About Me

I design materials!

Characterization

There is a whole new world when you go sub-nanometer!

Characterization

Electron Microscopy (EM):

As a materials scientist, I have been directly engaged with several research porjects where understading the materials' behavior requres looking into their nano-scale feature. Electron microspcope is the key tool in this respect. Scanning electron microscopy (SEM) is the go-to techniques when surface and morphoplogical information are required. It can also provide sruface compositional analyais via energy-dispersive X-ray spectroscopy (EDX)/SEM. Moreover, combining SEM with focused ion beam (FIB) technique provides a strong tool for micro- and nanoscale manipulation of struture. On the other hand, transmission electron microscopy (TEM) is a strong technique with a wide range of capabilities. These include: crystal orentation relationships, bright- and dark-field imaging, diffraction pattern (SAD) analysis for crystalline materials such as metals, nano-composites, catalyst nanoparticles; electron energy loss spectroscopy (EELS) for chemical bonding state and elemental analysis of almost any material; spectrum imaging and elemental analyais in high resolution using scanning TEM (STEM) mode; atomic-level analysis using high resolution TEM (HRTEM). For examples of my works in this field, please see below. Besides EM, I have extensive experience in a variety of characterization techniques. Below is a list of techniques and my corresponding experience with them:

• Gas sorption analysis (nitrogen, carbon monoxide, water vapor, hydrogen)

  Surface area (BET) and pore size distribution (BJH) analysis of fuel cell catalyst and gass diffusion layers, Li-ion battery electrodes, Mg-based thin film alloys for hydrogen storage

• X-ray photoelectron spectroscopy (XPS)

  Top-surface elemental and chemical bonding state identification of catalyst thin films for the oxidation reduction reaction (ORR) in fuel cell

• X-ray diffraction pattern (XRD)

  Phase identification, grain size and strain analyais in crystalline materials, tracing the microstructural evlolution of catalysed magnesium for hydrogen storage during the durability testing

• Atomic force microscopy (AFM)

  Observing roughness features of nano-fabricated srufaces of varying roughness scales for wettability studies, nanoscale mechanical properties of shape memory alloy thin films

• Thermal properties measurments via differential scanning calorometry (DSC) and thermogravimetry (TGA)

  Estimating the heat of formation and decomposition in hydrogen storage alloys, estimating the wieght percentage of carbon in fuel cell catalyst layer

Electrochemistry

Electrochemical Analysis:

Electrochemical analysis offer a wide range of application towards characterizing and developing new materials for energy conversion devices. This field involves chemical changes in materials due to the passage of electric current or the production of electrical energy sue to chemical reaction. These analyses can provide thermodynamics information during a reaction, creating unstable intermediate species, estimating trace amount of metallic or organic species in a solution and the rate of reaction on the surface of a particular material.

I have extensively used electrochemical analysis for creating and performance testing of materials within a wide range of application including:
- Fuel cell electrocatalyst design and durability testing
- Li and Na-ion battery electrode material design and durability testing
- Interfacial and surface analysis using an unconventional electrochemical device
- Corrosion testing of stainless steel alloys 

Techniques I have used in the past 6 years are as follows:
- Cyclic Voltametry (CV)
- Adsorptive Stripping Voltammetry (AdSV)
- Square Wave Voltammetry (SWV)
- Corrosion testing
- Electrochemical Impedance Spectroscopy (EIS): mathematical modeling and experimental

Synthesis

Materials Synthesis:

Over the past 12 years, I have been involved with numerous projects wehre the synthesis of a materials with desired properties, geometry and functonality played important role. I have gained working knowledge and hands-on experience with a broad range of creating new materials. These include conventional well-developed metallurgical methods as well as unconventional recently-developed techniques. Below is a summary of the methods I have utilized in the past with examples:

• Developing Metallic Alloys via Casting

  Developed a new generation of Sn-based lead-free solder alloys by addition of rare-earth metals, a new metal mixing tool during melting process was desgined

• Physical Vapor Deposition (PVD) via Magnetron Sputtering

  - Developed a new series of ternary Mg-based alloys for solid state hydrogen storage with excellent durability and fast kinetics at low temperature.  
  - Created trimetallic Pt-based alloys with enhanced ORR activity for PEM fuel cell application.
  - Developed Fe and Nb doped TiO ₂films as model systems for Na-ion Batteries
  - Designed a series of thin corrosion resistant layers for stainless steel

• Chemical Vapor Deposition (CVD)

  - Developed carbon nanotubes (CNTs) on various substrates with and without the use of buffer layer using different types of growth catalyst
  - Fabricated Graphene on thin copper sheets, performed graphene transfer onto desired substrates such as Pt for electrocatalytic application 
  - Created Si and ge nanowires for Li- and Na-ion batteries

• Plasma Etching and Treatment

  - Utlized O ₂, Ar, CF ₄, CH ₃F, SF ₂gas mixtures to obtain well-defined and uniform surface features on Si and carbon susbtrates
  - Optimized the plasma etching process to achieve desired surface morphoplogy  

• Ink-jet Printing of Functional Materials

  - Produced PEM fuel cell catalyst layers with defined geometry and known composition
  - Improved and modified the ink-jet printing procedure to maximize production and reduce cost

• Polymer Synthesis

  - Addition polymerization through initiation, propagation and termination 
  - Coplymerization
  - Polymeric surfaces via spin soating, grafting, etc.

• Wear resistant coating using welding

R&D

Research and Development:

During my Phd studies in the University of Alberta, I have gained deep understanding of R&D in clean energy systems. This has helped me expand my previous experience of R&D in my undergraduate internship program. During my BSc studies, I became involved in R&D activities in RGC Co., an engineering company in the field of corrosion protection and pipe coating products. During my tenure at the University of Alberta, I have collaborated in several industrial partnership programs where I provided materials characterization insight to the R&D team of industry partners. My most important R&D expertise comes from my involvement in the catalyst layer and modeling team in Automotive Fuel Cell Cooperation Corp. (AFCC), the world class R&D facility of Mercedes-Benz, Ford Motor Company, and Daimler AG for fuel cell commercialization in Burnaby, BC. As a postdoctoral research scientist in AFCC, I am involved with several R&D activities including product development and quality control. I am currently leading a project on the structure, property and performance correlation of hydrogen fuel cells for automotive application in this position.