Introduction to Luning Zhang's group @ Tongji University
Chemical reactions in nature, industrial processes, and our body invovle energy absorption and release. Photons not only deliver energy for chemistry processes, they are also excellent reporters for even the smallest energy exchange of a chemical reaction. In our group, we study how to use different kinds of laser techniques for probing molecular interactions on nanometer scale.
A more detailed summary is given blow:
Objectives
To develop new optical imaging and spectroscopic tools that can probe physical, chemical, and biological processes under small length scales.
The objectives are therefore two folds. First, we want to develop new optical techniques, aiming at single molecule and nanometer scale resolutions, so as to probe small changes in pH, temperature, charges, molecular orientation, bonding, etc. Second, we hope to apply these new techniques in solving some basic and important chemistry problems, such as behavior under small length scale, non-equilibrium dynamics, and single molecule recognition.
Scientific Background
My encounter with research was a project on the reactions of metal atoms with carbon dioxide and water molecules. By trapping reaction intermediates in argon at 10 K, we were able to study the species at ease using infrared spectroscopy, and to search for interesting reaction pathways relevant to catalysis, carbon dioxide activation, and water splitting. I continued to pursue more chemistry problems at U.C. Berkeley. My major was physical chemistry and my dissertation was supervised by Professor Yuen-Ron Shen, a famous physicist. My Ph.D. research was done in the physics department (Birge Hall), an experience that greatly broadened my perspectives for chemistry. In physics, people search for a clear physical picture of a problem, with well-defined mechanism and scientific principles. This approach often helps to clarify the sporadic and blurry chemistry information in my research.
During my Ph.D. research, I used nonlinear optics techniques such as sum-frequency vibrational spectroscopy (SFVS) and second-harmonic generation (SHG) to look into molecule-level details of solid-liquid interfaces. I studied competitive molecular adsorption, water molecule orientation, surface charge, and behavior of supherhydrophobic nanoporous surfaces. My strong interest in soft condensed matter developed from the scientific training during my MSc. and Ph.D. studies.
I spent two years at SRI International (originally Stanford Research Institute) as a postdoc researcher. I participated in two applied projects: surface etching of carbon-based materials using nitrogen atoms, and doping effect on the thermal transport properties of ultra-high temperature ceramics (UHTC). These projects were funded by NASA and AFOSR (Air Force Office of Scientific Research). During my postdoc studies, in addition to lasers, I got hold onto an AFM in the lab and quickly realized its uniqueness in bridging the gap of chemistry and physics problems. This experience helped me to develop a strong interest in developing scanning probe microscopic tools in combination with optical techniques.
My first formal job was an innovator working on applied technology incubation at Siemens. After 15 months of fruitful industrial research and training. I started my teaching career at Tongji University. Here at TJU, I find a perfect place to integrate my solid scientific training and enthusiasm for teaching and research, and I am able to devote to the education of graduate and undergraduate students. In our group, we invent and refine tools for precision control and optical characterization of molecules and nano-objects such as cells and nanoparticles. Our research interests are given in the "Research" section on this webpage.
Perspectives
As stated beautifully in the Encyclopedia of Analytical Chemistry: The ultimate goal of analytical chemistry is the detection, analysis, and manipulation of single molecules. Moreover, we have to face the fact that often these molecules exist under extreme conditions such as nanoscale confinement, fast conformation/concentration fluctuation, quick transport, short lifetime, etc. Therefore, new tools need to be developed to extract novel chemical and physical information from these systems.
I envision that in the next decade, analytical chemistry will overlap more with, and also borrow more ideas from condensed matter physics, biology, and material chemistry to tackle molecular events under extreme but real life-related conditions. Interesting findings and principle breakthroughs about molecules in action will emerge with the help of analytical chemistry at small scales.
Chemistry is an amazing subject and our daily life hinges on it. It will be of great encouragement to us if the research summarized here may in some way be userful for the society and help improve human life.