Chromogenic humidity sensor

[0060]3D RGB Diagrams of PSS-b-PMB Sensors Under Different Humidities

[0061]At different RHs, the PSS-b-PMB films with different sulfonation levels exhibit characteristic reflection colors, which are plotted inside the 3D cube in FIG. 3. The z-axis shows equilibrium water uptake values of 5 μm thick freestanding films while the sulfonation levels of 240 nm thick PSS-b-PMB films and relative humidities are represented on x-and y-axis, respectively. Filled symbols in the 3D cube represent experimental data while the 3D color surface within the cube was obtained using a Renka-Cline gridding algorithm, which is part of the OriginPro 8.5(R) software package.

[0062]As can be seen in left-front portions of the cube, the PSS-b-PMB films in a dry condition at an RH of 30% appear violet, and undergo a color change with an increase in RH. The thin films with relatively low sulfonation levels change in color from violet to blue while a considerable window of color diagram is occupied by green / yel...