The present invention discloses a nanofiltration composite membrane, a preparation method and application thereof. The preparation method comprises: A) preparing 2D nano-material dispersion; B) first preparing a solution of a polymer material with a certain concentration, continuously adding a poor solvent under stirring conditions to subject the polymer material to chemical reaction to obtain a dispersion containing negatively charged polymer gel particles; C) subjecting the nano-material dispersion in step A) and the dispersion prepared in step B) to blending, membrane preparation and drying, and then placing the membrane into an alkaline solution with a certain concentration and pure water for soaking to obtain a nanofiltration composite membrane. The nanofiltration composite membrane can efficiently remove heavy metal complex ions through the synergistic effect of pore size screening and charge repulsion. Moreover, the rejection rate and flux of the nanofiltration composite membrane have not changed obviously after use for a long time.

One aspect of the present disclosure provides a production method for a porous membrane including pores, and concave portions having an average opening diameter greater than an average pore diameter of the pores on at least one of a pair of main surfaces, the method including a step of forming the concave portion on a surface to be the main surface.

The invention provides systems and methods for substantially improving the compaction resistance of isoporous block copolymer (BCP) film by adding a high molecular weight hydrophilic additive in the casting dope formulation. Systems and methods disclosed also disclose several other multifunctional enhancements to film properties including: low fouling propensity, improved permeability, improved permeability retention upon drying, and ability to tune the substructure and pore size of these novel BCP films. These porous BCP films are useful in filtration and separations applications and are amenable to standard manufacturing practices.

The present invention pertains to separators for electrochemical devices comprising vinylidene fluoride copolymers having improved thermal stability, to a process for their manufacture, and to electrochemical devices comprising the same.

The invention provides systems and methods for substantially improving the compaction resistance of isoporous block copolymer (BCP) film by adding a high molecular weight hydrophilic additive in the casting dope formulation. Systems and methods disclosed also disclose several other multifunctional enhancements to film properties including: low fouling propensity, improved permeability, improved permeability retention upon drying, and ability to tune the substructure and pore size of these novel BCP films. These porous BCP films are useful in filtration and separations applications and are amenable to standard manufacturing practices.

The invention provides systems and methods for substantially improving the compaction resistance of isoporous block copolymer (BCP) film by adding a high molecular weight hydrophilic additive in the casting dope formulation. Systems and methods disclosed also disclose several other multifunctional enhancements to film properties including: low fouling propensity, improved permeability, improved permeability retention upon drying, and ability to tune the substructure and pore size of these novel BCP films. These porous BCP films are useful in filtration and separations applications and are amenable to standard manufacturing practices.

Disclosed are linear/random/statistical copolymers comprising three types of monomeric units: hydrophobic monomeric units, zwitterionic monomeric units, and charged or ionizable monomeric units. Also provided are thin film composite membranes whose selective layer is comprised of the copolymers disclosed herein, and the methods of use thereof.

Disclosed are linear/random/statistical copolymers comprising three types of monomeric units: hydrophobic monomeric units, zwitterionic monomeric units, and charged or ionizable monomeric units. Also provided are thin film composite membranes whose selective layer is comprised of the copolymers disclosed herein, and the methods of use thereof.

A method for in situ production of antimicrobial filtration membranes that uses self-assembly of surfactants such as block copolymers as a template. The mesophase structure (for example hexagonal or lamellar) can be determined, and membrane pore size can be controlled in the nanometer range, by changing the block copolymer and the amounts of the components such as the block copolymer, aqueous solution, monomer, crosslinker, and initiator. The monomer phase cures in the template and there is no need for organic solvents and coagulation bath or other post-modification. As-synthesized membranes were found to have pore sizes with a narrow size distribution in the range of 3-4 nm with a molecular weight cutoff of 1500 g/mol and displayed both excellent fouling resistance and high permeance of water, vastly outperforming a conventional NIPS UF membrane. The monomer can comprise a quaternary ammonium group so that the membrane is antibacterial. The block copolymer can comprise hydrophilic blocks which form the surfaces of the membrane pores, rendering them hydrophilic.

A method for in situ production of antimicrobial filtration membranes that uses self-assembly of surfactants such as block copolymers as a template. The mesophase structure (for example hexagonal or lamellar) can be determined, and membrane pore size can be controlled in the nanometer range, by changing the block copolymer and the amounts of the components such as the block copolymer, aqueous solution, monomer, crosslinker, and initiator. The monomer phase cures in the template and there is no need for organic solvents and coagulation bath or other post-modification. As-synthesized membranes were found to have pore sizes with a narrow size distribution in the range of 3-4 nm with a molecular weight cutoff of 1500 g/mol and displayed both excellent fouling resistance and high permeance of water, vastly outperforming a conventional NIPS UF membrane. The monomer can comprise a quaternary ammonium group so that the membrane is antibacterial. The block copolymer can comprise hydrophilic blocks which form the surfaces of the membrane pores, rendering them hydrophilic.