Eisenthal Group

Department of Chemistry
Columbia University
3000 Broadway, New York, NY 10027



Group Website

    We study equilibrium and dynamical properties of molecules at interfaces.  Many important chemical processes occur at liquid interfaces.  Examples include cell membranes which host a variety of vital reactions in biology and life science, air/water interface (environmental importance), solid/liquid and liquid/liquid interfaces in catalysis and electrochemistry, surfaces of self-organized structures such as phospholipid bilayers, liposomes, and micelles, and surfaces of colloids and nanoparticles.
    Experiments performed in our lab are a unique combination of ultrafast (femtosecond) and surface-selective capabilities.
    We use nonlinear optical spectroscopies to selectively probe molecules in the the very thin interfacial region (~10 ).  The second order nonlinear optical processes of Second Harmonic Generation (SHG) and Sum Frequency Generation (SFG) are symmetry-forbidden in bulk media, but allowed at interfaces.
     In our experiments we use femtosecond lasers to perform ultrafast time-resolved measurements.  This allows to observe motions and reactions of molecules at interfaces in real time.  Our current time resolution is ~100 fs.
    Here are examples of static molecular properties at liquid interfaces that have been characterized in our group:
        * pK of acids and bases
        * Orientation of adsorbed molecules
        * Electronic spectra
        * Polarity
        * Surface potential of charged interfaces
        * Surface properties of microscopic particles: metal nanoparticles, liposomes, semiconductor quantum dots, clays, polymer beads, emulsions
        * Biomembrane surfaces
    Dynamical molecular processes at interfaces include
        * Intermolecular energy transfer
        * Orientational relaxation
        * Photoisomerization
        * Solvation dynamics

 Recent publications

Group Members
Prof. Kenneth B. Eisenthal  ( kbe1@columbia.edu )
   Dr. Yi Rao, research scientist (yr2122@columbia.edu  )
   Dr. Louis Haber, post-doc scientist (lh2485@columbia.edu)
   Sung Young Hong, graduate student (sh2580@columbia.edu)
   Sheldon Kwok, undergraduate student (sjk2154@columbia.edu)

  Havermeyer Hall             Offices:  Room 604-605                Laser Labs:  Room 603                Wet Lab: Room 610
  Department of Chemistry,  Columbia University, 3000 Broadway, New York, NY 10027
  Phone: (212) 854-2094

 Department of Chemistry home page