Research

A Generic Supercritical CO2 Process for the Creation of Nano-Scale Wires And 3-D Meso-Scale Porous Structures for a Large Class of Inorganic Materials And Alloys

Application of Calcium Carbonate Scaffolds Fabricate by Supercritical (sc)-CO2 for Tissue Engineering

Fabrication of ZnO Nanostructures Using Supercritical Technologies

We have synthesized ZnO nanowires, nanorods, and other nanostructures using supercritical CO2 media. These nanostructures are attractive components for nanoscale electronic, optical, and photonic device applications because of their advanced characteristics. Recently, ZnO nanostructures have been used for a variety of nano-devices applications including ultraviolet photodetectors, FETs, diodes, gas sensing, light emitting device arrays, etc.

De-wetting Thin Film

Such low-dimensional nanostructures provide a promising building block for the fabrication of various miniaturized devices and systems for applications in electrochemical, biological, and energy-related fields, Micro-fluidics, and related areas, but also as a potential bio-micro platform to promote the advancement of bionanotechnology.

Characterization of Micro-algal Cells

The rapid and reliable detection of micro-organisms with a high grade of sensitivity and selectivity is quite challenging for various emerging fields, e.g., clinical diagnosis, bio-fuels, pharmaceutical, and etc. Biofuels, an alternative to conventional fuel created from renewable biological sources such as vegetable oils and animal fats. From biodiesel perspectives, Algae has demonstrated rapid growth, high productivity, acts as a dominant feedstock to store oil with high energy conversion efficiency. It contains proteins, carbohydrates, lipids (fatty acids), and nucleic acids in different proportions.

Vibrational spectroscopic techniques have created a number of technical and scientific advancements for identification and quantification of various microorganisms for bulk environment as well as single-cell analysis. Raman-spectroscopy is exclusively adapted for biological applications as it offers better contrast and ability to examine liquid samples than IR. For micro-algae characterization, we use Confocal Raman Microscopy (CRM), a combination of confocal optical microscopy with Raman spectroscopy with adaptable data acquisition rates for quick and reliable differentiation of fatty acids in algal cells. The chain length and degree of unsaturation of fatty acids for diverse algal samples have calculated.

Biomaterials Synthesis in sc-CO2 Formulations

Extension of the molecular-cluster assembled materials to bioengineering would solve an important problem in the field of rapid analysis of bio-molecular interactions, which is essential to detection of genetic polymorphisms, analysis and discovery of metabolic pathways, characterization of mechanisms of drug action, and adverse drug response, and deciphering of the molecular basis of life processes. Biomolecules are typically printed from aqueous mixtures, making the process highly susceptible to variations in ambient humidity, surface wetting phenomena, and surfactancy behavior of the molecules being deposited leading to non-uniform deposition coverage, effectively altering the surface concentration of the capture species, and making the extent of binding between targets and capture molecules extremely difficult to quantify via automated algorithms that are necessary to process thousands of reactions per experiment. When printed from sc-CO₂ formulations, we expect to be able to deliver precise amounts of these bio molecules which are expected to form uniform self-assembled films on specific array sites.

Our study with pharmaceutical materials to create molecular clusters of drugs (e.g., insulin), would enable drugs that could cross the blood brain barrier, novel drug delivery systems such as non-contact injection directly into the blood stream through the skin, and drugs directly printed inside carrier materials.

Nanoindentation of Organic Thin Film

Synthesis of surfactant-free dispersion and superhydrophobic Film by Supercritical CO2

Molecular Clusters and Cluster Assembled Solids

This work is based on the pioneering research by a group of scientists at Kodak, under leadership of Professor Jagannathan, that have led to the development of a supercritical CO₂ based process for the synthesis of stable molecular clusters of a number of organic materials. The molecular clusters with size in the range 1-10 nm, were quite stable with lifetimes greater than two years and also exhibited a strong dependence of photoluminescence (PL) on the precipitation process parameters. Photoluminescence was tunable over 10-100 nm and new PL features could be resolved depending on precipitation conditions. They demonstrated a strong tendency to readily self assemble into (micron thick) three dimensional superlattice structures on various substrates at room temperature. The molecular clusters were liquid-like at room temperature. In one example, their super-hydrophobic property extended through an overcoat of 20 nm thick gold/palladium. Efficient, functional OLED devices were built with these molecular cluster films implying efficient electrons and holes transport.

This work is exciting because it opens up a new class of organic nanomaterials held together by weak van der Waals forces that are exceptionally stable and possess properties that rival their inorganic counterparts, even in the absence of an ordered structure or quantum confinement effects.

At NYUAD Engineering, we continue this new field of research, confirm and establish these novel phenomena on a solid foundation for a broad class of materials, improve the precipitation process to generate reliable data for a number of materials and generate sufficient data to enable new theoretical insights and spur new research.

* These pictures are pre-peer reviewed version of the following articles: