Ilana Perelshtein | Bar-Ilan University (original) (raw)

Papers by Ilana Perelshtein

Research paper thumbnail of Eradication of multi-drug resistant bacteria by a novel Zn-doped CuO nanocomposite

Small (Weinheim an der Bergstrasse, Germany), Jan 9, 2013

Zinc-doped copper oxide nanoparticles are synthesized and simultaneously deposited on cotton fabr... more Zinc-doped copper oxide nanoparticles are synthesized and simultaneously deposited on cotton fabric using ultrasound irradiation. The optimization of the processing conditions, the specific reagent ratio, and the precursor concentration results in the formation of uniform nanoparticles with an average size of ≈30 nm. The antibacterial activity of the Zn-doped CuO Cu₀.₈₈Zn₀.₁₂O in a colloidal suspension or deposited on the fabric is tested against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) bacteria. A substantial enhancement of 10,000 times in the antimicrobial activity of the Zn-CuO nanocomposite compared to the pure CuO and ZnO nanoparticles (NPs) is observed after 10 min exposure to the bacteria. Similar activities are observed against multidrug-resistant bacteria (MDR), (i.e., Methicillin-resistant S. aureus and MDR E. coli) further emphasizing the efficacy of this composite. Finally, the mechanism for this enhanced antibacterial activity is presen...

Research paper thumbnail of 1. Coating antibacterial nanoparticles on textiles: Towards the future hospital in which all textiles will be antibacterial

Synthesis and Characterization, 2013

Research paper thumbnail of Electrochemical reduction of trinitrotoluene on core–shell tin–carbon electrodes

Electrochimica Acta, 2008

In this work, we studied the electrochemical process of 2,4,6-trinitrotoluene (TNT) reduction on ... more In this work, we studied the electrochemical process of 2,4,6-trinitrotoluene (TNT) reduction on a new type of electrodes based on a core–shell tin–carbon Sn(C) structure. The Sn(C) composite was prepared from the precursor tetramethyl-tin Sn(CH3)4, and the product contained a core of submicron-sized tin particles uniformly enveloped with carbon shells. Cyclic voltammograms of Sn(C) electrodes in aqueous sodium chloride solutions

Research paper thumbnail of A novel sonochemical synthesis of antlerite nanorods

Ultrasonics sonochemistry, 2015

Antlerite - Cu3(OH)4SO4 was prepared, for the first time, by the sonochemical method from an aque... more Antlerite - Cu3(OH)4SO4 was prepared, for the first time, by the sonochemical method from an aqueous solution of CuSO4, without any additives. The source of OH(-) is a result of protonation of SO4(2-) forming HSO4(-) and OH(-). The extreme local conditions inside the cavity that are developed during the bubble collapse (pressure is above 1000atm and the temperature is higher than 5000K) lead to the formation of the crystalline mineral. A suggested mechanism for the mineral formation is proposed. Due to the collapse of the bubbles, the distances between the opposite charge Cu(2+) and SO4(2-) ions is shortened and a crystallization process is initiated. In addition, the reaction is a one-step process with short irradiation time of less than 30min. The chemo-physical analysis of the sonochemically obtained product has revealed the presence of single phase antlerite nanorods.

Research paper thumbnail of Toxicity Evaluation of a New Zn-doped CuO Nanocomposite with Highly Effective Antibacterial Properties

Toxicological sciences : an official journal of the Society of Toxicology, Jan 26, 2015

The increased resistances to conventional antibiotics determine a strong need for new antibacteri... more The increased resistances to conventional antibiotics determine a strong need for new antibacterials, and specific syntheses at the nanoscale promise to be helpful in this field. A novel Zinc-doped Copper oxide nanocomposite (nZn-CuO) has been recently sonochemically synthesized and successfully tested also against multi-drug resistant bacteria. After synthesis and characterization of the physico-chemical properties, the new nZn-CuO is here evaluated by the Frog Embyo Teratogenesis Assay-Xenopus (FETAX) test for its toxicological potential and this compared with that of nCuO and nZnO synthesized under the same conditions. No lethal effects are observed, while malformations and growth retardation slightly increase after nZn-CuO exposure. Nevertheless, these effects are smaller than those of nZnO. NP uptake by embryo tissues increase significantly with increasing NP concentrations, while no significant accumulation and adverse effects are seen after exposure to soluble Cu(2+) and Zn(2...

Research paper thumbnail of Making the hospital a safer place by sonochemical coating of all its textiles with antibacterial nanoparticles

Ultrasonics sonochemistry, 2015

The ability to scale-up the sonochemical coating of medical textiles with antibacterial nanoparti... more The ability to scale-up the sonochemical coating of medical textiles with antibacterial nanoparticles is demonstrated in the current paper. A roll-to-roll pilot installation to coat textiles was built taking into consideration the requirements of the sonochemical process. A long-run experiment was conducted in which 2500m of fabric were coated with antibacterial ZnO nanoparticles (NPs). The metal oxide NPs were deposited from an ethanol:water solution. In this continuous process a uniform concentration of coated NPs over the length/width of the fabric was achieved. The antibacterial efficiency of the sonochemically-coated textiles was validated in a hospital environment by a reduction in the occurrence of nosocomial infections. NP-coated bed sheets, patient gowns, pillow cover, and bed covers were used by 21 patients. For comparison 16 patients used regular textiles. The clinical data indicated the reduced occurrence of hospital-acquired infections when using the metal oxide NP-coat...

Research paper thumbnail of Structural, magnetic, electrical and electrochemical properties of NiFe2O4 synthesized by the molten salt technique

Research paper thumbnail of An ultrasonic technology for production of antibacterial nanomaterials and their coating on textiles

Beilstein journal of nanotechnology, 2014

A method for the production of antibacterial ZnO nanoparticles has been developed. The technique ... more A method for the production of antibacterial ZnO nanoparticles has been developed. The technique combines passing an electric current with simultaneous application of ultrasonic waves. By using high-power ultrasound a cavitation zone is created between two zinc electrodes. This leads to the possibility to create a spatial electrical discharge in water. Creation of such discharge leads to the depletion of the electrodes and the formation of ZnO nanoparticles, which demonstrate antibacterial properties. At the end of this reaction the suspension of ZnO nanoparticles is transported to a specially developed ultrasonic reactor, in which the nanoparticles are deposited on the textile. The nanoparticles are embedded into the fibres by the cavitation jets, which are formed by asymmetrically collapsing bubbles in the presence of a solid surface and are directed towards the surface of textile at very high velocities. Fabrics coated with ZnO nanoparticles by using the developed method showed g...

Research paper thumbnail of Tannic acid NPs – Synthesis and immobilization onto a solid surface in a one-step process and their antibacterial and anti-inflammatory properties

Ultrasonics Sonochemistry, 2014

Tannic acid nanoparticles were synthesized from an aqueous solution without the use of stabilizer... more Tannic acid nanoparticles were synthesized from an aqueous solution without the use of stabilizers via a sonochemical process. In order to avoid the dissolution of the formed nanoparticles, the sonochemical reaction was performed in the presence of a cotton fabric: following their formation, the tannic acid nanoparticles were embedded into the cotton substrate in a one-step process. The bioactive properties of the tannic acid coated surface were examined towards the inhibition of myeloperoxidase and collagenase, two major enzymes related with inflammatory processes. In addition, the antibacterial activity of the tannic acid nanoparticles coated textiles was evaluated against Staphylococcus aureus and Pseudomonas aeruginosa.

Research paper thumbnail of Pilot scale sonochemical coating of nanoparticles onto textiles to produce biocidal fabrics

Surface and Coatings Technology, 2009

The pilot installation is designed for the scale up of sonochemically assisted coating of textile... more The pilot installation is designed for the scale up of sonochemically assisted coating of textile fabrics with various kinds of nanoparticles. The installation can coat up to 50 m of continuous cotton fabric per run with CuO or ZnO nanoparticles. The structure and morphology of the metal oxides adhering to the fabric on the coated cotton have been characterized by XRD and HR SEM, and shown to be nanocrystalline oxides (~10-20 nm in size). The coating is homogeneous, stable and retains its biocidal properties through at least 20 washing cycles. The CuO-cotton bandages demonstrated good antimicrobial properties against E. coli bacteria.

Research paper thumbnail of Sonochemical coating of silver nanoparticles on textile fabrics (nylon, polyester and cotton) and their antibacterial activity

Nanotechnology, 2008

Silver nanoparticles were synthesized and deposited on different types of fabrics using ultrasoun... more Silver nanoparticles were synthesized and deposited on different types of fabrics using ultrasound irradiation. The structure of silver-fabric composites was studied by physico-chemical methods. The mechanism of the strong adhesion of silver nanoparticles to the fibers is discussed. The excellent antibacterial activity of the Ag-fabric composite against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) cultures was demonstrated.

Research paper thumbnail of Air stable core–shell multilayer metallic nanoparticles synthesized by RAPET: fabrication, characterization and suggested applications

Journal of Materials Chemistry, 2012

ABSTRACT We have developed a novel synthesis of carbon coated Cu@Ag and Ag@Cu core–shell nanopart... more ABSTRACT We have developed a novel synthesis of carbon coated Cu@Ag and Ag@Cu core–shell nanoparticles by a rapid, cheap, solvent-less and straightforward method of fabrication. The technique by which these composites are prepared is called RAPET (Reaction under Autogenic Pressure at Elevated Temperatures). The X-ray diffraction measurements confirm the presence of two separated phases – silver and copper – and negate the possibility of alloy formation. Elemental mapping obtained by electron energy-loss spectroscopy (EELS) and line-scan analysis confirm the core–shell structure. Colloidal suspensions of Cu@Ag@C nanostructures were prepared and their stability was examined by dynamic light scattering (DLS) measurements. The mechanism of formation of the multilayer nanostructures is discussed here.

Research paper thumbnail of A One-Step Process for the Antimicrobial Finishing of Textiles with Crystalline TiO2 Nanoparticles

Chemistry - A European Journal, 2012

Titanium oxide (TiO(2)) nanoparticles (NPs) in their two forms, anatase and rutile, were synthesi... more Titanium oxide (TiO(2)) nanoparticles (NPs) in their two forms, anatase and rutile, were synthesized and deposited onto the surface of cotton fabrics by using ultrasonic irradiation. The structure and morphology of the nanoparticles were analyzed by using characterization methods such as XRD, TEM, STEM, and EDS. The antimicrobial activities of the TiO(2)-cotton composites were tested against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) strains, as well as against Candida albicans. Significant antimicrobial effect was observed, mainly against Staphylococcus aureus. In addition, the combination of visible light and TiO(2) NPs showed enhanced antimicrobial activity.

Research paper thumbnail of One-Step Solvent-Free Synthesis and Characterization of Zn1−xMnxSe@C Nanorods and Nanowires

Advanced Functional Materials, 2008

The carbon-encapsulated, Mn-doped ZnSe (Zn 1Àx Mn x Se@C) nanowires, nanorods, and nanoparticles ... more The carbon-encapsulated, Mn-doped ZnSe (Zn 1Àx Mn x Se@C) nanowires, nanorods, and nanoparticles are synthesized by the solvent-free, one-step RAPET (reactions under autogenic pressure at elevated temperature) approach. The aspect ratio of the nanowires/nanorods is altered according to the Mn/Zn atomic ratio, with the maximum being observed for Mn/Zn ¼ 1:20. A 10-20 nm amorphous carbon shell is evidenced from electron microscopy analysis. The replacement of Zn by Mn in the Zn 1Àx Mn x Se lattice is confirmed by the hyperfine splitting values in the electron paramagnetic resonance (EPR) experiments. Raman experiments reveal that the Zn 1Àx Mn x Se core is highly crystalline, while the shell consists of disordered graphitic carbon. Variable-temperature cathodoluminescence measurements are performed for all samples and show distinct ZnSe near-band-edge and Mn-related emissions. An intense and broad Mn-related emission at the largest Mn alloy composition of 19.9% is further consistent with an efficient incorporation of Mn within the host ZnSe lattice. The formation of the core/shell nanowires and nanorods in the absence of any template or structure-directing agent is controlled kinetically by the Zn 1Àx Mn x Se nucleus formation and subsequent carbon encapsulation. Mn replaces Zn mainly in the (111) plane and catalyzes the nanowire growth in the [111] direction.

Research paper thumbnail of Sonochemical synthesis, structural, magnetic and grain size dependent electrical properties of NdVO4 nanoparticles

NdVO 4 nanoparticles are successfully synthesized by efficient sonochemical method using two diff... more NdVO 4 nanoparticles are successfully synthesized by efficient sonochemical method using two different structural directing agents like CTAB and P123. The phase formation and functional group analysis are carried out using X-ray diffraction (XRD) and fourier transform infra red (FT-IR) spectra, respectively. Using Scherrer equation the calculated grain sizes are 27 nm, 24 nm and 20 nm corresponding to NdVO 4 synthesized by without surfactant, with CTAB and P123, respectively. The TEM images revealed that the shape of NdVO 4 particles is rice-like and rod shaped particles while using CTAB and P123 as surfactants. The growth mechanism of NdVO 4 nanoparticles is elucidated with the aid of TEM analysis. From electrical analysis, the conductivity of NdVO 4 nanoparticles synthesized without surfactant showed a higher conductivity of 5.5703 Â 10 À6 S cm À1 . The conductivity of the material depends on grain size and increased with increase in grain size due to the grain size effect. The magnetic measurements indicated the paramagnetic behavior of NdVO 4 nanoparticles.

Research paper thumbnail of Antibacterial Properties of an In Situ Generated and Simultaneously Deposited Nanocrystalline ZnO on Fabrics

ACS Applied Materials & Interfaces, 2009

Zinc oxide (ZnO) nanoparticles were synthesized and deposited on the surface of cotton fabrics us... more Zinc oxide (ZnO) nanoparticles were synthesized and deposited on the surface of cotton fabrics using ultrasound irradiation. Optimization of the process resulted in a homogeneous distribution of ZnO nanocrystals, 30 nm in size, on the fabric surface. The mechanism of the ultrasound-assisted coating was proposed. The antibacterial activities of the ZnO-fabric composite were tested against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) cultures. A significant bactericidal effect, even in a 0.75% coated fabric (wt %), was demonstrated.

Research paper thumbnail of Ultrasound Radiation as a “Throwing Stones” Technique for the Production of Antibacterial Nanocomposite Textiles

ACS Applied Materials & Interfaces, 2010

Ultrasound irradiation was applied as a "throwing stones" technique for coating... more Ultrasound irradiation was applied as a "throwing stones" technique for coating cotton bandages with MgO and Al(2)O(3) commercially obtained nanoparticles. The homogeneous distribution of the nanoparticles without any aggregation on the fabrics was demonstrated. The antibacterial activities of the MgO/Al(2)O(3)-fabric nanocomposite were tested against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) cultures. A significant bactericidal effect, even in a concentration <1% (by weight), was detected.

Research paper thumbnail of Eradication of multi-drug resistant bacteria by a novel Zn-doped CuO nanocomposite

Small (Weinheim an der Bergstrasse, Germany), Jan 9, 2013

Zinc-doped copper oxide nanoparticles are synthesized and simultaneously deposited on cotton fabr... more Zinc-doped copper oxide nanoparticles are synthesized and simultaneously deposited on cotton fabric using ultrasound irradiation. The optimization of the processing conditions, the specific reagent ratio, and the precursor concentration results in the formation of uniform nanoparticles with an average size of ≈30 nm. The antibacterial activity of the Zn-doped CuO Cu₀.₈₈Zn₀.₁₂O in a colloidal suspension or deposited on the fabric is tested against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) bacteria. A substantial enhancement of 10,000 times in the antimicrobial activity of the Zn-CuO nanocomposite compared to the pure CuO and ZnO nanoparticles (NPs) is observed after 10 min exposure to the bacteria. Similar activities are observed against multidrug-resistant bacteria (MDR), (i.e., Methicillin-resistant S. aureus and MDR E. coli) further emphasizing the efficacy of this composite. Finally, the mechanism for this enhanced antibacterial activity is presen...

Research paper thumbnail of 1. Coating antibacterial nanoparticles on textiles: Towards the future hospital in which all textiles will be antibacterial

Synthesis and Characterization, 2013

Research paper thumbnail of Electrochemical reduction of trinitrotoluene on core–shell tin–carbon electrodes

Electrochimica Acta, 2008

In this work, we studied the electrochemical process of 2,4,6-trinitrotoluene (TNT) reduction on ... more In this work, we studied the electrochemical process of 2,4,6-trinitrotoluene (TNT) reduction on a new type of electrodes based on a core–shell tin–carbon Sn(C) structure. The Sn(C) composite was prepared from the precursor tetramethyl-tin Sn(CH3)4, and the product contained a core of submicron-sized tin particles uniformly enveloped with carbon shells. Cyclic voltammograms of Sn(C) electrodes in aqueous sodium chloride solutions

Research paper thumbnail of A novel sonochemical synthesis of antlerite nanorods

Ultrasonics sonochemistry, 2015

Antlerite - Cu3(OH)4SO4 was prepared, for the first time, by the sonochemical method from an aque... more Antlerite - Cu3(OH)4SO4 was prepared, for the first time, by the sonochemical method from an aqueous solution of CuSO4, without any additives. The source of OH(-) is a result of protonation of SO4(2-) forming HSO4(-) and OH(-). The extreme local conditions inside the cavity that are developed during the bubble collapse (pressure is above 1000atm and the temperature is higher than 5000K) lead to the formation of the crystalline mineral. A suggested mechanism for the mineral formation is proposed. Due to the collapse of the bubbles, the distances between the opposite charge Cu(2+) and SO4(2-) ions is shortened and a crystallization process is initiated. In addition, the reaction is a one-step process with short irradiation time of less than 30min. The chemo-physical analysis of the sonochemically obtained product has revealed the presence of single phase antlerite nanorods.

Research paper thumbnail of Toxicity Evaluation of a New Zn-doped CuO Nanocomposite with Highly Effective Antibacterial Properties

Toxicological sciences : an official journal of the Society of Toxicology, Jan 26, 2015

The increased resistances to conventional antibiotics determine a strong need for new antibacteri... more The increased resistances to conventional antibiotics determine a strong need for new antibacterials, and specific syntheses at the nanoscale promise to be helpful in this field. A novel Zinc-doped Copper oxide nanocomposite (nZn-CuO) has been recently sonochemically synthesized and successfully tested also against multi-drug resistant bacteria. After synthesis and characterization of the physico-chemical properties, the new nZn-CuO is here evaluated by the Frog Embyo Teratogenesis Assay-Xenopus (FETAX) test for its toxicological potential and this compared with that of nCuO and nZnO synthesized under the same conditions. No lethal effects are observed, while malformations and growth retardation slightly increase after nZn-CuO exposure. Nevertheless, these effects are smaller than those of nZnO. NP uptake by embryo tissues increase significantly with increasing NP concentrations, while no significant accumulation and adverse effects are seen after exposure to soluble Cu(2+) and Zn(2...

Research paper thumbnail of Making the hospital a safer place by sonochemical coating of all its textiles with antibacterial nanoparticles

Ultrasonics sonochemistry, 2015

The ability to scale-up the sonochemical coating of medical textiles with antibacterial nanoparti... more The ability to scale-up the sonochemical coating of medical textiles with antibacterial nanoparticles is demonstrated in the current paper. A roll-to-roll pilot installation to coat textiles was built taking into consideration the requirements of the sonochemical process. A long-run experiment was conducted in which 2500m of fabric were coated with antibacterial ZnO nanoparticles (NPs). The metal oxide NPs were deposited from an ethanol:water solution. In this continuous process a uniform concentration of coated NPs over the length/width of the fabric was achieved. The antibacterial efficiency of the sonochemically-coated textiles was validated in a hospital environment by a reduction in the occurrence of nosocomial infections. NP-coated bed sheets, patient gowns, pillow cover, and bed covers were used by 21 patients. For comparison 16 patients used regular textiles. The clinical data indicated the reduced occurrence of hospital-acquired infections when using the metal oxide NP-coat...

Research paper thumbnail of Structural, magnetic, electrical and electrochemical properties of NiFe2O4 synthesized by the molten salt technique

Research paper thumbnail of An ultrasonic technology for production of antibacterial nanomaterials and their coating on textiles

Beilstein journal of nanotechnology, 2014

A method for the production of antibacterial ZnO nanoparticles has been developed. The technique ... more A method for the production of antibacterial ZnO nanoparticles has been developed. The technique combines passing an electric current with simultaneous application of ultrasonic waves. By using high-power ultrasound a cavitation zone is created between two zinc electrodes. This leads to the possibility to create a spatial electrical discharge in water. Creation of such discharge leads to the depletion of the electrodes and the formation of ZnO nanoparticles, which demonstrate antibacterial properties. At the end of this reaction the suspension of ZnO nanoparticles is transported to a specially developed ultrasonic reactor, in which the nanoparticles are deposited on the textile. The nanoparticles are embedded into the fibres by the cavitation jets, which are formed by asymmetrically collapsing bubbles in the presence of a solid surface and are directed towards the surface of textile at very high velocities. Fabrics coated with ZnO nanoparticles by using the developed method showed g...

Research paper thumbnail of Tannic acid NPs – Synthesis and immobilization onto a solid surface in a one-step process and their antibacterial and anti-inflammatory properties

Ultrasonics Sonochemistry, 2014

Tannic acid nanoparticles were synthesized from an aqueous solution without the use of stabilizer... more Tannic acid nanoparticles were synthesized from an aqueous solution without the use of stabilizers via a sonochemical process. In order to avoid the dissolution of the formed nanoparticles, the sonochemical reaction was performed in the presence of a cotton fabric: following their formation, the tannic acid nanoparticles were embedded into the cotton substrate in a one-step process. The bioactive properties of the tannic acid coated surface were examined towards the inhibition of myeloperoxidase and collagenase, two major enzymes related with inflammatory processes. In addition, the antibacterial activity of the tannic acid nanoparticles coated textiles was evaluated against Staphylococcus aureus and Pseudomonas aeruginosa.

Research paper thumbnail of Pilot scale sonochemical coating of nanoparticles onto textiles to produce biocidal fabrics

Surface and Coatings Technology, 2009

The pilot installation is designed for the scale up of sonochemically assisted coating of textile... more The pilot installation is designed for the scale up of sonochemically assisted coating of textile fabrics with various kinds of nanoparticles. The installation can coat up to 50 m of continuous cotton fabric per run with CuO or ZnO nanoparticles. The structure and morphology of the metal oxides adhering to the fabric on the coated cotton have been characterized by XRD and HR SEM, and shown to be nanocrystalline oxides (~10-20 nm in size). The coating is homogeneous, stable and retains its biocidal properties through at least 20 washing cycles. The CuO-cotton bandages demonstrated good antimicrobial properties against E. coli bacteria.

Research paper thumbnail of Sonochemical coating of silver nanoparticles on textile fabrics (nylon, polyester and cotton) and their antibacterial activity

Nanotechnology, 2008

Silver nanoparticles were synthesized and deposited on different types of fabrics using ultrasoun... more Silver nanoparticles were synthesized and deposited on different types of fabrics using ultrasound irradiation. The structure of silver-fabric composites was studied by physico-chemical methods. The mechanism of the strong adhesion of silver nanoparticles to the fibers is discussed. The excellent antibacterial activity of the Ag-fabric composite against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) cultures was demonstrated.

Research paper thumbnail of Air stable core–shell multilayer metallic nanoparticles synthesized by RAPET: fabrication, characterization and suggested applications

Journal of Materials Chemistry, 2012

ABSTRACT We have developed a novel synthesis of carbon coated Cu@Ag and Ag@Cu core–shell nanopart... more ABSTRACT We have developed a novel synthesis of carbon coated Cu@Ag and Ag@Cu core–shell nanoparticles by a rapid, cheap, solvent-less and straightforward method of fabrication. The technique by which these composites are prepared is called RAPET (Reaction under Autogenic Pressure at Elevated Temperatures). The X-ray diffraction measurements confirm the presence of two separated phases – silver and copper – and negate the possibility of alloy formation. Elemental mapping obtained by electron energy-loss spectroscopy (EELS) and line-scan analysis confirm the core–shell structure. Colloidal suspensions of Cu@Ag@C nanostructures were prepared and their stability was examined by dynamic light scattering (DLS) measurements. The mechanism of formation of the multilayer nanostructures is discussed here.

Research paper thumbnail of A One-Step Process for the Antimicrobial Finishing of Textiles with Crystalline TiO2 Nanoparticles

Chemistry - A European Journal, 2012

Titanium oxide (TiO(2)) nanoparticles (NPs) in their two forms, anatase and rutile, were synthesi... more Titanium oxide (TiO(2)) nanoparticles (NPs) in their two forms, anatase and rutile, were synthesized and deposited onto the surface of cotton fabrics by using ultrasonic irradiation. The structure and morphology of the nanoparticles were analyzed by using characterization methods such as XRD, TEM, STEM, and EDS. The antimicrobial activities of the TiO(2)-cotton composites were tested against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) strains, as well as against Candida albicans. Significant antimicrobial effect was observed, mainly against Staphylococcus aureus. In addition, the combination of visible light and TiO(2) NPs showed enhanced antimicrobial activity.

Research paper thumbnail of One-Step Solvent-Free Synthesis and Characterization of Zn1−xMnxSe@C Nanorods and Nanowires

Advanced Functional Materials, 2008

The carbon-encapsulated, Mn-doped ZnSe (Zn 1Àx Mn x Se@C) nanowires, nanorods, and nanoparticles ... more The carbon-encapsulated, Mn-doped ZnSe (Zn 1Àx Mn x Se@C) nanowires, nanorods, and nanoparticles are synthesized by the solvent-free, one-step RAPET (reactions under autogenic pressure at elevated temperature) approach. The aspect ratio of the nanowires/nanorods is altered according to the Mn/Zn atomic ratio, with the maximum being observed for Mn/Zn ¼ 1:20. A 10-20 nm amorphous carbon shell is evidenced from electron microscopy analysis. The replacement of Zn by Mn in the Zn 1Àx Mn x Se lattice is confirmed by the hyperfine splitting values in the electron paramagnetic resonance (EPR) experiments. Raman experiments reveal that the Zn 1Àx Mn x Se core is highly crystalline, while the shell consists of disordered graphitic carbon. Variable-temperature cathodoluminescence measurements are performed for all samples and show distinct ZnSe near-band-edge and Mn-related emissions. An intense and broad Mn-related emission at the largest Mn alloy composition of 19.9% is further consistent with an efficient incorporation of Mn within the host ZnSe lattice. The formation of the core/shell nanowires and nanorods in the absence of any template or structure-directing agent is controlled kinetically by the Zn 1Àx Mn x Se nucleus formation and subsequent carbon encapsulation. Mn replaces Zn mainly in the (111) plane and catalyzes the nanowire growth in the [111] direction.

Research paper thumbnail of Sonochemical synthesis, structural, magnetic and grain size dependent electrical properties of NdVO4 nanoparticles

NdVO 4 nanoparticles are successfully synthesized by efficient sonochemical method using two diff... more NdVO 4 nanoparticles are successfully synthesized by efficient sonochemical method using two different structural directing agents like CTAB and P123. The phase formation and functional group analysis are carried out using X-ray diffraction (XRD) and fourier transform infra red (FT-IR) spectra, respectively. Using Scherrer equation the calculated grain sizes are 27 nm, 24 nm and 20 nm corresponding to NdVO 4 synthesized by without surfactant, with CTAB and P123, respectively. The TEM images revealed that the shape of NdVO 4 particles is rice-like and rod shaped particles while using CTAB and P123 as surfactants. The growth mechanism of NdVO 4 nanoparticles is elucidated with the aid of TEM analysis. From electrical analysis, the conductivity of NdVO 4 nanoparticles synthesized without surfactant showed a higher conductivity of 5.5703 Â 10 À6 S cm À1 . The conductivity of the material depends on grain size and increased with increase in grain size due to the grain size effect. The magnetic measurements indicated the paramagnetic behavior of NdVO 4 nanoparticles.

Research paper thumbnail of Antibacterial Properties of an In Situ Generated and Simultaneously Deposited Nanocrystalline ZnO on Fabrics

ACS Applied Materials & Interfaces, 2009

Zinc oxide (ZnO) nanoparticles were synthesized and deposited on the surface of cotton fabrics us... more Zinc oxide (ZnO) nanoparticles were synthesized and deposited on the surface of cotton fabrics using ultrasound irradiation. Optimization of the process resulted in a homogeneous distribution of ZnO nanocrystals, 30 nm in size, on the fabric surface. The mechanism of the ultrasound-assisted coating was proposed. The antibacterial activities of the ZnO-fabric composite were tested against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) cultures. A significant bactericidal effect, even in a 0.75% coated fabric (wt %), was demonstrated.

Research paper thumbnail of Ultrasound Radiation as a “Throwing Stones” Technique for the Production of Antibacterial Nanocomposite Textiles

ACS Applied Materials & Interfaces, 2010

Ultrasound irradiation was applied as a "throwing stones" technique for coating... more Ultrasound irradiation was applied as a "throwing stones" technique for coating cotton bandages with MgO and Al(2)O(3) commercially obtained nanoparticles. The homogeneous distribution of the nanoparticles without any aggregation on the fabrics was demonstrated. The antibacterial activities of the MgO/Al(2)O(3)-fabric nanocomposite were tested against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) cultures. A significant bactericidal effect, even in a concentration <1% (by weight), was detected.