الفهرس 
CHAPTER I General Introduction and Literature SurveyOnly 14 pages are availabe for public view
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Abstract
Lanthanide based inorganic nanomaterials exhibit strong and narrow spectrum; long lifetime (nanosecond to millisecond) and large stokes shifts characteristics. The practical applications of lanthanide ions based nanomaterials require their dispersion into thermally and chemically stable, inexpensive and biocompatible matrices such as silica glasses.
Upon the above text, the main objective of this thesis is optimization the preparation conditions such as doping concentration and surfactant as well as dispersion into silica matrix to produce a new high photoluminescent lanthanide based nanomaterials for sensing applications such as latent fingerprint detection, glucose and heavy metal detection.
The thesis consists of three chapters:
Chapter I gives a general introduction including theoretical background about nanotechnology, the basics of lanthanide metal ion luminescence and the effects of surfactant on the properties of nanomaterials. Furthermore, the properties of Lanthanide doped inorganic nanomaterials and their importance as a fluorescent sensor for glucose, heavy metal and latent fingerprint were reported.
Chapter II demonstrates different experimental techniques and data analysis methods used in this thesis.
Chapter III aims studying the effect of lanthanide doping (x = 0.01, 0.03, 0.05, 0.07 mol) and surfactant, as well as dispersion into silica matrix on the crystal, morphological, optical, and photoluminescent properties of Ln3+:Bi4Si3O12 (Ln3+:BSO). Also, the optimized nano-phosphor (0.03 mol Ln3+:BSO dispersed into silica matrix) was applied as a latent fingerprint. Moreover, the amino functionalized 0.03 mol Sm3+:BSO/SiO2 (Sm3+:BSO/SiO2/NH2) sensor was prepared and applied in analytical determination of glucose. Also, Ln3+:BSO/SiO2/NH2 (Ln3+ = Pr3+ and Dy3+) sensor was applied for sensing metals.
The results obtained in this chapter were summarized as follows:
A. X mol Ln3+:Bi4Si3O12 (Ln3+:BSO) (Ln3+ = Pr3+, Sm3+, Eu3+, Dy3+, Er3+; x = 0.01, 0.03, 0.05, 0.07 mol) were prepared using sol–gel method followed by heat treatment.
B. To optimize the preparation conditions, the effect of annealing temperatures, doping concentrations, and different surfactants as well as dispersion into silica matrix on the crystal, morphological, optical and photoluminescent properties of Ln3+:BSO nanophosphor were studied. The obtained results were summarized as follows:
1. The effect of annealing study for pure samples confirms that the major Bi4Si3O12 phase (BSO) was observed at annealing temperature equal 900C.
2. The XRD patterns of Ln3+: Bi4Si3O12 where (Ln3+ = Pr3+, Sm3+, Eu3+, Dy3+, Er3+) (x = 0.01, 0.03, 0.05, 0.07 mol) annealed at 900C for 2h in air showed that the main diffraction peak of BSO phase (2 = 32.60) was slightly shifted to low angle as an influence of Ln3+ ion doping. By comparison, it can be found that the crystal size of Ln3+:BSO phosphor ( Ln3+= Pr3+, Sm3+, Eu3+, Dy3+, Er3+) was increased than that of pure BSO. This means that Ln3+ doping to BSO enhances the crystal growth.
3. The full width at half maximum (FWHM) of main diffraction peak was increased in the presence of different surfactants and silica matrix. This indicated that the presence of surfactant and silica matrix can hinder BSO nanophosphor crystal growth and as a consequence decrease its crystal size.
4. TEM image of pure BSO shows a highly aggregated cluster from BSO nanoparticles. Doping of BSO with Ln3+ ion leads to the formation of aggregates from irregular nano-flake shape. Addition of surfactants in the preparation decreased the Ln3+:BSO crystal size. Highly separated uniform nano-spherical shape with small average size (3 nm) appears in case of Ln3+:BSO (Ln3+ = Sm3+, Pr3+ and Dy3+) dispersed into silica matrix.
5. The absorption band edge of BSO was shifted towards lower wavelength by increasing Ln3+ ion concentration. At high doping contents, sharp absorption bands in visible region (400-900 nm) were observed, which can be assigned to the intra configurational 4f → 4f transitions of Ln3+ ions.
6. The band gap energy values for all Ln3+:BSO (Ln3+= Pr3+, Sm3+, Eu3+, Dy3+, Er3+) phosphors were high relative to undoped sample. This is due to Moss–Burstein effect.
7. The 0.03 mol Ln3+:BSO (Ln3+= Pr3+, Sm3+, Eu3+, Dy3+, Er3+) prepared in the presence of different surfactants have a low band gap energy relative to the same sample prepared without surfactant.
8. In case of 0.03 mol Ln3+:BSO (Ln3+= Pr3+, Sm3+, Eu3+, Dy3+, Er3+) dispersed into silica matrix, the absorption edge was blue shifted with a band gap (3.1- 3.61 eV) as a result of confinement of BSO into small size in silica pores.
9. The excitation and emission bands increased by increasing doping concentration until optimum dopant value (0.03 mol) and then decreased again.
10. The excitation and emission spectra of 0.03 mol Ln3+:BSO prepared in the presence of different surfactants also decreased. This indicated that the energy transfer probability decreased in the presence of different surfactants.
11. Pr3+: BSO exhibited two distinctive emission peaks at 505 (blue), 594 and 612 nm (yellow) under UVC excitation. The net emission is a faint pink color
12. Sm3+:BSO nano-phosphor exhibit strong orange red emission. These emission lines lie are at 564, 601 and 650 nm.
13. Eu3+:BSO was characterized with red emission lines at 575, 595, 612, 653, and 705 nm.
14. Dy3+: BSO at different doping concentrations exhibited two distinctive emission peaks of Dy3+ at 488 (blue) and 575 nm (yellow) under UVC excitation. The net emission is a faint yellow color.
15. Er3+: BSO can act as a down and up converting materials. Er3+: BSO can excite with UV and NIR to give a visible emission.
16. The proposed energy transfer mechanisms for Ln3+: BSO (Ln3+ = Pr3+; Eu3+; Sm3+; Dy3+ and Er3+) was discussed.
17. The PL lifetime measurements show that the low doping concentrations (0.01 and 0.03) gave the highest PL lifetime.
18. The lifetime of 0.03 mol Ln3+:BSO (Ln3+= Pr3+, Sm3+, Eu3+, Dy3+, Er3+), dispersed in silica is slightly longer than pure samples due to shielding of Ln3+ from the environmental factors such as adsorbed water molecules by both bismuth silicate and silicon structural units.
19. The long PL lifetime and high intense luminescent 0.03 mol Ln3+: BSO/SiO2 (Ln3+ = Pr3+; Sm3+ and Dy3+) nanophosphor, was successfully developing the latent fingerprint on different surfaces.
20. The 0.03 mol Sm3+:BSO/SiO2 surface was functionalized with amino group Sm3+:BSO/SiO2/NH2 and used as fluorescent sensor for glucose.
21. The Ln3+:BSO/SiO2/NH2 (Ln3+ = Pr3+ and Dy3+) sensing abilities were investigated by addition of different cations (Co2+, Cr3+, Cd2+, Al3+, Cu2+, Zn2+, Pb2+ and Fe3+). It was found that the highest Ksv values were found in case of Fe3+ in comparison with other tested metal ions. The detection limit of Fe3+ using Ln3+:BSO/SiO2/NH2 (Ln3+ = Pr3+ and Dy3+) was 1x10-9 mol L-1. No change in the PL lifetime values of Ln3+:BSO/SiO2/NH2 (Ln3+ = Pr3+ and Dy3+) before and after addition of Fe3+. These results demonstrated that the quenching process follows static mechanism.