Surface Modification on Medical Polymer Films
Using Remote Microplasma
H. Fukunaga, and M. Blajan, K. Shimizu
Organization for Innovation and, Social Collaboration, Shizuoka University,Jyouhoku, Hamamatsu, 432-8561, Japan
E-mail：shimizu@cjr.shizuoka.ac.jp

RESULTSINTRODUCTION
This study introduces the surface
treatment of polymer sheet developed
for medical use by using microplasma.
This sheet is fabricated for the medicaluse, and the adhesive force is importantwhen is applied on wounds. Microplasma
treatment was used in order to improve
the adhesive force which is related tothe hydrophilic property of the sheet.

(1) Relation of Treatment Timeand Contact Angle(3) The depth of treatment by
microplasma
Treated
Untreated(1)Microplasma Electrodes
Fig. 3 Treatment time versus
contact angle(Using gas is Ar,N2, room air).
Table 2 Applied voltage for surface
treatment.
Process gas

Fig. 1 Microplasma electrodes.
Perforated metal plates covered with
dielectric layer were used as aelectrodes.A spacer with a hexagonalhole with 7mm side was inserted
between electrodes in order to increasea gas flow and to secure the desired
gap length(Fig. 1).

45.6°

The depth of surface treatment wasmeasured by XPS. The arrow on theFig. 6 shows the point which
untreated C-C bonds and treated C-Cbonds intersect. According to thissurface treatment have ended in thispoint and the depth was about 20 nm.

(4)The damage of polymer films
After microplasma treatment
The Fig. 7 shows the damege image ofpolymer surface taken by SEM.
Surface of treated polymer becomeharsher compared with untreatedpolymer surface.

Electrodes

Fig. 4 Image of water droplet on thepolymer film.

PolymerfilmHVGASContact angle was reduced to 30° in
10 seconds using Ar as shown in Fig. 3.
Air and N2 microplasma did notaffected so much as using Ar. Thesecondition are shown in Table 2.

78.3°(2) Experimental Setup

HV probe

ArN2
Air

Applied voltage
[kV]
0.9
1.3
1.4Fig. 6 The depth of modification
using microplasma (Process gas;Ar,Treatment time; 15 s, Applied
voltage; 0.9 kV).

The water droplet on the surface oftreated polymer film changed to amore elongated shape without plasma
treatment as shown in Fig. 4.

Current probeOscilloscope

Fig. 2 An experimental setup for
surface treatment of polymer sheet.

(2)Surface Analysis by XPS

CONCLUSIONS

A neon transformer was used as an AChigh voltage power supply. Treatedpolymer film surface modifications were
estimated by using XPS, emission
spectrometer and a contact angle
meter(Fig. 2). These condition are shownin Table 1.

Microplasma
treatment
polymer film was carried out.

.

Gas flow late [L/min]

5

Process gas

Ar,N2,Air

Distance of between
electrodes and polymer sheet[mm]1Fig. 7 The SEM Image on thepolymer film. (The left photo;
untreated, The right photo; Arplasma treatment) Treatment time;
7 s Applied voltage; 0.9 kV.

Fig. 5 The XPS spectra of the C1scomponent (Blue line; Untreated, Redline; Ar plasma treatment ).
The C-C,C-H bond decreased and C-O,
C=O bonds decreased compared withuntreated polymer films (Fig. 5).

for1. The minimum contact angle
decreased to about 45° after
Ar microplasma treatment.
2. Hydrophilic group increased andthehydrophobicgroupdecreased after microplasmatreatment.
3.The depth of treatment wasabout 20 nm measured by XPS
analysis.