Taimur Athar

Wet Synthesis of Copper Oxide Nanopowder

ABSTRACT A simple and efficient synthesis of cuprous oxide and cupric oxide nanoparticles was carried out with controlled surface properties via soft chemistry approach. The monodisperse and versatile Cu2O and CuO nanoparticles were characterized with the help of FT-IR, UV-Vis, TGA/DSC, XRD, SEM-EDX, TEM, and BET. From the XRD analysis, the size of Cu2O and CuO nanoparticles were calculated as 31 nm and 32 nm, respectively, which is calculated with the help of Scherer equation, as supported by TEM. The morphology of the nanoparticles can be controlled by tuning the amount of KOH and nature of solvent. Chemie douce approach is a novel, cheap, and convenient technique suitable for industrial production.

Wet Synthesis of Monodisperse Cobalt Oxide Nanoparticles

Ultrafine and monodispersable colloidal cobalt oxide nanoparticles were successfully synthesized quantitatively via soft chemical approach with controlled particle size and microstructural properties for their use in technological applications. The particle size, shape, and other microstructural properties are directly influenced by their reaction conditions. The FT-IR studies give information for phase purity, and ultraviolet absorption spectroscopy helps to study the optical properties. Thermal analysis gives the information about thermal stability. With the help of X-ray diffraction pattern, the size of the particle was calculated. An electron microscope studies help in morphological characterization, and Brunauer-Emmett-Teller method gives information about surface area. Cobalt oxide nanoparticle tends to orient itself with its narrow size distribution having a crystal size around 50 nm.

Metal Oxide Nanopowder

Research into soft chemical techniques has gained an importance for the synthesis of high quality advanced nanosized materials with desired properties at the low crystallization temperature. The closer interaction between the material chemists and alkoxide chemists has led to the molecular design of more suitable precursors, for fabrication of functional material has resulted in synergetic developments in both the fields. Metal alkoxide is a versatile precursor and is used for the synthesis of functional gradient nanomaterials, and characterization of materials was carried out in term of composition, microstructure and specific surface area. The write-up provides simple and convenient routes to many building blocks for assembling the structure with novel properties and its functional use in nanotechnology.

Super paramagnetic iron oxide and gadolinium (FeGdO3) nanopowder synthesized by hydrolytic approach passes high level of biocompatibility and MRI-based dual contrast property for competent molecular imaging and therapeutic interventions

The synthesis of monodispersable FeGdO3 nanopowder with well-defined architectural framework was carried out by using metal chloride as a single source molecular precursor by modifying reaction conditions to obtain an ultra-pure surface area for better understanding the chemistry involved in micro to nanoscale. By controlling the reaction parameters at the molecular level helps to synthesize a technology oriented nanomaterials with high crystalline particle size and shape with required surface morphologies at the nanoscale. The FeGdO3 nanomaterial was characterized by XRD, SEM, TEM, thermal analysis and FT-IR. The x-ray diffraction patterns indicate the formation of square planar crystallite size of 41.65 nm after annealing. The integral properties of nanomaterial depend upon the synthetic approach through self-assembly which helps in the formation of primary nuclei from metal chloride as smart molecular precursor. This opens a new exciting vista for a better understanding of the reaction conditions and growth mechanisms. We used two cell types; human mesenchymal stem cells (MSCs) derived from umbilical cord blood and human neuronal cells to evaluate the toxicity and dual contrast properties of FeGdO3 nanoparticles further their application in high contrast imaging and stem cell labeling and tracking. We found that various concentrations of FeGdO3 nanoparticles do not influence the cellular mechanisms involved in cell survival and proliferation which proves high biocompatibility nature of FeGdO3 nanoparticles with cells. Enhanced signal intensity during low-field MRI (1.5T) with iron oxide and gadolinium provides its further clinical implications as dual contrast imaging agent with more advancements.

SYNTHESIS OF β-DIKETIMINATE DERIVATIVES OF ZINC ALKOXIDES: CATALYTIC PROPERTIES FOR RING OPENING POLYMERIZATION

A series of zinc (II) complexes has been prepared based on a β-diketiminate ligand framework and exhibits the highest rate of polymerization with better stereoselectivity in the formation of polylactic from the rac-lactide with aggregation and narrow polydisperties. Degree of aggregation and their reactivity’s depends on the nature of alkoxy groups, the role of metal ion, solvent and their structural properties. The nature of substituent group on β-diketiminate ligand exerts a significant change affecting both the degree of selectivity and the rate of polymerization. The polymerizations are living, as evidenced by the narrow polydisperties and with their linear nature and average molecular weight.

An Approach for Synthesis and Characterization of Zirconia Nanopowder via Microwave Thermal Process

We applied a simple, versatile and an efficient non-toxic methodology based on microwave irradiation process to prepare a gel from n-zirconium butoxide without using any solvent at ambient temperature to open new possibilities to control particle size distribution, surface chemistry and agglomeration. The alkoxy-derived gel changed to tetragonal zirconia powder on heating at 400°C with crystalline particles size (3 ∼ 5 nm). Zirconia exhibited strong luminescence under a UV laser. The presence of a organic moieties as impurities exhibit a strong luminescence in zirconia powder. From the structural analysis it is concluded that the morphology of the oxide strongly depends on the nature of the precursors and the synthetic methology.

A Novel Approach for the Synthesis of Ti- and Zr-oxo Species as Precursors for Metal Oxide Nanopowder

ABSTRACT Thermal and microwave irradiation treatment of Ti(OPri)4 and Zr(OBu)4 leads to the formation of homogenous and transparent oxo-alkoxy derivatives of titanium and zirconium in a quantitative yield. The oxo-alkoxy derivatives were characterized with the help of FT-IR, NMR, UV, Raman, GC–mass spectroscopy, and elemental analysis. The physicochemical properties of gel differ considerably from their corresponding parent metal alkoxides. Hence, the gel can be considered as an immediate precursor for the preparation of functional metal oxide nanomaterials under mild conditions with control over particle size and its distribution, surface chemistry, and particle agglomeration. The morphology of the metal oxides strongly depends on the nature of the precursor and as well as synthetic methodology.

Synthesis of Nanostructured Material and Its Applications as Surgical Tools and Devices for Monitoring Cellular Activities

Since the beginning of twenty-first century assembling of nanobricks with innovation and creativity lead to functional structural framework in order to fabricate a reliable–reproducible result-oriented nanodevice remains a synthetic challenge to the researchers and technologist. The use of nanomaterials as diagnostic tools is relatively a new area in medical research. The soft chemical approach help for synthesis of nanoparticle with distinctive physical, chemical, and electronic properties for various biosciences–clinical applications, opens new possibilities with controlled size particle and its distribution, surface chemistry, and agglomeration, which has attracted a remarkable interest in recent years precisely to label and to track abnormalities in vivo administration. Many contrast cell labeling and tracking strategies were used based on metal oxide nanopowder with high biocompatible to give a better contrast due to their Lewis-acid behavior of metal ions. With fast research in nano-biotechnology, demands for new synthetic approach for clinical functional materials have attracted interest for scientists. In coming times, it will revolutionize clinical studies both in vitro and vivo imaging with desired chemical composition, crystal phase, and surface morphology by better understanding biological barriers to target the drug at the malfunctional sites. Open image in new window

Smart precursors for smart nanoparticles

Smart precursors based on metal alkoxide are used as a versatile single-source molecular precursor for the synthesis of high-tech, functional, colloidal smart nanomaterials with a well-defined structural framework having a good crystallinity phase selectivity, and high chemical homogeneity. The synthesis of cost-effective metal alkoxide can be designed based on the principle of geometrical molecular structure at low temperature in inert atmosphere. The concept depends on the electronegativity as well as electronic configuration of the central metal ion with highest nuclearity. Chemical modifications in the organic moiety in the precursor allow the synthesis of smart functional materials with novel properties. By tuning the reaction conditions, the rate of agglomeration, surface morphology, and polydispersity index can be controlled in smart materials. The presence of M O C bond polarities and degree of polymerization helps to control the size, shape, and thermal stability in functional nanomaterials, keeping the stoichiometric ratio under control by understanding the surface chemistry. Improved understanding of the donor–acceptor properties in metal alkoxide leads to the design of self-assembling nanostructured frameworks at the micro- to nanoscale. Refining our knowledge in surface chemistry to understand the structural parameters helps in controlling thermodynamic–kinetic parameters at the bench scale towards the production level. The characterization of molecular precursors and their corresponding nanomaterials was carried out with the help of various types of spectroscopy, including FTIR, UV, Raman, thermal analysis, XRD, NMR, SEM, and TEM. The chapter highlights the state of the art for the cost-effective synthesis of ultrapure functional nanomaterials from single-source molecular precursors, to understand the structural–functional surface properties relationship based on chemical–thermal stability with the help of the Lewis acidic behavior of the metal ion involved in the process.

Chapter 14 – Metal Oxide Nanopowder

Research into soft chemical techniques has gained an importance for the synthesis of high quality advanced nanosized materials with desired properties at the low crystallization temperature. The closer interaction between the material chemists and alkoxide chemists has led to the molecular design of more suitable precursors, for fabrication of functional material has resulted in synergetic developments in both the fields. Metal alkoxide is a versatile precursor and is used for the synthesis of functional gradient nanomaterials and characterization of materials was carried out in term of composition, microstructure and specific surface area. The write-up provides simple and convenient routes to many building blocks for assembling the structure with novel properties and its functional use in nanotechnology.