Tailor-made surface properties of particles with a hydrophilic or hydrophobic polymer shell mediated by supercritical CO2.
Controlling the surface characteristics of inorganic materials with an organic shell is of great interest for control of the properties of the final material. A challenge is thus to be able to deposit a polymer shell with different solvation properties onto the surface of inorganic particles and to have a good control of the thickness of the organic layer without a prefunctionalization of surfaces. We demonstrate, in this paper, a method for coating silica particles (170-550 nm), used as model substrates, with either a hydrophilic (polyethylene glycol) or a hydrophobic polymer (polybutadiene hydroxy terminated) using a supercritical antisolvent process (precipitation from a compressed antisolvent). Several operating parameters were studied to control precisely the thickness of the deposited layer (from 2 to 30 nm), which was characterized using TEM, FESEM, XPS, and UV-visible techniques. This work demonstrates that supercritical antisolvent processes are powerful methods and good alternatives to conventional coating techniques toward the development of hybrid and/or core-shell nanomaterials.
Institut de Chimie de la Matière Condensée de Bordeaux, ICMCB-CNRS and ENSCPB, Université Bordeaux I, 87 avenue du docteur Albert Schweitzer, 33608 Pessac cedex, France.
Samuel
S
Marre
François
F
Cansell
Cyril
C
Aymonier