@article{Sheetz_Li_Smith_2020, title={Isothermal measurements of a Langmuir monolayer of a non-polar fluorocarbon chain molecule.}, volume={92}, url={https://pwvas.org/index.php/pwvas/article/view/717}, DOI={10.55632/pwvas.v92i1.717}, abstractNote={<p><span dir="LTR">Traditionally Langmuir monolayers and lipids bilayers (including cell membranes) on water interfaces are made of amphiphilic molecules with both polar hydrophilic and non-polar hydrophobic parts.  It has been discovered that non-polar fluorocarbon chain molecules without the polar hydrophilic part, F(CF</span><span dir="LTR"><sub>2</sub></span><span dir="LTR">)</span><span dir="LTR"><sub>20</sub></span><span dir="LTR">F</span><span dir="LTR"><sub>, </sub></span><span dir="LTR">can also form Langmuir monolayers on water.  Here we report the surface pressure vs. area isotherm measurements of a F(CF</span><span dir="LTR"><sub>2</sub></span><span dir="LTR">)</span><span dir="LTR"><sub>20</sub></span><span dir="LTR">F</span><span dir="LTR"> film on water, which show </span><span dir="LTR">the film’s maximum compression modulus (greatest resistance to lateral compression) at about </span><span dir="LTR">30 Å</span><span dir="LTR"><sup>2</sup></span><span dir="LTR">/molecule, independent of the compression speed, like the Langmuir monolayers of long chain saturated fatty acids do.  The cross-section area of the fluorocarbon chain is 28.1 Å</span><span dir="LTR"><sup>2</sup></span><span dir="LTR"> in 3-D crystalline F(CF</span><span dir="LTR"><sub>2</sub></span><span dir="LTR">)</span><span dir="LTR"><sub>20</sub></span><span dir="LTR">F</span><span dir="LTR">.</span><span dir="LTR">   Our measurements confirm the formation of a Langmuir monolayer by F(CF</span><span dir="LTR"><sub>2</sub></span><span dir="LTR">)</span><span dir="LTR"><sub>20</sub></span><span dir="LTR">F</span><span dir="LTR">, </span><span dir="LTR">a non-polar fluorocarbon chain molecule.  </span><span dir="LTR">We observed a general trend that greater the lateral compression speed, lower the maximum compression modulus, lower the resistance to lateral compression.</span><span dir="LTR">Nicholas Sheetz and Clayton Smith are grateful to financial support from the National Science Foundation through the SOARS Research Fellowship at Shepherd University.</span></p>}, number={1}, journal={Proceedings of the West Virginia Academy of Science}, author={Sheetz, Nicholas and Li, Mengyang and Smith, Clayton}, year={2020}, month={Apr.} }