A. Elhissi

Photocatalytic, sonocatalytic and sonophotocatalytic degradation of Rhodamine B using ZnO/CNTs composites photocatalysts

A series of ZnO nanoparticles decorated on multi-walled carbon nanotubes (ZnO/CNTs composites) was synthesized using a facile sol method. The intrinsic characteristics of as-prepared nanocomposites were studied using a variety of techniques including powder X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM), transmission electron microscope (TEM), scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDX), Brunauer Emmett Teller (BET) surface area analyzer and X-ray photoelectron spectroscopy (XPS). Optical properties studied using UV-Vis diffuse reflectance spectroscopy confirmed that the absorbance of ZnO increased in the visible-light region with the incorporation of CNTs. In this study, degradation of Rhodamine B (RhB) as a dye pollutant was investigated in the presence of pristine ZnO nanoparticles and ZnO/CNTs composites using photocatalysis and sonocatalysis systems separately and simultaneously. The adsorption was found to be an essential factor in the degradation of the dye. The linear transform of the Langmuir isotherm curve was further used to determine the characteristic parameters for ZnO and ZCC-5 samples which were: maximum absorbable dye quantity and adsorption equilibrium constant. The natural sunlight and low power ultrasound were used as an irradiation source. The experimental kinetic data followed the pseudo-first order model in photocatalytic, sonocatalytic and sonophotocatalytic processes but the rate constant of sonophotocatalysis is higher than the sum of it at photocatalysis and sonocatalysis process. The sonophotocatalysis was always faster than the respective individual processes due to the more formation of reactive radicals as well as the increase of the active surface area of ZnO/CNTs photocatalyst. Chemical oxygen demand (COD) of textile wastewater was measured at regular intervals to evaluate the mineralization of wastewater.

PEGylated graphene oxide for tumor-targeted delivery of paclitaxel.

AIM The graphene oxide (GO) sheet has been considered one of the most promising carbon derivatives in the field of material science for the past few years and has shown excellent tumor-targeting ability, biocompatibility and low toxicity. We have endeavored to conjugate paclitaxel (PTX) to GO molecule and investigate its anticancer efficacy. MATERIALS & METHODS We conjugated the anticancer drug PTX to aminated PEG chains on GO sheets through covalent bonds to get GO-PEG-PTX complexes. The tissue distribution and anticancer efficacy of GO-PEG-PTX were then investigated using a B16 melanoma cancer-bearing C57 mice model. RESULTS The GO-PEG-PTX complexes exhibited excellent water solubility and biocompatibility. Compared with the traditional formulation of PTX (Taxol®), GO-PEG-PTX has shown prolonged blood circulation time as well as high tumor-targeting and -suppressing efficacy. CONCLUSION PEGylated graphene oxide is an excellent nanocarrier for paclitaxel for cancer targeting.

Characteristics and applications of titanium oxide as a biomaterial for medical implants

There is considerable interest in TiO2 for a wide range of applications; however, this chapter focuses mainly on its uses as a biomaterial, particularly for biomedical implant devices. The main characteristics required for this application have been considered. Methods for producing TiO2 and Ag doped TiO2 films are summarized. The interactions of the films containing body fluids, mainly with blood components such as proteins, are discussed. Various techniques, including surface analysis methods, have been employed to characterize the undoped and Ag doped TiO2 films. Their behaviour under normal conditions inside the body, such as physiological pH, has been investigated and results presented. © 2012 Woodhead Publishing Limited. All rights reserved.

Diamond Synthesis, Properties and Applications

Diamond is an ideal material for numerous applications such as cutting tools such as dental burs and drills due to its unique combination of chemical, mechanical and thermal properties. The most widely used method of growth diamond is chemical vapour deposition (CVD) namely hot filament and microwave plasma processes. The use of vertical filament chemical vapour deposition (VFCVD) process has been developed to uniformly coat complex shaped tools and is described in detail. The growth characteristics and film properties are described for use on dental burs and drills.

Diamonds synthesis, properties and applications

The depostition of diamond films using VFCVD onto tungsten carbide dental burs has been described. To enchance nucleation, growth and adhesion of the diamond substrate was pre-treated using a Murakami etch.The structure and morphology of the diamond coated bursa and uncoated burs have been compared.

Diamond deposition of tungstencarbide bursing VFCVD

The depostition of diamond films using VFCVD onto tungsten carbide dental burs has been described. To enchance nucleation, growth and adhesion of the diamond substrate was pre-treated using a Murakami etch.The structure and morphology of the diamond coated bursa and uncoated burs have been compared.

Diamond Deposition on Tungsten Carbide Burs Using VFCVD

The deposition of diamond films using VFCVD onto tungsten carbide dental burs has been described. To enhance nucleation, growth and adhesion of diamond substrate was pre-treated using a Murakami etch. The structure and morphology of the diamond coated burs and uncoated burs have been compared.

VFCVD diamond dental burs for improved performance

In this chapter the performance and life of dental burs coated with diamond has been investigated. The performance of various burs both coated with diamond films using VFCVD and un-treated burs have been compared. Results show that the diamond coated burs using VFCVD performed better in terms of life.

Precision machining of medical devices

Titanium may be considered a relatively new engineering material. It was discovered much later than the other commonly used metals, with its commercial application starting in the late 1940s. Its usage as an implant material began in the 1960s, despite the fact that it exhibits superior corrosion resistance and tissue acceptance when compared with stainless steels and Cr-Co-based alloys. This chapter reviews the use of titanium and titanium alloys for use in biomedical applications and its processing. © 2012 Woodhead Publishing Limited. All rights reserved.