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The main purpose of this study is to synthesize nano-hydroxyapatite/cellulose (nHAP/Cel) and nano-hydroxyapatite/chitosan (nHAP/CS) scaffolds via co-precipitation method for bone tissue engineering due to their suitable biocompatibility, cytotoxicity and mechanical properties. The characterizations of these scaffolds were investigated by Infrared absorption spectra (FT-IR), X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM). The cytotoxicity of these nanoparticles was evaluated with bone marrow cell using the 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazoliumbromide) (MTT) assay. The porosity of scaffolds was estimated 87%. The results indicate that the nano composite scaffolds have good morphology, tissue biocompatibility and biodegradability to be used for tissue engineering.

HA is a suitable material for the drug delivery due to its unique properties (including high biodegradation, bioactivity, and biocompatibility). Therefore, in recent years, many studies have been conducted in this field. Nevertheless, some restrictions like rapid drug release and low drug loading capacity are seen in former studies. The researchers suggested that these limitations can be addressed by modifying the producing procedure of HA and the augmentation of various materials for delaying drug release. Hence, novel mesoporous HA/GO nanocomposites were prepared through the chemical precipitation method in the presence of chitosan. HA nanoparticles and HA/GO nanocomposites were analyzed by several techniques including FT-IR, XRD, FE-SEM, TEM, BET, and TGA. In addition, the loading of naproxen and release behavior (pH = 7.4 and T = 37 °C) of the prepared samples were studied by UV–vis spectrophotometry. Our outcomes revealed that the crystalline size of the synthesized samples was in the range of 38–45 nm. The morphological structure analysis through FE-SEM and TEM analyses proved that HA/GO nanocomposites had a rod-like structure, and the morphological change in the HA/GO nanocomposites confirms that GO sheets and HA nanoparticles were successfully incorporated and synthesized nanocomposites with size less 50 nm. The mesoporous structure of the prepared samples was confirmed by BET analysis with an average pore diameter in a range of 15–50 nm and BET surface area of 14–33 m2/g. This can be considered as a very attractive characteristic of the prepared samples for drug delivery purposes. The ability of nanocomposites for naproxen delivery was analyzed as a drug delivery model under in vitro condition. With increasing weight ratio of GO, the percentage of drug loading has increased, so that for the HA/GO-0.3 g nanocomposite where the GO amount was at its maximum level, percentage of encapsulation efficiency (EE %) and percentage of drug loading capacity (LC %) 90.8% and 40.51% were obtained, respectively. Naproxen release studies in PBS showed that initial release for all samples occurred within the first 24 h, and subsequently the release rate was reduced gradually up to approximately 14 day. Under optimal situation, the synthesized nanocomposite with the maximum level of GO could maintain 56.2% of naproxen loaded after 14 days, which resulted from some drug molecules embedded deeply in HA/GO-0.3 g nanocomposite with more Go layers. Therefore, the results revealed that the HA/GO nanocomposites with the high loading efficiency and stable release capacity can be good candidates for sustained drug release.

Perovskite phase of CdTiO3 nanoparticles (CTO NP) was synthesized by a simple hydrothermal method at 180 °C for 12 h and 24 h. It was then annealed at 1050 °C for 3 h. Perovskite CdTiO3@S nanocomposites (CTO@S NCs) with a needle-like morphology were synthesized by mixing CTO and S powders at 600 °C for 2 h. The obtained samples were characterized by Fourier transform-infrared (FT-IR), X-ray diffraction (XRD), Thermogravimetric/differential scanning calorimetry analysis (TGA–DSC), Transmission electron microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDS), Zeta potential, N2 adsorption–desorption isotherms, and UV–visible diffuse reflectance spectroscopy (DRS). The optical, photoluminescence, and photocatalytic properties were investigated further. The diffuse reflection adsorption spectrum indicated that absorption peaks of the CTO@S NCs with the various S contents (5–30%) shifted towards the visible region. Tauc’s plots presented the band gap energy values for direct transitions, whereby 2.98 eV and 2.51 eV were obtained for CTO and CTO@S NCs (30), respectively. Photoluminescence spectra excited at both 370 nm and 400 nm wavelengths revealed a decline in the intensity of the emission spectra and had a minor red-shift at λex = 370 nm. The photocatalyst performance was investigated for degradation of Crystal violet (CV) and Congo red (CR) dyes under natural sunlight. The results showed that the degradation efficiency of CTO@S NCs was better than that of CTO NP in both dyes. Kinetics studies indicated CTO@S NCs fallowed Pseudo-first- order kinetics for CV degradation and pseudo-second-order kinetics for CR degradation.

ZnMnO3/Fe3O4 magnetic nanocomposites were fabricated via facile co-precipitation route and were calcined at 400 °C for 3 h. Synthesis of ZnMnO3/Fe3O4 magnetic nanocomposites were optimized by different weight percentages. Then, the as-synthesized sample was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), photoluminescence(PL), vibrating Sample Magnetometer (VSM), EDAX (Energy dispersive X-ray analysis), diffuse reflectance UV–Vis spectroscopy (DRS),ultraviolet–visible (UV–Vis) spectrometry, Bruner-Emmett-Teller (BET), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). Based on the results, elemental analyses of the samples were similar to those expected from the initial concentrations of the solutions used during synthesis. The x-ray diffraction pattern revealed that ZnMnO3/Fe3O4 has a cubic structure and average particle size of the catalyst was found 27.43 nm. In addition, Fourier transform infrared spectra could confirm the presence of hydroxyl group and Fe–O bond vibration in the catalyst. Further, the superparamagnetic behavior of the synthesized nanocomposite at room temperature was confirmed by VSM studies. Furthermore, the photocatalytic performance of ZnMnO3/Fe3O4 samples were evaluated based on the removal of Congo red (CR) in aqueous solution in 60 min of under visible light irradiation. The experiment demonstrated that 0.10 g of ZnMnO3/Fe3O4 nanocomposites can degrade (98.17%) 50 mg l−1 of Congo red (CR) solution. The mechanistic study using scavengers propose that the superoxide (O2·−) is the most reactive species involved in the photodegradation of organic dyes. The photocatalytic degradation of Congo red conformed the pseudo-first-order kinetic model and the rate constant achieved for 0.10 g l−1 of ZnMnO3/Fe3O4 was (k = 0.0384 min−1). Finally, the effect of reaction time, pH, and loading of ZnMnO3/Fe3O4 on degrading Congo red was studied. The synthesized ZnMnO3/Fe3O4 nanocomposite can be potentially applied as a magnetically separable photocatalyst to deal with water pollution problems.

In the present research, the mesoporous hydroxyapatite nanoparticles were synthesized by the chemical precipitation method in the absence and presence of different weight ratios (0, 0.1, and 0.3 g) of chitosan as an organic modifier. The effects of different weight ratios and pH values (8, 9, and 10) of chitosan on the structural characteristics of the mesoporous hydroxyapatite nanoparticles were also investigated. Then, all the prepared samples were calcined at 650 °C for 3 h and their structure, morphology, surface area, and pore size distribution were characterized by X-ray Diffraction (XRD) technique, Field Emission Scanning Electron and Transmission Electron Microscopy (FE-SEM & TEM), Fourier Transform Infrared spectroscopy (FT-IR), Energy Dispersive X-ray spectrometer (EDX), and finally Brunauer–Emmett–Teller (BET) technique. The XRD analysis showed that the crystalline size of the synthesized HA decreased from 38 to 24 nm at pH 8, 40 to 30 nm at pH 9 as well as from 48 to 32 nm at pH 10. The same trend of decrease in the crystalline size was observed when the chitosan concentration increased from 0.0 to 0.3 g. The results revealed that the crystalline size, pore size, and surface area of the synthesized HA can be controlled by adjusting the chitosan weight ratio in the initially prepared samples. Mesopores in HA were observed for the samples synthesized at different pH values, by removing the organic template. Furthermore, the pore size of the prepared chitosan/nHA samples was found to be 13–38 nm, which seems to be suitable for cell attachment and slow-release drug delivery, especially in treatment of osteoporosis.

In this paper, pH-sensitive magnetic hydrogels were prepared from carboxymethyl cellulose (CMC), β-cyclodextrin (β-CD) and chitosan (CS) without a toxic agent by a simple method as a new carrier for a controlled drug release. Magnetic (Fe3O4) nanoparticles were synthesized by chemical co-precipitation via in situ method under the presence of N2 gas. The effect of magnetic (Fe3O4) nanoparticles amounts on CMC, β-CD and CS hydrogel for drug delivery of Methotrexate (MTX) was investigated. The stability of hydrogel was evaluated using TGA, XRD, VSM, FT-IR, and FE-SEM measurements. The SEM images demonstrated the Fe3O4 distribution in the hydrogel, while XRD patterns confirmed the cubic crystalline phase of Fe3O4 nanoparticles. The hysteresis loop of low magnetic CMC/β-CD/CS hydrogel and high magnetic CMC/β-CD/CS hydrogel is 6.32 and 11.6 emug−1, respectively. The swelling manner of the CMC/β-CD/CS hydrogels was studied at a varied pH range 2–11. CMC/β-CD/CS hydrogel demonstrated slightly higher swelling amount as compared to magnetic CMC/β-CD/CS hydrogel. The prepared hydrogel showed a pH-sensitive swelling manner with great water-absorbing at pH 9. The maximum capacity of swelling in CMC/β-CD/CS hydrogel, low and high magnetic CMC/β-CD/CS hydrogels were obtained 8.8, 6.7 and 4.6 g g−1 respectively. In vitro, MTX release experiment was performed to attain the success of this new method of magnetic CMC/β-CD/CS hydrogel for drug delivery progress. The results showed that the release percent of CMC/β-CD/CS hydrogel was more significant than the other prepared hydrogel. The maximum drug release in CMC/β-CD/CS hydrogel, low and high magnetic CMC/β-CD/CS hydrogels were obtained 92.7, 80.4 and 58.3% at pH 7.4, respectively. Also, the MTX release investigated under an external alternating magnetic field (AMF). The studies illustrated that the response of hydrogel nanocomposite to external stimulants could be used for novel drug delivery systems.

Perovskites have been studied for several promising environmental field, but still challenging. We reported the successfully synthesis of the Zn-doped CdTiO3/TiO2 nanocomposites (ZDCT–NCPs) via the hydrothermal method. Characterization of the product was carried out by Fourier Transform Infra-Red spectroscopy (FT-IR), X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-ray Analysis (EDX). The photocatalytic properties of Zn-doped CdTiO3/TiO2 were studied by degradation of congo red (CR) under sunlight irradiation. The results reveal unique sunlight photocatalytic ability for the degradation of congo red (CR). The experimental demonstrated that 0.03 g of Zn-doped CdTiO3/TiO2 nanocomposites (ZDCT–NCPs) can degrade (up to 90% and 15 min) 50 cc of congo red (CR) solution.

Magnetic ZnFe2O4@MnO–graphene oxide and ZnFe2O4@MnO–reduced graphene oxide nanocomposites were prepared via a facile co-precipitation and hydrothermal methods and characterized by X-ray powder diffraction, diffuse reflectance UV–Vis spectroscopy, photoluminescence (PL) spectra, Transmission electron microscopy, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometry techniques and Bruner–Emmett–Teller (BET). The ZnFe2O4@MnO, ZnFe2O4@MnO–GO and ZnFe2O4@MnO–rGO nanoparticles were found to have a size of 20–40 nm and were spread out on the graphene oxide nanosheets and reduced graphene oxide nanosheets. Magnetic studies demonstrated that the ZnFe2O4@MnO–graphene oxide and ZnFe2O4@MnO–reduced graphene oxide nanocomposites can be easily separated from the solution by an external magnetic field. The photocatalytic degradation of Congo red dye (CR) was evaluated based on the removal of CR in aqueous solution in 35 min of visible light irradiation. The photocatalytic activity was affected by the structural and optical properties as well as the surface area of the samples. Compared with pure ZnFe2O4@MnO and ZnFe2O4@MnO–reduced graphene oxide nanocomposite, the ZnFe2O4@MnO–graphene oxide nanocomposite displayed a high photocatalytic activity on the photodegradation of Congo red. The prepared ZnFe2O4@MnO–graphene oxide nanocomposite can be potentially applied as a visible light responsive catalyst and magnetically separable photocatalyst and thus as a powerful separation tool for solving water pollution problems.

CdTiO3 was synthesized by hydrothermal method at low temperature of 180 °C for 24 h. CdTiO3@S composite with plate-like morphology was synthesized by mixing CdTiO3 and S powder under post-annealing at 600 °C for 2 h. The as-synthesized samples were investigated by techniques XRD, FE-SEM, EDS, TEM, FT-IR, TG-DSC, BET. The results showed that the synthesized of CdTiO3@S composite has led to the creation of defects and skew deviations in crystalline lattice. Optical properties and photocatalytic activity were studied using DRS and UV–Vis spectrophotometer. UV–Vis DRS indicated absorption peaks extended towards visible region. Band gap energy values were determined by Tauc plot for direct transitions which the values of 3.28 eV and 2.75 eV were obtained for CdTiO3 and CdTiO3@S respectively. Photocatalyst performance of CdTiO3 and CdTiO3@S were carried out for the degradation of crystal violet (CV) under natural sunlight. The results showed that the degradation efficiency of CdTiO3@S composite (99%) was better than that of pure CdTiO3 (35%), which is due to the presence of narrow band gap energy of CdTiO3@S. The effect of examining different photocatalytic parameters indicated that, photocatalytic activity of CdTiO3@S composite increases with decreasing CV dye concentration, increasing the photocatalyst dosage and in acidic pH. Kinetics studies have shown that the degradation of CV by the as-synthesized of photocatalysts follows the pseudo-first-order kinetics and the rate constant achieved for CdTiO3@S (k = 76.10−4 min−1) was much greater than of CdTiO3 (k = 4.10−4 min−1).

A Zn(II) complex with coumarin-hydrazone ligand, [ZnCl(HL)(CH3OH)0.76(H2O)0.24]·0.24(CH3OH) (1), was synthesized from the reaction of equimolar amount of ZnCl2·4H2O and (E)-2-hydroxy-N′-(1-(2-oxo-2H-chromen-3-yl)ethylidene)benzohydrazide (H2L) in methanol solvent. The complex was characterized by elemental analysis, spectroscopic methods and single crystal X-ray diffraction studies. Single crystal X-ray analysis indicated that the Zn(II) ion in complex 1 has a distorted square pyramidal environment and the coumarin-hydrazone ligand is coordinated as a mononegative tridentate ONO-donor ligand, (HL)−. The photoluminescent studies indicated that complex 1 has emission at about 470 nm. The catalytic potential of complex 1 was investigated for preparing tetrazole based compounds from the azide-nitrile cycloaddition reactions. The catalytic reactions were carried out in water as a green solvent. The results indicated that complex 1 is an active catalyst for preparing tetrazole compounds. The effects of temperature and electronic properties of the substituent connected to the nitrile group on the activity of this catalytic system were also considered.

CdTiO3 nano-structures were synthesized by hydrothermal method for 24 h@180 °C. It then was annealed at 450–1050 °C for 3 h and its effect was evaluated using XRD, FT-IR, TG-DSC, BET, FE-SEM, DRS, Raman, and EDS. Ilmenite phase was formed for. 180–850 °C. Transition to Perovskite occurred at 1050 °C. Direct band-gaps were determined by Tauc-plot which shows decrease with increased temperature. Photocatalyst performance evaluation of samples was done for degradation of Crystal violet dye under LED and sunlight. Degradation efficiency of CdTiO3-1050 °C was the best at both of LED/sunlight. Photoluminescence study shows a 400 nm excitation causes intense emission peaks at 478 nm (blue) and 530 nm (green).

Perovskite ZnTiO3 nanoparticles with the cubic structure were synthesized using the hydrothermal method at 160 °C for 12 h and annealed at 750 °C for 3 h. ZnTiO3@S NCs (nanocomposites) were prepared through solid-state reaction by ZnTiO3 and sulfur powders with different weight percentages (5–20%) at 550 °C for 2 h under Ar in the tube furnace. The crystal structure confirmation, morphology, purity, and surface chemical properties of the prepared samples were investigated by XRD, FT-IR, Fe-SEM, EDX, and BET analyses. The results revealed an increase in surface area, crystal size, and the presence of hierarchical porous in ZnTiO3@S NCs, which are due to the influence of sulfur in the ZnTiO3 structure. The optical properties and photocatalytic activity were evaluated by DRS and UV–Vis analysis, respectively. The band gap energy value obtained from the Tauc plots indicated that it narrowed with sulfur content elevation. The excellent photocatalytic activity of ZnTiO3@S NCs exhibited more than 93% degradation for the organic azo dyes of Crystal violet (CV) and Rhodamine B (RB) as a pollutant in 180 min under natural sunlight irradiation. The kinetic behaviors revealed that RB degradation follows the pseudo-first-order kinetic, according to R2 (0.9914), while the degradation of the CV follows the pseudo-second-order kinetic.

Gold coated magnetite core shell is a kind of nanoparticle that include magnetic iron oxide core with a thin layer nanogold. Fe3O4-gold core-shell nanostructure can be used in biomedical applications such as magnetic bioseparation, bioimaging, targeting drug delivery and cancer treatment. In this study, the synthesis and characterization of gold coated magnetite nanoparticles were discussed. Magnetite nanoparticles with an average size of 6 nm in diameter were synthesized by the chemical co-precipitation method and gold-coated Fe3O4 core-shell nanostructures were produced with an average size of 11.5 nm in diameter by reduction of Au(3+) with citrate ion in the presence of Fe3O4. Folate-conjugated gold coated magnetite nanoparticles were synthesized to targeting folate receptor that is overexpressed on the surface of cancerous cells. For this purpose, we used l-cysteine, as a bi-functional linker for attachment to gold surface and it was linked to the gold nanoparticles surface through its thiol group. Then, we conjugated amino-terminated nanoparticles to folic acid with an amide-linkage formation. These gold magnetic nanoparticles were characterized by various techniques such as X-ray powder diffraction (XRD) analysis, Fourier transform infrared spectrometer (FT-IR), UV-visible spectroscopy, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), dispersive analysis of X-ray (EDAX) and vibrating sample magnetometer (VSM) analysis. The magnetic and optical properties of Fe3O4 nanostructure were changed by gold coating and attachment of l-cysteine and folic acid to Fe3O4@Au nanoparticles.

Modified Fe 3 O 4 nanoparticles with (3-aminopropyl) triethoxysilane (APTES) were synthesized by post grafting method for loading the anti-inflammatory drug: (+)-(S)-2-(6- methoxynaphthalen-2-yl) propanoic acid -Naproxen and (RS) 2-(3-benzoylphenyl)-propionic acid -Ketoprofen. The prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FE- SEM), Energy Dispersive X-Ray Spectroscopy (EDX), Vibrating sample magnetometer (VSM), and Dynamic light scattering (DLS) diagrams. These nanoparticles have surface with free - NH2 groups can carry out ionic interaction with carboxylic groups and act as a carrier of drugs.

In the emphasis on knowledge as a key competitive factor in the global economy, corporations may be overlooking a major element customer knowledge. Customer knowledge management (CKM) creates new knowledge sharing platforms and processes between companies and their customers. Customer education is one of the best ways of Customer knowledge management. Despite companies growing interest for customer education and the recent awareness in marketing literature of this concept, research on customer education remains relatively scarce. In this research a model which details the relationships between customer education and customer satisfaction was proposed and validated for nanofood product. The existence of two mediating variables was unveiled: product usage and product-usage related knowledge and skills. The experimental fieldwork was conducted in partnership with nanofood companies and their customers. In this research, clear evidence has been provided that customer education positively impacts on customer satisfaction and that specific mechanisms explain such effects.

Magnetic oxide nanoparticles with proper surface coatings are increasingly being evaluated for clinical applications such as hyperthermia, drug delivery, magnetic resonance imaging, transfection and cell/protein separations. In this work, we investigated synthesis, magnetic properties of silica coated metal ferrite, (CoFe2O4)/SiO2 and manganese doped cobalt ferrite nanoparticles (Mnx-Co1-xFe2O4 with x = 0.02, 0.04 and 0.06)/SiO2 for possible biomedical application. All the ferrites nanoparticles were prepared by co-precipitation method using FeCl3.6H2O, CoCl2.6H2O and MnCl2.2H2O as precursors, and were silica coated by the Stober process in directly ethanol. The composition, phase structure and morphology of the prepared core/shell cobalt ferrites nanostructures were characterized by powder X-ray diffraction (XRD), Fourier Transform infra-red spectra (FTIR), Field Emission Scanning Electron Microscopy and energy dispersive X-ray analysis (FESEM-EDAX). The results revealed that all the samples maintain the ferrite spinel structure. While, the cell parameters decrease monotonically by increase of Mn content indicating that the Mn ions are substituted into the lattice of CoFe2O4. The magnetic properties of the prepared samples were investigated at room temperature using Vibrating Sample Magnetometer (VSM). The results revealed a strong dependence of room temperature magnetic properties on (1) doping content, x; (2) particle size and ion distributions.

In the past decade, preparation of low-dimensional semiconductor nanostructures has become a hotspot of materials research because of their attractive optical and electrical properties. Semiconductor nanoparticles have found wide spread application in varied fields of engineering. Since, p-type semiconductors, copper sulfides (Cu1.96S) were used in solar cells, optical filters and supersonic materials. In this work, we report on the synthesis of Cu1.96S semiconductor nanocomposites in the presence of PVP via a wet chemistry process and then covered by a layer of gold nanoparticles. Formation of a pure CuS phase, in the presence of a PVP nanostructure was confirmed by X-ray diffraction (XRD) analysis. Size and morphology of as-prepared nanostructure were studied using Transmission Electron Microscopic (TEM) images. The results revealed the formation of a dense Cu1.96S and roughly spherical nanoparticles with an average diameter of about 25-35 nm coated homogeneously with gold nanoparticle. Room temperature photoluminescence (PL) measurements of the prepared samples showed enhanced blue-green emission (350 to 600) nm and red emission from 600 to 800nm.

In this work, we report on the synthesis of superparamagnetic iron oxide nanoparticles at room temperature using microemulsion template phase consisting of cyclohexane, water, CTAB as cationic surfactant and butanol as a cosurfactant. Silica surface modification of the as-prepared nanoparticles was performed by adding TEOS directly to the alkaline medium. The structure, morphology, and magnetic properties of the products were characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM) at room temperature. The results revealed formation of iron oxide nanoparticles, with an average size of 8.8-12 nm, a superparamagnetism behavior with fast response to applied magnetic fields and zero remanence and coercivity.

In this paper, we report enhanced blue green emission of hexagonal shaped ZnO nanorods (NRS) grown via a simple hydrothermal method and silica coated then by using tetraethoxysilane (TEOS). The composition and structural characteristic of the prepared samples were studied by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy and Energy Dispersive X-ray analysis (FESEM-EDAX). The results revealed well crystallized hexagonal structure possessing a perfect and ideal growth habits of wurtzite zinc oxide grown along the [00 direction in preference in both the cases. Optical properties and quality of the prepared ZnO and silica coated ZnO nanorods were examined by UV-visible and FTIR spectroscopy. Photoluminescence (PL) spectra were used to study ZnO and silica coated ZnO nanorod electronic structure, which resulted in an obvious enhanced blue-green emission for ZnO nanorod and an intense red emission with a very low UV intensity for the silica coated nanorods. Appearance of intense red emission seems to be very promising since and it could favor more reliable fluorescence sensing in drug delivery fluorescent detection with a minor UV emission.

Immobilized enzymes enhance process robustness, allow longer duration of activity of enzymes, and re-use of the same enzymes in multiple cycles. Enzymes can be operated in the liquid form or immobilized on various supports. In this work, we prepared gold nanoparticle core-shell structure by assembling of the gold nanoparticles on the surface of amine-functionalized x-type zeolite and then used them for immobilization of the alkaline protease. Characterization of these assembled systems were carried out by UVvisible, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDAX). Biocatalytic activity of the alkaline protease in this bioconjugate system was examined and showed an increase in comparing with the free enzyme in solution.

Semiconductors have been suggested as ideal candidates for many electrical and optical applications and several groups have reported their successful synthesis in recent years. In particular, ZnS that is a direct wide band gap (3.91 eV) semiconductor and an important phosphor host lattice material, can be used in electroluminescent devices (ELD), due to its large band gap, which enables emission of visible light without absorption and efficient electron transport. In this work, we report synthesis and structural characteristics of gold covered core-shell nanometer size of ZnS/SiO2thin films as a patterning materials for use as a protective layer in optical phase change discs prepared through a simple sol-gel process. The results obtained by transmission electron microscopy (TEM) images showed that, as prepared core-shell materials were well-aligned nanoprticles grew in the same direction and through X-ray diffraction (XRD) analysis, we found that ZnS/SiO2core shell material was composed of crystalline ZnS core covered by an amorphous SiO2shell. Photoluminescence (PL) measurements performed on core-shell samples before and after gold coverig samples have provided information regarding stoichiometric vacancies or interstitial impurities and enhenced intensity of the green emission of ZnS nanowires at room temperature due to sheelding with SiO2.

Magnetic iron oxide nanoparticles with proper surface coatings are increasingly being evaluated for clinical applications such as hyperthermia, drug delivery, magnetic resonance imaging, transfection and cell/protein separations. In this work, silica coated iron oxide magnetic nanoparticles, which are very useful for delivering chemotherapeutic drugs, has been prepared by precipitation in an aqueous solution of iron (II) and iron (III) chlorides under basic condition. In this process, polyvinylpyrrolidone (PVP) has been used as a stablizer. Surface modifications of the as-prepared Fe3O4 Nps have been carried out by using tetraethoxysilane (TEOS). Silica coated nanoparticles have been characterized by Fourier transform infrared (FTIR) spectroscopy, Powder X- ray diffraction (XRD), Transmission electron microscopy (TEM) and Infrared (IR) spectroscopy

In this paper, we report preparation of hydrophilic hybrid nanocomposite coatings on glass substrates using Zinc acetate solutions based on 3-glycidoxypropyltrimethoxysilane (GPTMS), epoxy resin, aromatic amine (HY850), polyethylene glycol (PEG) and surfactant (polyoxyethylene(4)laurylether) by the sol-gel process. Furthermore, the effects of PEG addition to the precursor solutions on the hydrophilic property and microstructure of the resultant coating film were studied. The hydrophilic behavior study of the synthesized hybrid was performed by adding different amounts of polyethylene glycol precursor to the hybrid solution. Experimental results show that, among different amounts of PEGs, the best results are obtained by addition of PEGs (400) to the hybrid solution which can decrease the water contact angles down to 16 and using surfactant down to 0, and increase the free surface energy. Coated glass exhibits a higher strength than uncoated glass. Attenuated total reflectance infrared spectroscopic (ATR-IR) technique was used to characterize the structure of the hybrid films. The chemical structure of obtained network affects morphology of the coating. The morphology of the hybrid coatings was examined by transmission electron microscopy (TEM). The hybrid systems have a unit form structure and the inorganic phases were in the nanosize scale

The main goal of enzyme immobilization is industrial re-use of enzymes for many reaction cycles. In this purpose, simplicity and improvement of the enzyme properties have to be strongly associated with the design of protocols of enzyme immobilization. In the last decade, nanosized materials have been widely used as a support for enzyme immobilization, for instance, silica nanotubes, phospholipid bilayers, self-assembled monolayers Langmuir_Blodgett films, polymer matrices, galleries of alpha-zirconium, phosphate, mesoporous silicates such as MCM-41, silica nanoparticles. In this work, we report synthesis of core shell ZnO/SiO2 nanowires and used them as a support for immobilization of the alkaline protease. Characterization of this assembled systems was carried out by, Energy-dispersive X-ray spectroscopy (EDAX), Transmission electron microscopy (TEM) and Scanning electron microscopy (SEM). Biocatalytic activity of the alkaline protease in this bioconjugate system was examined and the results showed an increase of biocatalytic activity, in comparison with the free enzyme in solution.

In this work, we report enhancement of the stability and biocatalytic activities of the alkaline protease enzyme immobilized on a gold/TiO2 core-shell nanowires. Gold/TiO2 core-shell nanowires were firstly prepared by the sol-gel method using a mixture of aqueous solution of titanate and chloroauric acid (HAuCI4) under ambient temperature and atmospheric condition and calcined then. As prepared nanowire was found to have a good surface biocompatibility for immobilization of the alkaline protease enzyme. The results obtained in this work showed that alkaline protease immobilized on gold-TiO2 core shell is stable and bioactive at the alkaline pH and ambient temperature. The stability and the biocatalytic activity of the immobilized gold-TiO2 core shell nano composites were monitored by UV-visible spectroscopy. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and dispersive analysis of X-ray (EDAX) were used to characterize the size and morphology of the prepared materials.

In this work, Au–Ag nanoparticles (Au–Ag-bi-MNPs) have been prepared on amine functionalized Si-MCM-41 (NH 2 –Si-MCM-41) particles through a reduction of AgNO 3 and HAuCl 4 by NaBH 4 at ambient conditions. Au–Ag-bi-MNPs loaded on the NH2–Si-MCM-41, provide a good biocompatible surface for immobilization of the enzyme alkaline protease. This immobilization, presumably due to bonding between core shell nanoparticles and OH in serine 183 in alkaline protease seems to be of an ionic exchange nature. We found that the alkaline protease immobilized on the Au–Ag-bi-MNPs/Si-MCM-41 is an active biocatalyst, stable at different pH and temperature. The bio catalytic activity of free alkaline protease in solution was 64 U/mg (Units per milligram), whereas that of the alkaline protease immobilized on Au–Ag-bi-MNPs/Si-MCM-41 was 75 U/mg. This improvement of the biocatalytic activity may be due to a really increased activity per molecule of immobilized enzyme or to a purification of the enzyme. The alkaline protease molecules immobilized on the (Au–Ag)/ NH 2 -MCM-41 surface retained as much as 80% of the catalytic activity recorded at pH=8, and showed significant catalytic activity of alkaline protease in the bioconjugate material. The biocatalytic materials were easily separated from the reaction medium by mild centrifugation and exhibits excellent reuse and stability characteristics over four successive cycles. The optimum temperature ranged from 35 ∘ C–55 ∘ C and pH=8 for bioactivity of the alkaline protease in the assembly system was observed to be higher than that of the free enzyme in solution. The enzyme biocatalytic activity was monitored by UV-visible spectroscopy. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and dispersive analysis of X-RAY (EDAX) were used to characterize the size and morphology of the prepared materials.

Transparent mirror coated, SiO 2 –Ag/PV P nanocomposites were prepared on the Pyrex glass slides by dip-coating technique. Embedding of the silver (Ag) nanoparticles on silica modified polyvinyl pyrrolidone (PVP) was performed by the sol–gel method. As prepared transparent mirror coated SiO 2 –Ag/PV P nanocomposite films were finally characterized for surface morphology, chemistry, and nano size dimensions using various advanced analytical techniques including, UV visible, Fourier transform, infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), dispersive x-ray analaysis (EDAX) and transmission electron microscopy (TEM) analysis. It was found that all the prepared samples were almost uniform particles of Ag nanospheres of 7–8 nm diameters arranged as double paralleled nanowires with an average length of 200–450 nm and diameters of around 20–25 nm.

In recent years, nanosized mesoporous materials have received significant attention due to their impact in different processes. Several diverse applications of these materials, e.g. high density magnetic recording, magnetic fluids, magnetic refrigeration as well as in photocatalysis, solar cells, photosensors, have triggered considerable research activities in the area of nanotechnology. In this work, nanosize MCM-41 was synthesized and loaded then with TiO 2 using tetra butoxy titanium (TBT). As prepared TiO 2 loaded materials was investigated by using X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR). The photocatalytic activity of the prepared TiO 2 loaded MCM-41 was finally evaluated by the degradation of methyl orange under irradiation of UV light. The result showed that TiO 2 loaded on nanosize MCM-41 has higher photocatalytic activity than that of TiO 2 .

Enzymes are able to catalyze the most complex chemical processes under the mildest experimental and environmental conditions. However, in general, enzymes do not fulfill the requirements for industry. Therefore, most enzymes have to be greatly improved before industrial implementation. They may be immobilized by using very different protocols. Nanoparticles have been significantly used for coupling with biomolecules. They are excellent biocompatible surfaces for the immobilization of enzymes. In this work, we demonstrated that the alkaline protease enzyme immobilized on the TiO 2 nanoparticles assembled on the porous MCM-41 (Mobile Crystalline Material No. 41) particles could provide an active biocatalyst, stable at different pH and temperature. Absorption of the TiO 2 nanoparticles on the MCM-41 was monitored by UV–visible spectroscopy. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and dispersive analysis of X-RAY (EDAX) were used to characterize the size and morphology of the TiO 2 nanoparticles on the MCM-41.

A comparative study between hexachlorocyclotrisilane (1) and hexachlorocyclopropane (2) by ab initio method and natural bond orbital (NBO) analysis was carried out using 6-31G∗∗ basis set, implemented in GAUSSIAN 03 program. The s and p character of SiCl and Si–Si bonds obtained for the compounds were then used to examine the rehybridization effect from the strain energy. A higher strain energy in the former can be satisfactorily attributed to the weaker rehybridization capability of silicon relative to carbon in response to the angle strain such that SiCl bond strengthening is less effective. Strained XCl4 and X2Cl6 (X = C, Si) were used as models to show the rehybridization effect on the geometry and bond orbital energy.

Iron oxide magnetic nanoparticles have special properties such as stability, biocompatibility and high magnetic saturation that are used for bioapplications. To avoid aggregation of magnetic nanoparticles, their surface must be modified by coating materials. In this paper, we focused on synthesis of iron oxide (IO) nanoparticles with co-precipitation method and coating them with PVP, SiO2 and Au. The FT-IR, XRD, TEM, SEM and EDX show the surface modifications.

In recent years, more and more researchers are devoted themselves to studying nanocomposite hybrid materials. Since, the combination of different components in the nanosize range can yield new materials that may combine the advantages of each component and nanomaterials. Inorganic – organic hybrids nanocomposite materials is an example of this kind of materials, which have become a creative alternative with unusual features of the materials in industry. In fact, the art of combining dissimilar components to yield improved materials is not new. It goes way back to ancient construction materials like Adobe (Gomez-Romero et al., 2001). He used to build houses and buildings by a mixture made from the clay (inorganic) and straw (organic), where the straw was provided the mechanical properties for clay. However, the modern concept of hybrid materials goes way beyond the concept of a mixture between their components, actually falls between the concept of a mixture and a compound. A compound is formed by carrying out a chemical reaction between their components, where the properties of each part are eliminated to form a new material with different properties. In a mixture, a physical interaction between the components is involved. Whereas, the hybrid concept falls into a category where the interphase between their components is increased compared to a mixture, and their interactions will be at the molecular level (Judeinstein et al., 1996; Yacaman et al., 1996). The main idea in development of the hybrid materials was to take advantage of the best properties of each component that forms a hybrid, trying to decrease or eliminate their drawbacks getting in an ideal way a synergic effect; that results in the development of new materials with new properties. The first interest in the development of hybrid materials was mainly based on the design of hybrid polymers with special emphasis on structural hybrid materials. A variety of silicates, polysiloxanes etc. modified with organic groups or networks for improvement of mechanical properties, were the first type of hybrid materials investigated. The expectations for hybrid materials go further than mechanical strength, such as thermal and chemical stability. Magnetic hybrids (tricarboxilic substituted radical and Cu ions), Electronic hybrids used in electronics (transistors, diodes), and Functional Hybrids.