SYNTHESIS OF CARBON NANOTUBE (CNT) BY CHEMICAL VAPOR DEPOSITION (CVD)

 

Aim:

Synthesis of carbon nanotube by chemical vapor deposition.

Apparatus:

CVD reactor, substrate holder, Gas flow system, precursor gas, temperature control system, Scanning tunneling microscope (STM)

Principle:

Chemical vapor deposition (CVD) is a vacuum deposition method that produces high-quality, high-performance, solid materials. The process is often used in the semiconductor industry to produce thin films.

Characterization:

Characterization of CNT can be done by Scanning Tunnelling Microscope (STM)

·        STM can provide atomic resolution images of individual carbon nanotubes, allowing us to visualize their atomic structure, defects, and surface morphology.

·        STM can be used to study the electronic properties of CNT’s by measuring their local density of states with sub–nanometer spatial resolution

·        By analyzing the tunneling current between the STM tip and the CNT surface as a function of voltage, we can investigate the energy band structure, band gap and electronic states.

·        By applying voltage pulse to the STM tip, we can move and reposition individual nanotubes on the substrate, creating customized nanostructure and devices.

·        STM is used to selectively deposit (or) remove atoms and molecules from the surface of CNT, allowing for the controlled modification of their chemical and electronic properties.

·        STM can provide quantitative measurements of various physical properties of CNT such as diameter, length, chirality and surface roughness.

·        By analyzing STM images and conducting statistical analysis, we can extract valuable information about the size distribution, orientation and spatial arrangement of CNT on the substrate.

Application of CNT:

One of the application of CNT is nanomedicine. Role of CNT in nanomedicine is as follows:

·       Drug Delivery

        o   Serve as nanocarriers for drugs, genes, or imaging agents.

        o   Functionalized for targeted delivery to specific cells or tissues.

        o   Enhance drug delivery efficiency and reduce systemic side effects.

·       Imaging and Diagnostics

        o   Functionalized with contrast agents or fluorescent dyes for imaging.

        o   Used in modalities such as MRI and fluorescence imaging.

        o   Enable sensitive and accurate detection for diagnostics.

·       Tissue Engineering and Regenerative Medicine

        o   Serve as scaffolds for cell growth and tissue regeneration.

                     Provide structural support and promote tissue healing.

·       Biosensors

        o   Offer sensitive and selective detection of biomolecules.

        o   Enable early disease detection and monitoring.

·       Biocompatibility and Safety

o   Extensive research is focused on enhancing the biocompatibility and safety profile of CNTs for clinical applications, ensuring minimal toxicity and immune response.

·       Remote Controlled Drug Release

o   Functionalized CNTs can respond to external stimuli such as light, heat, or magnetic fields, enabling the controlled release of therapeutic payloads at specific sites.

Overall, CNTs in nanomedicine provide versatile platforms for drug delivery, imaging, diagnostics, tissue engineering, biosensors, and more applications with the potential to significantly impact healthcare.