| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 751273 | Sensors and Actuators B: Chemical | 2010 | 9 Pages |
New photo-crosslinkable benzophenone-containing polyelectrolytes were prepared by copolymerization of quaternary ammonium salt-containing monomer [2-(acryloyloxy)ethyl] dimethyl propyl ammonium bromide (AEPAB), styrene (ST), 2-hydroxyethylmethacrylate (HEMA), and 4-acryloyloxybenzophenone (BPA). These polyelectrolytes are self-crosslinkable copolymers for humidity-sensitive polyelectrolytes composed of copolymers with different contents of AEPAB/ST/HEMA/BPA = 70/25/3/2, 70/25/2/3, 70/23/5/2, and 70/23/4/3. Pretreatment of the alumina substrate with 3-glycidoxypropyltrimethoxysilane (GPTMS) containing silane-coupling agent was performed to anchor the humidity-sensitive membrane to the substrate through covalent bonds. The sensors were irradiated with UV light, causing the electronically excited benzophenone molecules to form a crosslinking reaction. The resistance ranged from 107 Ω to 103 Ω between 20% relative humidity (RH) and 95% RH, the humidity range required for a sensor operating at ambient humidity. Their water durability, long-term stability under various environments, hysteresis, and response and recovery times were measured and evaluated as a humidity-sensing membrane.
