Coating to control evaporation at high temperatures

• Main Author: Muhammad Irfan Halelur Rahman
• Other Authors: Huang Weimin
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/150855
• Institution: Nanyang Technological University

Air fresheners have become a familiar sight in most cars. In warm tropical countries like Singapore, the interior temperature of parked cars will be on the rise. This increases the evaporation of the air freshener which causes a strong pungent smell in the vehicle. Although there are various methods such as using manual dials, motors, and sensors to stop the evaporation of the perfume, there is no self-regulating mechanism that is effective yet cheap. As such, there is a need to create a self-regulating membrane that reduces evaporation but also remains affordable. This can be done by fabricating a Temperature-Sensitive Membrane (TSM) that consists of Silicone and Paraffin Wax. This membrane is self-regulating due to the material properties of silicone which has porous channels to allow the fragrance to diffuse through while wax exhibits volume expansion which block the porous channels of silicone hence controlling the evaporation In this study, E620 silicone with a hardness rating of 20A was used but however proved to be ineffective due to its low hardness. After which, a harder type of silicone, PDMS, was used and this revealed better results. PDMS proved to be better in controlling the evaporation due to having a higher hardness rating of 50A. Another observation made was that a TSM made only from PDMS silicone is sufficient to control the evaporation and wax may not be required. To test out this theory, samples with TSM made from different types of silicones were tested to observe its effectiveness in controlling evaporation.