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Fluorocarbon Coatings Via Plasma EnhancedChemical Vapor Deposition of 1H,1H,2H,2H-perfluorodecyl Acrylate - 2, Morphology,Wettability and Antifouling Characterizationa
Virendra Kumar,* Jerome Pulpytel, Hubert Rauscher, Ilaria Mannelli,Francois Rossi, Farzaneh Arefi-Khonsari
V. Kumar, J. Pulpytel, F. Arefi-KhonsariLaboratoire de Genie des Procedes Plasmas et Traitement deSurface, Universite Pierre et Marie Curie, ENSCP,11 rue Pierre etMarie Curie, 75231 Paris cedex 05, FranceFax: (þ33) 1 44276813; E-mail: vkrawat75@gmail.comV. KumarRadiation Technology Development Division, BARC, Trombay,Mumbai 400085, IndiaH. Rauscher, I. Mannelli, F. RossiInstitute for Health and Consumer Protection, EuropeanCommission Joint Research Centre, Ispra, Italy
a Part 1: cf. ref. [34]
Low surface energy fluorocarbon polymer coatings were prepared via plasma enhanced chemicalvapor deposition (PECVD) of 1H,1H,2H,2H-perfluorodecyl acrylate (PFDA) in a low pressureinductively excited RF plasma. The influence of plasma parameters, such as, deposition time,continuous wave (CW) and pulse modulated (PM) plasma mode, plasma power and plasma dutycycle (DC) on morphology and wettablity of the PFDA was investigated using field emissionscanning electron microscopy (FESEM) and contact angle (CA) measurement techniques. Theplasma mode, plasma power and pulse duty cycle played a pivotal role in tailoring the surfacemorphology, wettability and the surface energy of the PFDA coating. The water CA hysteresisvalues for PFDA coatings suggested the wetting characteristics of the coating satisfying Wenzelmodel of nanostructured solid-water wetted contact. Athin conformal PFDA coating transformed a super-hydro-philic Whatman filter paper into a super-hydrophobicand oleophobic surface, which has industrial appli-cations for development of durable, stain resistanceand liquid repellent papers. The antifouling propertyof PFDA coatings investigated by quartz crystal micro-balance (QCM) exhibited the protein repellent behavioragainst three model proteins namely, ovalbumin (OVA),human serum albumin (HSA) and fibrinogen (FGN).
Plasma Process. Polym. 2010, 7, 926–938
� 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim wileyonline
Introduction
Low surface energy surfaces having hydrophobic and
oleophobic characteristics are highly desirable for various
applications, such as biocompatible surfaces, antifouling
coatings, durable, waterproof and stain resistant paper,
textiles and wood, low dielectric constant material for
microelectronics, etc.[1–3] Fluorocarbon polymers are the
suitable candidates for these applications due to their
unique properties, such as high thermal stability, excellent
library.com DOI: 10.1002/ppap.201000038
Fluorocarbon Coatings Via Plasma Enhanced Chemical Vapor Deposition of 1H,1H,2H,2H-perfluorodecyl Acrylate - 2 . . .
chemical resistance, low friction coefficient, superior
weatherability, oil and water repellence, low flammability,
low dielectric constant, etc.[4–7]
Non-specific adsorption of proteins and associated
biofouling is one of the most significant limitations to
the end point utility of several biomaterial and marine
devices.[8] A large number of existing and emerging
biotechnological applications suffer from biofouling pro-
cess; including contact lenses, catheter tubes, blood
contacting devices, implant devices, biosensors, microflui-
dics and drug delivery systems. The adsorption of proteins
onto a biomaterial surface initiates a cascade of events
involved in biofouling process, including the biofilm
formation, that can ultimately result in inflammation,
infection and rejection of the material/implant causing
extra pain and medical cost to the patient.[8,9] In fact, the
primary mechanism in the attachment of microorganisms
to surfaces involves conditioning of the material surface by
protein adsorption from the biological fluid or protein and
glycoprotein secreted by the microorganism.[10–12] Marine
devices also suffer from the bio-fouling resulted from the
undesired accumulation of colonizing organisms, e.g.,
bacteria, cyanobacteria, algae, etc. The undesirable accu-
mulation of biomass on a ship hull leads to increased
weight and higher hydrodynamic drag resulting in lower
operational speeds and increased fuel consumption.[13]
Therefore, the development of efficient protein-resistant
coatings has great industrial relevance to the production of
antibiofouling surfaces.[14–19] The surface-free energy,
wettability and mechanical properties of the coating play
a vital role in defining the extent to which a surface can
resist biofouling or facilitate fouling release.[20–22] In this
regard, the potency of fluoropolymers[17,23,24] and silicone
elastomers,[25] which have emerged as the most promising
candidates, has been explained in terms of their inert-low
surface energy and interesting mechanical properties.[21,26]
In general, the conventional wet deposition methods of
fluoropolymer coatings involve various chemicals and
solvents and suffer from processing difficulties, such as
poor adhesion of coatings to the substrate due to the inert
nature of fluorocarbons and poor control over the thick-
ness.[27–33] On the other hand, the dry and solvent free
plasma enhanced chemical vapour deposition (PECVD) or
plasma polymerization process does not suffer from the
processing difficulties mentioned before, and offers a better
and effective process to deposit fluorocarbon coatings on
any substrate with good adhesion and better control over
thickness, chemistry, morphology and final properties of
the coatings.[34–40] Majority of the literature on the
fluorocarbon polymer coatings by PECVD process targeted
for different applications involve saturated low molecular
weight precursors, namely CF4, C2F6, C3F8, C3F6O, CH2F2,
CHF3, CF3CHF2 and C4F8.[41–48] For example, Vaswani et al.
have reported the applications of plasma polymerized
Plasma Process. Polym. 2010, 7, 926–938
� 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
fluorocarbon coatings from CF3CHF2 and C4F8 precursors for
enhancement of barrier properties and hydrophobic
characteristics of paper and regenerated cellulose sur-
faces.[48] However, recently, great attention has been paid
to produce fluorocarbon polymer coatings by plasma
polymerization of high molecular weight organic precursor
molecules containing polymerizable unsaturated acrylate
group with perfluoroalkyl pendant chain due to their
exceptional properties such as fast polymerization, require-
ment of mild processing conditions and hydrophobic as
well as oleophobic (i.e., liquid repellent) characteristics. The
extraordinary properties of these precursors are attributed
to the presence of acrylate group and the peculiar chemical
architecture of the perfluorocarbon polymer chains.[29,49,50]
Some of the examples of these precursors include
1H,1H,2H,2H-perfluorodecyl acrylate (PFDA),[34,51,52]
1H,1H,2H,2H-perfluorooctyl acrylate[53] and 1H,1H,2H-per-
fluoro-1-dodecene.[54,55] The majority of the applications of
the fluorocarbon coatings depend on the surface energy and
wettability of the surface, which is governed by the
topography and the morphology in addition to the chemical
composition of the coating. Surfaces with regularly aligned
and closely packed CF3 groups have been reported to exhibit
surface energy of 6.7 mJ �m�2, which is well below the 18–
20 mJ �m�2 value for polytetrafluoroethylene (PTFE).[28,36]
The main challenge is to preserve the chemical archi-
tecture of the precursor molecule in the plasma polymer-
ized coating to the maximum extent possible with tailor
capability of the surface morphology and wettability of the
coating.[37,51,54] In our earlier study, we have shown by
spectroscopic techniques that plasma polymerized PFDA
coating with wide range of chemistries could be produced
by varying plasma process parameters.[34] In the present
work, we have investigated the influence of plasma
parameters on the morphological and surface wettability
of the plasma polymerized PFDA coatings. Most of the
research works, carried out on plasma deposited perfluor-
oalkyl acrylate coating, have been targeted mainly to
achieve the low surface energy surfaces with liquid
repellent properties.[51–57] To the best of our knowledge,
no study has been aimed to explore the protein repellent
characteristics of plasma polymerized PFDA coatings.
Therefore, the objective of the present study has been
focused on the antifouling (i.e., protein repellent) as well as
the liquid repellent applications of the plasma polymerized
PFDA coatings.
Experimental Part
Materials
1H,1H,2H,2H-perfluorodecyl acrylate (PFDA) precursor
(CH2¼CH�COO�CH2CH2(CF2)7CF3, purity¼ 97%, Molecular weight
(M)¼518.17, Sigma–Aldrich, France) was used as received without
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V. Kumar, J. Pulpytel, H. Rauscher, I. Mannelli, F. Rossi, F. Arefi-Khonsari
further purification. Argon gas (Air Liquide, France, purity> 99.9%)
was used as a carrier gas. Thermanox cover slips (Nalge Nunc
International, Thermo Fisher Scientific, USA) and polished silicon
wafers (100) (Siltronix) were used as coating substrates. Whatman
quantitative filter paper grade 50 (Pore size 2.7mm, 97 g �m�2) were
procured from Sigma–Aldrich France. Three test proteins, namely,
ovalbumin (OVA, Sigma–A5503), human serum albumin (HSA, 30%
solution, Sigma-A6909) and fibrinogen (FGN, lyophilized Fraction I,
Type I, human, Sigma-F3879) were diluted in 10 mM PBS (pH 7.4) to a
final concentration of 50mg �mL�1 and used for quartz crystal
microbalance (QCM) analysis.
Plasma Deposition Setup
1H,1H,2H,2H-perfluorodecyl acrylate (PFDA) polymer coatings
were fabricated in a low pressure inductively excited radio
frequency-tubular quartz plasma reactor system (5 cm diameter,
40 cm length, base pressure of 3� 10�2 mbar). The schematics of
plasma deposition setup and technical details of the process have
been provided in our earlier work.[34] The flow rate of the precursor
was controlled by flow rate of carrier gas (i.e., Ar), which was
regulated and measured by electronic mass flow controllers (MKS
instruments). Prior to each experimental run, the reactor was
scrubbed and cleaned with detergent, organic solvents and dried
using a compressed air. The plasma reactor system was
reassembled and cleaned further with 20 W Ar plasma discharge
at 0.5 mbar pressure for 30 min. PFDA coatings were deposited at
working pressure of 0.5 mbar, precursor temperature of 65 8C,
precursor flow rate of 0.44 sccm, Argon flow rate of 20 sccm, unless
otherwise mentioned.
Coating Characterization Techniques
Field Emission Scanning Electron Microscopy (FESEM)
The morphology and thickness of the plasma polymerized coatings,
prepared under different plasma process conditions, were inves-
tigated by using FESEM. FESEM images were taken using Zeiss Ultra
55 FEGSEM with GEMINI Column on gold metallized PFDA coating
surfaces by sputter coating (Cressinton sputter coater-108 auto).
Electrons with accelerating voltage of 5 and 6 kV were used to
obtain the FESEM images. The thicknesses of the coatings were
measured from the cross-sectional images of fracturing PFDA
coatings deposited on silicon wafers.
Atomic Force Microscopy (AFM)
An atomic force microscope NTEGRA PRIMA from NT-MDT
was used to examine the topography and roughness of the
plasma polymer coatings deposited onto silicon wafer substrates.
The microscope was operated in semi-contact mode. All of the
AFM images were acquired at room temperature (�24 8C) in air
and are presented as unfiltered data. ‘NOVA’ SPM Software
was used for data acquisition and data processing. The average
surface roughness (Ra) values were derived from (10mm�10mm)
AFM images.
Plasma Process. Polym. 2010, 7, 926–938
� 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Contact Angle (CA) Measurement
Sessile drop CA values were measured using a video capture CA
apparatus (Digidrop GBX-3S system, France). For each measure-
ment, a 6mL droplet was dispensed onto the coating surface and the
CA was measured in a static as well as in a dynamic mode. The static
water contact angle (WCA) were measured just after the dispensing
the liquid drop on the surface and reported as an average (mean)
value� s (standard deviation), estimated from five individual CA
values measured per each sample. Surface energy of PFDA coatings
were estimated by static CA values measured for two probe liquids,
namely water and diiodomethane using Owen and Wendt
geometric mean Equation (1)[58]
1 þ cosuð Þg l ¼ 2 gdsgdl
� �1=2 þ gpsgpl
� �1=2h i
(1)
and
gs ¼ gps þ gds (2)
where u is the CA, gs and g l are the surface free energies of the solid
and liquid, respectively. The superscripts d and p refer to the
dispersive and polar components of surface energy, respectively.
Advancing CAs were measured by lowering the liquid droplet
towards the underlying surface until it just touched (without any
distortion of the circular shape) and measuring the CA while
increasing the volume of liquid drop until the CA remained
constant. Receding angle was measured by decreasing the
volume of the drop until the CA value remained constant and
the solid/liquid interface started to decrease.[59] The values
reported are the average value� s, estimated from five individual
measurements per sample. Water contact angle hysteresis (WCAH)
is defined as the difference between the advancing and receding
CAs. WCAH is originated by the presence of topographical and
chemical heterogeneities of the surface. The CA hysteresis is an
indication of the tendency of a liquid droplet to roll off across the
surface (i.e., in the case of low CAH value the droplet easily rolls off,
and vise versa). Two descriptions have been proposed for the
dependency of the wetting behavior on surface heterogeneity or
surface roughness: A very low CAH value for a rough surface
indicates the slippery behavior of composite rough surfaces (air
trapped in the grooves) satisfying Cassie–Baxter model, whereas,
high CAH value for a rough surface indicates the non-slippery
behavior of wetted rough surfaces satisfying the Wenzel
model.[53,60] Comparison of the Cassie–Baxter equation with the
Wenzel equation shows that the main difference between
composite (air trapped in the grooves) and rough surfaces is that
for most of finite CA values; the former predicts greater CAs relative
to the corresponding smooth surface, whereas this only holds true
in the latter case when CAs exceed 908CA on the flat substrate (i.e.,
less than 908 on a smooth surface gives rise to a smaller CA upon
roughening).[61]
Quartz Crystal Microbalance (QCM)
Recent studies have proven that the QCM-dissipation (QCM-D)
technique is very useful for the evaluation of surface-related
processes in liquids, including protein adsorption.[62–67] The QCM
instrument monitors resonating frequency change of the Au coated
DOI: 10.1002/ppap.201000038
Fluorocarbon Coatings Via Plasma Enhanced Chemical Vapor Deposition of 1H,1H,2H,2H-perfluorodecyl Acrylate - 2 . . .
sensor quartz disc due to the adsorption of protein molecules on it in
a time resolved manner. The change in the resonating frequency
(Df) of the sensor disc could be related to the mass change (Dm) of
the sensor disc due to adsorption or desorption of material using
Sauerbrey Equation (1).[68]
Fig(a)
Plasma
� 2010
Dm ¼ � C=n½ �: Dfð Þ (3)
where n is the overtone number and C is a mass sensitivity
constant. At 5 MHz, a frequency shift of 1 Hz corresponds to a mass
change of�18 ng � cm�2. Sauerbrey relation (1) is applicable to only
sufficiently thin and rigid adsorbed films.[67] However, the QCM
analysis has been widely used to obtain the adsorption behavior
and approximate mass of adsorbed protein on to various
substrates.[62,66] However, the trapped solvent molecules may
make the adsorbed protein layer soft, which influence the damping
of the quartz oscillation and the sensitivity constant of the sensor,
resulting in the error in the estimation of the deposited mass.
Therefore, we had already examined this aspect and found a low
dissipation shift (<0.1E-5 for HSA and OVA;<0.6E-5 for FGN) during
the protein adsorption process, which pointed out the formation of
a rigid protein layer where the viscoelastic effect was not
significant; allowing us to estimate approximate mass of absorbed
proteins using Sauerbrey equation. PFDA coatings were analysed
for their antifouling properties by measuring protein adsorption
using three different proteins, as a function of time in a continuous
flow mode using a Quartz crystal microbalance QCM-D E4
instrument (Q-Sense AB, Gothenburg, Sweden). All data presented
in this study correspond to the fifth overtone, which is less sensitive
to variations of the mounting conditions of different crystals.
Polished AT-cut and Au coated sensor quartz discs (14 mm in
diameter, 0.30 mm thick) with a fundamental frequency of 5 MHz
(Q-Sense AB, Gothenburg, Sweden) were used as substrate for PFDA
coatings for the QCM experiments. After assembling the sensor
quartz disc into the QCM, the plasma polymerized PFDA coated
surfaces were first exposed to 10� 10�3M PBS solution at pH 7.4, in
order to stabilize the system and obtain the base line. After that, the
protein solution with 50mg �mL�1 concentration in 10�10�3M PBS
was pumped continuously through the measurement chamber at a
flow rate of 20mL �min�1. The frequency changes due to adsorption
of proteins were monitored as a function of time. All QCM
adsorption experiments were performed at 25 8C� 0.02 8C in
duplicate.
ure 1. Field emission scanning electron microscopy (FESEM) imag10min (WCA¼ 1168), (b) 20min (WCA¼ 1218) and (c) 40min (WCA
Process. Polym. 2010, 7, 926–938
WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Results and Discussion
Plasma Deposition Time
Plasma deposition time is an important parameter that
governs the properties of plasma polymerized coatings
such as, coating thickness, morphology and topography of
the coating. PFDA coatings were deposited for various
deposition times and their surface morphology and
wettability were investigated by FESEM and WCA mea-
surement techniques, respectively. We have reported
earlier that the coating thickness increases linearly with
the deposition time, whereas, the surface chemistry of
PFDA coating was not influenced by plasma deposition
time.[34] Figure 1(a–c) shows the FESEM micro-images of
surfaces of PFDA coatings prepared at three different
deposition times that revealed the influence of deposition
time on the surface morphology of PFDA coating. At lower
deposition time the PFDA coating showed less prominent
with less number of nano-particulate structures appeared
on the coating surfaces. The particulate surface morphology
gradually became more prominent with the increase in the
deposition time. The WCA of the PFDA coatings increased
with the increase in deposition time (Figure 1 caption).
PFDA coating prepared at 10 min deposition time (thick-
ness¼ 120� 15 nm) exhibited WCA¼ 1168, which
increased to 1218 and 1268 for deposition time of 20 min
(thickness¼ 290� 45 nm) and 40 min (thickness¼ 580�50 nm), respectively. The increase in the hydrophobicity of
PFDA coatings with the increase in plasma deposition time
was mainly attributed to the increase in the roughness and
the change in the surface morphology to rougher with
nanostructured particulate features [Figure 1 (a–c)]. The
dependency of particulate size on the plasma deposition
time has also been reported in literature.[69,70] Effect of
deposition time on surface structures, morphology and
wettability of plasma fluorocarbon coatings produced from
tetrafluoroethylene precursor have also been reported
earlier by other research groups.[71,72] They have found
that the surface morphology alters from nanostructured
es of PFDA coating surfaces prepared at different deposition time¼ 1268) (Ppk¼ 1W, ton¼ 25ms, toff¼ 75ms).
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V. Kumar, J. Pulpytel, H. Rauscher, I. Mannelli, F. Rossi, F. Arefi-Khonsari
particulate to complex micro/nano sized ribbon like
structures with the increase of thickness of coating and
plasma deposition times, which was also manifested by the
significant increase in the WCA values. These observations
showed that the plasma deposition time influenced the
coating thickness, surface morphology and wettability but
not the chemical composition of the PFDA coatings.[34]
PM Versus CW Plasma Mode
Influence of the plasma operation modes i.e., CW and PM
plasma discharge modes on the composition, surface
structures and morphology of different plasma fluorocar-
bon coatings have been reported by other research
groups.[71,72] Figure 2 shows the FESEM images of PFDA
coatings prepared under PM and CW plasma modes. It could
be seen that PFDA coatings deposited under PM plasma
mode exhibit particulate nanostructured morphology
(Figure 2a), whereas, the PFDA coatings prepared in CW
plasma condition exhibit smooth surface morphology
(Figure 2b). AFM analysis also revealed that the PFDA
coating prepared under PM mode exhibit higher roughness
(Ra¼ 22.3 nm) as compared to that prepared under CW
mode (Ra ¼ 0.5 nm) (AFM images not shown). Cicala et al.
have also reported the difference in the surface morphology
and roughness of fluorocarbon films obtained by CW and
PM plasmas fed with C2F4 precursor.[71] The difference in
the surface morphology and roughness of fluorocarbon
coatings produced in CW and PM mode was attributed to
the difference in the growth mechanism.[51,71] CW plasma
process deposits coatings under more energetic condition,
as the energy is continuously being fed to the system, which
gives rise to high plasma density generating energetic
species through out the treatment time that cause
fragmentation, polymerization initiation of precursors,
generation of reactive sites on the coating and surface
modification of coating via etching/ablation processes
giving rise to smooth coatings surface. On the other hand,
PM plasma operates at low total power input i.e., equivalent
Figure 2. Field emission scanning electron microscopy (FESEM) imacoatings prepared under CW and PM plasma mode (ton¼ 25ms, toff¼(b) CW-1W.
Plasma Process. Polym. 2010, 7, 926–938
� 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
powerPeq conditions.[34,73] In PM plasma conditions, a more
ordered growth process occurs during plasma ‘off’ times
(toff), relative to complex processes during the highly
energetic plasma ‘on’ periods (ton). The lifetime of neutrals
(responsible for deposition/polymerization) is much higher
than those of the ions and electrons (responsible for surface
modifications by ablation/etching).[74] Therefore, PM
plasma process provides the control over the extent of
precursor fragmentation, coating degradation or surface
modification by varying ton/toff ratio, which regulates the
relative concentration of the ions and the neutrals during
the plasma off time. In PM plasma mode, the neutral radical
could stay longer and take part in the polymerization/
deposition process during plasma toff with minimal surface
modifications of coatings via etching/ablation caused by
ions, which was manifested by nanostructured rough
PFDA coatings.[75,76] In PM mode, upon reaching to a critical
number density of the radical species, rapid agglomeration
is triggered leading to the particulate morphology of the
coating.[77] However, in CW mode excessive secondary
products cause the partial pressure of precursor to drop to
an extent that precludes exclusive powder or particulate
formation. Moreover, in CW mode, the polymerization,
fragmentation and ablation processes take place simulta-
neously throughout the plasma discharge time leading to
smooth coating surface by competitive ablation and
polymerization (CAP) principle.[34] It could be concluded
that in CW plasma mode, the uniform and smooth film
growth resulted from the synergistic effect of deposition
and surface modification by etching/ablation of coatings.
On the contrary, the film growth in PM plasmas is mainly
governed by the growth of coalesced nuclei produced
during plasma off time, resulting in the rough and
particulate morphology of coatings.[72]
Table 1 shows static CA values and the surface free
energy for PFDA coatings on Thermanox, prepared
under PM and CW plasma modes using two test liquids
i.e., water and diiodomethane. The static CA values
are significantly higher for PFDA coatings prepared on
ges of the PFDA75ms) (a) PM-1W,
smooth Thermonox surfaces under PM
mode (PM-1W: ton/toff ¼ 10 ms/90 ms,
WCA¼ 126.58; CA of diiodomethane¼1058) as compared to that prepared under
CW mode (CW-1W: WCA¼ 107.08; CA of
diiodomethane¼ 93.08). The lower WCA
values (i.e., lower hydrophobicity) for
PFDA coatings prepared in CW mode as
compared to that prepared under PM
mode was attributed to de-fluorination
and lower CF2 and CF3, and incorporation
of oxygenated group in the PFDA coatings
prepared under CW plasma mode,[34] in
addition to the lack of surface roughness
(a smoother surface) in CW mode (FESEM
DOI: 10.1002/ppap.201000038
Table 1. Static CA of PFDA coatings on Thermanox coverslips andWhatman paper-50, and surface energy of PFDA coating surface depositedon Thermanox coverslips under different experimental conditions. (DC10: ton¼ 10ms, toff¼90ms, DC25: ton¼ 25ms, toff¼ 75ms, DC50:ton¼ 50ms, toff¼ 50ms, DC75: ton¼ 75ms, toff¼ 25ms).
Sample Static contact angle (degree) Surface energy
Water Diiodomethane mN�m�1
Thermonox Paper Thermanox paper Total Polar Dispersive
(gs) (gps ) (gd
s )
PM-1W-DC25 123.5� 1.5 144.0� 1.5 100.0� 1.5 122.0� 2.0 8.6 0.1 8.5
PM-4W-DC25 111.5� 1.8 136.0� 1.8 93.5� 1.2 111.0� 1.5 12.3 1.1 11.2
CW-1W 107.0� 1.5 135.0� 2.0 93.0� 1.5 117.0� 1.5 13.4 2.0 11.4
CW-5W 102.0� 1.5 129.0� 1.7 84.5� 1.9 102.0� 1.3 17.6 2.3 15.3
PM-1W-DC10 126.5� 1.5 151.0� 1.5 105.0� 1.4 122.0� 1.9 7.3 0.2 7.1
PM-1W-DC50 113.5� 2.0 – 98.5� 1.5 – 10.4 1.2 9.2
PM-1W-DC75 110.0� 2.6 – 96.5� 1.6 – 11.6 1.7 10.0
Fluorocarbon Coatings Via Plasma Enhanced Chemical Vapor Deposition of 1H,1H,2H,2H-perfluorodecyl Acrylate - 2 . . .
and AFM analysis). The similar trend of static CA was
exhibited for PFDA coatings prepared on rough Whatman
paper (PM-1W: ton/toff ¼ 10 ms/90 ms, WCA¼ 1518;CA of diiodomethane¼ 1228) as compared to that
prepared under CW mode (CW-1W: WCA¼ 1358; CA of
diiodomethane¼ 1178). However, the CA values were
significantly higher for PFDA coatings on Whatman paper
as compared to that on Thermanox surfaces, due to the
micro-roughness of paper surface. The high CA values for
water and diiodomethane clearly revealed the water
repellent (hydrophobic) and oil-repellent (oleophobic)
characteristic of PFDA coatings. The surface energy of PFDA
coating was found to be greatly influenced by the
plasma operation mode (Table 1). The surface energy of
PFDA coating prepared under PM mode exhibits very low
surface free energy (PM-1W, ton/toff ¼ 10 ms/90 ms:
gs ¼ 7.3 mN �m�1, gps ¼ 0.2 mN �m�1, gds ¼ 7.1 mN �m�1) as
compared to that prepared under CW mode (CW-1W:
gs ¼ 13.4 mN �m�1, gps ¼ 2.0 mN �m�1, gd
s ¼ 11.4 mN �m�1).
There was an increase in both the polar as well as the
dispersive component of the surface
energy when PM mode is changed to
CW plasma mode, which is explained by
de-fluorination leading to the decrease in
CF2 groups in perfluoroalkyl chain, and
incorporation of polar groups in CW
plasma operation mode.[34]
Figure 3. Effect of plasma power on the surface morphology of the coatings preparedunder CW and PM plasma mode (ton¼ 25ms, toff¼ 75ms) (a) PM-4W, (b) CW-5W.
Plasma Power
The influence of plasma power was also
reflected in the surface morphology,
hydrophobicity and surface energy of
the PFDA coatings. FESEM images shown
Plasma Process. Polym. 2010, 7, 926–938
� 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
in Figure 2 and Figure 3 clearly reveal that plasma power (in
both CW and PM mode) affect the surface morphology and
the distribution of nanostructures of PFDA coatings
surfaces. The surface morphologies of coatings alter from
rough morphology with dense and overlapped prominent
particulate nanostructures for PM-1W (Figure 2a) to
comparatively lesser rough morphology with very few
and less prominent particulate structures for PM-4W; it
seems the particles were embedded inside the polymer
coating film (Figure 3a). On the contrary, PFDA coating
prepared under CW at 1 W power (CW-1W) exhibited a
smooth surface with no particulate nanostructures
(Figure 2b), however, surprisingly, the increase in power
resulted in the formation of very tiny and well separated
nanoparticles (dust) on the surface for CW-5W (Figure 3b).
The deposition rate of plasma polymerized of PFDA coating
have been reported to decrease with the increase in plasma
power[51] due to the fact that at higher power conditions
species responsible for fragmentation and ablation (UV
radiation, ions or electron bombardment) dominate over
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V. Kumar, J. Pulpytel, H. Rauscher, I. Mannelli, F. Rossi, F. Arefi-Khonsari
those responsible for polymerization/deposition (i.e., radi-
cals). In PM mode, at higher plasma power condition,
combinations of processes: (i) the overlapping of coalesced
nuclei, (ii) the entrapment of agglomerated particles in to
the polymer coatings and (iii) the simultaneous occurrence
of a secondary reaction process (degradation/ablation
process) along with polymerization process, were respon-
sible for the less prominent particulate surface morphology.
The degradation and ablation of PFDA coating at higher
power condition has been manifested by the decrease in
F/C ratio and CF2 group concentration,[34] and decrease in
the thickness of the coating with the increase in plasma
power (PM-1W: thickness¼ 600� 50 nm; PM¼ 4 W: thick-
ness¼ 400� 25 nm; CW-1W: thickness¼ 190� 25 nm; CW-
5W: thickness¼ 50� 15 nm). In CW mode the formation of
very tiny nanoparticles on the coating surface at higher
power condition could be attributed to the high plasma
energy density that leads to generation of large concentra-
tions of reactive species creating a favorable condition for
the gas-phase reactions between radicals and other
species.[77,78] The variation in the coating thickness only
cannot justify the difference in the surface morphologies of
PFDA coatings because the chemical composition was also
found to be different for coatings prepared under varying
power conditions.[34] Therefore, the difference in the
surface morphology may be attributed to the different
growth mechanism of PFDA coating prepared under
different plasma power conditions.
Table 1 shows the effect of plasma power on the static CA
and the surface free energy for PFDA coatings prepared
under PM and CW plasma modes. The static CA decreased
drastically with the increase in the plasma power for PFDA
coating deposited on Thermanox as well as on Whatman
filter paper prepared under CW and PM plasma mode. The
total surface free energy, polar component and dispersive
component of surface energy increased with the increase in
Table 2. Advancing (ua) and receding (ur) WCA and WCAH of PFDA coaunder different experimental conditions.
Experimental condition Substrate
PM-1W-DC25 Thermanox
PM-4W-DC25 Thermanox
CW-1W Thermanox
CW-5W Thermanox
PM-1W-DC50 Thermanox
PM-1W-DC75 Thermanox
PM-1W-DC25 Whatman paper
PM-4W-DC25 Whatman paper
CW-1W Whatman paper
CW-5W Whatman paper
Plasma Process. Polym. 2010, 7, 926–938
� 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
the plasma power. The long perfluoroalkyl chains in PFDA
are responsible for showing very low polar and dispersive
interactions with polar and nonpolar liquids.[51] We have
reported that higher plasma power caused de-fluorination
of perfluoalkyl chain and incorporation of oxygenated polar
groups in the PFDA coating,[34] which was reflected here as
higher polar and dispersive surface energy. Moreover, PFDA
coatings prepared under PM plasma mode exhibited lower
surface energy values than those prepared under CW
conditions, which is attributed to higher chemical resem-
blance of coating to the monomer, higher F/C ratio and
higher roughness caused by particulate surface morphol-
ogy of PFDA coating prepared in PM plasma mode.
However, PFDA coatings prepared even at strong plasma
conditions (CW-5W) exhibited lower surface energy
(15.3 mJ �m�2) than that of PTFE coatings (18 mJ �m�2).[56,57]
Table 2 shows the advancing and receding WCAs and
water contact angle hysteresis (WCAH) of PFDA coatings on
Thermanox coverslip and Whatman paper prepared under
different plasma conditions. Similar to static CA, advancing
and receding CA showed lower values for higher power and
CW plasma conditions. The observed high WCAH value (358)for PFDA coating with highest roughness value
(Ra¼ 22.3 nm) prepared at PM-1W indicated that the level
of roughness is not sufficient for there to be a truly
composite interface (air-trapped) and so ruled out the
slippery-composite interface postulated by Cassie–Baxter
theory.[53] The wetting behavior satisfies the Wenzel model
of solid-water wetted contact, which predicts that surface
roughening decreases/increases the repellency of liquids
making a CA of less/greater than 908 on the corresponding
flat surface.[3,79,80] In PM plasma mode, the WCAH
decreased from 358 to 268 when the power is increased
from 1 to 4 W, whereas, in CW plasma mode, the WCAH
increased from 438 to 508when power is increased from 1 to
5 W. The particulate and rough morphology (for PM-1W)
tings on Thermanox coverslips and Whatman filter paper, deposited
ua ur WCAH
137.0� 1.6 102.0� 1.8 35
124.0� 1.4 98.0� 1.6 26
120.0� 2.1 77.0� 1.4 43
117.0� 1.0 67.0� 1.5 50
128.0� 1.6 94.0� 1.4 34
126.0� 1.9 85.0� 1.8 41
157.0� 2.0 140.0� 1.5 17
148.0� 2.1 122.0� 1.3 26
150.0� 1.6 122.0� 1.7 28
148.0� 1.8 111.0� 1.5 37
DOI: 10.1002/ppap.201000038
Fluorocarbon Coatings Via Plasma Enhanced Chemical Vapor Deposition of 1H,1H,2H,2H-perfluorodecyl Acrylate - 2 . . .
increased the actual surface area of
the coating surface in contact with the
liquid and, therefore, manifested as the
increased advancing CA (according to
the Wenzel theory) as compared to the
smooth surface in PM-4W and CW-1W
coatings. The decrease in the WCAH with
the increase in the power in PM mode is
attributed to the decrease in the surface
roughness that otherwise acts as a hurdle
for liquid to slide on the surface. More-
over, the higher WCAH for coatings
prepared in CW plasma mode is attrib-
uted to the polar interaction between the
water and the oxygenated polar groups
on coatings. The higher is the plasma
power in CW mode, the higher is the
concentration of polar groups generated
that eventually lead to higher WCAH
values.
Figure 4. Field emission scanning electron microscopy (FESEM) images of PFDA coatingsprepared under different DC of PM mode (Ppk¼ 1W) (a) DC¼ 10%, (b) DC¼ 25%,(c) DC¼ 50%, (d) DC¼ 75%, (e) CW (DC¼ 100%), (f) untreated silicone.
Pulse Plasma Duty Cycle (DC)
In PM plasma mode, at a fixed pulse
frequency, pulse DC governs the plasma
pulse characteristics such as ton/toff ratio
and equivalent power (Peq), and conse-
quently influences coating growth pro-
cesses (e.g., deposition, surface modifica-
tion), which is manifested by the
variation of chemical and morphological
characteristics of the polymer coat-
ings.[34,71,72,81] The influence of the DC
of the pulse plasma on surface morphol-
ogy of the PFDA coatings was revealed by
FESEM images of PFDA coating surfaces shown in Figure 4.
The size, density and distribution of the particulate
nanostructures of the PFDA coating surface altered with
the DC. At 10% DC small particulate structures in over-
lapped form appeared, but at 25% DC well separated, bigger
and prominent particulate surface morphology was
obtained. At 50% DC few particles and widely separated
but bigger globular structure with decreased particle
density appeared, and with further increase in DC, particle
size started decreasing and finally disappeared in CW (i.e.,
100% DC) conditions. In principle, increase in the DC of
plasma pulse leads the soft PM regime towards the strong
CW plasma regime (i.e., DC¼ 100%). At higher DC, higher
concentration of reactive species will be produced during
ton resulting higher probability of agglomeration of
coalesced nuclei, and higher fragmentation of the precursor
molecule and surface modification of the coatings, leading
to smooth surfaces.[34] The decrease in the coating thickness
with the increase in the DC of plasma pulse suggested the
Plasma Process. Polym. 2010, 7, 926–938
� 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
contribution of ablation leading to the depletion of PFDA
coatings at higher DC (DC¼ 10%: thickness¼ 700� 40 nm;
DC¼ 25%: thickness¼ 600� 50 nm; DC¼ 50%: thick-
ness¼ 450� 50 nm; DC¼ 75%: thickness¼ 205� 25 nm;
CW (DC¼ 100%: thickness¼ 190� 25 nm). Therefore, the
gradual change in the surface morphology of PFDA coatings
may be attributed to the alteration of relative contribution
of deposition and ablation/etching under different DC
conditions.[45]
In order to rule out the effect of thickness on the surface
morphology of PFDA coatings prepared under CW and PM
mode, we have taken the cross-sectional FESEM images of
the PFDA films (Figure 5) and compared the surface
morphology of two films prepared under CW and PM
mode having almost comparable thickness values
(DC¼ 75%: thickness¼ 205� 25 nm; CW (DC¼ 100%: thick-
ness¼ 190� 25 nm). A clear difference can be seen not only
in the surface morphology but also in the bulk morphology
of the two films prepared under PM and CW plasma mode.
www.plasma-polymers.org 933
Figure 5. Field emission scanning electron microscopy (FESEM) images of PFDA coatingsprepared under (a) DC¼ 75%, thickness¼ 205� 25 nm and (b) CW (DC¼ 100%), thick-ness¼ 190� 25 nm (Ppk¼ 1W).
934
V. Kumar, J. Pulpytel, H. Rauscher, I. Mannelli, F. Rossi, F. Arefi-Khonsari
Moreover, we have shown in our earlier study that the
chemical composition of the PFDA coatings also varied with
the change in plasma parameters i.e., CW and PM mode,
plasma power, DC (other experimental parameters are the
same).[34] These observations clearly suggest that the
coating thickness is not the parameter that governs the
surface morphology of the plasma polymerized PFDA
coating. Therefore, it can be concluded that the difference
in the surface morphology of PFDA coatings is attributed to
the difference in the growth processes involved in the
different plasma conditions.
The influence of DC on the surface wettability and
morphology of the PFDA coatings was revealed by gradual
decrease in the CA of water (from 126.58 for DC¼ 10% to
107.08 for DC¼ 100%) and diiodomethane (from 105.08for DC¼ 10% to 93.08 for DC¼ 100%) with the increase in
the DC of the plasma discharge (Table 1). It can be seen
that there is an increase in the total surface energy (from
7.3 mN �m�1 for DC¼ 10% to 13.4 mN �m�1 for DC¼ 100%)
as well as polar and dispersive component of surface
energy of the PFDA coating with the increase in the DC
of the plasma discharge (Table 1). The advancing and
receding CAs for water decreased and WCAH increased
with the increase in the DC of the plasma discharge
(Table 2), which is attributed to the increase in the polar
surface energy component and change
in the surface morphology.
Figure 6. Field emission scanning electron microscopy (FESEM) images of Whatmanpaper (a) untreated (b) PFDA coated (PM mode; ton¼ 25ms, toff¼ 75ms, Ppk¼ 1W).
Super-Hydrophobic Property of1H,1H,2H,2H-perfluorodecyl acrylate(PFDA) Coating on Paper
Figure 6 shows FESEM images of the
untreated and plasma polymerized
PFDA coated Whatman filter paper-50,
showing no structural damage to the
fibrous microstructure of paper. In addi-
tion, the ribbon like micro-fibrous mor-
phology of the paper was maintained
Plasma Process. Polym. 2010, 7, 926–938
� 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
and even became more prominently
visible after the thin coating of PFDA,
which leads to quite higher CAs
(ua¼ 1578) (Table 2). The conformal thin
coating of PFDA on the super-hydrophilic
paper transformed it into a super-hydro-
phobic surface, due to the combined
effect of the presence of micro-roughness
of intrinsic fibrous structured of paper
and high degree of fluorination. The
superhydrophobic property of plasma
polymerized fluorocarbon coatings with
ribbon like nanostructured morphology
produced from C2F4 precursor gas have
been reported by d’Agostino and cow-
orkers.[73] Moreover, the static CA of 1228 for diiodo-
methane on PFDA coated paper revealed the oleophobic
property of the PFDA coatings, which is attributed
to the long perfluorinated carbon chain length contain-
ing CF2 and terminal CF3 groups present in the PFDA
coatings.[51,55]
The PFDA coated Whatman paper (PM-1W-DC25) exhi-
bits higher advancing and receding CA and lower WCAH
value (ua¼ 1578, uc ¼ 1408, WCAH¼ 178) as compared to
PFDA coated smooth Thermanox substrates (ua¼ 1378,uc ¼ 1028, WCAH¼ 358) (Table 2). However, the lowest
WCAH value of 178 found for Whatman paper at PM-1W-
DC25 conditions is quite high and therefore, the CA theories
suggest that the super-hydrophobic character of these
surfaces follow the Wenzel model of solid-water wetted
contact leading to sticking (non-slippery) behavior of
PFDA coated paper surfaces.[60,82] In principle, mere rough-
ness is not directly correlated to slippery super-hydro-
phobicity; rather the height and distribution of the
structures are more important factors for slippery super-
hydrophobicity. In general, structures with greater
height and lower density result in reduction of hysteresis,
which is an essential requirement to reach a Cassie–Baxter
regime showing a slippery character for self cleaning
applications.[82]
DOI: 10.1002/ppap.201000038
120001000080006000400020000-25
-20
-15
-10
-5
0
Untreated Au
PFDA coating
∆Fr
eque
ncy/
Hz
Time/s
(a)
-25
-20
-15
-10
-5
0
Untreated Au
PFDA coating
(b)
Time/s
∆Fre
quen
cy/H
z
120001000080006000400020000
120001000080006000400020000
-100
-80
-60
-40
-20
0
Untreated Au
(c)
PFDA coating ∆Fr
eque
ncy/
Hz
Time/s
Figure 7. Time-dependent QCM frequency responses of untreatedAu coated QCM crystal sensor and Au coated QCM crystal sensorcoated with plasma polymerized PFDA film (PM mode, DC¼ 25%,Ppk¼ 1W) when contacted with protein solutions (a) OVA, (b) HSAand (c) FGN. The arrow shows the point of injection of proteinsolution.
Fluorocarbon Coatings Via Plasma Enhanced Chemical Vapor Deposition of 1H,1H,2H,2H-perfluorodecyl Acrylate - 2 . . .
Protein Repellent Property of 1H,1H,2H,2H-perfluorodecyl acrylate (PFDA) Coatings
Low-surface-energy polymeric coatings, such as fluorocar-
bon coatings offer a potential means of inhibiting the
biofouling process by presenting a non-stick surface to
biofouling species.[83,84] Increased interest in this approach
was motivated by the observation that the well-known
gorgonian corals with low surface energy natural antifoul-
ing surfaces do not allow the colonization by marine micro-
organism.[85]
The protein repellent properties of the PFDA surfaces (PM
mode; ton¼ 25 ms, toff ¼ 75 ms, Ppk ¼ 1 W, thickness �50 nm) were analyzed by QCM in a continuous flow mode.
Three different proteins, namely, OVA, HSA and FGN in PBS
solution were injected individually and their adsorption
behavior was studied by monitoring frequency as a
function of time. QCM has been widely utilized as an easy
technique for online investigation of surface-related
processes in liquids, including protein adsorption.[62–67]
In the present study, we have used decrease in the
frequency as an approximate measure of the adsorbed
protein for making a comparison among the adsorption
levels of three different proteins on a same PFDA surface
under the identical conditions. Moreover, the dissipation
shift during the protein adsorption process were found to be
low (<0.1E-5 for HSA and OVA;<0.6E-5 for FGN), indicating
the formation of a rigid layer of proteins, which rules out the
significant influence of viscoelastic effect; allowing us to
compare the adsorption behavior of different protein
molecules on PFDA coatings and untreated Au surfaces.
The higher dissipation shift in case of FGN was attributed to
its higher adsorbed amount leading to thicker layers, which
can imbibe water molecules that make the protein layer
soft with a resulting damping of the quartz oscillation. In
fact, several reports are available on the estimation of
amount of proteins adsorbed by QCM using Sauerbrey
relation and the adsorption behavior of proteins on various
hydrophilic and hydrophobic surfaces, using Sauerbrey
equation.[62,86,87] Rickert have reported that despite the
high hydration of the protein layers, viscosity-induced
effects play a negligible role and that the frequency
decrease reflects primarily mass changes at the surface.[66]
Quartz crystal microbalance (QCM) frequency responses
of untreated Au coated quartz crystal and PFDA coated Au
coated quartz crystal for OVA, HSA and FGN are presented in
Figure 7a, b and c, respectively. For untreated as well as
PFDA coated QCM crystal surfaces, the frequency decreased
sharply immediately after injection of protein solutions due
to adsorption of protein molecules, after that the frequency
almost leveled off indicating the saturation of protein
adsorption. The initial fast decrease in resonance frequency
followed by second slower adsorption process indicated an
irreversible protein adsorption process that depends on the
Plasma Process. Polym. 2010, 7, 926–938
� 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.plasma-polymers.org 935
936
V. Kumar, J. Pulpytel, H. Rauscher, I. Mannelli, F. Rossi, F. Arefi-Khonsari
type of protein, number of available binding sites and
surface energy of substrates, which determines the final
coverage. Plasma polymerized PFDA coatings showed lower
adsorption of proteins as compared to gold surfaces, which
indicated the inert and protein repellent, i.e., anti-biofoul-
ing characteristics of PFDA coatings towards adsorption of
protein biomolecule. The extent of frequency change of
QCM sensor due to the adsorption of protein molecules
varied for different proteins, indicating different adsorp-
tion behavior of different proteins. From the QCM analysis,
it was observed that coating of PFDA on Au surfaces reduced
the protein adsorption by�50%, 70% and 17% for OVA, HSA
and FGN, respectively. Another interesting aspect of protein
repellent characteristics of surface is the kinetics of
adsorption. The kinetics of protein adsorption on untreated
Au coated QCM crystal was found to be faster than on PFDA-
coated Au coated QCM crystal. The adsorption kinetics of
OVA and HSA on PFDA coatings was slower as compared to
FGN. The variation in the adsorption kinetics and the
antifouling characteristics of PFDA coatings against differ-
ent protein molecules is attributed to the varying affinity of
the coating surfaces towards protein molecules, due to
difference in the surface-chemical properties of different
protein molecules. Another factor is the number of contacts
between the macromolecule and the substrate surface;
multiple contact formation leads to higher and stronger
adsorption. FGN being a hydrophobic and bigger protein
molecule (MW� 340 kDa) as compared to HSA
(MW� 66 kDa) and OVA (MW� 45 kDa) interacted with
substrate through hydrophobic interaction and offers
higher numbers of contact sites for adhesion, which leads
to faster and higher adsorption as compared to other
proteins.[88] Evans-Nguen and Schoenfisch have reported
that protein (FGN) adsorption could be substantially higher
on hydrophilic surface provided that the surface is
positively or negatively charged.[89] Similar results have
been reported by Choukourov et al. where they have also
found that the FGN adsorbs faster and in higher amount on
gold surface than on CF3-terminated SAM, which was
attributed to the influence of the surface charge present on
gold surface.[86]
Conclusion
The deposition time, CW and PM plasma mode, plasma
power and pulse DC play crucial role in tailoring the surface
morphology, CA and surface free energy characteristics of
the plasma polymerized PFDA coating. The plasma poly-
merized PFDA coating has been successfully utilized to
transform a super-hydrophilic surface of Whatman filter
paper into a super-hydrophobic and oleophobic surface due
to the conformal low surface energy thin PFDA coating with
high degree of fluorination complemented by the micro-
Plasma Process. Polym. 2010, 7, 926–938
� 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
rough and fibrous microstructured morphology of paper.
Low-surface-energy PFDA coatings offer possible applica-
tions in paper industry for the development of water
repellent, oil repellent, stain resistance papers. The protein
adsorption study showed that PFDA coating exhibited
significant protein repellent behavior against three model
proteins namely, OVA, HSA and FGN, suggesting a potential
means of inhibiting the biofouling of material substrates by
presenting a non-stick surface.
Acknowledgements: ACTECO-EC project (515859-2) is acknowl-edged for financially supporting the work. Authors sincerely thankto Dr. D. Mataras, Dr. Ergina Farsari, PTL, University of Patras,Greece for AFM analysis, Dr. Reza Jafari from ENSCP, Paris,Dr. G. Giudetti from JRC, Italy and other partners of the project fortheir active support and discussion.
Received: March 20, 2010; Revised: June 11, 2010; Accepted: July8, 2010; DOI: 10.1002/ppap.201000038
Keywords: antifouling; fluorocarbon coating; 1H,1H,2H,2H-per-fluorodecyl acrylate (PFDA); hydrophobic; morphology; oleopho-bic; plasma enhanced chemical vapor deposition (PECVD); proteinadsorption; surfaces
[1] F. Arefi-Khonsari, M. Tatoulian, ‘‘Plasma processing of poly-mers by a low frequency discharge with asymmetrical con-figuration of electrodes’’, in: Advanced Plasma Technology,R. d’Agostino, P. Favia, H. Ikegami, Y. Kawai, N. Sato, F. Arefi-Khonsari, Eds., Wiley-VCH Verlag GmbH & Co. KGaA, Wein-heim 2007, p. 137.
[2] L. Feng, S. Li, Y. Li, H. Li, L. Zhang, J. Zhai, Y. Song, B. Liu, L. Jiang,D. Zhu, Adv. Mater. 2002, 14, 1857.
[3] W. Chen, A. Y. Fadeev, M. C. Hsieh, D. Oner, J. Youngblood, T. J.McCarthy, Langmuir 1999, 15, 3395.
[4] C. J. Drumond, Z. R. Vasic, N. Geddes, M. C. Jurich, R. C.Chatelier, T. R. Gengenbach, H. J. Griesser, Colloids Surf., A:Physicochem. Eng. Aspects 1997, 117, 129.
[5] C. M. G. Carlsson, G. Strom, Langmuir 1991, 7, 2492.[6] F. Denes, Z. Q. Hua, E. Barrios, R. A. Young, J. Evans,
J. Macromol. Sci., Pure Appl. Chem. 1995, 32, 1405.[7] H. T. Sahin, S. Manolache, R. A. Young, F. Denes, Cellulose 2002,
9, 171.[8] B. D. Ratner, S. J. Bryant, Ann. Rev. Biomed. Eng. 2004, 6, 41.[9] P. Kingshott, H. J. Griesser, Curr. Opin. Solid State Mater. Sci.
1999, 4, 403.[10] J. S. Dickson, M. Koohmarare, Appl. Environ. Microbiol. 1989,
55, 832.[11] C. G. Kumar, S. K. Anand, Int. J. Food Microbiol. 1998, 42, 9.[12] K. Kamino, K. Inoue, T. Maruyama, N. Takamatsu,
S. Harayama, Y. Shizuri, J. Biol. Chem. 2000, 275, 27360.[13] R. L. Townsin, Biofouling 2003, 19S, 9.[14] E. Ostuni, B. A. Grzybowski, M. Mrksich, C. S. Roberts, G. M.
Whitesides, Langmuir 2003, 19, 1861.[15] J. F. Hester, P. Banerjee, Y. Y. Won, A. Akthakul, M. H. Acar,
A. M. Mayes, Macromolecules 2002, 35, 7652.
DOI: 10.1002/ppap.201000038
Fluorocarbon Coatings Via Plasma Enhanced Chemical Vapor Deposition of 1H,1H,2H,2H-perfluorodecyl Acrylate - 2 . . .
[16] J. Groll, E. V. Amiregoulova, T. Ameringer, C. D. Heyes,C. Rocker, U. Nienhaus, M. Moller, J. Am. Chem. Soc. 2004,126, 4234.
[17] J. P. Youngblood, L. Andruzzi, C. K. Ober, A. Hexamer, E. J.Kramer, J. Callow, J. A. Finlay, M. E. Callow, Biofouling 2003,19, 91.
[18] S. Tosatti, S. M. DePaul, A. Askendal, S. VandeVondele, J. A.Hubbell, P. Tengvall, M. Textor, Biomaterials 2003, 24, 4949.
[19] V. E. Wagner, J. T. Koberstein, J. D. Bryers, Biomaterials 2004,25, 2247.
[20] J. A. Finlay, M. E. Callow, L. K. Ista, G. P. Lopez, J. A. Callow,Integr. Comput. Biol. 2002, 42, 1116.
[21] R. F. Brady, Jr., I. L. Singer, Biofouling 2000, 16, 1.[22] G. B. Sigal, M. Mrksich, G. M. Whitesides, J. Am. Chem. Soc.
1998, 120, 3464.[23] R. A. Pullin, T. G. Nevell, T. Tsibouklis, Mater. Lett. 1999, 39,
142.[24] R. F. Brady, Jr., S. J. Bonafede, D. L. Schmidt, Surf. Coat. Int.
1999, 82, 582.[25] M. Berglin, K. J. Wynne, P. Gatenholm, J. Colloid Interface Sci.
2003, 257, 383.[26] E. G. Shafrin, W. A. Zisman, J. Phys. Chem. 1960, 64, 519.[27] T. Shimizu, Modern Fluoropolymers, J. Scheirs, Ed., John Wiley
and Sons Ltd., New York 1997, p. 513.[28] A. F. Thunemann, A. Lieske, B. R. Paulke, Adv. Mater. 1999, 11,
321.[29] I. J. Park, S. B. Lee, C. K. Choi, K. J. Kim, J. Colloid Interface Sci.
1996, 181, 284.[30] T. M. Chapman, R. Benrashid, K. G. Marra, J. P. Keener,
Macromolecules 1995, 28, 331.[31] J. Hopgen, M. Moller, Macromolecules 1992, 25, 1461.[32] M. Morita, H. Ogisu, M. Kubo, J. Appl. Polym. Sci. 1999, 73,
1741.[33] D. L. Schmidt, C. E. Coburn, B. M. DeKoren, G. E. Potter, G. F.
Meyers, D. A. Fischer, Nature 1994, 368, 39.[34] V. Kumar, J. Pulpytel, F. Arefi-Khonsari, Plasma Process.
Polym. 2010, DOI: 10.1002/ppap.201000043 (in this issue).[35] H. Mugurama, I. Karube, Trends. Anal. Chem. 1999, 18, 63.[36] R. Daw, S. Candan, A. J. Beck, A. J. Devlin, I. M. Brook,
S. MacNeil, R. A. Dawson, R. D. Short, Biomaterials 1998,19, 1717.
[37] J. G. Calderon, A. Harsch, G. W. Gross, R. B. Timmons, J. Biomed.Mater. Res. 1998, 42, 2541.
[38] J. T. Grant, H. Jiang, S. Tullis, W. E. Johnson, K. Eyink, P. Fleitz,T. J. Bunning, Vacuum 2005, 80, 12.
[39] D. Jung, S. Yeo, J. Kim, B. Kim, B. Jin, D.-Y. Ryu, Surf. Coat.Technol. 2006, 200, 2886.
[40] A. Hiratsuka, H. Muguruma, K. H. Lee, I. Karube, Biosens.Bioelectron. 2004, 19, 1667.
[41] N. M. Mackie, N. F. Dalleska, D. G. Castner, E. R. Fisher, Chem.Mater. 1997, 9, 349.
[42] I. T. Martin, E. R. Fisher, J. Vac. Sci. Technol., A 2004, 22,2168.
[43] K. Takahashi, K. Tachibana, J. Appl. Phys. 2001, 89, 893.[44] C. B. Labelle, S. J. Limb, K. K. Gleason, J. Appl. Phys. 1997, 82,
1784.[45] C. B. Labelle, K. K. Gleason, J. Appl. Polym. Sci. 1999, 74,
2439.[46] R. d’Agostino, Plasma Polymerization, Treatment, and
Etching of Fluoropolymers, Academic, San Diego, CA 1990,p. 95.
[47] E. J. Winder, K. K. Gleason, J. Appl. Polym. Sci. 2000, 78, 842.[48] S. Vaswani, J. Koskinen, D. W. Hess, Surf. Coat. Technol. 2005,
195, 121.
Plasma Process. Polym. 2010, 7, 926–938
� 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
[49] J. E. Chase, F. J. Boerio, J. Vac. Sci. Technol., A, Vac. Surf. Films2003, 21, 607.
[50] P. Graham, M. Stone, A. Thorpe, T. G. Nevell, J. Tsibouklis,J. Fluorine Chem. 2000, 104, 29.
[51] S. R. Coulson, I. S. Woodward, J. P. S. Badyal, Chem. Mater.2000, 12, 2031.
[52] S. R. Coulson, I. Woodward, J. P. S. Badyal, S. A. Brewer,C. Willis, J. Phys. Chem. B 2000, 104, 8836.
[53] D. O. H. Teare, C. G. Spanos, P. Ridley, E. J. Kinmond,V. Roucoules, J. P. S. Badyal, Chem. Mater. 2002, 14, 4566.
[54] S. R. Coulson, I. Woodward, J. P. S. Badyal, S. A. Brewer,C. Willis, Langmuir 2000, 16, 6287.
[55] L. Laguardia, D. Ricci, E. Vassallo, A. Cremona, E. Mesto,F. Grezzi, F. Dellera, Macromol. Symp. 2007, 247, 295.
[56] T. Nishino, M. Meguro, K. Nakamae, M. Matsushita, Y. Ueda,Langmuir 1999, 15, 4321.
[57] M. Gupta, K. K. Gleason, Langmuir 2006, 22, 10047.[58] D. K. Owens, R. C. Wendent, J. Appl. Polym. Sci. 1969, 13,
1741.[59] R. E. Johnson, R. H. Dettre, Wettability, J. C. Berg, Ed., Marcel
Dekker, New York 1993, Ch. 1, p. 13.[60] R. di Mundo, F. Palumbo, R. d’Agostino, Langmuir 2008, 24,
5044.[61] J. L. Moillet, Water Proofing and Water Repellency, Elsevier,
London 1963, p. 28.[62] P. A. George, B. C. Donose, J. J. Cooper-White, Biomaterials
2009, 30, 2449.[63] T. Hayakawa, M. Yoshinari, K. Nemoto, Biomaterials 2004, 25,
119.[64] F. Hook, J. Voros, M. Rodahl, R. Kurrat, P. Boni, J. J. Ramsden,
M. Textor, N. D. Spencer, P. Tengvall, J. Gold, B. Kasemo,Colloids Surf., B Biointerfaces 2002, 24, 155.
[65] A.-S. Andersson, K. Glasmastar, D. Sutherland, U. Lidberg,B. Kasemo, J. Biomed. Mater. Res. 2003, 64A, 622.
[66] J. Rickert, A. Brecht, W. Gopel, Anal. Chem. 1997, 69, 1441.[67] M. Rodahl, F. Hook, C. Fredriksson, C. A. Keller, A. Krozer,
P. Brzezinski, M. Voinova, B. Kasemo, Faraday Discuss. 1997,107, 229.
[68] G. Sauerbrey, Z. Phys. 1959, 155, 206.[69] A. V. Kabashin, M. Meunier, Mater. Sci. Eng., B 2003, 101, 60.[70] Y. Leterrier, Prog. Mater. Sci. 2003, 48, 1.[71] G. Cicala, A. Milella, F. Palumbo, P. Favia, R. d’Agostino,
Diamond Relat. Mater. 2009, 12, 2020.[72] D. Liu, J. Gu, Z. Feng, D. Li, J. Niu, Thin Solid Films 2009, 517,
3011.[73] P. Favia, G. Cicala, A. Milella, F. Palumbo, P. Rossini,
R. d’Agostino, Surf. Coat. Technol. 2003, 169–170, 609.[74] J. S. Chang, S. Masuda, ‘‘Mechanism of pulse corona induced
plasma chemical process for removal of NOx and SO2 fromcombustion gases,’’ in: Conference Record of the 23rd AnnualMeeting of the IEEE Industry Applications Society, Pittsburgh,PA 1988, p. 1628.
[75] R. C. Weast, M. J. Astle, CRC Handbook of Chemistry andPhysics, 63rd edition, CRC Press Inc., Boca Raton, Florida1982, p. F185.
[76] N. Inagaki, Plasma Surface Modification and PlasmaPolymerization, CRC press, Inc., Boca Raton, Florida 1996,p. 233.
[77] C. Hollenstein, Plasma Phys. Controlled Fusion 2000, 42, R93.[78] C. Bichler, T. Kerbstadt, H. C. Langowski, U. Moosheimer, Surf.
Coat. Technol. 1997, 97, 299.[79] A. Hozumi, O. Takai, Thin Solid Films 1997, 303, 222.[80] O. Takai, A. Hozumi, Y. Inoue, T. Komori, Bull. Mater. Sci. 1997,
20, 817.
www.plasma-polymers.org 937
938
V. Kumar, J. Pulpytel, H. Rauscher, I. Mannelli, F. Rossi, F. Arefi-Khonsari
[81] H. Qiu, F. S. Sanchez-Estrada, R. B. Timmons, J. Photopolym. Sci.Technol. 2000, 13, 29.
[82] W. L. E. Magalhaes, M. L. de Souza, Surf. Coat. Technol. 2002,155, 11.
[83] M. Quirynen, J. Dent. 1994, 22, 13.[84] A. A. Thorpe, T. G. Nevell, J. Tsibouklis, Appl. Surf. Sci. 1999,
137, 1.[85] N. H. Vrolijk, N. M. Targett, R. E. Baier, A. E. Baier, Biofouling
1990, 2, 39.
Plasma Process. Polym. 2010, 7, 926–938
� 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
[86] A. Choukourov, A. Grinevich, N. Saito, O. Takai, Surf. Sci. 2007,601, 3948.
[87] S. P. Sakti, P. Hauptmann, B. Zimmermann, F. Buhling,S. Ansorge, Sens. Actuators, B: Chem. 2001, 78, 257.
[88] J. L. Ortega-Vinuesa, P. Tengvall, I. Lundstrom, J. Colloid Inter-face Sci. 1998, 207, 228.
[89] K. M. Evans-Nguen, M. H. Schoenfisch, Langmuir 2005, 21,1691.
DOI: 10.1002/ppap.201000038
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