Low friction surfaces are widely studied across many fields of engineering. Recent advances have allowed for the inexpensive and straightforward strategy of producing a surface with hydrophobic qualities. This slippery, omniphobic, covalently attached, liquid (SOCAL) surface exhibits qualities of low contact angle hysteresis and low sliding angles. The production process involves the dipping of the substrates into a solution of isopropanol, dimethyldimethoxysilane, and concentrated sulfuric acid followed by a drying phase, which promotes the graft polycondensation of several long polymer chains. I present my own fabrication of this surface, along with an analysis of its hydrophobic properties. Two SOCAL surfaces on glass slides were analyzed, with their only difference as the ambient relative humidity (RH) of the drying phases. The results confirm published statements that a higher RH promotes lower hysteresis, and I was able to obtain a surface that exhibited similar properties to published values. Throughout multiple tests, I observed hysteresis values averaging at 11.44° for the low humidity surface, and values averaging at 6.58° for the high humidity surface, which had a range from 2.7° to 11.4°. Comparing these to published values of 2.5° across a range from 0.3° to 4.2°, the average values do not agree well, but there is clear overlap between the two findings. The high humidity sample was found to contain a sliding angle of 2°, which compares well with published findings of 4°.
Mechanical Engineering and Material Sciences Independent Study
Date of Submission
Hawa, Angelo and Weisensee, Patricia, "Fabrication and Analysis of SOCAL Surfaces" (2021). Mechanical Engineering and Materials Science Independent Study. 147.