sixth lesson sixth lesson. surface properties surface properties
TRANSCRIPT
TREATMENT BY SPECIFIC FLUORNATED COMPONDS ON TEXTILES, FIBER, LEATHER, PAPER, AND OTHERS GIVES ADDED VALUES OF WATER AND OIL REPELLENCY, STAIN RESISTANCE, AND
SOIL RELEASE ABILITY
• The surface tension of the perfluoroalkyl group [Rf group : -(CF2CF2)nCF3] is the lowest of all solids on the earth
SURFACE TENSION
n-PerfluoroheptanePFC-HC co-polymers
PFOS AS ENVARIONMENTAL RISK
Data extracted from the Swedish Chemical
Inspectorate (Keml) and EPA Dossier August 2004
LABILE COATING Via PFOS
F
SO2N
H2
F
SO2N
H2
F
SO2N
H2
FSO
2NH
2
F
SO2N
H2
F
SO2N
H2
H2OH2O
H2OH2O
Legame fisico deboleTessuto da trattare
Idrorepellenza temporanea
• Perfluoroalkyl chains give water and oil repellency and soil release ability• Alkyl acrylate chains give the ability to form a film and maintain softness • Vinyl chloride and crosslinking monomer gives durability.
FLUORINATED COPOLYMER AS FABRIC COMPONENTS
• Treatment with Fluoropolymers: perfluoroalkyl groups [Rf group: -(CF2CF2)nCF3] cover the surface of the fiber
FLUORINATION OF FIBERS SURFACE
BOTH OF TREATMENTS WITH SILICONE AND FLUOROPOLYMERS CAN REPELLE WATER AND SAUCE, BUT ONLY TREATMENT WITH FLUOROPOLYMERS CAN COMPLETELY REPELLE OIL
FLUOROPOLYMER’ S SURFACE TENSION (10MN/M) IS LOWER THAN THAT OF OIL (20MN/M), ENABLING IT TO REPELL OIL
AFTER TREATMENT WITH SR AGENT, THE CLOTH IS OIL STAIN RESISTANT. IF STAINED, ORDINARY WASHING PROCEDURE WILL REMOVE THE STAIN COMPLETELY
BEFORE WASHING, PERFLUOROALKYL GROUPS [RF GROUP : -(CF2CF2)NCF3] ORIENT TO THE SURFACE AND REPELLE OIL STAINS. AND DURING WASHING, RF GROUP AND HYDROPHILIC GROUPS CHANGE PLACES(FLIP-FLOP), MAKING IT EASY TO RELEASE OIL STAINS
• In order to engineer a barrier fabric to meet the changing needs, three areas were addressed:
1. Selection of a hydrophobic fiber.
2. Construction of a fabric with a small pore size.
3. Use of chemical finishes to enhance barrierperformance.
Engineering Fabrics with Improved Barrier Properties
COSTRUIRE UN TESSUTO CARATTERIZZATO DA MIGLIORATE PROPRIETÀ BARRIERA
Chemical Finishes
•Today almost all “standard” performance surgical fabrics (disposable and reusable) use fluorochemical finishes to impart higher levels of repellency.
•Without fluorochemicals, these filament polyester fabrics would only have about 1/3 of their barrier properties.
TRATTAMENTI SUPERFICIALI DI FINITURA
Impact Penetration Test
Impact Penetration Test
• The impact penetration test is used to determine the penetration of liquids upon impact (e.g., splash by a liquid during a surgical procedure). In this test, an AATCC Impact Penetration Tester is used with blotter paper. The blotter paper is weighed on an analytical balance and placed under the surface of sample of clothing material. The sample is sprayed on its outside surface with 500 mL of liquid from a height of 61 cm. The blotter paper is then reweighed after exposure to liquid impact. The increase in weight is reported as the impact resistance.
VALUTARE IL POTERE BARIERA
LABILE COATING Via PFOS
F
SO2N
H2
F
SO2N
H2
F
SO2N
H2
FSO
2NH
2
F
SO2N
H2
F
SO2N
H2
H2OH2O
H2OH2O
Legame fisico deboleTessuto da trattare
Idrorepellenza temporanea
F F F F F F
COATING IDROLITICAMENTE STABILE
H2OH2O
H2O H2O
Legame Chimico Stabile Tessuto da trattare
Idrorepellenza permanente
Perfluorodiacyl Peroxides
RO
FH2O2 O
O
O
O
RR
NaOH/H2O
Solvent2 +- NaF
FF
FSYNTHESIS
C. Corvaja, A. Famulari, L. Franco, M. Galimberti, P. Metrangolo, W. Navarrini, G. Resnati, M. Sansotera, Chem. Today, 2006, 24, 3, 17-22.
CF2
OO
O
O
CF2
CF2
CF2
CF3
CF3
Perfluorodi-n-butyryl Peroxide50%
CF3
OO
O
O
CF3
CF3F
CF3F
Perfluorodi-iso-butyryl Peroxide70%
CF3
OO
O
O
CF2
CF2
CF3
Perfluorodipropionyl Peroxide30%
Yields
SO
O
O
O
CF3
CF3F
SF
O
O
O
O
F
F
Perfluoro-di-2-sulphonyl-propionyl Peroxide
50%
Electron Paramagnetic ResonanceHyperfine Coupling Constants (Gauss)
3240 3330 3420
Magnetic Field (Gauss)
87,8; 11,4
3200 3300 3400
Magnetic Field (Gauss)
70,2; 19,7
3150 3200 3250 3300 3350 3400 3450 3500
Magnetic Field (Gauss)
86,4; 16,5; 3,3
3150 3200 3250 3300 3350 3400 3450 3500
Magnetic Field (Gauss)
70,8 ; 17,1
CO2RR O
O
O R
O
R O
O
O R
O
.2 + 2F F
FF F
THERMOLYSIS
Fluoropolymer 2010, 13-16 June 2010, Meze, France
Perfluoroalkylation of Aromatic Substrates
G. Resnati, I. Wlassics, M. Sansotera, P. Metrangolo, W. Navarrini, Chem. Today, 2007, 25, 3, 23-25.
OO
O
O
RR Solvent
OH
O
R CO2ArR+ Ar - H ++F
F FF
R
O
O O
O
R R
O
O O
O
R
CO2.2 + 2RF F F F F
Thermolytic Initiation
RO O
RO
ORH
CO2
RO
O
RH
.
+ +
.RF
F
F
FF
F
Electron Transfer Propagation
Carbocation Aromatization
RO
O
RHR
R
O
O H+ + +
FF
F
F
REACTION MECHANISM
64%68%39%
96%(4%)a
69%(31%)a
89%(4%)a
86%97%95%
Yields
ProductAr-H
R
CH3 CH3
R
Cl Cl
R
CF2CF3R =F CF2CF2CF3
R =FCFCF3 R =
2F
a. Yields of benzylic by-products.
The reaction has been confirmed by:- GC-MS analyses;
- 1H-NMR and 19F-NMR analyses.
19th International Symposium on Fluorine Chemistry, Jackson Hole, USA 2009
Perfluoroalkyl radicals are able to link covalently the unsaturated moieties.
O
OH C
OH
C
O
O
COO
C
O
O
C
C
O
O
O
C
O
OH
C
CO
O
O
C
O
O
O
C
OOC C CO O
Perfluoroalkylation of Carbon Black
It is formed by polycyclic structured aggregates with several functional groups at the edge.
Carbon Black
Fluoropolymer 2010, 13-16 June 2010, Meze, France
R
O
O HCO2R
O
O O
O
RR+
F+ +
F FF
Perfluorodiacyl Peroxides
Perfluoropolyether Peroxides
CF2CF2 O CF2CF2O
T O CF2 O CF2CF2O H O CF2 O CF2CF2O O
CF3 C O F C O FCF2
+ + +
AMW 39000; m/n 1.15; v~43
vm n
Tm n v
O T'm n
T
T, T' = , ,
_HFCF2CF2O RFH CF2CF
O
RF
O O
W. Navarrini, M. Sansotera, P. Metrangolo, P. Cavallotti, G. Resnati., PCT WO 2009/019243 A1
Perfluoroalkylation of Carbon Black
Solvent
n
n
R
R
R +F F
F = Perfluoroalkyl chains, Perfluoropolyether chains
CONTACT ANGLE CHARACTERIZATIONPeroxide Treated Carbon
(x 102 mmolsup/m2)Contact Angle
Untreated Carbon Not stable
Perfluorodipropionyl Peroxide
1,6 17°
3,2 80°
8,0 138°
Perfluorodi-iso-butyryl Peroxide
1,6 137°
3,2 139°
8,0 134°
Perfluorodi-n-butyryl Peroxide1,6 56°
3,2 157°Perfluorodi-2fluorosulphonyl-propionyl Peroxide 3,2 31°
Z-Fomblin Peroxide
0,14 140°
0,46 180°
0,86 180°
2 sec 4 sec 6 sec 8 sec
Untreated Carbon
Perfluorodipropionyl Peroxide
Perfluorodi-iso-butyryl Peroxide
Perfluorodi-n-butyryl Peroxide
Z-Fomblin Peroxide
19th International Symposium on Fluorine Chemistry, Jackson Hole, USA 2009
Perfluoroalkylation of Carbon Black
Solvent
n
n
R
R
R +F F
F = Perfluoroalkyl chains, Perfluoropolyether chains
CONTACT ANGLE CHARACTERIZATION
Fluoropolymer 2010, 13-16 June 2010, Meze, France
M. Sansotera, W. Navarrini, G. Resnati, A. Famulari, C.L. Bianchi, P.A. Guarda, Carbon, submitted
HYSTERESIS
ARCA MeasurementsThe difference between the advancing (Adv-CA) and receding (Rec-CA) contact angle values. Range: (8-20 μl)
0
2
4
6
8
10
CA
Hys
tere
sis
(°)
PFPE CF3CF2CF20.46 0.86
Applications of Perfluoroalkylated Carbon
Black in Fuels Cells
Fluoropolymer 2010, 13-16 June 2010, Meze, France
Membrane
Anodic Catalytic Layer
Cathodic Catalytic Layer
Microporous Layer (MPL) and
Gas Diffusion Layer (GDL)
Bipolar plates
Ionomeric MembranesPerfluorosulphonic PolymersThe addition of fluorinated polymers, acting as binders, stabilizes the catalyst particles on the membrane.
Strato macroporoso290-400 ?m
GAS DIFFUSION LAYER
250-400 μm
Strato microporoso10-100 ?m
MICROPOROUS LAYER10-30 μm
Strato catalitico10-50 ?m
CATALYTIC LAYER (CL)5 -10 μm
MPL• Electric contact between GDL and CL• “Barrier” to water produced at cathode GDL• Homogeneous gas diffusion on CL• Water removal from CL• Electric contact between CL and bipolar plate
l
nn
n
i
iiBrii
i
iiA 1lnlnEV
0Cell
Applications of Perfluoroalkylated Carbon
Black in Fuels Cells
Fluoropolymer 2010, 13-16 June 2010, Meze, France
0.5
1.2
Cel
l V
olt
age
(V)
Current Density (mA/cm2) 1000
Theoretical EMF or Ideal Voltage
Activation Polarization(Reaction Rate Loss)Ohmic Polarization(Resistance Loss)
Concentration Polarization(Gas Transport Loss)
Operation VoltageCurve
Generalized Polarization (Kinetic) Loss Equation
Applications of Perfluoroalkylated Carbon
Black in Fuels Cells
Fluoropolymer 2010, 13-16 June 2010, Meze, France
GAS DIFFUSION LAYER (GDL)
Treatment to increase the Hydrophobicity
Typically a PTFE coating5-30%wt
CARBON FIBERTISSUE
PTFE 10%wt
Applications of Perfluoroalkylated Carbon
Black in Fuels Cells
Fluoropolymer 2010, 13-16 June 2010, Meze, France
FUEL CELL TEST
GAS DIFFUSION LAYER (GDL)
Preliminary Results
Open Circuit Voltage0.94 V
(Good Performance: OCV > 0.9 V)
PFPE 0.24%wt
Covalently Linked to GDL
Synthesis and characterization of environmental friendly fluorosilicone reactive polymeric coatings based on Perfluorinated alkylic chains. These fluorosilicone compounds as a functional material have excellent properties imparted by both fluorine and silicon. Fluoro-silicon coupling agents were found to have high modification ability, in particular: UV-transparency, antireflective films, water and oil repellency on various surfaces.
Wet out cause damp ,clammyfeeling
Water bead off
CA(Water):103±1 deg
CA(Water):42±3 deg
Before treatment
After treatment
7) Perfluorinated alkylic chains fluorosilicone coating
PROJECTS UNDER DEVELOPMENT
Parma - Marzo 2012