Stimuli-responsive polymer membrane and method of making the same

A method for making a stimuli-responsive (SR) polymer membrane with a two-dimensional array of circular microscopic pores comprising the acts of:

• preparing a solution composed of a SR polymer with pendant cross-linkable groups and a low-volatile liquid pore-forming additive (porogen);
• casting of said solution onto a surface of a solid or polymer substrate to obtain a microporous thin film membrane;
• decreasing solubility of said additive by adding of a small amount of a nonsolvent from vapor;
• inducing a nonsolvent-induced microphase separation of said additive in said solution followed by drying of said polymer and evaporation of said additive;
• controlling a pore size of said membrane by varying a vapor pressure of said nonsolvent during said casting process;
• cross-linking of the SR polymer constituting said membrane to produce a polymer network (SR polymer gel);
• changing a swelling degree of said membrane upon application of specific chemical and/or physical stimuli;
• and
• further comprising the acts of regulating of said pores' size and permeability (for liquids, molecules, and nanoparticles) of said responsive membrane due to said membrane's swelling;
• controlling a swelling degree of said SR polymer membrane,
• using enhanced transmission surface plasmon resonance spectroscopy,
• preparing said membrane on a transparent substrate covered with gold nanoislands;
• dispersing said gold nanoislands in said membrane's body;
• monitoring a shift of absorptivity maximum due to a change in an inter-particle distance occurring upon swelling and shrinking of said membrane's body;
• monitoring changes in a swelling degree of said SR polymer membrane, using transmission surface plasmon resonance spectroscopy, in which a shift of absorptivity maximum due to a change in an inter-particle distance occurring upon swelling and shrinking of said membrane's body is measured.

A method for making a stimuli-responsive (SR) polymer membrane with a two-dimensional array of circular microscopic pores comprising the acts of:

• preparing a solution composed of a SR polymer with pendant cross-linkable groups and a low-volatile liquid pore-forming additive (porogen);
• casting of said solution onto the surface of a solid or polymer substrate to obtain a microporous thin film membrane;
• decreasing solubility of said additive by adding of a small amount of a nonsolvent from vapor;
• inducing a nonsolvent-induced microphase separation of said additive in said solution followed by drying of said polymer and evaporation of said additive;
• controlling a pore size of said membrane by varying a vapor pressure of said nonsolvent during said casting process
• cross-linking of said SR polymer constituting said membrane to produce a polymer network (SR polymer gel);
• and;
• further comprising the acts of:
• changing a swelling degree of said membrane upon application of specific chemical and/or physical stimuli;
• and
• regulating of said pores' size and permeability (for liquids, molecules, and nanoparticles) of said responsive membrane due to the membrane's swelling;
• and
• further comprising the acts of:
• making a hybrid layer with stimuli-controlled surface wettability using said SR polymer membrane;
• modifying said membrane's surface by a layer of a hydrophilic component (polymer or surface-functionalized inorganic nanoparticles);
• immobilizing of a hydrophobic component (polymer or surface-functionalized inorganic nanoparticles) inside said membrane's pores;
• and
• modifying said membrane's surface by a layer of a hydrophobic component (polymer or surface-functionalized inorganic nanoparticles);
• immobilizing a hydrophilic component (polymer or surface-functionalized inorganic nanoparticles) inside said membrane's pores.