Silver nanoparticles of mean size 16 nm were synthesized by inert gas condensation （IGC） method. Crystalline structure, morphology and nanoparticles size estimation were conducted by X-ray diffraction （XRD） and tr...Silver nanoparticles of mean size 16 nm were synthesized by inert gas condensation （IGC） method. Crystalline structure, morphology and nanoparticles size estimation were conducted by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. Antibacterial activity of these silver nanoparticles as a function of particles concentration against gram-negative bacterium Escherichia coli （E. coli） was carried out in liquid as well as solid growth media. Scanning electron microscopy （SEM） and TEM studies showed that silver nanoparticles after interaction with E.coli have adhered to and penetrated into the bacterial cells. Antibacterial properties of silver nanoparticles are attributed to their total surface area, as a larger surface to volume ratio of nanoparticles provides more efficient means for enhanced antibacterial activity.展开更多
Designing and synthesis of cost effective bulk metallic glasses （BMGs） has been of considerable interest during the last decade so that they can be made commercially viable. Among these, Zr-based BMGs have been repo...Designing and synthesis of cost effective bulk metallic glasses （BMGs） has been of considerable interest during the last decade so that they can be made commercially viable. Among these, Zr-based BMGs have been reported extensively due to their attractive properties, An alloy having composition Zr65Cu18Ni9A18 was designed and synthesized using 2-3 N pure materials by Cu mould casting. The alloy was characterized by X- ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive X-ray spectroscopy （EDS） and high temperature differential scanning calorimetry （DSC）. Thermal parameters like supercooled liquid region △Tx, reduced glass transition temperature Trg, γ and δ parameters were evaluated. Mechanical properties like microhardness, nanohardness, elastic modulus and fracture strength were measured. The alloy showed wide supercooled liquid region of 129＋1 K with improved thermal stability. The alloy has considerable fracture strength along with fair amount of ductility.展开更多
The adherent thermal layering was undertaken by chemical vapor deposition （CVD） method using saturated solution of boric acid in ultra pure CH3OH. The influence of temperature was studied by varying temperature from...The adherent thermal layering was undertaken by chemical vapor deposition （CVD） method using saturated solution of boric acid in ultra pure CH3OH. The influence of temperature was studied by varying temperature from 100 to 600℃ during the process of boron deposition. The most optimum temperature was found to be 200℃. The effect of time span was observed from 6 to 120 h. The generation of micro or nano-scale thickness could be achieved by reducing time span of the experiment. The behavior of CVD was characterized by using scanning electron microscope, absorbance spectrohotometer and atomic emission spectrograph.展开更多
Stable binary single source precursors （SSP） for the deposition of thin films of ceramic semiconductors of composition SnO·GeO were synthesized by close circuit chemical vapour deposition （CCCVD） method. Elem...Stable binary single source precursors （SSP） for the deposition of thin films of ceramic semiconductors of composition SnO·GeO were synthesized by close circuit chemical vapour deposition （CCCVD） method. Elemental analysis and spectroscopic techniques were used to characterize the precursors. Scanning electron microscopy （SEM） and energy dispersive spectroscopy （EDS） were employed to characterize the thin films. Resistivity measurements were conducted to show that the films are of semiconducting nature.展开更多
文摘Silver nanoparticles of mean size 16 nm were synthesized by inert gas condensation （IGC） method. Crystalline structure, morphology and nanoparticles size estimation were conducted by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. Antibacterial activity of these silver nanoparticles as a function of particles concentration against gram-negative bacterium Escherichia coli （E. coli） was carried out in liquid as well as solid growth media. Scanning electron microscopy （SEM） and TEM studies showed that silver nanoparticles after interaction with E.coli have adhered to and penetrated into the bacterial cells. Antibacterial properties of silver nanoparticles are attributed to their total surface area, as a larger surface to volume ratio of nanoparticles provides more efficient means for enhanced antibacterial activity.
基金The National Natural Science Foundation of China （50471077） the Ministry of Science and Technology of China （2006CB605201, 2005DFA50860） supported this work.
文摘Designing and synthesis of cost effective bulk metallic glasses （BMGs） has been of considerable interest during the last decade so that they can be made commercially viable. Among these, Zr-based BMGs have been reported extensively due to their attractive properties, An alloy having composition Zr65Cu18Ni9A18 was designed and synthesized using 2-3 N pure materials by Cu mould casting. The alloy was characterized by X- ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive X-ray spectroscopy （EDS） and high temperature differential scanning calorimetry （DSC）. Thermal parameters like supercooled liquid region △Tx, reduced glass transition temperature Trg, γ and δ parameters were evaluated. Mechanical properties like microhardness, nanohardness, elastic modulus and fracture strength were measured. The alloy showed wide supercooled liquid region of 129＋1 K with improved thermal stability. The alloy has considerable fracture strength along with fair amount of ductility.
文摘The adherent thermal layering was undertaken by chemical vapor deposition （CVD） method using saturated solution of boric acid in ultra pure CH3OH. The influence of temperature was studied by varying temperature from 100 to 600℃ during the process of boron deposition. The most optimum temperature was found to be 200℃. The effect of time span was observed from 6 to 120 h. The generation of micro or nano-scale thickness could be achieved by reducing time span of the experiment. The behavior of CVD was characterized by using scanning electron microscope, absorbance spectrohotometer and atomic emission spectrograph.
文摘Stable binary single source precursors （SSP） for the deposition of thin films of ceramic semiconductors of composition SnO·GeO were synthesized by close circuit chemical vapour deposition （CCCVD） method. Elemental analysis and spectroscopic techniques were used to characterize the precursors. Scanning electron microscopy （SEM） and energy dispersive spectroscopy （EDS） were employed to characterize the thin films. Resistivity measurements were conducted to show that the films are of semiconducting nature.
