No abstract

The solÀgel and electrospinning techniques were combined to produce poly(vinylpyrrolidone) (PVP)/titanium-(IV) oxide composite fibers from solutions containing PVP and titanium tetraisopropoxide. Either magnesium nitrate hexahydrate or zirconyl(IV) nitrate hydrate was added to the solutions as a source of magnesium or zirconium dopant, respectively. Upon calcination of the as-spun fibers, metal-doped titania fibers were obtained. The presence of either magnesium or zirconium dopant affected both the physical and chemical properties of the as-synthesized titania fibers and even retarded the formation of the rutile phase. Various characterization techniques were employed to confirm the increased content of Ti 3þ defects and oxygen vacancies within the titania structures resulting from the presence of the metal dopants. These defects were found to trap photoexcited charges (i.e., electrons and holes), thus retarding the recombination of electronÀhole pairs. This led to an enhancement of the photocatalytic activity of the titania structures.

Electrospun fabrics, prepared from 5, 7 and 10%w/v were Poly(vinyl alcohol) (PVA) solutions successfully prepared. The electrospinning condition was 15 kV, distance 15 cm, flow rate of 1 ml/hr and spinning time of 5 hours. Physical properties of electrospun PVA fabrics were analysed by SEM, FE-SEM and contact angle measurement.The contact angle of the electrospun PVA fabrics was 54.5°, characterizing the hydrophilicity of the fabrics. Hydrophobic properties of the electrospun PVA fabrics were improved by plasma treatment using radio frequency inductively coupled plasma (RF-ICP). RF-ICP plasma treatment of the electrospun PVA fabrics were carried out sulphurhexafluorene (SF6) gas with pressure of 0.5 Torr, RF power of 30W and treating time of 30, 60, 90 and 120 seconds. Effects of the PVA solution concentration and plasma treating time on hydrophobicity of the electrospun PVA fabrics were determined by contact angle that result of contact angle of treated fabrics increased when treated time increased and they decreased when concentration of fabrics increased.

Electrospun polyacrylonitrile (PAN) fabrics were prepared by electrospinning with 7%w/v concentration to dissolve in dimethylformamide (DMF) and spinning time 12 h. Radio frequency inductively couple plasma (RF-ICP) at 13.56 MHz were used to improve PAN fabrics surface by O2 gas in plasma treatment that became to hydrophilic properties of PAN fabrics surface. Physical properties were determined by scanning electron microscopy (SEM) and contact angle measurement which found that characterized on PAN fabrics surface after plasma treatment with increased treated time had been damaged on these fabrics surface which measured contact angle measurement with water were range 29.3 to 74.7. Chemical properties were analysed by fourier transform infrared spectroscopy (FTIR) that had been found peak intensities of aliphatic C-H band at 1450 and 2930 cm-1 and peak intensities of cyclic C=O bands at 1732 cm-1 and peak intensities of saturated nitriles at 2243 cm-1 and peak intensities of hydroxyl O-H band at 3600-3650 cm-1.