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Synthesis and Characterization of Advanced Nano heat transfer Fluid
Syed Tajammul Hussain*, Muhammad Adnan Saqlain
Nano Science and Catalysis Division, National Centre for Physics, Islamabad
AbstractAn advanced nano-heat transfer fluid (NHTF) consisting of a eutectic mixture of Alkali metal Nitrate salts doped with silica nano particles at 1% mass concentration with a low melting point, high thermal stability and High Specific heat capacity has been developed. These properties produce a wide temperature operating range Heat Transfer Fluid and enable effective thermal storage for parabolic trough concentrating solar power plants (CSP) as compared to in use molten salt heat transfer fluid that usually has a high melting point, typically 220°C or higher, which limits its use due to the risk of freezing. The advanced NHTF exploits eutectic behavior with a novel composition of materials and nano particles, resulting in a low melting point of 117 °C, a thermal stability limit over 500 °C and an increase in Specific Heat Capacity by 15% owing to the presence of suspended Silica Nano particles. The advanced NHTF described was developed using simple experiment design. Additional work is ongoing to functionalize the nano particles to increase its load % in the Eutectic of salt thereby increasing thermo physical properties of the NHTF and to assess its long term performance in real operating conditions for concentrating solar power applications or other high temperature processes.
Key WordsCSP, Nano particles, HTF, NHTF, Thermal Stability
Center of Research Excellence in Nanotechnology (CENT)and the Chemistry Department
KFUPM
Metal-oxide Nanostructured Materials as Chemical Sensors
Dr. Ahsanulhaq Qurashi
(CENT)
Abstract
The presentation provides insight into a broad spectrum of the state of the art research activities and development that focus on the metal-oxide nanostructured (MOXN) systems. This talk includes diverse synthetic methods that lead to form these nanostructures. In addition, the plausible synthetic mechanisms will be discussed. A wide range of remarkable characteristics organized into sections covering a number of nanostructured metal-oxides, such as ZnO, In2O3, SnO2, and TiO2, etc. will be presented. Current efforts on MOXN gas sensors will be conversed. MOXN based hydrogen sensors, their fabrication and current status will be the primary focus of this presentation. Also at the end, some additional efforts for the fabrication of chemical sensors through electrochemical method will be briefly illustrated.
Nanostructured CdTiO3 thin films prepared from a single source precursor by AACVD
Syed Tajammul Hussain*1, Shahzad Abu Bakar 1, Matthias Zeller2.1National Center for Physics, Quaid-I-Azam University, Islamabad 45320, Pakistan, and 2 STaRBURSTT-
Cyberdiffraction Consortium @ YSU & Department of Chemistry, Youngstown State University, 1 University Plaza Youngstown, OH 44555-3663, USA
Abstract
Crack free, crystalline and nanostructured CdTiO3 thin films were prepared by aerosol assisted chemical vapor deposition (AACVD) from a single source hetero-bimetallic precursor, [Cd4Ti4(dmae)4(TFA)8(OAc)4O6] 1 [where dmae = N, N-dimethyaminoethanolate, TFA = triflouroacetate, OAc = acetate]. The precursor, prepared in high yield by simple chemical techniques, was characterized by melting point, elemental, thermal (TGA/DTA) and single crystal X-ray analysis. 1 undergoes facile decomposition at 450°C and has sufficient solubility in common organic solvents to be useable in aerosol assisted chemical vapor deposition. Thin films of CdTiO3 were deposited on fluorine doped SnO2 coated conducting glass substrate in one single step. The thin films were characterized by scanning electron microscopy, energy dispersive X-ray, powder X-ray diffraction and Rutherford backscattering spectrometry analysis, proving the formation of carbonaceous impurity free, crystalline and single phase CdTiO3 thin films. The surface morphology of the films is mesoporous with homogeneously dispersed nanoparticles of an average grain size of 31 nm with no preferred orientation and excellent adhesion to the substrate. Cd and Ti are homogeneously distributed in a 1:1 ratio. Optical and electrical studies were conducted by UV-vis/Diffuse Reflectance spectroscopy, impedance spectroscopy and Hall Effect measurements and the estimated optical bandgap is about 2.45 eV.
Multiwall carbon nanotubes (MWCNTs) for lithium-ion batteries
Syed Tajammul Hussaina, Syed Mustansar Abbas*a
aNano Science & Catalysis Division, National Centre for Physics, Quaid-i-Azam University, Islamabad, 45320, Pakistan
Abstract:The considerable demand for lithium ion secondary batteries with high energy storage
density, useful in the portable electronic products, has spawned many explorations of new lithium intercalation materials with superior performance both as cathodes and as anodes. In common Li ion batteries, graphitic carbon anodes are employed instead of metallic Li electrodes because of safety and cycle efficiency considerations. However, graphite is far from being an ideal host material. Its use results in a specific capacity reduction from 3860 mAh/g for metallic Li to 372 mAh/g for graphitic anodes. The problem can be circumvented by optimizing the electrode morphology with the development of nano structured configurations specially MWCNTs capable of buffering the large volume changes and thus, of assuring long cycle life combined with high specific capacity.
Keywords: Carbon nanotubes, Lithium-ion battery, Anode material, electrochemical properties, cycling
Synthesis of Nano Particles
Syed Tajammul Hussain*a, Syed Danish Alia
aNano Science and Catalysis Division, National Centre for Physics, Islamabad
Abstract
The art and science of fabricating structures with nano dimensions as well as accuracy is of the immense concern to any one investigating into nanotechnology. In the recent years, there has been a tremendous leap in the potential applications of metallic as well as non-metallic nanostructures. Nanotechnology has initiated a big hop and appears to be all set for bringing in revolution in the development and advancement of techniques involved in the synthesis and fabrication of nano particles. This article addresses the science of some technique such as, hydrothermal, micro emulsion, laser ablation, sonochemical method, sol gel, thermal decomposition, chemical vapor deposition, spray pyrolysis, co-precipitation, used for the development of nano materials and structures involving semiconductors, magnetic multilayered nanowires, conducting polymers, nanotubes and wires. The morphology, size and shape of the synthesized nano particles depend upon the synthetic technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and energy dispersive X-ray spectroscopy (EDX) are used to characterize the nano particles.
Keywords: Nanotechnology, Nanoparticles synthesis, Synthetic techniques
Catalytic Dewaxing of Heavy Petroleum Feeds.
Syed Tajamul Hussain*, Ikhtiar Ahmad, M. Aziz Choudhary
Nano Science & Catalysis Division, National Centre for Physics, Quaid-i-Azam University, Islamabad
Department of Chemistry, University of Azad Jammu & Kashmir, Muzaffarabad
Abstract
The increasing demand for transportation fuels and increasing pressure on environment has made the governments world over to regulate quality, composition and economics of transportation fuels especially gasoline and diesel oil. Over 90% of fuels and lubricating oils are obtained from petroleum and refineries demand technologies for maximum conversion of less important heavy feeds into lower fractions (gasoline, diesel & lube oils) of higher demand. Nano-heterogeneous catalysis effectively replaces many conventional oil refining processes. Catalytic dewaxing is such a process to convert waxy heavy petroleum fractions into diesel, lube oil and fuel gases and also enhances the flow properties of fuels. The catalysts for dewaxing are supported porous materials like zeolites, alumino-silicates and metal oxides. These catalysts have high surface area, optimum porosity and sufficient surface active sites which perform duel function i.e. cracking and hydrogenation. By using the shape selective catalysts the only targeted products can be achieved which is the beauty of catalytic dewaxing process.
Key words: Nano- heterogeneous catalysis, dewaxing, supported catalysts.
Green House Emission Control Technology
Syed Tajammul Hussaina, Zulifaqar Alib, Nawaz Chaudharyb
aNS&CD National Center for physics QAU campus Islamabad
bCollege of Earth and Environmental Sciences Punjab University Lahore
Abstract
In the history of civilization, the 20th century can be characterized as a century of explosive growth in energy consumption and rapid increase in population worldwide. Due to industrial revolution and rapid change in living standards environmental problems due to emission of pollutants such as NO x, SOx and Particulate matter (PM), but also green house gases such as CO2, CH4 become a burning issue of this century. There are increasing concerns for global climate change and thus become a world wide issue for reducing the emission of GHG particularly CO2. Utilization of CO2 has become an important global issue due to the significant and continuous rise in atmospheric carbon dioxide concentration. Nano Technology can play a major role for the best utilization of CO2. By the application of Nano catalysts we can convert the GHG (CO2) into value added products such as methanol and dimethyl ether.
Key words: NOx, SOx, GHG’s, Particulate matter, Nano Technology
Jatropha Curcas: Energy for Future
Syed Tajammul Hussaina, Waqas Ahmeda
aNano Science & Catalysis Division, National Centre for Physics, Islamabad, Pakistan.
Abstract:
Increasing utilization of fossil fuels, emission of Green House Gases (GHGs) such as CO2, CO, SOx, NOx and particulate matter associated with burning of fossil fuels cause great threat to safe and clean environment. Biodiesel is a Fatty Acid Methyl Ester, which mainly constitute of Triglycerides TG’s and Free Fatty Acids (FFA’s). Advantages of selection of Jatropha over the other alternatives of biofuel obtained from food crops such as maize, soya bean, sugar cane and palm ensures little or no carbon debt and offers immediate and sustained Green House Gas. The Nanocatalyst synthesized was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and BET. The average crystallite size was calculated from XRD data and surface area was calculated by BET. Base catalyzed trans-esterification & nanotechnology were optimized. By using nanotechnology the biodiesel was obtained at ambient temperature & time. The physical properties like color, pour point, flash point, specific gravity and kinematic viscosity were found to be very close to the standard ASTM values. Biodiesel produced from traditional trans-esterification method and nanotechnology was characterized by FT-IR, GC-MS, 1H & 13C NMR.
Keywords: Greenhouse gases, nanotechnology, transesterification
Coal clean fuel for the future
Syed Tajammul Hussaina,Nisar Ahmadb,Bakhtiar Muhammadb
aNanoscience &Catalysis Division NCP QAU Campus Islamabad,
bHazara University Mansehra
ABSTRACT
Coal can be converted to liquid or gaseous fuels through a number of processes. Some of these were pioneered in the Second World War to provide fuel for airplanes and tanks. One of the impartment is indirect coal liquefaction in which coal first combines with oxygen and steam or water to produce synthesis gas (also known as syngas), which is most often a mixture of carbon monoxide and hydrogen. Toxic metals can be removed from the syngas through a carbon filter. The syngas can then be converted to synthetic fuels (diesel) by Fischer-Tropsch synthesis. Fischer-Tropsch diesel does not have the infrastructure problems and can be transported through the existing infrastructure and used in existing engines. They offer a substantial opportunity to reduce dependence on petroleum, and offer modest environmental benefits. Direct coal liquefaction skips the syngas formation step, and includes technologies such as distillation and hydrogenation (adding hydrogen to coal-water slurry). The addition of hydrogen improves the H/C ratio, bringing the resulting product closer to lighter hydrocarbons such as those found in gasoline or diesel fuel. It also removes sulfur, allowing for clean-burning fuel. Direct liquefaction results in a crude oil, which is then be further refined.
Technological innovations can remove many of the difficulties associated with the use of coal as an energy resource. By converting coal to liquid or gaseous fuels, it will be possible to use it for transportation, greatly reducing the risks of price shocks associated with increasing demand for oil outpacing supply. Gasification and liquefaction can remove nearly all of the sulfur and mercury from the coal, dramatically reducing pollutant emissions. If carbon sequestration is proven to be effective, coal-derived liquid fuels could have lower CO2 emissions than conventional diesel or gasoline. Production of liquid fuels from coal offers a viable option for energy security for Pakistan and other coal-rich countries.
Key Words:Coal,Syngas,Fischer Tropsch synthesis and synthetic Fuel.
Nanoparticles for Industrial Exhaust Control
Syed Tajammul Hussain*, Naeem Shahzad**, and M.A. Baig**Nano-Science and Catalysis Division, National Centre for Physics*, National University
of Sciences and Technology**, Islamabad.
Abstract
In Pakistan, awareness regarding harmful effects of air pollution is minimal. There is absolutely no control on air emissions by industrialists and factory owners. Industrial activity without adequate air emission treatment or control is one of the major causes of the ambient air quality’s deterioration in the country. It has not been possible to assess the magnitude of industrial air pollution as there is limited air pollution data available and that too is restricted to big cities and provincial capitals. Pakistan has responded to its environmental problems by passing laws, establishing environmental protection institutions and by developing human resources and technical capabilities through local and foreign assistance, but in-spite of all these measures many aspects of the environmental degradation have remained uncontrolled and under regulated.
NOx and SOx, are the major air pollutants. In addition to this, H2S gas with a characteristic rotten egg smell and having extremely low odour threshold (0.0004 ppm) and high toxicity is also of a great environmental concern. 300 pm concentrations of H2S in air can result in death for long term exposures and concentrations up to 2000 ppm for few minutes only, may be fatal for humans. Out of the 10,652 producible oil wells in Michigan, USA; 1,360 wells had H2S levels exceeding 300 ppm.
Keeping in view the poor response of the industrialists in Pakistan towards environmental laws and regulations regarding air pollution, this study focuses on developing a technique for in-situ treatment of industrial exhaust gases focusing on H2S gas at high temperatures by using TiO2
nano particles, so that simultaneous destruction of H2S gas could be investigated for brick kilns, power generation and gasification processes which are carried out at high temperatures. Initial experimental results at lab scale have shown a decrease of 99% in the H2S gas concentrations. This technique is likely to help in the in-situ treatment of this malodorous toxic gas resulting in considerable abatement of air pollution in Pakistan without installing any new device or changing the existing practices of exhaust gases by the industrialists making it easy for them to comply with the environmental laws and regulations.
Keywords
TiO2 nano particles, catalysis, fixed bed catalysis system, H2S destruction.
Gas Chromatography–Mass Spectrometry (GC-MS)
Syed Tajamul Hussain and Anila Iqbal
Nano Science & Catalysis Division, National Center for Physics, Quaid-i-Azam University Campus, Islamabad, 44000 Pakistan.
Abstract
Gas chromatography–mass spectrometry (GC-MS) is a method that combines the features of gas-liquid chromatography and mass spectrometry to identify different substances within a test sample. The GC-MS is composed of two major building blocks: the gas chromatograph and the mass spectrometer. The gas chromatograph utilizes a capillary column which depends on the column's dimensions as well as the phase properties. The difference in the chemical properties between different molecules in a mixture will separate the molecules as the sample travels the length of the column. The molecules take different amounts of time to come out of the gas chromatograph, and this allows the mass spectrometer downstream to capture, ionize, accelerate, deflect, and detect the ionized molecules separately. The mass spectrometer does this by breaking each molecule into ionized fragments and detecting these fragments using their mass to charge ratio. Ionization takes place through different modes and analysis is governed by different rules. Applications of GC-MS include drug detection, environmental analysis, explosives investigation, and identification of unknown samples.
Key words: Gas chromatography, mass spectrometry, capillary column, drug detection, environmental analysis
Modeling and simulation of materials using DFT
Akhtar Hussain
Pakistan Institute of Nuclear Science and Technology, P.O., Nilore, Islamabad
Regular Associate at NCP, QAU, Islamabad
Abstract
Research of present era rests on three pillars theory, experiment and simulation. Before 2000, experimentation was by far the main option to validate a hypothesis or theory. Nnowadays computer simulation often provides a faster, easier and less expensive way for investigations. Density Functional Theory (DFT) is the most popular and versatile computational method available in condensed-matter physics, computational physics and chemistry and it has enjoyed a dramatic surge of interest since the 90s. It is a quantum mechanical modeling method used to investigate the electronic structures of atoms, molecules, and the condensed phases. The principle of DFT is that all the properties of a system of interacting particles can be described by a unique functional of the ground state single particle density, σ(r), which provides all information embedded in the many-body wave function of the ground state of the system. DFT can be applied to compute a variety of tasks including energetical, structural, vibrational, optical etc. properties of nano-materials. Many codes have been developed to implement DFT. Below is an example regarding the study of Water Gas Shift Reaction on Au/TiO2 catalyst to understand the applications of DFT.
The water gas shift reaction has been investigated using density functional theory (DFT) applied to Au(100), stepped Au(310) and anatase (001) surfaces. The results reveal that Au is not able to catalyze the reaction by itself. Out of CO, CO2, H2O and H2, only CO adsorbs with moderate adsorption energy at low coordinated sites whereas the other molecules interact only weakly with Au. Activation of water is impossible on the Au surfaces. However, H2O adsorbs dissociatively on the anatase (001) surface, and diffusion of OH and H is realistic. We believe that spillover of dissociated water from the metal oxide to the gold is feasible, without studying how this happens in detail at the interface. Two mechanisms were investigated and compared. They have dissociation of water on titania and migration of OH and H to the Au surface in common, which is in principle the rate limiting step. The first mechanism happens via disproportionation of two OH groups on the gold into water and an O-atom. The latter reacts with CO. In the alternative mechanism, CO combines with OH to a carboxyl intermediate, which subsequently reacts with another OH to CO2 and H2O. Finally, H-atoms recombine on the gold surface to complete the catalytic cycle.
FUNCTIONALIZATION OF CARBON NANOTUBES FOR NANOCOMPOSITE DEVELOPMENT
Syed Tajammul Hussain, Faisal Abbas
Nano Science and Catalysis Division, National Center for Physics, QAU Islamabad
Institute of Physics & Electronics University of Peshawar, Peshawar
Abstract
SWCNTs have been functionalized by H2SO4:HNO3 and HNO3:H2O2 treatments. Nanocomposite materials of conducting organic polymers and carbon nanotubes were obtained by in-situ polymerization of functionalized single-walled carbon nanotubes (CNTS) and the corresponding monomer. The synthetic, morphological and electrochemical properties of PPY/CNTs, PANI/CNTs, PTh/CNTs, PEDOT/CNTs and PPY+PANI+PTh+PEDOT/CNTs nanocomposites films were compared.
The synthesized materials were thoroughly characterized.
Key Words: Functionalization, Nanocomposite, Alignment, Electrical Conductivity, Applications.
Quantum Dots
Syed Tajammul Hussain*, Shahid Iqbal
*Nanoscience and Catalysis Division, National Centre for Physics, Quaid-i-Azam University, Islamabad, 45320 Pakistan.
Abstract
Quantum dots (QDs) are semiconductor nano crystals composed of groups II-IV or III-V elements. QDs are defined as particles with physical dimensions ranging from 1 to 10 nm, comparable to the exciting Bohr radius. Semiconductor nano crystal QDs are one of the most demanding classes of new materials and constitute an active field of research. QDs have excellent optical properties, such as widely tunable absorption spectra, photoluminescence (PL) efficiency, superior thermal and photochemical stability, etc. They have the ability to tune emission spectra by varying their size, shape and composition. Semiconductor quantum dots reveal physical and electronic properties very different from those observed for the bulk solid semiconductor. These differences arise mainly from quantum confinement effects due to the reduction of band structure into discrete quantum levels resulting from the limited size of the particle. The QDs are known to have unique chemical and electronic properties having potential usage in the fields of electronics, sensors, optics, catalysis, biological labels.
Key words: Quantum dots; Quantum confinement; Photo physical properties
Nanotechnology in Solar Cells
Nisar Ali1, Sayed Tajammul Hussain2, M.A.Iqbal3
1, 2Nano Science and Catalysis division, National Centre for Physics Quaid-i-Azam University, Islamabad, 45320 Pakistan.
3University of the Punjab, Lahore
Abstract
The hundred percent conversion of light energy (photon) into electrical energy is the dream of photovoltaic researchers. The nano technology provides a way to fabricate a solar cell with maximum efficiency along with the smaller amount of material used during fabrication. In second generation solar cells (thin films), the window layer is of much interest because it must be n-type, highly transparent, highly conductive, and will have reduced lattice mismatch with the absorbing layer. The engineering of the band gap of semiconductors and optical properties as well can be accomplished with the help of nano technology.
Key words: Photovoltaics, thin films, window layer, solar cells, nano technology.
Synthesis, characterization and photocatalytic activity of Bi2O3-Co3O4 Nanocomposites
Syed Tajamul Hussaina*, Syed Munir Aslamb, Muneeb ur Rehmanb
aNano Science & Catalysis Division, National Centre for Physics, Quaid-i-Azam University, Islamabad, 45320. Pakistan,
bKohat University of Science & Technology, Kohat, Pakistan.
Abstract
Bi2O3- Co3O4 composites were synthesized by the reaction of Bismuth nitrate pentahydrate with Cobalt Nitrate hexhydrate in the presence of dilute nitric acid with addition of 1 M KOH solution at room temperature. The prepared samples were washed several times to remove any traces of potassium and nitrates. The band gap was determined using transformed diffuse reflectance spectroscopy according to the Kubelka-Munk theory. The results show that band gap of Bi2O3- Co3O4 decreases from 1.29 to 0.94 eV and also particle sizes decreased from 6.82 nm to 4.23 nm on variation of concentration products were characterized by powder X-ray diffraction (XRD) and Scanning electron microscopy (SEM). Their photocatalytic activity was investigated for the liquid-phase photocatalytic degradation of methyl orange (MO) and methyl blue (MB) diluted in water under visible light irradiation. It was observed that the coupled oxides Bi2O3- Co3O4
mainly comprises of nano sized Bi2O3 and Co3O4, and they have better photocatalytic activity for the degradation of MO than Bi2O3 or Co3O4 alone. Moreover, the calcinations temperature had an obvious effect on the size of the coupled oxide particles.
Key Words: Coupled semiconductor, Photocatalyst, Methyl Orange and Methyl Blue degradation, Sun radiation.
Characterization of Nanomaterials
Syed Tajammul Hussain and Bushra Ismail
Nanoscience and Catalysis Division, National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 44000 Pakistan
Abstract
The fundamentals of nanotechnology lie in the fact that the properties of materials change dramatically due to their down sizing. Thus nanotechnology has motivated the scientist and technologists to discover some newer methods for the characterization of nano materials. The role of characterization techniques is to establish a correlation between the structure, shape and chemical composition of nano materials with their properties. Characterization of nano materials contains two main steps: structural analysis and property measurements. Structural analysis can be conducted using the following techniques: Atomic absorption spectroscopy (AAS), energy dispersive X-Ray spectroscopy (EDS), secondary ions mass spectroscopy (SIMS), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), low energy X-ray emission spectrometry (LEXES), Rutherford backscattering spectroscopy (RBS), mass spectroscopy (MS), Particle (Photon) induced X-Ray spectroscopy (PIXE), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence spectroscopy (XRF), X-ray reflectivity (XRR), X-ray diffraction (XRD), Fourier transform infra red spectroscopy (FTIR), Raman spectroscopy (RS), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), scanning electron microscopy (SEM), Auger electron spectroscopy (AES), atomic force microscopy (AFM), differential scanning calorimetry (DSC), differential thermal analysis (DTA), thermo gravimetric analysis (TGA), dielectric thermal analysis (dTA), etc. The mechanical, optical, magnetic, electric and dielectric properties can be studied using dynamic mechanical analysis (DMA), universal testing machine (UTM), emission spectroscopy (ES), absorption spectroscopy (AS), magnetic susceptibility (MS), and two or four point probe method.
Key words: Atomic absorption spectroscopy (AAS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Particle induced X-Ray spectroscopy (PIXE)
Synthesis of highly efficient nano photocatalyst for water purification
Syed Tajammul Hussain, Rashid Alvi
Nanoscience and Catalysis Division, National Centre for Physics, 45320, Islamabad.
Abstract
Novel ultra-efficient tiania based nano photocatalyst was synthesized by reverse micro emulsion method. The materials are characterized for X-ray diffraction (XRD), FTIR, RBS, DRS, TGA, SEM and BET. The catalyst exhibited homogeneous distribution of dopants, large surface area, high quantum efficiency and enhanced optical properties with synthesis methodology adopted. At lower second metal ions doped concentration the matrix responded with extraordinary photocatalytic properties. The doped photocatalyst showed remarkable activity against E. coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus feacalis.
Keywords: Photocatalysis; Microemulsion; Titania; Disinfection
Nanomedicines
Tajammul Hussain, Samina NazirNanoscience and Catalysis Division, National Centre for Physics, Quaid-i-Azam University
Campus, Shahdara valley road, Islamabad 45320, Pakistan.
Abstract:Nowadays, nanoparticles are playing an ever increasing role in biomedical research and clinical applications. The distinctive physical properties of engineered nano materials are being exploited in the field of nanomedicine for applications as diverse as drug delivery and targeting, diagnosis, gene therapy, biomarkers, programmed delivery and many others. Different types of nano materials such as metal nanoparticles, quantum dots, SPIONS, dendrimers, liposomes, nano pores are being used in developing advanced nanomedicines with enhanced efficacy and security. Furthermore, nano materials have also found their application in synthesis of biomaterials for construction of artificial bones, teeth, stents and pace-makers.
Key words: Nanomedicines, nano materials, drug-delivery, diagnosis, biomaterials.
Synchrotron light source and its role in exploring Science
Nadeem Tahir
University of Lawrence Berkeley National Lab, USA
Abstract
Synchrotrons are particle accelerators, massive machines built to accelerate sub-atomic particles to almost the speed of light. They produce synchrotron radiation, an amazing form of light that researchers are shining on molecules, atoms, crystals and innovative new materials in order to understand their structure and behavior. An over view of Advance Light Source and facilities to carry out science research should be address in this presentation. I would discuss the study on structural, electronic and optical properties of chemically synthesized Sn1-XZnXO2 (x = 0.00 to 0.10) nano particles. X-ray diffraction and Scanning electron microscope measurements show that nano particles are spherical in nature and nano crystallite are well indexed to rutile structure. The energy dispersive x-ray analysis confirms the presence of Zn in these samples. The electronic structure of these nano particles is studied by soft x-ray absorption near edge (XANES) spectroscopy. O K-edge and M4,5-edge XANES spectra with different Zn doping are compared. M5 and M4 pre edge features are related to the surface states which only appear in nanostructures. The band gap has been calculated by x-ray emission and x-ray absorption spectroscopy. Red shift in the band gap is related to the presence of uncoordinated surface atoms. These uncoordinated surface atoms not only affects the Fermi level position but also changes the structure of the conduction band by introducing additional Sn-related electronic states close the conduction band minimum. These additional states are due to oxygen vacancies and are attributed to a surface reconstruction of SnO2 nano particles.
NANOBIOCATALYSIS
Syed Tajammul Hussain and Tariq Mahmood
Nano Science and Catalysis Division, National Centre for Physics, Quaid-i-Azam University, Islamabad, 45320. Pakistan.
Abstract
Nanobiotechnology is an important branch of Nanotechnology. Nanobiocatalysis, in which enzymes are incorporated into nanostructured materials, has emerged as a rapidly growing area. Nanostructures, including nanoporous media, nanofibers, carbon nanotubes and nanoparticles, have manifested great efficiency in the manipulation of the nanoscale environment of the enzyme and thus promise exciting advances in many areas of enzyme technology. This presentation will describe these recent developments in nanobiocatalysis and their potential applications in various fields such as in detergents dairy and biofuel cells.
Key words: Nanobiotechnology, Nanobiocatalysis, Enzyme, Applications of Enzymes.
The Emergence of Nano Technology
Syed Tajammul Hussain,
Nano Science and Catalysis Div. National Centre For Physics, Quaid-i-Azam University Campus, Islamabad.
Abstract
The presentation describes the origin, history and technology contribution towards the predicted economics revolution by 2015. This technology will have an economic impact of 2.5 Trillion US $ which is the largest contribution then the combined IT revolution. How this will happen in the coming years will also be described.
This presentation will particularly focus towards the development of new concepts for our young students, teachers and business executives that they should focus their attention towards the development of this emerging field at college level so that we could initiate our R & D towards the solution of country Energy/Environment/Agriculture and Medical Problems. This will help us to capture some of the 2.5 trillion US $ market.
The contribution of National Centre For Physics in the development of this technology towards the solution of country problems will also be presented as an example that what miracles this technology could bring if the Government of Pakistan support this R & D. The survival of our country today’s onward lies in the conversion of nano science into technology for which concentrated efforts are required from all quarters.
Carbon nanotubes, properties and applications
Syed Tajammul Hussain, Asima Siddiqa
National Centre for Physics, QAU, Islamabad
Abstract:
A Carbon Nanotube is a tube-shaped material, made of carbon, having a diameter measuring on the nanometer scale. Since their discovery in 1991 by Iijima, carbon nanotubes have been of great interest, both from a fundamental point of view and for future applications. Carbon Nanotube is simply rolled up graphene sheet like a rolled-up chicken wire with a continuous unbroken hexagonal mesh and carbon molecules at the apexes of the hexagons. There are two main types: Single walled and multiwall carbon nanotubes. Single-walled nanotubes (SWNTs) consist of a single graphite sheet seamlessly wrapped into a cylindrical tube. Multiwall nanotubes (MWNTs) comprise an array of such nanotubes that are concentrically nested like rings of a tree trunk. Various techniques have been developed to produce nanotubes including arc discharge, laser ablation, high pressure carbon monoxide (HiPco), and chemical vapor deposition (CVD). They exhibit extraordinary strength and unique electrical properties, and are efficient thermal conductors. Many potential applications have been proposed for carbon nanotubes, including conductive and high-strength composites; energy storage and energy conversion devices; sensors; field emission displays and radiation sources; hydrogen storage media; and nanometer-sized semiconductor devices, probes, and interconnect.
Key Words: Carbon Nanotubes, synthesis techniques, sensors, energy storage, electrical properties.
Scanning Electron microscope
Farida Yasmin
Abstract
The Scanning Electron Microscope (SEM) is widely used in a number of industries and laboratories to investigate the micro, nano structure and chemistry of a range of both organic and inorganic materials. The main components of the SEM are the source of electrons, the column which contains electromagnetic lenses and a sample chamber. The microscope is rather like an optical microscope in that one of its main purposes is to ‘see’ detail in samples at resolutions greater than is possible with the human eye. However, since it uses electrons as the source of illumination rather than light as used in an optical microscope, far superior resolutions are obtainable.
Basics of Transmission Electron Microscope
Sana Rani
Abstract
The transmission electron microscope (TEM) operates on the same basic principles as the light microscope but uses electrons instead of light. The resolution of a light microscope is limited by the wavelength of light. TEMs use electrons as “light source” and their much lower wavelength make it possible to get a resolution a thousand times better than with a light microscope. Electrons are fired from the electron gun. A positively charged electrode (anode) attracts the electrons and accelerates them into an energetic beam. This electron beam is converted into a thin and focused beam by using different electrostatic and magnetic lenses and metallic apertures. Then electrons strike the specimen resulting in various types of interactions inside the specimen. TEMs are the most powerful electron microscopes: we can use them to see things just 1 nanometer in size, so they effectively magnify by a million times or more. The possibility for high magnifications has made the TEM a valuable tool in both medical, biological and materials research.
