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In this study, green ZnO/polypyrrole (ppy)/cellulose acetate (CA) film was prepared via solvent casting. This film was used as supporting material for glucose oxidase (GOX) to sensitize a glucose biosensor. First, Zinc oxide (ZnO) nanoparticles have been prepared via the green route using olive leaves extract as a reductant. ZnO/ppy nanocomposite has been synthesized by a simple in-situ chemical oxidative polymerization of pyrrole (Py) monomer using FeCl3 as an oxidizing agent. The produced materials and the composite films were characterized using X-ray diffraction analysis (XRD), scanning electron microscope (SEM), Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA). Glucose oxidase was successfully immobilized on the surface of the prepared membrane and then ZnO/polypyrrole/cellulose acetate/GOX composite was deposited on the platinum electrode for determination of the current at different initial concentrations of glucose. Current measurements proved the suitability and the high sensitivity of the constructed biosensor for the detection of glucose levels in different samples. The performance of the prepared biosensor has been assessed by measuring glucose concentration for different samples with known concentrations. The results affirmed the reliability of the developed biosensor towards real samples which suggests the wide-scale application of the proposed biosensor.

Pure and doped SnO2 with V2O5 nanopowders were synthesized via sol–gel method using different V2O5 ratios. Novel thin films of SnO2:V2O5 were thermally vacuum deposited from the nanopowders and utilized for gas sensor devices to detect volatile organic compounds hazardous gases. The morphological and crystalline structure, textural properties, functional groups, optical properties and thermal behavior were investigated by FESEM, XRD, HRTEM, surface area BET, FTIR and UV–Visible spectroscopy, respectively, for both the nanopowders, and thin films. From XRD patterns, the average calculated crystallite sizes decreased from 7.8 nm to 4.5 nm as the V2O5 concentration was varied from 0 to 10%. FESEM and HRTEM show that all the synthesized nanomaterials composed of mesoporous networks of aggregated nanoparticles that almost spherical. Thus, V2O5 doped SnO2 nanopowders synthesized by sol–gel method exhibited the structural and textural features required to be used as an active area for gas sensor devices. The effect of various doping weight amounts (1, 5 and 10 wt%) of V2O5 as the dopant element enhanced the gas response time and sensitivity. The electrical behavior of the sensors was determined by measuring the resistance of two deposited platinum electrodes for sensor’s devices for different kinds of gases (LPG, H2, NH3 and acetone) at different temperatures.

Flash Floods resemble one of the most strenuous challenges that we face in the 21st century. Therefore, identifying the flooded areas is imperative to avert the negative consequences. An enormous number of researchers tended to study the impact of flash floods on vast areas which puts up some challenges if we want to address this deleterious effect of flash floods on small urban cities. This research focused on investigating and mitigating the devastating effect of flash floods on Fifth District– Egypt where the flash flood strikes many times a year. Furthermore, the study was developed on both community and building scale. The purpose of studying the community scale is to assess the risk level that may occur during certain predicted hydrographs. Moreover, this study was also conducted on a building scale to examine the effect of water excess on buildings and how many buildings are in the flood streamlines. The water depth was calculated in front of each building to make fully appraisal on the buildings state. Moreover, 32 underground tanks were utilized as protective measures. These tanks were located at the streamlines where the water flow accumulates. After applying the mitigation measures, the water depth decreased in the main streamlines as well as 153 m3 of the rainfall water was collected and could be reused after treatment. Eventually, the analytical hierarchy process was used to generate the weights of each component of flood hazard map. This map is essential to determine the most prone areas in the studied region.

$$\hbox {WO}_{3}$$ doped with NiO nanopowders with different NiO concentrations were prepared by sol–gel technique. The fabrication of the thin films for gas sensors applications was utilized using thermal vacuum evaporation technique. The morphological structure, crystallinity and optical properties of $$\hbox {WO}_{3}$$ and NiO-doped $$\hbox {WO}_{3}$$ nanopowders were characterized using scanning electron microscopy, X-ray diffraction and UV–Vis spectrophotometer, respectively. The electrical behaviors of the sensors were determined and measured by the two platinum electrodes sensor’s resistance with different gases at various temperatures. The results show that a great response to $$\hbox {CO}_{2}$$ gas was 164% at 5% doping ratio which is applicable for all environmental and industrial fields. GSM module by MAX circuit was applied on gas sensor devices to send a wireless message telling that there is a leakage in the area which the sensor installed.

Electrospun nanofibers for gas sensor application were effectively prepared from polyvinyl alcohol and pluronic solution with different percentages of titanium dioxide ( $$\hbox {TiO}_{2}$$ ) nanoparticles. Nanofibers membrane was subject to detailed analysis by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and thermal gravimetric analysis (TGA). Adding $$\hbox {TiO}_{2}$$ nanoparticles to the blended solution increased nanofibers diameters from $$280 \pm 20$$ to $$310 \pm 30\ \hbox {nm}$$ . The gas sensor response of $$\hbox {TiO}_{2}$$ nanofibers (as a function of temperature) was estimated toward liquid petroleum gas (LPG), $$\hbox {CO}_{2}$$ , and $$\hbox {O}_{2}$$ and compared with pure nanofibers. The maximum response value (100%) was obtained for LPG at $$160\,{^{\circ }}\hbox {C}$$ with $$\hbox {TiO}_{2}$$ nanofibers (0.01%). These results show promising gas sensing characteristics (such as lower operating temperatures and sufficient gas responses) for those nanofibers materials.

An innovative magnetic nano-fiber composite was prepared via hybridization nano-magnetite zinc oxide and cellulose acetate (CA) using electrospinning technique. The affinity of synthesized composite nano-fiber for phenol adsorption from aqueous solution was monitored. Different parameters that effected on the fabrication of pure CA nano-fiber were optimized. The most proper fabricated CA nano-fiberr was achieved using 10% CA that was dissolved at acetone and dimethylacetamide (DMAc) solution with mixing ratio 2:1 the electrospinning applied voltage was 20 KV and the appropriate separation distance was 25 cm using 0.5 ml/h flow rate. Different weights of magnetic zinc oxide were immobilized onto the most proper fabricated CA nano-fiber (10% CA) to fabricate novel ZnO magnetic CA composite nanofiber. The various fabricated CA based nano-fibers either after and before magnetic ZnO immobilization were characterized using SEM, XRD and FTIR. The phenol sorption affinities of the various fabricated CA nano-fibers were tested using synthetic polluted wastewater in batch manner. It was recorded that magnetite ZnO CA hybrid nanofiber with 0.1% magnetic zinc oxide immobilization represents the most efficient fabricated nanofiber compared with other studied fabricated CA based nano-fiber. This novel composite nano-fiber has ability to adsorb 64% of phenol within 2 h. The various parameters affecting the phenol sorption process onto this novel fabricated composite were optimized. It was evident that the increment at both the solution pH and temperature has negative impact on the phenol sorption process onto the novel fabricated magnetic ZnO CA composite nano-fiber.

Glass samples with the chemical formula x CKD—(100 − x) (5Na 2 O–65 B 2 O 3 –9 Bi 2 O 3 –21PbO), (0 ⩽ x ⩽ 32 mol%) were prepared. The density and the ultrasonic estimations of the investigated glasses were analyzed at room temperature before and after the impact of two dosages of gamma irradiation to study the effect of both CKD and gamma radiation. It was found that the density, and the ultrasonic parameters are sensitive to the variety of the content of CKD and the effect of γ-radiation. Replacement of oxides with higher atomic weights such as Bi 2 O 3 and PbO by CKD decreases the density. Analysis of the behavior of the ultrasonic parameters demonstrates that creation of CaO 6 and SiO 4 on one hand and an alternate transformation between BO 4 and BO 3 structural units, on the other hand, affect the increase of the ultrasonic velocities and the elastic moduli. Moreover, the density and the ultrasonic parameters decrease somewhat with the increase of the doses of γ-irradiation. The variations of the previous physical parameters can be referred to the creation of radiation imperfections, which occupied the voids inside the glass structure.

Different compositions of Se 80−x S 20 Zn x (with x = 0, 2.5, 5, 7.5, 10) thin films have been deposited by thermal evaporation technique. A shrinking on optical transmission spectra produce due to the inhomogeneities of the thickness of the thin film. Thus the deformation of non-uniform thickness should be taken into consideration during calculation of optical constants of Se 80−x S 20 Zn x thin films in terms wedge shape model that suggested by Swanepoel. The refractive-index dispersion of Se 80−x S 20 Zn x thin films is discussed using the single-oscillator wemple-DiDomenico model. The optical band gaps of the films have been determined in terms of Tauc relation of amorphous phase (indirect transition). The chemical bond approaches and electronegativities of the involved elements in Se 80−x S 20 Zn x have been used to understand the trend of both the optical constants and energy gab variation with increasing Zn contents.

A novel nanopolymeric composite powdered material was prepared by physical immobilization of the sol-gel prepared zirconia nanoparticles (ZrO2NPs) into poly (acrylonitrile- co-pyrrole) (poly (AN-co-py)) copolymer. The prepared copolymer composite was characterized using scanning electron microscope (SEM) and Fourier Transfer infrared spectrophotometer (FT-IR). SEM images investigated its homogeneous spherical morphological structure with an average diameter of 60 nm. The potential of this nanopolymeric composite material to remove a basic dye (Basic Red 46) was evaluated in a batch process. The improvement in material dosage, solution pH, and temperature has positive impact on the dye decolonization process. The maximum dye decolonization was 87.7% that recorded using 0.5 g from the composite matrix within 150 min. The kinetic data analysis indicated that the dye adsorption is a second-order process. The results indicated that the prepared nanopolymeric composite could be an alternative for more costly adsorbents used for dye removal.

In the present work, poly acrylonitrile-co-styrene (poly (AN-co-ST)) copolymer was prepared using solution polymerization. The synthesized copolymer was fabricated into nanofiber using electrospinning technique with an average diameter of approximately 220 nm, were successfully synthesized. This nanofiber was functionalized with surface carboxylic acid groups. Characterization of the poly (AN-co-ST) nanofiber and its modified nanofibers were studied by SEM, FTIR, and TGA, and the chemical modification process has positive effect on the mechanical properties of the produced nanofiber as elucidated from the tensile stress–strain test. The chemically modified copolymer nanofiber (CMCN) was evaluated for decolorization of C.I. Basic violet 14 from aqueous solutions. The decolorization process onto the nanofiber was relatively fast and the equilibrium was achieved within 30 min. The influence of the different parameters affecting the dye sorption process was established. The increment on both the pH and the temperature of the dye solution enhance the dye sorption onto the prepared chemically modified nanofiber. Meanwhile, the presence of cation salts accompanying the dye ions hinders the dye sorption process onto the prepared nanofiber. The chemically modified nanofiber proved its effectiveness as adsorbent material for dye decontamination from the polluted wastewater.

Prospective involvement of metal oxide nanomaterials as a prominent agriculture practice for improving existing crop production directed the present investigation for synthesizing of ZnO and TiO2 nanomaterials as an attempt to enhance the transplants production of some Solanaceae crops. The morphological characterizations of the prepared nanomaterials indicated that the hydrothermal synthesized ZnO was produced in nanorod structure with an average aspect ratio of 7. However, SEM and TEM micrographs of microwave prepared TiO2 evident that it has a nanoparticle structure with an average diameter of 43 nm. The BET results confirmed the high specific areas of the two prepared metal oxide nanomaterials. The two synthesized metal oxide nanomaterials were coated in gel and mixed with the seeds of eggplant, pepper and tomato crops at four concentrations 0, 50, 100 and 150 mg/L, whilst the control seeds were germinated in distilled water without gel-coating. The results pointed to the outstanding effect of TiO2 and ZnO nanoparticles on germination characters and seedlings growth. The maximum transplants lengths, fresh and dry weight were recorded at the level 100 mg/L whatever the crop plant used. Hastening germination operation of nanomaterials-gel coated seedlings compared to control plants may be ascribed to the reduction of mean germination time and coefficient variation of the germination process besides increasing the mean germination rate and the synchrony of germination traits. Overall, better performance of growing transplants has been accredited for nanoparticles-gel coated seedlings more than the control treatments which could be efficient for the safer production of transplants in an innovative way., Agricultural science; Environmental science; Biochemistry; Biotechnology; Physiology; Plant biology; Analytical chemistry; Inorganic chemistry; Nanotechnology; Food safety; Food technology; Nutrition; Capsicum annuum L.; Nano-TiO2; Germination; Nano-ZnO.; Solanum melongena L.; Nanomaterials-gel coated seedlings; Solanum lycopersicum L.; Agriculture

This paper reports the effect of replacement of selenium by indium on the thermal stability and crystallization kinetics of Se90−x–Zn5–Te5–Inx (x = 0, 2, 4, 6, 8, 10) glassy alloys. Assessment of the thermal stability of these glassy alloys was achieved using various simple quantitative methods based on the characteristic temperatures of DSC curves. In this case, kgl may be more suitable for estimating the glass thermal stability in the above composition range. The kinetic parameter Kr (T) is added to the stability criteria. The results of all thermal stability parameters confirm that the thermal stability increases with increasing indium at expense of selenium in Se90−x–Zn5–Te5–Inx glassy alloys. These results have been discussed in terms of cohesive energy and average heat of atomization. Finally, according to the average values of Avrami indices, $$\left\langle n \right\rangle$$ = 2 for the crystallization peaks means volume nucleation and two-dimensional growth for all the compositions.

Glasses from cement kiln dust and lead barium bismuth borate were prepared by the melt quenching method and studied by using FTIR and ultrasonic techniques before and after exposure to gamma irradiation at doses up to 120 kGy. The FTIR results indicated a deformation of the lead borate based glasses with the replacement of PbO by Bi2O3 which was attributed to the appearance of Bi–O stretching vibrations in [BiO6] structural units and generated excess of non-bridging oxygens. This deformation affected the [BO3] units which are indicated from the lower decreasing rate of N4 as a function of Bi2O3. The high covalency of Pb–O and B–O bonds compared with that of Bi–O or Si–O attracts the excess of non-bridging oxygens and resulted in a relaxation of the glass network. The relaxation decreased the ultrasonic velocities and the bulk modulus and hence the rigidity of the glass despite the increase of the density which was attributed to the replacement of Bi2O3 instead of PbO. The structural and rigidity changes due to composition variations showed a decreasing manner to the effects of radiation. The density of the glass increased while the ultrasonic velocities decreased. This behavior modulated the compositional behavior of the elastic moduli on Bi2O3 content.

Nano-ZnO has been successfully implemented in particles, rods, and tubes nanostructures via sol-gel and hydrothermal techniques. The variation of the different preparation parameters such as reaction temperature, time, and stabilizer agents was optimized to attain different morphological structures. The influence of the microwave annealing process on ZnO crystallinity, surface area, and morphological structure was monitored using XRD, BET, and SEM techniques, respectively. The antimicrobial activity of zinc oxide produced in nanotubes structure was examined against four different multidrug resistant bacteria: Gram-positive (Staphylococcus aureusandBacillus subtilis) and Gram-negative (Escherichia coliandPseudomonas aeruginosa) strains. The activity of produced nano-ZnO was determined by disc diffusion technique and the results revealed that ZnO nanotubes recorded high activity against the studied strains due to their high surface area equivalent to 17.8 m2/g. The minimum inhibitory concentration (MIC) of ZnO nanotubes showed that the low concentrations of ZnO nanotubes could be a substitution for the commercial antibiotics when approached in suitable formula. Although the annealing process of ZnO improves the degree of material crystallinity, however, it declines its surface area and consequently its antimicrobial activity.

New bismuth alkali borate glasses based on cement kiln dust (CKD) have the chemical formula xCKD–(100 − x) (B2O3–Bi2O3–Na2O–BaO) were fabricated by the conventional melt quenching technique. The glasses were analyzed by room temperature FTIR, density and ultrasonic measurements to study the effect of CKD on the structure and the mechanical parameters of the glasses. The physical parameters such as the density and the elastic moduli of the studied bismuth alkali borate network are sensitive to the concentration of CKD. The results indicate a creation of CaO6 and SiO4 on one hand and a mutual conversion between BO4 and BO3 structural units on the other hand. These units control the short-range order of the glasses and the non-linearity decrease of the density and the increase of the ultrasonic parameters. The results were interpreted in terms of the vibrations of the various structural units and the type of bonding between different atoms.

A novel structures of nanomaterials gas sensors array constructed using ZnO, and ZnO doped with Al via sol–gel technique. Two structure arrays are developed; the first one is a double sensor array based on doping with percentages of 1% and 5%. The second is a quadrature sensor array based on several doping ratios concentrations (0%, 1%, 5% and 10%). The morphological structures of prepared ZnO were revealed using scanning electron microscope (SEM). X-ray diffraction (XRD) patterns reveal a highly crystallized wurtzite structure and used for identifying phase structure and chemical state of both ZnO and ZnO doped with Al under different preparation conditions and different doping ratios. Chemical composition of Al-doped ZnO nanopowders was performed using energy dispersive X-ray (EDS) analysis. The electrical characteristics of the sensor are determined by measuring the two terminal sensor’s output resistance for O2, H2 and CO2 gases as a function of temperature. Keywords: Sol–gel method, Quadrature gas sensor, Nanostructures, Doping ratios

This article presents the nano-architecturing of highly sensitive SnO2–based gas sensors prepared by molecular imprinting technique with the presence of acetone and/or ammonia solvents to develop a sensor that has the ability to detect both gases which is being developed for the first time. Nanoparticles are prepared via hydrothermal method and then they have been characterized by field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and N2 adsorption-desorption analyzer (BET) to determine their morphology, crystal structure, optical properties and surface area properties respectively. Four SnO2 films are fabricated using spin coating under different conditions of introducing ammonium hydroxide or acetone during the hydrothermal synthesis. Regular microsheets of about 5 μm in length and 500 nm thickness have been built up from nanoparticles of sizes ranged from 20 to 50 nm depending on the preparation conditions. The sensing properties of the fabricated sensors are tested against (ammonium hydroxide, acetone, LPG, oxygen and benzene), where the results showed that when the participation of the solvent during the synthesis process, it increases the response for these gaseous. The performance of the gas sensor devices is demonstrated and got higher values (about 90%) for Ammonia gas when the device is template with ammonium hydroxide and water and washed with water (SD) and limit of detection (600 ppb). Also, high sensitivity (about 77%) for Acetone is recorded for the device is template with ammonium hydroxide and acetone and washed with acetone (SA) and limit of detection (280 ppb).

Optical properties of amorphous Se80 − xTe20Bix thin films with different compositions (x = 0, 2, 4, 6 and 8 at.%) deposited by evaporation technique have been investigated by optical spectrophotometry measurements in the wavelength range of 400–2500 nm. An optical characterization method for uniform films based on Swanepoel's ideas (envelope method) has been employed to extract the refractive index n and film thickness d, with accuracies better than 1%. It was found that the refractive index increases with increasing the concentration of Bi at the expense of Se content. The increasing in refractive index n is interpreted in terms of polarizability and the mean coordination number. The dispersion of the refractive index is discussed in terms of the single oscillator Wemple–DiDomenico model. The fundamental parameters for the investigated semiconducting thin films Se80 − xTe20Bix e.g. absorption coefficient and band gap are calculated in the strong absorption region of transmittance and reflectance spectra. The possible optical transition in these films is found to be allowed indirect transition with energy gap Egoptdecreases from 1.467 to 1.035 eV with increasing Bi content at expense of Se. Finally, the decrease in the optical band gap with increasing Bi content in Se80 − xTe20Bix has been explained in terms of the chemical bond approach.

ZnO nanostructures including nanorods and nanoparticles were synthesized via sol–gel technique. The factors were optimized in order to acquire undoped and doped ZnO that have nanorod morphological structures with high aspect ratio. Effect of reaction times (3, 6, 12, 24, and 48 h) has been studied to optimize the best preparation conditions. The morphological structure, diameter and length of ZnO nanorods were determined using scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM). Nanoparticles of about 10 nm and nanorods with diameter about 100 nm were measured using (HRTEM). The maximum aspect ratio of nanorods has a value of 12 for 24 h reaction times. X-ray diffraction (XRD) patterns for the as-synthesized ZnO nanopowders reveal a highly crystallized wurtzite structure. XRD also used for identifying phase structure and chemical state of ZnO and ZnO doped with Sb under different reaction times and different doping ratios. Chemical composition of the Sb-doped ZnO nanopowders was performed with energy dispersive X-ray (EDX) and inductive coupled plasma mass spectroscopy (ICP-AES), which also concluded the doping ratios of the reactions results. Effect of doping on the band gap values for ZnO nanopowders has been studied using UV–vis spectroscopy. The gas response of the homemade devices based on Sb-doped ZnO nanopowders toward O2, CO2 and Acetone vapor as a function of temperature was measured and compared with undoped ZnO films. The response and recovery times have been studied.

In this study, an antibacterial electrospun nanofibers for wound dressing application was successfully prepared from polyvinyl alcohol (PVA), Pluronic F127 (Plur), polyethyleneimine (PEI) blend solution with titanium dioxide nanoparticles (TiO2 NPs). PVA-Plur-PEI nanofibers containing various ratios of TiO2 NPs were obtained. The formation and presence of TiO2 in the PVA-Plu-PEI/ TiO2 composite was confirmed by X-ray diffraction (XRD). Transmission electron microscopy (TEM), Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), mechanical measurement, and antibacterial activity were undertaken in order to characterize the PVA-Plur-PEI/TiO2 nanofiber morphology and properties. The PVA-Plu-PEI nanofibers had a mean diameter of 220 nm, and PVA-Plur-PEI/TiO2 nanofibers had 255 nm. Moreover, the antimicrobial properties of the composite were studied by zone inhibition against Gram-negative bacteria, and the result indicates high antibacterial activity. Results of this antibacterial testing suggest that PVA-Plur-PEI/TiO2 nanofiber may be effective in topical antibacterial treatment in wound care; thus, they are very promising in the application of wound dressings.

Different compositions of Cu-doped ZnSe in ternary alloy Zn1−x Cu x Se thin films (with x = 0, 0.025, 0.05, 0.075 and 0.10) were evaporated (thickness 1 µm) onto glass substrate using electron beam evaporation method. The X-ray diffraction analysis for both powder and films indicated their polycrystalline nature with zinc blende (cubic) structure. The crystallite size was found to increase, while the lattice microstrain was decreased with increasing Cu dopant. The optical characterization of films was carried out using the transmittance spectra, where the refractive indices have been evaluated in transparent and medium transmittance regions using the envelope method, suggested by Swanepoel. The refractive index has been found to increase with increasing Cu content. The dispersion of refractive index has been analyzed in terms of the Wemple–DiDomenico single-oscillator model. The oscillator parameters, the single-oscillator energy E o, the dispersion energy E d and the static refractive index n 0, were estimated. The optical band gap was determined in strong absorption region of transmittance spectra and was found to increase from 2.702 to 2.821 eV with increasing the Cu content. This increase in the band gap was well explained by the Burstein–Moss effect.

High surface area zinc oxide material in nanorod morphological structure was synthesized using an ultrasonic technique in the presence of polyvinyl pyrrolidone as stabilizing agent. The crystallite, morphology, and surface area of the prepared white powder material were identified using XRD, SEM, and BET techniques, respectively. X-ray analysis confirms the high purity of synthesized ZnO. The evaluated specific surface area of prepared ZnO was 16.7 m2/g; this value guarantees high efficiency for water purification. The feasibility of synthesized ZnO nanorods for phosphorus sorption from aqueous solution was established using batch technique. Nano-zinc oxide exhibits high efficiency for phosphorus removal; the equilibrium state was recorded within 90 minutes. The most effective hydrogen ion concentration of the polluted solution was recorded at pH = 1 for phosphorus decontamination. The equilibrium of phosphorus sorption onto ZnO nanorods was well explained using both Langmuir and Temkin isotherm models. The calculated maximum monolayer sorption capacity was 89 mg/g according to Langmuir isotherm at 27°C. In order to explain the phosphorus sorption mechanism onto the prepared ZnO nanorods, three simplified kinetic models of pseudo-first order, pseudo-second order, and intraparticle diffusion rate models were tested. Kinetics was well fitted by pseudo-second order kinetic model with a contribution of intraparticle diffusion.

Different compositions of Co-doped zinc oxide [(Zn(1−x)Co x O) (x = 0, 0.02, 0.04, 0.06, 0.08 and 0.10)] thin films were evaporated onto highly clean glass substrates by thermal evaporation technique using a modified source. The structural properties investigated by X-ray diffraction revealed hexagonal wurtzite ZnO-type structure. The crystallite size of the films was found to decrease with increasing Co content. The optical characterization of the films has been carried out using spectral transmittance and reflectance obtained in the wavelength range from 300 to 2500 nm. The refractive index has been found to increase with increasing Co content. It was further found that optical energy gap decreases from 3.28 to 3.03 eV with increasing Co content from x = 0 to x = 0.10, respectively. The dispersion of refractive index has been analyzed in terms of Wemple–DiDomenico (WDD) single-oscillator model. The oscillator parameters, the single-oscillator energy (E o), the dispersion energy (E d), and the static refractive index (n 0), were determined. The nonlinear refractive index of the Zn(1−x)Co x O thin films was calculated and revealed well correlation with the linear refractive index and WDD parameters which in turn depend on the density and molar volume of the system.

Zirconium tungesto-vanadate cation exchange material was successfully architectured at open ended nanotubes morphological structure in the presence of polyvinyl alcohol as a stabilizing agent using microwave route. The ion exchange capacity (IEC) of the material was recorded as 4.8 meq/g of about 640 m(2)/g for a specific surface area. The x-ray diffraction pattern of the material implies its crystallinity. Both scanning and transmission electron microscopes identified the average aspect ratio of the architectured nanotubes as 6.5 and its hollow structure. The material posed 96.4 % cadmium ion decontamination within 90 min compared with 84 % strontium decontamination at the same time.

As an innovative cation exchange material, nanozirconium tungestovanadate prepared using homogeneous precipitation technique was immobilized into alginate matrix and evaluated for cationic dye decolourization. Physicochemical properties of the prepared composite material were examined to determine its crystallinity, morphology, and ion exchange capacity. The SEM and TEM images of the prepared zirconium tungestovanadate identified that it was prepared in homogeneous structure with spherical shape in average diameter 22 nm. However, the optical microscope image of the composite matrix confirms the good distribution of nanozirconium tungestovanadate into the polymeric matrix. Batch technique was utilized to test the cation exchange efficiency of the prepared composite material toward C.I. basic violet 16 dye decolourization. The optimum immobilized dosage from nanozirconium tungestovanadate into the polymeric matrix to achieve 99% dye decolourization from 50 ppm initial dye concentration was recorded as 8 g/L. The dye sorption process onto the prepared material is described as an endothermic process. The dye sorption process at equilibrium was following both Langmuir and Freundlich isotherm models. The kinetic sorption behaviour of dye onto the composite matrix is correlated to pseudo-second-order equation model.

Zinc oxide nano-powder was prepared using sol-gel technique to be encapsulated onto polymeric blend composed from alginate and polyvinyl alcohol to fabricate novel bio-composite beads of nano-zinc oxide. The XRD patterns of both zinc oxide nano-powder and its polymeric hybrid were crystalline in their nature. The FTIR analysis of the fabricated ZnO polymeric hybrid confirms the binding between zinc oxide and the polymeric matrix. The BET analysis demonstrated that the calculated specific surface area of the formulated ZnO beads that equal to 22.8 m2/g is comparatively less than that of the free ZnO nano-powdered that equivalent to 64.9 m2/g. The thermal stability of ZnO nano-powdered dramatically decreased with its immobilization into the polymeric alginate and PVA matrix. The formulated beads had very strong mechanical strength and they are difficult to be broken up to 1500rpm. Moreover, this hybrid beads are chemically stable at the acidic media. The formulated ZnO hybrid beads verified to be good adsorbent material for C.I basic blue 41 (CB41).

The sol-gel prepared zinc oxide nanopowder was immobilized onto alginate-polyvinyl alcohol polymer blend to fabricate novel biocomposite beads. Various physicochemical characterization techniques have been utilized to identify the crystalline, morphological, and chemical structures of both the fabricated zinc oxide hybrid beads and their corresponding zinc oxide nanopowder. The thermal stability investigations demonstrate that ZnO nanopowder stability dramatically decreased with its immobilization into the polymeric alginate and PVA matrix. The formulated beads had very strong mechanical strength and they are difficult to be broken up to 1500 rpm. Moreover, these hybrid beads are chemically stable at the acidic media (pH < 7) especially within the pH range of 2–7. Finally, the applicability of the formulated ZnO hybrid beads for C.I. basic blue 41 (BB41) decolorization from aqueous solution was examined.

A harmful environmental problem such as cement kiln dust (CKD) was considered as a source of CaO and SiO2, which are useful oxides for the glass industry. So, Na2O, B2O3, Bi2O3, PbO and CKD were used to fabricate new borate based glasses. The structure of the prepared glasses was studied by FTIR before and after gamma irradiation at doses up to 120 kGy. Analysis of FTIR before irradiation revealed that CKD split the characteristic broad band of the vibrations of BO3 structural units into two bands and created two effective ranges of concentrations which were confirmed by N4 calculations. After gamma irradiation, the intensity of the FTIR bands decreased and the structure of glass was weakened when 0 ≤ CKD ≤ 23.5 mol% as a result of energy transferred by gamma rays. Increasing CKD beyond this limit created bridging oxygens, more covalent bonds and interlinked the structural groups of the glass network which may resist the irradiation effects. The glass containing 32 mol% of CKD showed higher resistance for radiation effects which was attributed to its strong covalent bonds and to [BiO6] and [PbO6] structural units.

The present work reports slightly modification of the conventional chemical synthesis of polyaniline (PANI) to be nanotube structure without the need for any template or structural directing materials. PANI preparation was optimized by the oxidation of two different precursors: aniline and aniline hydrochloride with ammonium persulfate (APS) as oxidizing agent in various aqueous media of strong, weak acid and in alkaline medium at different pH values. Structural and morphological properties of the products are characterized by SEM, XRD and FTIR. Results showed the strong dependence of PANI nanotube on the acidity at certain pH value during the oxidation of aniline by APS. It is founded that, the optimum condition for preparation of PANI nanotube was obtained under oxidation of aniline monomer by APS in aqueous media of weak acid medium at pH five degree.