الفهرس 
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Abstract
Titanium nanoribbons (TNRs) were successfully prepared through alkaline hydrothermal method. A straight and non-hollow ribbons of widths ranged from 30-200 nm were formed. The structural study showed the existence of two mixed phases (Hydrogen titanate and TiO2-(B)). Bare and 0.5 % wt TNRs–modified membranes were fabricated via phase inversion method. By adding TNRs, the membrane was transformed from symmetric to asymmetric type. The modified membrane showed desirable and enhanced properties and performance versus bare PES membrane. The incorporation of TNRs enhances mechanical properties, total porosity and the hydrophilicity of PES membrane. TNRs addition improves the salt rejection% of PES membrane. The rejection of TNRs /PES membrane reached 82.4% with a flux rate 29.39 (Kg/m2.h) for high salinity solution of 20000 (mg/l). The enhanced properties and low-cost fabrication make the modified membrane a key parameter in the water desalination industry.
In addition, TNRs/CNTs nanocomposite was successfully synthesized by a chemical vapor deposition of CNTs using hydrothermally synthetic TNRs supported by the FeCo-Al2O3 catalyst. The synthesized TNRs and TNRs /CNTs nanocomposite were characterized by different techniques including XRD, FT-IR, TEM, SEM and UV-Vis spectrophotometer. The results reflected the transformation of hydrothermally synthetic TiO2-B and hydrogen titanate nanoribbon into a single phase TiO2-B NRs with nanopits structures. The single phase TiO2-B NRs was functionalized with FeCo-Al2O3 catalyst and composited with carbon nanotubes by the chemical vapor deposition method. The composite composed of tube-like nanostructures forming interlocked network from CNTs and TiO2-B NRs. The composite exhibited stronger and wider optical absorption band than TNRs. Also, the band gap energy was reduced from 3.11 eV for TNRs to 3.09 for TNRs/CNTs nanocomposite. Moreover, the photocatalytic properties of TNRs and TNRs/CNTs composite were studied toward the photodegradation of methylene blue dye under sunlight. The effect of irradiation time, dye concentration, and catalyst dose on the photocatalytic properties of TNRs and TNRs/CNTs were addressed. The degradation mechanism and reaction kinetics were discussed. Using TNRs/CNTs composite, the irradiation time can be reduced to 50% compared to the same dose of TNRs. Moreover, TNRs/CNTs showed higher stability than TNRs photocatalyst and can repeatedly be used with very limited photo-corrosion.
Also, TNRs/MWCNTs nanocomposite with mass ratio 1:1 was successfully synthesized by hydrothermal method followed by CVD. A porous structure from TNRs/MWCNTs incorporated with PES membrane by adding different amounts from the nanocomposite to casting solution. Bare-PES and blend membranes were prepared by phase inversion method. Cross-sectional SEM images of membranes depict the change in the structure from the spongy-like structure for bare- PES to macro voids structure for TNRs/MWCNTs/PES membrane. The incorporation of TNRs/MWCNTs enhances the hydrophilicity and mechanical properties of PES membranes. The inclusion of 0.5%wt TNRs/MWCNTs raises the tensile strength of PES membrane from 45.7 to 96.6 kg/cm2. The nanocomposite decreases the porosity of the blended membranes and increases their salt rejection %. The highest average salt rejection of membranes was 99.54 %, 99.84%, 98.53%, and 94.06%, respectively at 2000, 5000, 7000, and 20000 mg/l NaCl when membrane blended with 0.5% wt of TNRs/MWCNTs, whereas the average salt rejection was 61.63%, 50.9%, 41.7 %, and 75% using bare-PES. The addition of TNRs/MWCNTs enhances the ac electrical conductivity, dielectric constant and dielectric loss. The modified membranes showed good anti-fouling nature and high removal of congo red dye. The optimum concentration of TNRs/MWCNTs embedded to PES was 0.5%wt. Finally, the addition of optimized ratio of TNRs/MWCNTs nanocomposite endowed the microfiltration PES membrane new and excellent properties to act as LPRO membrane.