO2 selectivity for flat and hollow fiber membranes. In the case of hollow fibers, the fall of gas permeance is also connected with the appearance of the sponge-like layer at the outer surface of membranes. The increase of selectivity and decline of permeance indicates the reduction of selective layer pore size and its densification, which agrees well with the calculation results of the average membrane density. The results obtained are relevant to any polymeric casting solution containing NMP and/or PEG and treated at temperatures above 60 °C.

scholarly journals A Biofouling Resistant Zwitterionic Polysulfone Membrane Prepared by a Dual-Bath Procedure

Membranes ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 69
Author(s):  
Irish Valerie B. Maggay ◽  
Hana Nur Aini ◽  
Mary Madelaine G. Lagman ◽  
Shuo-Hsi Tang ◽  
Ruth R. Aquino ◽  
...  
Keyword(s):  
Blood Cell ◽  
Biomedical Applications ◽  
Cell Attachment ◽  
Solution Viscosity ◽  
Recovery Ratio ◽  
Polysulfone Membrane ◽  
Casting Solution ◽  
Random Polymer ◽  
Ft Ir

This study introduces a zwitterionic material to modify polysulfone (PSf) membranes formed by a dual bath procedure, in view of reducing their fouling propensity. The zwitterionic copolymer, derived from a random polymer of styrene and 4-vinylpyrridine and referred to as zP(S-r-4VP), was incorporated to the PSf solution without any supplementary pore-forming additive to study the effect of the sole copolymer on membrane-structuring, chemical, and arising properties. XPS and mapping FT-IR provided evidence of the modification. Macrovoids appeared and then disappeared as the copolymer content increased in the range 1–4 wt%. The copolymer has hydrophilic units and its addition increases the casting solution viscosity. Both effects play an opposite role on transfers, and so on the growth of macrovoids. Biofouling tests demonstrated the efficiency of the copolymer to mitigate biofouling with a reduction in bacterial and blood cell attachment by more than 85%. Filtration tests revealed that the permeability increased by a twofold factor, the flux recovery ratio was augmented from 40% to 63% after water/BSA cycles, and irreversible fouling was reduced by 1/3. Although improvements are needed, these zwitterionic PSf membranes could be used in biomedical applications where resistance to biofouling by cells is a requirement.

scholarly journals Effect of Solution Viscosity on the Precipitation of PSaMA in Aqueous Phase Separation-Based Membrane Formation

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1775
Author(s):  
Wouter Nielen ◽  
Joshua Willott ◽  
Julia Galicia ◽  
Wiebe de Vos
Keyword(s):  
Acetic Acid ◽  
Phase Separation ◽  
Aqueous Phase ◽  
Acid Concentration ◽  
Defect Formation ◽  
Solution Viscosity ◽  
Coagulation Bath ◽  
Additive Concentration ◽  
Nanofiltration Membranes ◽  
Casting Solution

Aqueous phase separation (APS) is a recently developed sustainable alternative to the conventional organic solvent based nonsolvent-induced phase separation (NIPS) method to prepare polymeric membranes. In APS, polyelectrolytes are precipitated from aqueous solutions through pH or salinity switches. Although APS differs from NIPS in the polymer and solvents, they share many tuning parameters. In this work, we investigate the APS-based preparation of membranes from poly(styrene-alt-maleic acid) (PSaMA) with a focus on acid concentration in the coagulation bath, and polymer and additive concentration in the casting solution. Nanofiltration membranes are prepared using significantly lower concentrations of acid: 0.3 M HCl compared to the 2 M of either acetic or phosphoric acid used in previous works. It is shown that higher polymer concentrations can be used to prevent defect formation in the top layer. In addition, acetic acid concentration also strongly affects casting solution viscosity and thus can be used to control membrane structure, where lower acetic acid concentrations can prevent the formation of macrovoids in the support structure. The prepared nanofiltration membranes exhibit a very low molecular weight cutoff (210 ± 40 dalton), making these sustainable membranes very relevant for the removal of contaminants of emerging concern. Understanding how the parameters described here affect membrane preparation and performance is essential to optimizing membranes prepared with APS towards this important application.

Effect of Solution Properties and Operating Parameters on Needleless Electrospinning of Poly(Ethylene Oxide) Nanofibers Loaded with Bovine Serum Albumin

2019 ◽  
Vol 16 (10) ◽  
pp. 913-922 ◽  
Author(s):  
Ramprasath Ramakrishnan ◽  
Jolius Gimbun ◽  
Praveen Ramakrishnan ◽  
Balu Ranganathan ◽  
Samala Murali Mohan Reddy ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Salt Content ◽  
Electrospinning Process ◽  
Solution Viscosity ◽  
Operating Parameters ◽  
Solution Properties ◽  
Wire Electrode ◽  
Needleless Electrospinning

Background: This paper presents the effect of solution properties and operating parameters of polyethylene oxide (PEO) based nanofiber using a wire electrode-based needleless electrospinning. Methods: The feed solution was prepared using a PEO dissolved in water or a water-ethanol mixture. The PEO solution is blended with Bovine Serum Albumin protein (BSA) as a model drug to study the effect of the electrospinning process on the stability of the loaded protein. The polymer solution properties such as viscosity, surface tension, and conductivity were controlled by adjusting the solvent and salt content. The morphology and fiber size distribution of the nanofiber was analyzed using scanning electron microscopy. Results: The results show that the issue of a beaded nanofiber can be eliminated either by increasing the solution viscosity or by the addition of salt and ethanol to the PEO-water system. The addition of salt and solvent produced a high frequency of smaller fiber diameter ranging from 100 to 150 nm. The encapsulation of BSA in PEO nanofiber was characterized by three different spectroscopy techniques (i.e. circular dichroism, Fourier transform infrared, and fluorescence) and the results showed the BSA is well encapsulated in the PEO matrix with no changes in the protein structure. Conclusion: This work may serve as a useful guide for a drug delivery industry to process a nanofiber at a large and continuous scale with a blend of drugs in nanofiber using a wire electrode electrospinning.

scholarly journals Effect of Acidic Solution Viscosity on Enamel Erosion

2013 ◽  
Vol 92 (3) ◽  
pp. 289-294 ◽  
Author(s):  
A. Aykut-Yetkiner ◽  
A. Wiegand ◽  
A. Bollhalder ◽  
K. Becker ◽  
T. Attin
Keyword(s):  
Acidic Solution ◽  
Solution Viscosity ◽  
Enamel Erosion

scholarly journals Fabrication of a lead ion selective membrane based on a polycarbazole Sn(iv) arsenotungstate nanocomposite and its ion exchange membrane (IEM) kinetic studies

RSC Advances ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 4210-4220
Author(s):  
Mohd. Zeeshan ◽  
Rais Ahmad ◽  
Asif Ali Khan ◽  
Aftab Aslam Parwaz Khan ◽  
Guillermo C. Bazan ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Polyvinyl Chloride ◽  
Cation Exchanger ◽  
Kinetic Studies ◽  
Ion Exchange Membrane ◽  
Lead Ion ◽  
Solution Technique ◽  
Casting Solution ◽  
Selective Membrane ◽  
Exchange Membrane

A polycarbazole-Sn(iv) arsenotungstate (Pcz-SnAT) nanocomposite cation exchanger membrane (CEM) was prepared via the casting solution technique utilizing polycarbazole-Sn(iv) arsenotungstate and PVC (polyvinyl chloride) as a binder.

Structure and Solution Properties of High Molecular Weight Butadiene-Styrene Copolymers

1957 ◽  
Vol 30 (1) ◽  
pp. 315-325
Author(s):  
R. B. MacFarlane ◽  
L. A. McLeod
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Complex Structure ◽  
Mixed Solvents ◽  
Solution Time ◽  
Solution Viscosity ◽  
Solution Properties ◽  
Molecular Weight Range ◽  
Viscosity Measurements ◽  
Commercial Practice

Abstract Production of high molecular weight copolymers of butadiene and styrene for use in oil-extended rubbers has aroused interest in the solution properties of copolymers above the molecular weight range commonly encountered in commercial practice. It has been observed that solubility of such polymers in toluene is a time-dependent phenomenon and the apparent solubility can increase continuously, in the absence of agitation, for as long as 800 hours. Although a standard Harris cage solubility test may show the presence of 50% gel, other properties do not confirm the presence of any appreciable quantities of insoluble material. Mild agitation rapidly promotes almost complete solubility. Dilute solution viscosity measurements are very misleading unless the influence of solution time is recognized and apparent intrinsic viscosities rise progressively with time of contact of the sample with solvent. This time-dependence of solution has been found to occur at conversions higher than 50% and is also a function of the amount of modifier used in the polymerization recipe. It has not been possible to shorten the solution time for viscosity measurements by mild heating or gentle agitation. Mixed solvents cause a change in the amount of increase of the apparent intrinsic viscosity but do not shorten the time to equilibrium. Measurement of the slope constant in the Huggins viscosity equation indicate that these solubility and viscosity effects coincide with the appearance of a marked degree of branching in the polymer molecules. The effect is, therefore, interpreted as being caused by the relatively slow disentanglement of molecules of complex structure.

Effect of aging heat time and annealing temperature on the properties of nanocrystalline tin dioxide thin films

2017 ◽  
Vol 31 (12) ◽  
pp. 1750114
Author(s):  
Imad H. Kadhim ◽  
H. Abu Hassan
Keyword(s):  
Thin Films ◽  
Tin Dioxide ◽  
Sol Gel ◽  
Stable Solution ◽  
Solution Viscosity ◽  
Pure Ethanol ◽  
Rutile Structure ◽  
Heat Time ◽  
Chloride Dihydrate ◽  
P Type

Nanocrystalline tin dioxide (SnO2) thin films have been successfully prepared by sol–gel spin-coating technique on p-type Si (100) substrates. A stable solution was prepared by mixing tin(II) chloride dihydrate, pure ethanol, and glycerin. Temperature affects the properties of SnO2 thin films, particularly the crystallite size where the crystallization of SnO2 with tetragonal rutile structure is achieved when thin films that prepared under different aging heat times are annealed at 400[Formula: see text]C. By increasing aging heat time in the presence of annealing temperatures the FESEM images indicated that the thickness of the fabricated film was directly proportional to solution viscosity, increasing from approximately 380 nm to 744 nm, as well as the crystallization of the thin films improved and reduced defects.

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