Surface Modification of Medical Polymer Films
by Remote Microplasma
Hodaka Fukunaga, Marius Blajan and Kazuo Shimizu
Organization for Innovation and, Social Collaboration, Shizuoka University,Jyouhoku, Hamamatsu, 432-8561, Japan
E-mail：shimizu@cjr.shizuoka.ac.jp

INTRODUCTIONRESULTSThis study introduces the surface treatmentof polymer sheet developed for medical use byusing microplasma. This sheet is fabricated forthe medical use, and the adhesive force isimportant when is applied on wounds.
Microplasma treatment was used in order toimprove the adhesive force which is related tothe hydrophilic property of the sheet.[1](1) Emission Spectroscopy

Intensity [a.u.](1)Microplasma Electrodes

Ar Ⅰpeaks

Fig. 8 O/C ratio of surface analysis by XPS.
410

415

420

425

430

435440

Wavelength [nm]Fig. 4 Emission spectroscopy（Process gas; 1% N2 in Ar).
ArⅠ peaks were observed by emission
spectroscopy using an ICCD camera(Fig. 4).
These active species cut surface bonds andcontributed to make new surface bonds.

Increase of C/O ratio
corresponding thecontact angle degreased was observed asshown in Fig. 8.

(4) The depth of treatment bymicroplasma
Untreated
Treated(2) Relation of Treatment Time andContact Angle
Fig. 1 Microplasma electrodes.
Perforated metal plates covered with
dielectric layer were used as a electrodes.
A spacer with a hexagonal hole with 7mm side
was inserted between electrodes in order toincrease a gas flow and to secure the desired
gap length(Fig. 1).

Fig. 2 The image of microplasma electrodes
during discharge(2) Experimental Setup

HV probe

Fig. 5 Treatment time versus contactangle(Using gas is Ar,N2, room air).
Contact angle was reduced to 30° in 10
seconds using Ar as shown in Fig. 5. Air andN2 microplasma did not affect compared withusing Ar.

78.3°

45.6°

Electrodes

Polymerfilm

HVGAS

Fig. 9 The depth of modification using
microplasma (Process gas; Ar,Treatment
time; 15 s, Applied voltage; 0.9 kV).

Current probe

Oscillo scope

Fig. 6 Image of water droplet on the film.
The water droplet on the surface of treatedpolymer film changed to a more elongatedshape without plasma treatment as shown inFig. 6.

The depth of surface treatment wasmeasured by XPS. The arrow on the Fig. 9shows the point which untreated C-C bonds
and treated C-C bonds intersect. According
to this result, surface treatment have ended
in this point and its depth was about 20 nm.

(5)The damage of polymer films
After microplasma treatment
The Fig. 10 shows the damege image ofpolymer surface taken by SEM.
Surface of treated polymer become harsher
compared with untreated polymer surface.

100 mm

100 mm(3)Surface Analysis by XPS

XPSContact angle
meterFig. 10 The SEM Image on the polymer film.
(The left photo; untreated, The right photo;
Ar plasma treatment) Treatment time; 7 sApplied voltage; 0.9 kV.

ICCD camera

Fig. 3 An experimental setup forsurface treatment of polymer sheet.
A neon transformer was used as an AC highvoltage power supply. Treated polymer film
surface modifications were estimated by using
XPS, emission spectrometer and a contact
angle meter(Fig. 3). These condition are shownin Table 1.
Table 1 An experimental condition
Gas flow late [L/min]
Process gas

5Ar, N2, Air

Distance of between electrodes andpolymer sheet [mm]1CONCLUSIONS
1. The minimum contact angle decreased toabout 45° after Ar plasma treatment.

Fig. 7 The XPS spectra of the C1s component(Blue line; Untreated,Red line; Ar plasma treatment ).
The C-C, C-H bond decreased and C-O, C=O
bonds decreased compared with untreatedpolymer films (Fig. 7).

2.Hydrophilic group increased and thehydrophobicgroupdecreased
after
microplasma treatment.
3. The depth of treatment was about 20 nm
measured by XPS analysis.

Reference[1] K. Shimizu, A. Umeda , M. Blajan, Jpn. J.
Appl. Phys.50, 08KA03, 2011.
.