Authors : A.M. Maizan, K. Kuzilati and H.H. Luqman
Abstract: Alkali-Activated Material (AAM) is a compound which undergo alkali silicate activation and formed into an aluminosilicate compound. In this research, AAM was proposed as the new Controlled Release Fertilizer (CRF) coating material as it exhibits specific properties to improve CRF coating, eco-friendly and manufactured through sustainable production process. Thus, the droplet impact behaviour of the modified AAM solution was studied to determine the wettability of the solution on the urea surface by identifying the surface tension and contact angle. Besides that, the maximum spreading factor of the modified AAM droplet was analyzed to observe the spreading behaviour of the droplet between within time intervals. The AAM solution was formulated by using 3:1 weight ratio of fly ash based powder and 10 M sodium hydroxide solution. Modified AAM solution was formed by adding up 1-4 wt.% nanoclay into the solution as a filler to improve the AAM microstructure. The droplet impact experiment of the modified AAM solution was observed by using high speed camera. In the experiment, the droplet impact behaviour of the AAM solution was analyzed by varying the wt.% nanoclay added. From the experiment, the AAM solution with 0 wt.% nanoclay was identified to have the highest wettability as indicated by its lowest surface tension and smallest contact angle but it has the lowest maximum spreading factor. On the other hand, the AAM solution with 4 wt.% nanoclay was found to have the lowest wettability as indicated by its highest surface tension and largest contact angle but it provides the largest maximum spreading factor as low penetration and low dissolution of AAM solution occurs at this amount.
A.M. Maizan, K. Kuzilati and H.H. Luqman, 2017. Droplet Impact Behaviour of Modified Alkali-Activated Material Solution on Urea Surface. Journal of Engineering and Applied Sciences, 12: 2770-2776.