Outstanding antifouling performance of poly(vinylidene fluoride) membranes: Novel amphiphilic brushlike copolymer blends and one‐step surface zwitterionization

Abstract

In this study, we endowed a poly(vinylidene fluoride) (PVDF) membrane with outstanding antifouling ability by blending the hierarchical amphiphilic brushlike copolymer [poly(hydroxyethyl methacrylate)-b-polydimethylsiloxane-b-poly(hydroxyethyl methacrylate)]-gpoly(N,N-dimethylamino-2-ethyl methacrylate) with different initial monomer/initiator feed ratios and performing a one-step surface zwitterionization of spontaneously segregated poly(N,N-dimethyl aminoethyl methacrylate) segments. Interestingly, nanoscale granular micelles were formed on the surface during zwitterionization because of the migration and self-assembly of the amphiphilic copolymer; this contributed to the membrane hydrophilicity and antifouling ability. During the filtration of the model foulant bovine serum albumin (BSA) aqueous solution, the BSA rejection ratio and flux recovery ratio increased remarkably to 94.8 and 100.0%, respectively. Moreover, the modified membranes also possessed stable and durable antifouling properties after three cycles of BSA filtration. Thus, this study provided a versatile method for constructing a PVDF ultrafiltration membrane that could achieve high permeability and good antifouling properties in efficient wastewater treatment.

Branched Polymers: Synthesis and Application

“…The application of branched polymers in biomedicine has been summarized previously, , and we will not further discuss it here. In the following, we mainly introduce the applications of branched polymers in solid polymer electrolytes for Li batteries, ,− coatings and membranes, − surfactants, − and hydrogels. − …”

“…He's group prepared polymer membranes with excellent antifouling property first by blending PVDF with amphiphilic brush polymer poly(hydroxyethyl methacrylate)-b-polydimethylsiloxane-b-poly(hydroxyethyl methacrylate)]-g-poly(N,Ndimethylamino-2-ethyl methacrylate) [(PHEMA-b-PDMS-b-PHEMA)-g-PDMAEMA) and then by surface modification via zwitterionicalization as shown in Figure 6A. 84 The water contact angle of the obtained polymer membrane was significantly reduced. In the filtration of bovine serum albumin (BSA) aqueous solution, it was found that the BSA rejection and flux recovery of the membrane were significantly increased to 94.8% and 100.0%, respectively.…”

“…Polymer membranes are widely used in seawater desalination, wastewater treatment, and gas separation and purification due to the advantages of low toxicity, tailorable functionality, and relatively low cost. − Compared with membranes made from linear polymers, membranes made from branched polymers have higher porosity and better permeability due to the presence of a large number of branched chains that are loosely packed . Changing the branching degree and the molecular weight of branched polymers not only can regulate the porosity of the branched polymer membranes but also can introduce a large number of functional terminals into the branched chains, which can improve the adsorption capacity of the branched polymer membranes and allows them to be suitable for different applications.…”

“…In this Perspective, we discuss some of their general synthesis methods based on the structural classification of branched polymers and stimulate the valid synthesis of well-defined branched polymers. Furthermore, we summarize several potential applications of branched polymers on solid polymer electrolytes for Li batteries, ,− coatings and membranes, − surfactants, − and hydrogels − based on their intrinsic characteristics, such as good solubility, low viscosity, and high fraction of terminals. Finally, we also speculate about possible directions for the synthesis and application of branched polymers.…”

Preparation And Characterizations Of Poly(vinyl butyral)/Caprolactam/Polyethylene Glycols Hydrophilic Flat‐sheet Membrane Through Thermally Induced Phase Separation

“…Currently, hydrophobic microporous membranes such as Polyamide (PA), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE) and poly(aromatic ether sulfone) (PAES) are used for membrane separation. However, membrane fouling that is frequently encountered during membrane separation, which leads to deterioration of membrane properties, reduces membrane life, and limits its wide application. Many ways can reduce membrane fouling.…”