Extrinsic periodic information interpolates between monostable and bistable states in intracellular calcium dynamics

The present work focuses on the preparation of Polyphenylsulfone (PPSU) membranes with enhanced antifouling surfaces through an incorporation of sulfonated Polyphenylsulfone (PPSU-SO 3 H), which acts as both, surface modifying agent and macromolecular additive. Initially, Sulfonated polyphenylsulfone (PPSU-SO 3 H) was synthesized by using chlosulfonic acid via bulk modification method. The degree of sulfonation (DS, %) of PPSU-SO 3 H was calculated by using NMR (nuclear magnetic resonance).The phase inversion technique was used to prepare all asymmetric membranes by allowing the PPSU-SO 3 H (different wt %) to entangle with the PPSU membrane matrix. All prepared membranes were characterized by using scanning electron microscope (SEM), X-ray diffraction analysis (XRD), contact angle analysis (CA), mechanical strength analysis, molecular weight cut off (MWCO), porosity (%), mean pore size, and BSA adsorption studies. The performance efficiency of the membranes was evaluated by using BSA protein as a model foulant in terms of permeability, rejection (SR %), R m (hydraulic resistance), R c (cake layer resistance), R p (pore plugging resistance), R r (reversible fouling), R ir (irreversible fouling), and FRR (flux recovery ratio). V C 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41986.

Section: Characterization Of Membranesmentioning

confidence: 99%

Development of new hybrid ultrafiltration membranes by entanglement of macromolecular PPSU‐SO₃H chains: Preparation, morphologies, mechanical strength, and fouling resistant properties

Arumugham

Kaleekkal

Doraiswamy

2015

“…The PVP immobilized on/in the PVDF membrane attracted more sulfobetaine monomer into the membrane interior for subsequent graft polymerization onto the membrane surface and subsurface, and a thick poly(sulfobetaine) grafting layer was formed . The grafting amount was as high as 721 ± 13 μg/cm 2 .…”

Section: Our Workmentioning

confidence: 99%

“…It has been acknowledged that membrane separations have low energy consumption, easy operation in continuous flow, have environmentally friendly properties, and are a technology of significant note, not only for wastewater treatment but also for agro‐food, biotechnological, and biomedical markets . Microfiltration (MF) and ultrafiltration (UF) are pressure‐driven membrane processes that retain macromolecules or high molecular‐weight compounds, excluding bacteria and viruses .…”

Section: Introductionmentioning

confidence: 99%

Making polymeric membranes antifouling via “grafting from” polymerization of zwitterions

Imbrogno

Belfort

et al. 2014

Protein‐fouling of membranes has negative effects on the wide applications of membrane materials, such as poly(vinylidene fluoride) (PVDF), poly(ether sulfone) (PES)/polysulfone (PSf). Zwitterionic materials have recently been used and identified from high throughput screens of large libraries of monomers to modify membranes due to their stable anti‐protein‐fouling properties. “Grafting from” polymerization is a technique involving monomers that are polymerized using an initiation reaction on the membrane surface. It is regarded as a simple, useful, and versatile modification approach to increase the anti‐fouling properties of a membrane. This strategy provides controllable introduction of graft chains with a high density and a long‐term chemical stability due to covalent attachment of graft chains. Graft density, chemistry, chain length, and conformation are all important parameters that need to be considered. This article presents a mini‐review of recent progress on the “grafting from” polymerization of zwitterionic monomers on the surfaces of PVDF and PES/PSf membranes, including an introduction of zwitterions and methods of graft polymerization. Various approaches such as free radical graft polymerization, photo‐induced graft polymerization, and plasma‐induced graft polymerization were compared based on uniformity and amount of grafted zwitterionic polymer, relative flux of modified membranes, simplicity and environment pollution of operation, and cost of technique. The application of different approaches and the performance of poly(zwitterion)‐grafted PVDF and PES/PSf membranes are summarized according to recent research. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41781.

“…Recently, block copolymers have exhibited high resolutions in separation applications. The self‐assembly of block copolymers provides membranes with highly ordered pores and nearly identical pore sizes called isoporous membranes; this makes precise separation possible . A typical example is in virus filtration .…”

Section: Introductionmentioning

confidence: 99%

Fabrication of dual‐layer poly(styrene‐b‐4‐vinyl pyridine)–poly(vinylidene fluoride) membranes with tailored pore sizes under 10 nm via surface quaternization

Liu²,

Liu

et al. 2018

Block copolymer membranes can be applied to precise size-based separation because of their highly ordered surface morphology and adjustable pore sizes. However, there is a lower limit of the scale of block copolymer self-assembly; this makes it a challenge to tailor the pore size down to below 10 nm. In this study, poly(styrene-b-4-vinyl pyridine) membranes were modified to quaternized selective layers with pores smaller than 10 nm and were supported by poly(vinylidene fluoride) hollow fibers as the substrate to provide a high mechanical strength. Two reactants, methyl iodide and 2-chloroacetamide, were used in the quaternization. With this one-step chemical modification, the molecular weight cutoff was reduced from 190 to 8 kDa, and the surface pore sizes were narrowed down from 20-30 to 3 nm; this bridged the gap of tailored pore sizes down to below 10 nm. Such membranes are promising candidates for low-molecular-weight separation with high resolution.