Compositions containing thermally-induced self-assembly of nonionic surfactants and their application in smart glass technologies

A method of preparing an apparatus for controlling transparency of a window, wall or roof comprising:

• preparing a hydrogel membrane composition having a variable opacity and an opaque-transparent transition temperature (OTTT), the hydrogel membrane composition consisting of:
• a. a thermally induced self-assembly surfactant consisting of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (EPE), wherein the EPE is in an amount of 0.1-2.0 w/v % of the hydrogel membrane composition;
• b. sodium dodecyl sulfate as a modifier, wherein the sodium dodecyl sulfate is in an amount of 0.1-0.7 w/v % of the hydrogel membrane composition;
• c. a liquid carrier;
• and
• d. a hydrogel base material consisting of agarose, wherein the agarose is in an amount of 0.1-2.0 w/v % of the hydrogel membrane composition;
• positioning at least two transparent panes and forming a void between the panes;
• and
• positioning the hydrogel membrane composition within the void between the panes thereby forming the apparatus for controlling transparency of a window, wall or roof,
• wherein the OTTT of the hydrogel membrane composition is adjustable by maintaining the ratio of modifier to EPE at 1-7 to 10 within the hydrogel membrane composition and the hydrogel membrane composition becomes opaque at or above the OTTT.