Electrospinning of Chitosan (CHT) - Modern Trends in Chemistry and Chemical Engineering - page 85

Different amount of CHT was then added to MWNTs dispersion for preparation of a
8-12% wt solution and then sonicated for another 5 min. Figure 5.2 shows two differ-
ent protocols used in this study.
Figure 5.2. Two protocols used in this study for preparation of MWNTs/CHT dispersion (a) Current
study and (b) Ref. [35].
In next step, organic acid solution added to obtain a CHT/MWNT solution with to-
tal volume of 5 mL and fi nally the dispersion was stirred for another 10 h. The Sample
2 was prepared using second technique. Same amount of MWNTs were dispersed in
CHT solution, and the blend with total volume of 5 mL were sonicated for 10 min and
dispersion was stirred for 10 h [35].
Electrospinning of CHT/MWNT Dispersion
After the preparation of spinning solution, it transferred to a 5 mL syringe and be-
came ready for spinning of nanofibers. The experiments carried out on a horizontal
electrospinning setup shown schematically in Fig. 5.1. The syringe containing CHT/
MWNTS solution was placed on a syringe pump (New Era NE-100) used to dispense
the solution at a controlled rate. A high voltage DC power supply (Gamma High Volt-
age ES-30) employed to generate the required electric field for electrospinning. The
positive electrode and the grounding electrode of the high voltage supplier attaches
respectively to the syringe needle and flat collector wrapped with aluminum foil where
electrospun nanofibers accumulates via an alligator clip to form a nonwoven mat. The
voltage and the tip-to-collector distance fixed respectively on 18-24 kV and 4-10 cm.
In addition, the electrospinning carried out at room temperature and the aluminum foil
removed from the collector.
Measurements and Characterizations Method
A small piece of mat placed on the sample holder and gold sputter-coated (Bal-Tec).
Thereafter, the micrograph of electrospun CHT/MWNT fibers obtained using scan-
ning electron microscope (SEM, Phillips XL-30). Fourier transform infrared spectra
(FTIR) recorded using a Nicolet 560 spectrometer to investigate the interaction be-
tween CHT and MWNT in the range of 800-4000 cm -1 under a transmission mode.