Supercritical CO2 based processing of amorphous fluoropolymer Teflon-AF: Surfactant-free dispersions and superhydrophobic films |
| |
| Affiliation: | 1. State Key Laboratory of Remote Sensing Science, and College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China;2. Center for Global Sea Level Change, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates;3. Division of Geodetic Science, School of Earth Sciences, The Ohio State University, OH 43210, USA;4. Ministry of Education Laboratory Key Laboratory for Earth System Modeling, and Center for Earth System Science, Tsinghua University, Beijing 100084, China;5. Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720-3114, USA;1. Department of Computer Science, Jordan University of Science and Technology, 22110, Jordan;2. Staffordshire University, Stafford, UK;3. Department of Computer Science, North Carolina State University, Raleigh, NC, USA;4. IBM Corporation, Center for Advanced Studies, Research Triangle Park, NC, USA |
| |
| Abstract: | We report the application of a modified RESS process to create and collect in high yield nanoparticles of an amorphous fluoropolymer, Teflon-AF1600. The nanoparticles with diameters ranging from 10 to 100 nm can be synthesized from polymer solutions in supercritical CO2 at 300 bar and 60 °C. The nanoparticles are collected by formation of dry ice in a liquid nitrogen-cooled trap. Nanoparticles embedded in dry-ice can be dispersed in organic solvents (acetone, ethanol, and n-heptane) creating surfactant-free dispersions. When dispersed in water, the nanoparticles self-assemble at the air–water interface forming a mechanically robust, superhydrophobic film. The film can support large water droplets (up to volume 250 μL) without breaking and is impermeable to water. The films cast from dispersions as well as those lifted-off water surface, are highly porous and superhydrophobic in nature (water contact angle θadv = 162°). This work demonstrates the utility of supercritical fluids based processing of fluoropolymers. |
| |
| Keywords: | RESS Teflon-AF Nano particles |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
