Responsive filtration membranes by polymer self-assembly

Kaner, Papatya; Bengani-Lutz, Prity; Sadeghi, Ilin; Asatekin, Ayşe

doi:10.1142/s2339547816500096

Cited by 25 publications

(16 citation statements)

References 113 publications

(148 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, hydrophobicity is also important in some specific membrane water treatment applications such as oil–water separation and membrane distillation. While previous studies have found good candidates for this class of materials, through targeted design of functional, self‐organizing polymers specifically for this application, better performance can be achieved. The most common approaches here are to either make use of constituents that will segregate to the membrane surface or to employ post‐processing treatments …”

Section: Introductionmentioning

confidence: 99%

Electrospun fiber membranes from blends of poly(vinylidene fluoride) with fouling‐resistant zwitterionic copolymers

Govinna

Kaner

Ceasar

et al. 2018

Polymer International

Self Cite

View full text Add to dashboard Cite

Nonwoven super‐hydrophobic fiber membranes have potential applications in oil–water separation and membrane distillation, but fouling negatively impacts both applications. Membranes were prepared from blends comprising poly(vinylidene fluoride) (PVDF) and random zwitterionic copolymers of poly(methyl methacrylate) (PMMA) with sulfobetaine methacrylate (SBMA) or with sulfobetaine‐2‐vinylpyridine (SB2VP). PVDF imparts mechanical strength to the membrane, while the copolymers enhance fouling resistance. Blend composition was varied by controlling the PVDF‐to‐copolymer ratio. Nonwoven fiber membranes were obtained by electrospinning solutions of PVDF and the copolymers in a mixed solvent of N,N‐dimethylacetamide and acetone. The PVDF crystal phases and crystallinities of the blends were studied using wide‐angle X‐ray diffraction and differential scanning calorimetry (DSC). PVDF crystallized preferentially into its polar β‐phase, though its degree of crystallinity was reduced with increased addition of the random copolymers. Thermogravimetry (TG) showed that the degradation temperatures varied systematically with blend composition. PVDF blends with either copolymer showed significant increase of fouling resistance. Membranes prepared from blends containing 10% P(MMA‐ran‐SB2VP) had the highest fouling resistance, with a fivefold decrease in protein adsorption on the surface, compared to homopolymer PVDF. They also exhibited higher pure water flux, and better oil removal in oil–water separation experiments. © 2018 Society of Chemical Industry

show abstract

Section: Introductionmentioning

confidence: 99%

Electrospun fiber membranes from blends of poly(vinylidene fluoride) with fouling‐resistant zwitterionic copolymers

Govinna

Kaner

Ceasar

et al. 2018

Polymer International

Self Cite

View full text Add to dashboard Cite

show abstract

“…Most studied methods of preventing fouling aim to create highly hydrophilic membrane surfaces through surface functionalization, either by post-treatment [13][14][15][16][17][18][19][20][21][22][23] or by surface-segregating additives. [24][25][26][27][28][29][30][31][32] Zwitterionic materials are strongly fouling resistant as a result of compactly bound water molecules that are organized as a hydration layer around the zwitterionic head groups. [33] To develop fouling resistant and high flux UF membranes, several groups have incorporated zwitterionic groups on membrane surfaces and shown increased resistance to fouling, specifically by protein solutions.…”

Section: Introductionmentioning

confidence: 99%

Zwitterion-containing polymer additives for fouling resistant ultrafiltration membranes

Kaner

Rubakh

Kim

et al. 2017

Journal of Membrane Science

Self Cite

114

View full text Add to dashboard Cite

Fouling is likely the most important obstacle to the use of membranes in many applications, especially in those that the feed contains high concentrations of organics such as oil and biomacromolecules. Zwitterions, defined as molecules with equal numbers of positively and negatively charged functional groups, show excellent fouling resistance and hydrophilicity. These features can be incorporated into ultrafiltration (UF) membranes during their manufacture by blending a commodity polymer like polyvinylidene fluoride (PVDF) with a copolymer containing zwitterionic groups. This approach can be used directly in existing membrane production systems, with no need for post-processing. Research to date, however, does not provide any guidelines for designing or selecting a zwitterion-containing polymer for this purpose to achieve the best possible performance. In this work, we synthesized copolymers of methyl methacrylate (MMA), whose homopolymer is compatible with PVDF, with two different zwitterionic copolymers, sulfobetaine methacrylate (SBMA) and sulfobetaine-2-vinylpyridine (SB2VP). These copolymers were not previously investigated as surface segregating additives in membrane manufacture. We investigate the impact of different copolymer properties such as zwitterion chemistry, copolymer composition (i.e. zwitterionic/hydrophobic monomer ratio), and blend composition on the performance of membranes manufactured from their blends with PVDF. We report how changing these variables affect the morphology, selectivity, permeance and fouling resistance of membranes, and associate this data with design rules for selecting favorable copolymers. Our study showed that, in contrast to previous literature, increasing the hydrophilic/zwitterionic monomer amount in the additive copolymer does not always result in improved membrane performance. Instead, during membrane formation by non-solvent induced phase separation (NIPS), copolymer additives with high zwitterion content (51-52 wt%) undergo macrophase separation from PVDF, and the product membrane shows poor performance. On the other hand, with the appropriate copolymers that contain 18-19 wt% zwitterionic monomer, membranes with significantly higher permeance and remarkable fouling resistance can be attained even with very small amounts of additive copolymer. Zwitterionic additive contents as low as 5 wt% in PVDF can lead to membranes with doubled water flux (up to 99 L/m 2 .h.bar) and complete irreversible fouling resistance against oil suspensions and protein solutions. Only 10 wt% additive can yield membranes with even higher flux (up to 165 L/m 2 .h.bar), and complete resistance to irreversible fouling by an oil suspension in 24-hour dead-end fouling experiments. This degree of fouling resistance have not previously been reported for PVDF-based membranes, to our knowledge, and indicates the promise of this membrane modification approach for a wide range of applications.

show abstract

“…Self-assembly is a promising tool for generating membranes with functional nanostructures using scalable, easier to implement methods. − For example, the self-assembly of a polymer within the pores of a TE membrane through ionic interactions has been reported to narrow the pores down to 6–9 nm, ideal for protein separations but still too large for separating small molecules. The porosity of these membranes is, however, still very low, and tailoring the pore size and the functionality is very difficult and limited by the polymer structure.…”

mentioning

confidence: 99%

Selective Transport through Membranes with Charged Nanochannels Formed by Scalable Self-Assembly of Random Copolymer Micelles

2017

Self Cite

View full text Add to dashboard Cite

Membranes that can separate compounds based on molecular properties can revolutionize the chemical and pharmaceutical industries. This study reports membranes capable of separating organic molecules of similar size based on their electrostatic charge. These membranes feature a network of carboxylate-functionalized 1-3 nm nanochannels, manufactured by a simple, scalable coating process: a porous support is coated with a packed array of polymer micelles in alcohol, formed by the self-assembly of a water-insoluble random copolymer with fluorinated and carboxyl functional repeat units. The interstices between these micelles serve as charged nanochannels through which water and solutes can pass. The negatively charged carboxylate groups lead to high separation selectivities between organic solutes of similar size but different charge. In single-solute diffusion experiments, neutral solutes permeate up to 263 times faster than negatively charged compounds of similar size. This selectivity is further enhanced in experiments with mixtures of these solutes. No permeation of the anionic compound was observed for over 24 h. In filtration experiments, these membranes separate anionic and neutral organic compounds while exhibiting water fluxes comparable to that of commercial membranes. Furthermore, carboxylate groups can be functionalized, creating membranes with nanopores with customizable functionality to enable a broad range of selective separations.

show abstract

Responsive filtration membranes by polymer self-assembly

Cited by 25 publications

References 113 publications

Electrospun fiber membranes from blends of poly(vinylidene fluoride) with fouling‐resistant zwitterionic copolymers

Electrospun fiber membranes from blends of poly(vinylidene fluoride) with fouling‐resistant zwitterionic copolymers

Zwitterion-containing polymer additives for fouling resistant ultrafiltration membranes

Selective Transport through Membranes with Charged Nanochannels Formed by Scalable Self-Assembly of Random Copolymer Micelles

Contact Info

Product

Resources

About