Diamond-like nanocomposite (DLN) thin films, comprising the networks of a-C:H and a-Si:O were dep... more Diamond-like nanocomposite (DLN) thin films, comprising the networks of a-C:H and a-Si:O were deposited on pyrex glass or silicon substrate using gas precursors (e.g., hexamethyldisilane, hexamethyldisiloxane, hexamethyldisilazane, or their different combinations) mixed with argon gas, by plasma enhanced chemical vapor deposition technique. Surface morphology of DLN films was analyzed by atomic force microscopy. High-resolution transmission electron microscopic result shows that the films contain nanoparticles within the amorphous structure. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and x-ray photoelectron spectroscopy (XPS) were used to determine the structural change within the DLN films. The hardness and friction coefficient of the films were measured by nanoindentation and scratch test techniques, respectively. FTIR and XPS studies show the presence of C-C, C-H, Si-C, and Si-H bonds in the a-C:H and a-Si:O networks. Using Raman spectroscopy, we also found that the hardness of the DLN films varies with the intensity ratio ID/IG. Finally, we observed that the DLN films has a better performance compared to DLC, when it comes to properties like high hardness, high modulus of elasticity, low surface roughness and low friction coefficient. These characteristics are the critical components in microelectromechanical systems (MEMS) and emerging nanoelectromechanical systems (NEMS).
We describe a simple experiment on the diffraction of monochromatic light by interfering liquid s... more We describe a simple experiment on the diffraction of monochromatic light by interfering liquid surface waves. The surface wave profile, which acts as a reflection phase grating for incident light, is generated by electrically driven vertical oscillations of two or more slightly immersed exciters. The theoretical intensity of the diffracted light agrees well with observations. In particular, we show the relation between the intensity and the amplitude ͑height͒ of the surface wave. Although invisible to the naked eye, the interference of liquid surface waves can be optically detected from the characteristic features of the diffraction pattern. In addition, we can measure the amplitude, wavelength, and phase velocity of the surface wave that propagates along the line joining the exciters.
386 Abstract: In this article, we describe a simple optics-based non-destructive experimental tec... more 386 Abstract: In this article, we describe a simple optics-based non-destructive experimental technique devised with the necessary background theoretical formulation to study the liquid properties like surface tension and surface capillary wave profile like wavelength and phase velocity of pure and impure water. Experimentally, we have estimated the surface tension of pure water using this optical method is (73.6+ 1.5) dyne/cm. We have also studied the variation of surface tension of water with adding organic and inorganic impurities using this same method. Finally we estimate the wavelength and phase velocity of capillary wave using the measured values of surface tensions of the above liquids.
Electrochemical communication during biofilm formation has recently been identified. Bacteria wit... more Electrochemical communication during biofilm formation has recently been identified. Bacteria within biofilm‐adopt different strategies for electrochemical communication such as direct contact via membrane‐bound molecules, diffusive electron transfer via soluble redox‐active molecules, and ion channel‐mediated long‐range electrochemical signaling. Long‐range electrical signals are important to communicate with distant members within the biofilm, which function through spatially propagating waves of potassium ion (K+) that depolarizes neighboring cells. During propagation, these waves coordinate between the metabolic states of interior and peripheral cells of the biofilm. The understanding of electrochemical communication within the biofilm may provide new strategies to control biofilm‐mediated drug resistance. Here, we summarized the different mechanisms of electrochemical communication among bacterial populations and suggested its possible role in the development of high level of a...
Introduction Nanoscience are the emerging field in modern technology with numerous applications i... more Introduction Nanoscience are the emerging field in modern technology with numerous applications in biomedical and manufacturing of new smart materials1. In the last two decades’ nanotechnology integrates with the mechanical and electronic engineering to develop micro/nano-electromechanical systems (MEMS/NEMS) devices, which have diverse applications in different fields of science and engineering. These devices are potentially applicable for different sensing, actuating as well as biomedical analysis purposes2. Recently quantum dots have acquired much attention in biological fields owing to its unique size, tunable light absorption and J. Indian Chem. Soc., Vol. 97, No. 11b, November 2020, pp. 2372-2384
Nanotechnology offers a significant advantage in science, engineering, medicine, medical surgery,... more Nanotechnology offers a significant advantage in science, engineering, medicine, medical surgery, foods, packing, clothes, robotics, and computing from the beginning of the twenty-first century. As the potential scientific discovery always contains some good and bad effects on human civilization and the environment, nanotechnology is not an exception. The major drawbacks include economic disruption along with imposing threats to security, privacy, health, and environment. The introduction of the chapter discusses the historical background of nanotechnology. Later it also discusses the advancement of nanotechnology to date with its benefits. Major drawbacks of nanotechnology arise in human health due to the enormous involvement in medicine, food, agriculture, etc. This chapter also deals with environmental nano pollution and its effect on society, highlighting the social-economic disruption due to the rapid use of nanotechnology. Nano pollution affects not only human beings but also ...
In this paper, we correlate the internal stress and the characteristics of a vibrational mode in ... more In this paper, we correlate the internal stress and the characteristics of a vibrational mode in wet foam. Using microscope images, we estimate the average size of the bubbles in wet foam, at specific time intervals, over a duration of 24 h. Raman spectra are also recorded at the same time intervals, over the same time frame. We show that the internal stress, originated from the microscopic structural change of foam with aging, can be related to the observed Raman shift of the low-frequency methylene rocking mode of the constituent surfactant molecules in foam. In this paper, we also show the capability of the Raman spectroscopy to reveal the crystallinity in foamy materials, when studied for a longer period of time.
Interfering liquid surface waves are generated by electrically driven vertical oscillations of tw... more Interfering liquid surface waves are generated by electrically driven vertical oscillations of two or more equispaced pins immersed in a liquid (water). The corresponding intensity distribution, resulting from diffraction of monochromatic light by the reflection phase grating formed on the liquid surface, is calculated theoretically and found to tally with experiments. The curious features of the diffraction pattern and its relation to the interference of waves on the liquid surface are used to measure the amplitude and wavelength of the resultant surface wave along the line joining the two sources of oscillation. Finally, a sample diffraction pattern obtained by optically probing surface regions where interference produces a lattice--like structure is demonstrated and qualitatively explained.
International Journal of Computer Applications, Oct 28, 2011
ABSTRACT Diamond-like nanocomposite (DLN) thin films were deposited on pyrex glass or silicon sub... more ABSTRACT Diamond-like nanocomposite (DLN) thin films were deposited on pyrex glass or silicon substrate by plasma enhanced chemical vapor deposition (PECVD) method. These types of films have their unique number of structural, mechanical and tribological properties, which are quite similar with MEMS material properties. DLN films provide a number of unique and attractive characterization properties that are unattainable from diamond-like carbon (DLC) films, silicon or other materials. These properties include high hardness, high modulus of elasticity, very low surface roughness, low friction coefficient, high tensile strength, low thermal expansion coefficient, good wear resistance property and biocompatibility. Due to these properties, DLN films can highly applicable in MEMS/NEMS devices. There are two different ways of applications of DLN films in MEMS/NEMS: either a surface coating material or a structural material. In this paper, we suggest the use of DLN films as a coating material mainly to improve the wear and friction of micro components and reduce stiction between microstructure and their substrate. The high mechanical properties of this type of DLN films exploited the design of high frequency resonator and comb deriver for sensing and actuating applications. As a biocompatible material, we can use DLN films for detection of bio-molecules in biological research and disease diagnosis.
The structural and tribological properties of diamond-like nanocomposite (DLN) thin films, deposi... more The structural and tribological properties of diamond-like nanocomposite (DLN) thin films, deposited by radio frequency plasma enhanced chemical vapor deposition (rf-PECVD) on the pyrex glass or silicon substrate using the combinations of siloxane and silazane based gas precursors, are discussed. High resolution transmission electron microscopy (HRTEM) result shows the DLN film structure with different nanoparticle size. The surface morphology of
Nanotechnology is an emerging field of science and technology with numerous applications in biome... more Nanotechnology is an emerging field of science and technology with numerous applications in biomedical fields and manufacturing new materials. To extract gold nanoparticles with different techniques, green biosynthesis is in under exploration due to its cost effective ecofriendly preparation with controllable shape, size and disparity, tremendous physical and chemical inertness, optical properties related with surface plasmon resonance, surface modification, surface bio-conjugation with molecular probes, excellent biocompatibility and less toxicity. This review article presents the overview of green biosynthesis of gold nanoparticles (AuNP) and their recent biomedical applications.
American Journal of Nano Research and Application, 2014
Nanotechnology is an emerging field of science and technology with numerous applications in biome... more Nanotechnology is an emerging field of science and technology with numerous applications in biomedical fields and manufacturing new materials. To extract gold nanoparticles with different techniques, green biosynthesis is in under exploration due to its cost effective ecofriendly preparation with controllable shape, size and disparity, tremendous physical and chemical inertness, optical properties related with surface plasmon resonance, surface modification, surface bio-conjugation with molecular probes, excellent biocompatibility and less toxicity. This review article presents the overview of green biosynthesis of gold nanoparticles (AuNP) and their recent biomedical applications.
ournal of Nanopharmaceutics and Drug Delivery, 2014
Nanobiotechnology is an important emerging field of nanotechnology, which has been dramatically ... more Nanobiotechnology is an important emerging field of nanotechnology, which has been dramatically developed for different diverse applications. Biosynthesis of different nanoparticles exhibits enormous growth in popularity from the beginning of twenty first century. Recently, silver and gold nanoparticles are extremely used for different applications such as optoelectronic devices, ultrasensitive chemical and biological sensors, catalysts, separation sciences, drug delivery, can- cer treatment, DNA and RNA analysis, gene therapy, antibacterial agent etc. Out of different synthesis techniques for nanoparticles, the biosynthesis (or green synthesis) is more ecofriendly and cost effective with their chemical stability, excellent biocompatibility, easy fabrication process, convenient surface bio-conjugation with molecular probes, excellent optical properties related to surface plasmon resonance and low toxicity. In this article, we have tried to review the dif- ferent biosynthesis process of silver and gold nanoparticles and their potential biomedical applications. Analyzing the available research upto date, this article presents recent trends and future prospects of biosynthesized silver and gold nanoparticles and suggests significant improvement in this field.
Surface waves on liquids act as a dynamical phase grating for incident light. In this article, we... more Surface waves on liquids act as a dynamical phase grating for incident light. In this article, we revisit the classical method of probing such waves (wavelengths of the order of mm) as well as inherent properties of liquids and liquid films on liquids, using optical diffraction. A combination of simulation and experiment is proposed to trace out the surface wave profiles in various situations (\emph{eg.} for one or more vertical, slightly immersed, electrically driven exciters). Subsequently, the surface tension and the spatial damping coefficient (related to viscosity) of a variety of liquids are measured carefully in order to gauge the efficiency of measuring liquid properties using this optical probe. The final set of results deal with liquid films where dispersion relations, surface and interface modes, interfacial tension and related issues are investigated in some detail, both theoretically and experimentally. On the whole, our observations and analyses seem to support the claim that this simple, low--cost apparatus is capable of providing a wealth of information on liquids and liquid surface waves in a non--destructive way.
Diamond-like nanocomposite (DLN) thin films, comprising the networks of a-C:H and a-Si:O were dep... more Diamond-like nanocomposite (DLN) thin films, comprising the networks of a-C:H and a-Si:O were deposited on pyrex glass or silicon substrate using gas precursors (e.g., hexamethyldisilane, hexamethyldisiloxane, hexamethyldisilazane, or their different combinations) mixed with argon gas, by plasma enhanced chemical vapor deposition technique. Surface morphology of DLN films was analyzed by atomic force microscopy. High-resolution transmission electron microscopic result shows that the films contain nanoparticles within the amorphous structure. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and x-ray photoelectron spectroscopy (XPS) were used to determine the structural change within the DLN films. The hardness and friction coefficient of the films were measured by nanoindentation and scratch test techniques, respectively. FTIR and XPS studies show the presence of C-C, C-H, Si-C, and Si-H bonds in the a-C:H and a-Si:O networks. Using Raman spectroscopy, we also found that the hardness of the DLN films varies with the intensity ratio ID/IG. Finally, we observed that the DLN films has a better performance compared to DLC, when it comes to properties like high hardness, high modulus of elasticity, low surface roughness and low friction coefficient. These characteristics are the critical components in microelectromechanical systems (MEMS) and emerging nanoelectromechanical systems (NEMS).
We describe a simple experiment on the diffraction of monochromatic light by interfering liquid s... more We describe a simple experiment on the diffraction of monochromatic light by interfering liquid surface waves. The surface wave profile, which acts as a reflection phase grating for incident light, is generated by electrically driven vertical oscillations of two or more slightly immersed exciters. The theoretical intensity of the diffracted light agrees well with observations. In particular, we show the relation between the intensity and the amplitude ͑height͒ of the surface wave. Although invisible to the naked eye, the interference of liquid surface waves can be optically detected from the characteristic features of the diffraction pattern. In addition, we can measure the amplitude, wavelength, and phase velocity of the surface wave that propagates along the line joining the exciters.
386 Abstract: In this article, we describe a simple optics-based non-destructive experimental tec... more 386 Abstract: In this article, we describe a simple optics-based non-destructive experimental technique devised with the necessary background theoretical formulation to study the liquid properties like surface tension and surface capillary wave profile like wavelength and phase velocity of pure and impure water. Experimentally, we have estimated the surface tension of pure water using this optical method is (73.6+ 1.5) dyne/cm. We have also studied the variation of surface tension of water with adding organic and inorganic impurities using this same method. Finally we estimate the wavelength and phase velocity of capillary wave using the measured values of surface tensions of the above liquids.
Electrochemical communication during biofilm formation has recently been identified. Bacteria wit... more Electrochemical communication during biofilm formation has recently been identified. Bacteria within biofilm‐adopt different strategies for electrochemical communication such as direct contact via membrane‐bound molecules, diffusive electron transfer via soluble redox‐active molecules, and ion channel‐mediated long‐range electrochemical signaling. Long‐range electrical signals are important to communicate with distant members within the biofilm, which function through spatially propagating waves of potassium ion (K+) that depolarizes neighboring cells. During propagation, these waves coordinate between the metabolic states of interior and peripheral cells of the biofilm. The understanding of electrochemical communication within the biofilm may provide new strategies to control biofilm‐mediated drug resistance. Here, we summarized the different mechanisms of electrochemical communication among bacterial populations and suggested its possible role in the development of high level of a...
Introduction Nanoscience are the emerging field in modern technology with numerous applications i... more Introduction Nanoscience are the emerging field in modern technology with numerous applications in biomedical and manufacturing of new smart materials1. In the last two decades’ nanotechnology integrates with the mechanical and electronic engineering to develop micro/nano-electromechanical systems (MEMS/NEMS) devices, which have diverse applications in different fields of science and engineering. These devices are potentially applicable for different sensing, actuating as well as biomedical analysis purposes2. Recently quantum dots have acquired much attention in biological fields owing to its unique size, tunable light absorption and J. Indian Chem. Soc., Vol. 97, No. 11b, November 2020, pp. 2372-2384
Nanotechnology offers a significant advantage in science, engineering, medicine, medical surgery,... more Nanotechnology offers a significant advantage in science, engineering, medicine, medical surgery, foods, packing, clothes, robotics, and computing from the beginning of the twenty-first century. As the potential scientific discovery always contains some good and bad effects on human civilization and the environment, nanotechnology is not an exception. The major drawbacks include economic disruption along with imposing threats to security, privacy, health, and environment. The introduction of the chapter discusses the historical background of nanotechnology. Later it also discusses the advancement of nanotechnology to date with its benefits. Major drawbacks of nanotechnology arise in human health due to the enormous involvement in medicine, food, agriculture, etc. This chapter also deals with environmental nano pollution and its effect on society, highlighting the social-economic disruption due to the rapid use of nanotechnology. Nano pollution affects not only human beings but also ...
In this paper, we correlate the internal stress and the characteristics of a vibrational mode in ... more In this paper, we correlate the internal stress and the characteristics of a vibrational mode in wet foam. Using microscope images, we estimate the average size of the bubbles in wet foam, at specific time intervals, over a duration of 24 h. Raman spectra are also recorded at the same time intervals, over the same time frame. We show that the internal stress, originated from the microscopic structural change of foam with aging, can be related to the observed Raman shift of the low-frequency methylene rocking mode of the constituent surfactant molecules in foam. In this paper, we also show the capability of the Raman spectroscopy to reveal the crystallinity in foamy materials, when studied for a longer period of time.
Interfering liquid surface waves are generated by electrically driven vertical oscillations of tw... more Interfering liquid surface waves are generated by electrically driven vertical oscillations of two or more equispaced pins immersed in a liquid (water). The corresponding intensity distribution, resulting from diffraction of monochromatic light by the reflection phase grating formed on the liquid surface, is calculated theoretically and found to tally with experiments. The curious features of the diffraction pattern and its relation to the interference of waves on the liquid surface are used to measure the amplitude and wavelength of the resultant surface wave along the line joining the two sources of oscillation. Finally, a sample diffraction pattern obtained by optically probing surface regions where interference produces a lattice--like structure is demonstrated and qualitatively explained.
International Journal of Computer Applications, Oct 28, 2011
ABSTRACT Diamond-like nanocomposite (DLN) thin films were deposited on pyrex glass or silicon sub... more ABSTRACT Diamond-like nanocomposite (DLN) thin films were deposited on pyrex glass or silicon substrate by plasma enhanced chemical vapor deposition (PECVD) method. These types of films have their unique number of structural, mechanical and tribological properties, which are quite similar with MEMS material properties. DLN films provide a number of unique and attractive characterization properties that are unattainable from diamond-like carbon (DLC) films, silicon or other materials. These properties include high hardness, high modulus of elasticity, very low surface roughness, low friction coefficient, high tensile strength, low thermal expansion coefficient, good wear resistance property and biocompatibility. Due to these properties, DLN films can highly applicable in MEMS/NEMS devices. There are two different ways of applications of DLN films in MEMS/NEMS: either a surface coating material or a structural material. In this paper, we suggest the use of DLN films as a coating material mainly to improve the wear and friction of micro components and reduce stiction between microstructure and their substrate. The high mechanical properties of this type of DLN films exploited the design of high frequency resonator and comb deriver for sensing and actuating applications. As a biocompatible material, we can use DLN films for detection of bio-molecules in biological research and disease diagnosis.
The structural and tribological properties of diamond-like nanocomposite (DLN) thin films, deposi... more The structural and tribological properties of diamond-like nanocomposite (DLN) thin films, deposited by radio frequency plasma enhanced chemical vapor deposition (rf-PECVD) on the pyrex glass or silicon substrate using the combinations of siloxane and silazane based gas precursors, are discussed. High resolution transmission electron microscopy (HRTEM) result shows the DLN film structure with different nanoparticle size. The surface morphology of
Nanotechnology is an emerging field of science and technology with numerous applications in biome... more Nanotechnology is an emerging field of science and technology with numerous applications in biomedical fields and manufacturing new materials. To extract gold nanoparticles with different techniques, green biosynthesis is in under exploration due to its cost effective ecofriendly preparation with controllable shape, size and disparity, tremendous physical and chemical inertness, optical properties related with surface plasmon resonance, surface modification, surface bio-conjugation with molecular probes, excellent biocompatibility and less toxicity. This review article presents the overview of green biosynthesis of gold nanoparticles (AuNP) and their recent biomedical applications.
American Journal of Nano Research and Application, 2014
Nanotechnology is an emerging field of science and technology with numerous applications in biome... more Nanotechnology is an emerging field of science and technology with numerous applications in biomedical fields and manufacturing new materials. To extract gold nanoparticles with different techniques, green biosynthesis is in under exploration due to its cost effective ecofriendly preparation with controllable shape, size and disparity, tremendous physical and chemical inertness, optical properties related with surface plasmon resonance, surface modification, surface bio-conjugation with molecular probes, excellent biocompatibility and less toxicity. This review article presents the overview of green biosynthesis of gold nanoparticles (AuNP) and their recent biomedical applications.
ournal of Nanopharmaceutics and Drug Delivery, 2014
Nanobiotechnology is an important emerging field of nanotechnology, which has been dramatically ... more Nanobiotechnology is an important emerging field of nanotechnology, which has been dramatically developed for different diverse applications. Biosynthesis of different nanoparticles exhibits enormous growth in popularity from the beginning of twenty first century. Recently, silver and gold nanoparticles are extremely used for different applications such as optoelectronic devices, ultrasensitive chemical and biological sensors, catalysts, separation sciences, drug delivery, can- cer treatment, DNA and RNA analysis, gene therapy, antibacterial agent etc. Out of different synthesis techniques for nanoparticles, the biosynthesis (or green synthesis) is more ecofriendly and cost effective with their chemical stability, excellent biocompatibility, easy fabrication process, convenient surface bio-conjugation with molecular probes, excellent optical properties related to surface plasmon resonance and low toxicity. In this article, we have tried to review the dif- ferent biosynthesis process of silver and gold nanoparticles and their potential biomedical applications. Analyzing the available research upto date, this article presents recent trends and future prospects of biosynthesized silver and gold nanoparticles and suggests significant improvement in this field.
Surface waves on liquids act as a dynamical phase grating for incident light. In this article, we... more Surface waves on liquids act as a dynamical phase grating for incident light. In this article, we revisit the classical method of probing such waves (wavelengths of the order of mm) as well as inherent properties of liquids and liquid films on liquids, using optical diffraction. A combination of simulation and experiment is proposed to trace out the surface wave profiles in various situations (\emph{eg.} for one or more vertical, slightly immersed, electrically driven exciters). Subsequently, the surface tension and the spatial damping coefficient (related to viscosity) of a variety of liquids are measured carefully in order to gauge the efficiency of measuring liquid properties using this optical probe. The final set of results deal with liquid films where dispersion relations, surface and interface modes, interfacial tension and related issues are investigated in some detail, both theoretically and experimentally. On the whole, our observations and analyses seem to support the claim that this simple, low--cost apparatus is capable of providing a wealth of information on liquids and liquid surface waves in a non--destructive way.
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