Plasma polymerization of (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) yields thin films containing stable nitroxide radicals that have properties analogous to that of nitric oxide (NO) without short lifetimes. This property gives TEMPO films a wide variety of potential applications. Typically, control of the final film chemistry is difficult and the plasma discharge conditions must be tailored to in order to maximize the retention of these nitroxide groups during the polymerization and deposition process. In this study, plasma diagnostics and surface analysis of the deposited films were carried out to determine the optimal plasma conditions for the retention of nitroxide groups. These techniques included energy-resolved mass spectrometry, heated planar probe ion current measurements, deposition rate measurements, and x-ray photoelectron spectroscopy (XPS). Results show that operating the plasma with a combination of low input powers and high pressures produces a collisional discharge in which fragmentation of the TEMPO molecule is suppressed, leading to good retention of nitroxide groups. Ion energy distribution functions and quartz crystal microbalance measurements support the soft landing theory of ion deposition on the substrate within this γ-mode, in which the flux of low energy, soft landed ions form the primary contribution to film growth. XPS analysis of deposited polymers shows 75.7% retention of N—O groups in the polymer films deposited in a 25 Pa 5 W discharge.

1.
D.
Thiry
,
S.
Konstantinidis
,
J.
Cornil
, and
R.
Snyders
,
Thin Solid Films
606
,
19
(
2016
).
2.
L.
Detomaso
,
R.
Gristina
,
G. S.
Senesi
,
R.
D’Agostino
, and
P.
Favia
,
Biomaterials
26
,
3831
(
2005
).
3.
I.
Gancarz
,
J.
Bryjak
,
G.
Poźniak
, and
W.
Tylus
,
Eur. Polym. J.
39
,
2217
(
2003
).
4.
A.
Cireli
,
B.
Kutlu
, and
M.
Mutlu
,
J. Appl. Polym. Sci.
104
,
2318
2322
(
2007
).
5.
L. M.
Watkins
,
A. F.
Lee
,
J. W. B.
Moir
, and
K.
Wilson
,
ACS Biomater. Sci. Eng.
3
,
88
(
2017
).
6.
S.
Saboohi
,
B. R.
Coad
,
H. J.
Griesser
,
A.
Michelmore
, and
R. D.
Short
,
Phys. Chem. Chem. Phys.
19
,
5637
(
2017
).
7.
A.
Choukourov
,
H.
Biederman
,
D.
Slavinska
,
L.
Hanley
,
A.
Grinevich
,
H.
Boldyryeva
, and
A.
Mackova
,
J. Phys. Chem. B
109
,
23086
(
2005
).
8.
D.
Hegemann
,
E.
Körner
, and
S.
Guimond
,
Plasma Processes Polym.
6
,
246
(
2009
).
9.
C. L.
Rinsch
,
X.
Chen
,
V.
Panchalingam
,
R. C.
Eberhart
,
J. H.
Wang
, and
R. B.
Timmons
,
Langmuir
12
,
2995
(
1996
).
10.
A. P.
Ameen
,
R. J.
Ward
,
R. D.
Short
,
G.
Beamson
, and
D.
Briggs
,
Polymer
34
,
1795
(
1993
).
11.
B. R.
Coad
,
M.
Jasieniak
,
S. S.
Griesser
, and
H. J.
Griesser
,
Surf. Coat. Technol.
233
,
169
(
2013
).
12.
S.
Eufinger
,
W. J.
Van Ooij
, and
T. H.
Ridgway
,
J. Appl. Polym. Sci.
61
,
1503
(
1996
).
13.
R. C.
Ross
and
J.
Jaklik
,
J. Appl. Phys.
55
,
3785
(
1984
).
14.
J.
Behnisch
,
F.
Mehdorn
,
A.
Holländer
, and
H.
Zimmermann
,
Surf. Coat. Technol.
98
,
875
(
1998
).
15.
F.
Truica-Marasescu
and
M. R.
Wertheimer
,
Plasma Processes Polym.
5
,
44
(
2008
).
16.
S. A.
Voronin
,
M.
Zelzer
,
C.
Fotea
,
M. R.
Alexander
, and
J. W.
Bradley
,
J. Phys. Chem. B
111
,
3419
(
2007
).
17.
Q.
Chen
,
R.
Förch
, and
W.
Knoll
,
Chem. Mater.
16
,
614
620
(
2004
).
18.
L.
Denis
,
P.
Marsal
,
Y.
Olivier
,
T.
Godfroid
,
R.
Lazzaroni
,
M.
Hecq
,
J.
Cornil
, and
R.
Snyders
,
Plasma Processes Polym.
7
,
172
(
2010
).
19.
S.
Fraser
,
R. D.
Short
,
D.
Barton
, and
J. W.
Bradley
,
J. Phys. Chem. B
106
,
5596
(
2002
).
20.
S.
Saboohi
,
M.
Jasieniak
,
B. R.
Coad
,
H. J.
Griesser
,
R. D.
Short
, and
A.
Michelmore
,
J. Phys. Chem. B
119
,
15359
(
2015
).
21.
N.
Barraud
,
M.
Kelso
,
S.
Rice
, and
S.
Kjelleberg
,
Curr. Pharm. Des.
21
,
31
(
2014
).
22.
S.
Korde Choudhari
,
M.
Chaudhary
,
S.
Bagde
,
A. R.
Gadbail
, and
V.
Joshi
,
World J. Surg. Oncol.
11
,
1
(
2013
).
23.
W.
Wang
,
Y.
Lee
, and
C. H.
Lee
,
Biotechnol. Adv.
33
,
1685
(
2015
).
24.
T. D.
Michl
 et al.,
ACS Appl. Nano Mater.
1
,
6587
(
2018
).
25.
T. D.
Michl
,
D. T. T.
Tran
,
H. F.
Kuckling
,
A.
Zhalgasbaikyzy
,
B.
Ivanovská
,
L. E.
González García
,
R. M.
Visalakshan
, and
K.
Vasilev
,
RSC Adv.
10
,
7368
(
2020
).
26.
T. D.
Michl
 et al.,
Biointerphases
15
,
031015
(
2020
).
27.
J. D.
Whittle
 et al.,
Plasma Processes Polym.
10
,
767
(
2013
).
28.
A.
Morrison
and
A. P.
Davies
,
Org. Mass Spectrom.
3
,
353
(
1970
).
29.
L.
O’Toole
,
R. D.
Short
,
A. P.
Ameen
, and
F. R.
Jones
,
J. Chem. Soc. Faraday Trans.
91
,
1363
(
1995
).
30.
D. B.
Haddow
,
R. M.
France
,
R. D.
Short
,
J. W.
Bradley
, and
D.
Barton
,
Langmuir
16
,
5654
(
2000
).
31.
A. J.
Beck
,
S.
Candan
,
R. D.
Short
,
A.
Goodyear
, and
N. S. J.
Braithwaite
,
J. Phys. Chem. B
105
,
5730
(
2001
).
32.
L.
O’Toole
,
A. J.
Beck
,
A. P.
Ameen
,
F. R.
Jones
, and
R. D.
Short
,
J. Chem. Soc. Faraday Trans.
91
,
3907
(
1995
).
33.
P. N.
Brookes
,
S.
Fraser
,
R. D.
Short
,
L.
Hanley
,
E.
Fuoco
,
A.
Roberts
, and
S.
Hutton
,
J. Electron Spectrosc. Relat. Phenom.
121
,
281
(
2001
).
34.
C.
Daunton
,
L. E.
Smith
,
J. D.
Whittle
,
R. D.
Short
,
D. A.
Steele
, and
A.
Michelmore
,
Plasma Processes Polym.
12
,
817
(
2015
).
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