Chem. Pap.
have been investigated (Karimi et al. 2015a, b). Among
the metal complexes, the environmentally sensitive flu-
Synthesis of tris(8-hydroxyquinoline) aluminum
(AlQ
)
3
orophore tris(8-hydroxyquinoline) aluminum (AlQ ) has
3
attracted much attention due to its spectral sensitivity
AlQ
and Ohkaku 1971; Badiei and Goldooz 2012). In a typical
synthesis AlCl (0.01 mol) was added to the ethanol
3
was prepared according to the literature (Nakamoto
(
C o¨ lle and Br u¨ tting 2004). Furthermore, AlQ is capable
3
to modify organic (Meyers and Weck 2003) and inor-
ganic materials (Wang et al. 2006a) and displaying
significant fluorescence in both media. The stability of
3
solution (100 ml) of 8-HQ (0.03 mol) and triethylamine
(0.03 mol) under stirring at room temperature overnight.
The precipitates were centrifuged and washed with ethanol
AlQ in a broad range of media made it a successful and
3
powerful molecular probe to study different environ-
ments. AlQ3 is also becoming the subject of intense
interest because it offers a vast range of potential
applications in low-voltage OLED design which include
easy synthesis, relative stability, good electron transport,
and emitting properties (Tang and VanSlyke 1987; Lee
et al. 2008; Antony et al. 1999). It was found that
for several times to obtain yellowish-green AlQ
1
3
powder.
H
NMR (DMSO, 500 MHz): 8.86 (1H, dd,
J
J
= 4.7 Hz, J
= 1.2 Hz), 8.82 (1H, dd, J
= 4.7 Hz,
= 1.2 Hz),
2
1
2
2
1
= 1.2 Hz), 8.30 (1H, dd, J = 8.4 Hz, J
1
8.22 (2H, t, J = 6.8 Hz), 7.53–7.49 (3H, m), 7.44 (1H, dd,
J
J
J
= 8.3 Hz, J
= 4.7 Hz), 7.36 (1H, dd, J
= 8.3 Hz,
1
1
2
1
2
= 4.7 Hz), 7.23 (1H, d, J = 4.2 Hz), 7.18 (1H, dd,
1
aggregation of fluorophores such as AlQ can influence
3
= 8.3 Hz, J
2
= 4.7 Hz) 7.13–7.06 (6H, m). The
is shown Fig. 1.
H
the fluorescent peak wavelength (Li et al. 2006). Con-
sequently, small changes in fluorophore surrounding can
lead to large shifts in the fluorescence maximum.
NMR spectrum of AlQ
3
Synthesis and AlQ
silica SBA-15
functionalization of mesoporous
3
Moreover, AlQ complexes, as optically active materi-
3
als, should be immobilized in a solid support or embedded
in a soft matter matrix from the viewpoint of their potential
applications in the nanotechnology field, such as in pho-
tovoltaic devices, waveguiding, photodetection and sens-
ing. Among the various matrices, polymers are
suitable materials for optic devices, since they are cheap,
can be transparent, flexible, and easily processed.
SBA-15 type mesoporous silica was synthesized using
TEOS as silica precursor, Pluronic P123 as a structure
directing agent, and HCl to make the media acidic,
according to the literature (Hashemi et al. 2009; Shahbazi
et al. 2011). The surface functionalization of SBA-15 with
AlQ
chloroform solution of AlQ
for 12 h. Briefly, 1 g SBA-15 was suspended in 60 ml of
chloroform and an excess amount of AlQ complex was
added to the above solution at ambient temperature. The
resulting AlQ -SBA-15 solid was collected by centrifuga-
tion and washed with chloroform for several times.
was conducted by soaking the dried SBA-15 in the
3
In this work, for the first time, the control over the
position of maximum emission peak for fluorophore can be
3
complex at room temperature
achieved using embedded AlQ complexes into different
3
3
types of host materials including poly(methyl methacry-
late-co-butyl acrylate) (PMMA-co-PBuA) nanoparticles
and mesoporous silica as organic and inorganic hosts,
3
respectively, and assembly of AlQ -functionalized meso-
3
porous silica materials in polymer matrix as organic–
inorganic composite materials.
Synthesis of PMMA-co-PBuA and AlQ -PMMA-co-
3
PBuA nanoparticles
Conventional emulsion polymerization has been chosen to
synthesize PMMA-co-PBuA nanoparticles. The polymer-
ization was carried out in a three-neck flask with a con-
denser containing water (85 ml), MMA (7.5 g), BuA
Experimental
Materials
(7.5 g), SDS (0.7 g) and K S O (0.08 g). The polymer-
2 2 8
Pluronic P123 with composition EO PO EO and
20
ization reaction was carried out under continuous stirring
for 5 h in N
atmosphere at 75 °C. After that, the obtained
solution was a milky emulsion. The average particle size of
the resulting PMMA-co-PBuA nanoparticle was 48 nm
measured with dynamic light scattering (DLS).
2
0
70
average molecular weight of 5800 was purchased from
Aldrich. Tetraethyl orthosilicate (TEOS), the silica source,
2
8
-hydroxyquinoline (8-HQ), methyl methacrylate (MMA),
butyl acrylate (BuA), K S O (KPS) and sodium dodecyl
2 2 8
sulfate (SDS) were purchased from Merck. All of the other
reagents and solvents were of analytical reagent grade and
used without further purification.
The AlQ
were prepared by adding different weight percent (0.01,
0.1, 1 wt%) of AlQ to MMA and BuA monomers through
ultrasonic vibration followed by emulsion polymerization.
3
-PMMA-co-PBuA composite nanoparticles
3
1
23