الفهرس 
Doping of PolymersOnly 14 pages are availabe for public view
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Abstract
The present study is divided into two parts:
First part: In-situ formation of conductive polyaniline thin
skins onto radiation grafted polypropylene films (PP-g-
PAA)/PANI.
Second part: Gamma radiation enhancement of
photocatalytic activity of conducting polyaniline–TiO2
nanocomposites (PANI-TiO2) for degradation of methyl
orange dye (MO) under visible light.
The results obtained can be summarized as follows:
I) In-situ Formation of Conductive Polyaniline
Thin Skins onto Radiation Grafted
Polypropylene Films (PP-g-PAA)/PANI:
1- High energy radiation processing was applied to
polypropylene films in order to graft functional groups
on the otherwise chemically inert material that could
promote the formation of a chemically bonded
polyaniline.
2- Electronic absorption spectra of pristine PP films,
confirmed the optical transparency and colorless
appearance of all the substrates, except ortho and meta
substituted phenylenediamines, which imparted the
yellow color for their characteristic absorption in the blue
range (430-480 nm).
3- For all grafted and functionalized films after
polymerization of aniline, a typical broad absorption
peak in the visible range, peaking at ~800 nm and above,
with a long tail extending toward the near-IR region was
observed.
4- For all systems, the -* transition peak of benzenoids,
appeared at 420-430 nm.
5- When PANI-ES was converted into its base forms, the
polarone absorption peak was replaced by the peak at
about 540-570nm.
6- The treatment with NMP, which removed the emeraldine
base which was not attached to the substrate, caused a
significant reduction in optical density of electronic
spectra of all systems.
7- FTIR analysis was carried out on polypropylene films
after each derivatisation step, as well as on all the hybrid
skin–core PP-g-PAA/PANI films confirmed the success
of each step of treatment.
8- Radiation grafting of acrylic acid introduced a vibration
band at 1716 cm-1 which was replaced by the stretching
vibration of acyl chloride groups at 1790 cm-1 after
treatment with SOCl2.
9- Derivatisation with any of the diamines caused
disappearance of the band at 1790 cm-1 and the
appearance of two new strong bands at about 1670 and
1575cm-1.
10- The FTIR spectra of the PANI films as prepared
showed the appearance of 1552, 1462, 1165 and 850
cm−1 which indicated the formation of PANI in its doped
form.
11- The analysis of both the topographical features of the
films surface and the morphology of their cross-sections,
as obtained by shearing the films in liquid nitrogen after
cutting a small pre-crack opening were investigated by
Scanning electron microscopy (SEM).
12- SEM images showed that the surface of PP films
appears rather smooth and featureless, while after
deposition of polymerized AA monomer on the surface
became much rougher.
13- It could be noticed that the first treatment, with thionyl
chloride, didn’t induce modifications of the surface
morphology of PP-g-PAA substrates. Moreover, the
treatment with different amines didn’t not significantly
change the morphology.
14- Contrariwise, the presence of PANI coatings on the
polymeric substrates induced a drastic change of surface
morphology, from smooth to granular at the nanoscale.
15- The electrochemical behaviour of the PP-g-PAA/PANI
for the functionalized films was investigated by cyclic
voltammetry in the potential range between −0.6 and
+0.8V in 1.0M HCl solution.
16- The voltammogram recorded at 100mV/s for the PP-g-
PAA/PANI functionalized films under nitrogen flux: in
the forward scan (from the open-circuit potential towards
positive potentials) an oxidation peak occurs; whilst in
the reverse scan was present.
17- It was apparent from the impedance spectroscopy results
that electrical properties of the composite films changed
strongly depending on the amine group used for the
functionalization.
18- The electrical conductivities of the corresponding PP-g-
PAA functionalized films after polymerization of PANI
in the doped state (PANI-ES) were higher than those
before PANI, by approximately 9 orders of magnitude
reaching 6.3x10-3.
19- The growth process of polyaniline (PANI) during the
electrochemical polymerization resulted in an increment
in the conductivity of the functionalized film reaching
0.3x10-1 S/cm.
20- It can be concluded from the previous results that the
PP-g-PAA/PANI functionalized hybrids have potential
application in the field of antistatic packaging of
2. Gamma Radiation Enhancement of
Photocatalytic Activity of Conducting
Polyaniline–TiO2 Nanocomposites (PANI-TiO2)
for Degradation of Methyl Orange Dye (MO)
under Visible Light
1- A series of PANI–TiO2 nanocomposites with different
TiO2 wt%, aniline concentrations and An:APS ratios
were prepared by ‘in situ’ oxidative polymerization of
(PANI) using APS as oxidant in the presence of TiO2 solgel.
2- The sol-gel synthesis of titanium dioxide nanoparticles
using titanium isopropoxide (TTIP) as a precursor
consisted of two-step process, hydrolysis and
polycondensation. Moreover, redispersion of titanium
oxide (gel) to nano-titanium oxide (sol) also took place.
3- The FTIR spectrum of neat-TiO2 showed the presence of
a band at 1630 cm-1 and another broad band appearing at
3000-3400 cm-1.
4- All characteristic bands of doped PANI appeared in the
the spectrum of pristine PANI.
5- The FTIR spectrum of the composite contained
contributions from both TiO2 and PANI. However, some
bands of doped PANI shifted due to interactions with
TiO2 nanoparticles.
6- The absorption spectrum of TiO2 exhibited strong
absorption below 400 nm.
7- The spectrum of pristine PANI showed that the three
characteristic broad peaks of the doped PANI appeared at
about 320, 450 and 775 nm.
8- It could be noted that the characteristic peaks of the
doped PANI all appeared in the PANI-TiO2
nanocomposite, but there are some shifts compared with
pure PANI, and some new peaks are observed in the
PANI/TiO2 nanocomposites with different TiO2 wt%.
9- The absorption spectra of PANI-TiO2 nanocomposites
indicated that the impact of TiO2 nanoparticles had an
effect on the doping of conducting PANI, while this
effect should owe to an interaction at the interface of
PANI and TiO2 nanoparticles.
10- The UV–νis absorption spectra of PAN-TiO2
nanocomposites prepared at different aniline
concentrations [An] showed that the intensities of
characteristic peaks of PANI increase with increasing the
concentration of aniline till 0.25M.
11- The UV–νis absorption spectra of PAN-TiO2
nanocomposites prepared at different An:APS ratios
identified the paeks at 430 and 790 nm as higher and
lower energy polaron bands caused by protonation of
imine groups of polyaniline chain.
12- Since the exposure of the material to ionizing radiations
produces changes in the microstructural properties,
which in turn affects the optical properties of the
material, the influence of the irradiation on the UV-vis
absorption spectra of PANI-TiO2 nanocomposite were
studied. The change in the optical properties of PANITiO2
nancomposite as a result of gamma radiation could
be attributed to formation of Ti+3 ions. Ti+3 creates deep
acceptor levels for photogenerated electrons in TiO2, thus
effectively decreasing the band gap.
13- Results showed that the band gap energies of all the
PANI- TiO2 nanocomposites before and after exposure to
gamma radiation were lower than that of neat TiO2, so
the PANI- TiO2 nanocomposites could be excited to
produce more electron–hole pairs under visible light,
which could result in higher visible light photocatalytic
activities.
14- Therefore, UV–vis spectra indicated that the PANI- TiO2
nanocomposite is a promising material for the full use of
visible light.
15- The thermal stability of neat TiO2 was investigated. The
results revealed that nano-TiO2 is very stable in air and
almost no decomposition took place in the range of 20–
600○C.
16- It was found that the weight loss of PANI and PANITiO2
nanocomposites followed a three-step manner in
both cases.
17- from thermal analysis, it can be deduced that the
incorporation of TiO2 into PANI improved the thermal
stability of it. Moreover, it has been found that the extent
of thermal decomposition of PANI in nanocomposites, at
temperatures higher than ~ 400○C, became lower than
that of pure PANI.
18- The XRD patterns of the pristine TiO2 nanoparticles,
PANI-TiO2, and pure PANI showed that there was no
difference between XRD pattern of PANI-TiO2
nanocomposites and XRD pattern of pristine TiO2
nanoparticles, which revealed the deposition of PANI on
the surface of TiO2 nanoparticles that had no effect on
the crystallinity of TiO2 nanoparticles.
21- The XRD of the irradiated PANI-TiO2 nanocomposites
revealed that the relatively gamma irradiation doses had
a weak effect on the crystal structure of the
nanocomposite. After irradiation of PANI-TiO2
nanocomposite, due to the influence of gamma radiation
on nano-TiO2 particles, the crystalline behavior of nano
TiO2 was hampered.
22- By studying of photocatalytic degradation efficiency, it
was found that the photocatalytic degradation of methyl
orange increased gradually with increasing the TiO2wt%
up to 10wt% and maximum removal (86%) was achieved
after 240 min irradiation time.
23- By varying the concentration of aniline, the results
showed that the maximum photocatalytic degradation
efficiency was achieved at aniline concentration 0.25M.
24- At different An:APS molar ratios, the maximum
photocatalytic degradation efficiency was at An:APS
molar ratio 1:1.
25- An enhancement of the photocatalytic activity of gamma
irradiated PANI-TiO2 nanocomposties was observed. By
applying different irradiation doses onto PANITiO2(
10wt%), The removal of MO was increased to 97%
after irradiation time 180 min.
26- It can be concluded from the previous results that the
effect of gamma radiation plays an important role in the
photocatalytic activity of PANI-TiO2 nanocomposites