TY - JOUR
T1 - Supercritical CO2 based processing of amorphous fluoropolymer Teflon-AF
T2 - Surfactant-free dispersions and superhydrophobic films
AU - Khapli, Sachin
AU - Jagannathan, Ramesh
PY - 2014
Y1 - 2014
N2 - 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.
AB - 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.
KW - Nano particles
KW - RESS
KW - Teflon-AF
UR - http://www.scopus.com/inward/record.url?scp=84888877544&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84888877544&partnerID=8YFLogxK
U2 - 10.1016/j.supflu.2013.10.014
DO - 10.1016/j.supflu.2013.10.014
M3 - Article
AN - SCOPUS:84888877544
SN - 0896-8446
VL - 85
SP - 49
EP - 56
JO - Journal of Supercritical Fluids
JF - Journal of Supercritical Fluids
ER -