Open AccessMicrogravity Expulsion of PTFE Spheres from Water: An Experimental Study
Author(s) -
Ashlan Ahmed,
Rayhan Ahmed
Publication year - 2019
Publication title -
science documents
Language(s) - English
Resource type - Journals
eISSN - 2574-1721
pISSN - 2573-1882
DOI - 10.32954/synsdocs.2019.001.07
Subject(s) - polytetrafluoroethylene , materials science , natural rubber , spheres , contact angle , drop (telecommunication) , composite material , coating , wetting , compounding , drop impact , mechanical engineering , engineering , aerospace engineering
This paper presents the hypothesis and experimental results of expulsion of spheres that are made up of polytetrafluoroethylene(PTFE), also known as Teflon, and Teflon spheres layered with superhydrophobic substances, from water under microgravityconditions. The microgravity was simulated in a drop tower. The microgravity tests were conducted in the 2.2 Second Drop Tower atthe NASA Glenn Research Center in Cleveland, Ohio. The experimental test objects chosen were: a) the unmodified PTFE sphere toserve as the base case (30 mm diameter); b) a PTFE sphere of same diameter layered with butyl rubber (25 mm of PTFE and 5 mm ofbutyl rubber); and c) a PTFE sphere of same diameter layered with paraffin (25 mm of PTFE and 5 mm of Paraffin). We hypothesizedthat the PTFE sphere with a butyl rubber coating would rise the highest distance in the drop chamber due to its super-hydrophobicityas determined by the contact angle of the objects. We tested the effect of microgravity on fully submerged and partially submergedobjects in water. The expulsion data from our experimental runs in both fully and partially submerged protocols is presented, as wellas our analysis and recommendations. Our test resulted in measurable reduction of the hydrophobicity effect while exposed tomicrogravity. We propose new research regarding a compounding effect of hydrophobicity based on surface properties and roughnessof substances