Morphology enhancement of TiO
/PVP composite nanofibers
based on solution viscosity and processing parameters
of electrospinning method
Soraya Mirmohammad Sadeghi,
Mohammadreza Vaezi ,
Department of Nanotechnology and Advanced Materials, Materials and Energy Research Center, Karaj Iran
Department of Semiconductors, Materials and Energy Research Center, Karaj Iran
Iran Polymer and Petrochemical Institute, Tehran Iran
Correspondence to: M. Vaezi (E-mail: email@example.com)
In this work, different sol solutions with various titanium tetraisopropoxide (TIP)/glacial acetic acid ratios in 2-propanol
with 5 wt % poly(vinyl pyrrolidone) (PVP) (M
5 360,000 g/mol) were prepared and electrospun. Composition of the prepared sols
and as-spun TiO
/PVP nanofibers were determined by Fourier transform infrared and Raman spectroscopy methods. Morphology of
the electrospun TiO
/PVP nanofibers was studied by scanning electron microscopy and transmission electron microscopy (TEM)
techniques. Rheometry measurements of the sol solutions showed decrease of viscosity upon the addition of TIP to the polymer solu-
tions with constant polymer and acid concentrations. The sol solution having the lowest viscosity (at shear rate 10 s
) but the high-
est TIP/glacial acetic acid ratio showed beaded nanofibers morphology when electrospun under 10 and 12 kV applied voltage while
injection rate, needle tip to collector distance, and needle gauge were kept constant. However, smooth electrospun TiO
ite nanofibers with the average nanofibers diameters (148 6 79 nm) were achieved under the same condition when applied voltage
increased to 15 kV. TEM micrographs of the electrospun TiO
/PVP nanofiber showed that the TiO
particles with continuous struc-
ture are formed at the middle of the nanofiber and distributed along its axis.
2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135,
composite nanofibers; electrospinning; morphology; rheology; spectroscopy
Received 16 October 2017; accepted 13 January 2018
At the nanoscale, distinctive properties can be achieved by tai-
loring the morphology of the materials. One of these attractive
materials in terms of their interesting physical and chemical
characteristics is nanofibers prepared by electrospinning
method. The advantages are (i) controllable fiber diameter, (ii)
high surface-to-volume ratio, (iii) bearing porous structure, and
(iv) high aspect ratio have showed promises in applications
such as membranes, tissue engineering, sensors, solar cells,
optoelectronic devices, and catalysts.
There are many advanced methods for the preparation of one-
dimensional nanostructures, but electrospinning has shown its
priority with simplicity, low cost, and reproducibility. In this
method, an external electric field is exerted on the polymer-
based solutions or melts and continuous fibers of polymers,
inorganic materials, and/or composites are prepared by which
their diameters can be adjusted from nano- to microscale.
thermore, composite nanofibers can be simply made by this
procedure with the aid of a carrier polymer where the target
material is soluble or well dispersed in that polymer solution.
The role of carrier polymer is to adjust the viscosity of the solu-
tion used for fabrication of the electrospun nanofibers.
of the commonly used polymers as carrier medium are poly(vi-
nyl pyrrolidone) (PVP),
and poly(vinyl alcohol).
However, by combining nanoscale fillers into polymer solutions
for preparing composite solutions of organic and/or inorganic
materials another dimension was introduced to electrospinning
process and extended its application to the preparation of elec-
trospun composite nanofibers. One of these inorganic fillers is
Additional Supporting Information may be found in the online version of this article.
2018 Wiley Periodicals, Inc.
J. APPL. POLYM. SCI. 2018, DOI: 10.1002/APP.46337
46337 (1 of 11)