Methods for Obtaining Polymeric Membranes

Perepechkin, L. P.

doi:10.1070/rc1988v057n06abeh003370

Cited by 12 publications

(6 citation statements)

References 2 publications

(1 reference statement)

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“…An analogous procedure is used to make fibers by wet spinning61–64 where the solidification step is called “coagulation.” The pore structure, that is, pore size, shape, and volume, is affected by many factors. There is a sizable body of literature devoted to analysis of the phase inversion or coagulation process;65–76 however, the practice is still largely an empirical art.…”

Section: Filtration (Porous) Membranes and Processesmentioning

confidence: 99%

Water purification by membranes: The role of polymer science

Geise

Lee

Miller

et al. 2010

J Polym Sci B Polym Phys

863

694

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Two of the greatest challenges facing the 21st century involve providing sustainable supplies of clean water and energy, two highly interrelated resources, at affordable costs. Membrane technology is expected to continue to dominate the water purification technologies owing to its energy efficiency. However, there is a need for improved membranes that have higher flux, are more selective, are less prone to various types of fouling, and are more resistant to the chemical environment, especially chlorine, of these processes. This article summarizes the nature of the global water problem and reviews the state of the art of membrane technology. Existing deficiencies of current membranes and the opportunities to resolve them with innovative polymer chemistry and physics are identified. Extensive background is provided to help the reader understand the fundamental issues involved. Ph.D. students and two postdoctoral fellows performing fundamental research in gas and liquid separations using polymer membranes and barrier packaging. His research group focuses on include structure/property correlation development for desalination and vapor separation membrane materials, new materials for hydrogen separation and natural gas purification, nanocomposite membranes, reactive barrier packaging materials, and new materials for improving fouling resistance and permeation performance in liquid separation membranes. His research is described in more than 250 publications, and he has coedited four books on these topics. He has won a number of national awards for his research contributions, including the ACS

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Section: Filtration (Porous) Membranes and Processesmentioning

confidence: 99%

Water purification by membranes: The role of polymer science

Geise

Lee

Miller

et al. 2010

J Polym Sci B Polym Phys

863

694

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“…The value of its solubility parameter (δ t = 26.5 MPa 1/2 ) is closest to the value of the solubility parameter of sodium alginate (δ t = 37 MPa 1/2 ) (Table 2). "Soft" precipitation leads to forming the uniform fine porous layer [52]. The pores collapse when dry.…”

Section: Effect Of Non-solvent On Precipitation and Properties Of Sod...mentioning

confidence: 99%

Recovery of Model Pharmaceutical Compounds from Water and Organic Solutions with Alginate-Based Composite Membranes

2022

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In this work, we combined the non-solvent induced phase separation (NIPS) and further cross-linking by cations towards the preparation of nanofiltration membranes based on sodium alginate, a biodegradable, natural polymer. Acetone, ethanol, toluene, and hexane were used as non-solvents, and cations of calcium, silver, and aluminum—for polymer cross-linking, respectively. Results showed the precipitation strength of non-solvent played a noticeable role in the membrane’s performance; for instance, the toluene permeability changed by four orders of magnitude with the decrease of precipitation strength of the non-solvent: acetone (Ptoluene = 0.1 kg∙m−2∙h−1∙bar−1) < ethanol (3 kg∙m−2∙h−1∙bar−1) < hexane (41 kg∙m−2∙h−1∙bar−1) < toluene (415 kg∙m−2∙h−1∙bar−1). It was shown that simultaneous precipitation and crosslinking in aqueous solutions AlCl3 or AgNO3 must be used in the preparation of alginate membranes for the highly selective recovery of pharmaceutical compounds from organic media. These membranes show rejection R = 90–93% of substances with MW = 626 g/mol and ethanol permeability PEtOH = 1.5–2.5 kg∙m−2∙h−1∙bar−1. For the highly selective recovery of pharmaceutical compounds from water, the method of obtaining membranes must be changed. Precipitation in toluene and then crosslinking in aqueous solutions of AlCl3 or AgNO3 must be used sequentially instead of simultaneous precipitation and crosslinking in aqueous solutions of the same inorganic salts. The permeability of such membranes varied from 0.44 to 7.8 kg∙m−2∙h−1∙bar−1 depending on the crosslinking cation in the alginate. The rejection of model substances with MW 350 and 626 g/mol were on the level of 99%. Alginate membranes can be used to solve separation problems in the pharmaceutical field, for example, to isolate antibiotics from their extractants and remove the same antibiotics from aqueous pharmaceutical waste to prevent their accumulation in the environment and the emergence of resistant genes and bacteria.

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“…This kind of arrangement also gives rise to crystallinity in the polymer, making it suitable to be used in capillary fibre making. However, it must be noted that higher crystallinity reduces permeability in the membrane [20] .…”

Section: Position Of Side Groups and Chain Flexibility Of The Polymermentioning

confidence: 99%

“…It is soluble in decalin, toluene at 368 K, xylene at K, tetralin at 371 K, cyclohexene at 341 K, n-tetracosane at 374 K [22] . It shows moderate mechanical properties with average tensile modulus (102-310 MPa) and average tensile strength (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). MLD PE has molecular weight range of 4 × 10 4 -11× 10 4 g/mol and narrow range of PDI (2-2.5).…”

Section: Polyethylene (Pe)mentioning

confidence: 99%

A brief review on systematic approach to polymer selection for development of capillary/hollow-fibre membrane for practical applications

Mamtani,

Ghosh,

Adak

2023

Mater. Tech. Rep.

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Polymeric membranes are widely used for treatment of lean stream in chemical process industries. These membranes are used in different configurations such as tubular, plate & frame, disc-tube, spiral and capillary/hollow-fibre. Membrane modules with capillary/hollow-fibre configuration appears promising in ultrafiltration applications due to its relatively higher packing density, ease of backwashing, ease of cleaning and lower pressure drops since it can be operated at laminar flow regime with high cross-flow velocity. Hence, efforts are being made by researchers to make capillary/hollow-fibre membrane modules from various polymers, ranging from most hydrophilic polyacrylonitrile (PAN) to super-hydrophobic polypropylene (PP) and polytetrafluorethylene (PTFE). Here, we discuss the qualifying properties of the polymeric materials suitable to spin into capillary/hollow-fibre ultrafiltration membranes. Selection of polymers for making fibres requires in-depth knowledge of properties of base polymer and its processability/fabricability. The important properties to be considered for making capillary/hollow-fibre membrane are intrinsic structural properties of the base polymer like degree of crystallinity, tensile strength, tensile modulus, etc. The functional properties such as permeability, hydrophilicity/hydrophobicity etc. also plays role in selecting polymer for a given application. The polymer should also have appreciable dissolution in available solvents or should have degradation temperature higher than melting point so that it can be processed through appropriate membrane preparation process.

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Methods for Obtaining Polymeric Membranes

Cited by 12 publications

References 2 publications

Water purification by membranes: The role of polymer science

Water purification by membranes: The role of polymer science

Recovery of Model Pharmaceutical Compounds from Water and Organic Solutions with Alginate-Based Composite Membranes

A brief review on systematic approach to polymer selection for development of capillary/hollow-fibre membrane for practical applications

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