Date of Award


Document Type


Degree Name

Master of Science in Chemical Engineering (MSChE)


Chemical Engineering

First Advisor

Nolte, Adam

Second Advisor

Serbezov, Atanas

Third Advisor

Syed, Maarij


The need for sensors capable of operating in harsh environments such as those containing flammable, corrosive or reactive vapors is a niche which thin-film optical devices, with their robustness and ease of maintenance may effectively fill. Two such systems were developed using spin-coating techniques and evaluated for applicability as humidity sensors. The first is based on aggregated silica nano particles. The second is a poly electrolyte multi-layer film impregnated with silver nano particles which exhibited strong surface plasmon response. Ellipsometric experiments performed using a sealed test cell with constant humidity maintained using saturated salt solutions showed that the former responded strongly to changing humidity. The latter possessed interesting hysteresis behavior as analyzed in a climate-controlled glovebox via reflectometry, but proved insufficiently responsive to changing humidity. The silica nano particle substrate was found to be a simple, tunable sensor platform which may be viable for the detection of a wide variety of vapor-phase chemical species.