Welcome to Xi's group.
 The nature of intermolecular and intramolecular interactions is a basic topic in science;
however it is very difficult to be studied at a single molecular level. We have employed AFM-
based single molecule force spectroscopy (SMFS) to study the intermolecular and intra-
molecular interactions in macromolecular and supramolecular systems in single molecular level,
hence promoting significantly the progress of polymer science and opening new horizons for
supramolecular science. With the help of this nanotool, we have obtained some of the
important information which is not available by conventional characterizing methods, including
single chain mechanics, the interfacial conformation and adhesive energy of polymers, and
interaction between macromolecules and small molecules. Our recent research has focused on
understanding the intermolecular interactions in supramolecular systems. For example, pyrene-
labeled PEG chains can be used to directly measure the π-π interaction between the pyrene
and graphites, which revealed to be 55 pN. Many intermolecular interactions, such as
interactions between dendrons, intercalation interactions between dsDNA and acridine, can
be studied by this method as well. It is hoped that this line of research will provide physical
insights into the cooperativity of intermolecular interactions that governs molecular self-
Recently Published Papers:
 Macromolecules 2004, 37, 946;Macromolecules 2004, 37, 1839;Cur. Opin. Solid State
Mater. Sci. 2005, 9,140;J. Phys. Chem. B 2005, 109, 14807;Macromolecules 2005, 38, 861;
Macromolecules 2006, 39, 3480;Polymer 2006, 47, 2499;Angew. Chem. Int. Ed. 2007, 46,
8400;Langmuir 2007, 23, 7911;Langmuir 2007, 23, 9140;Polymer 2007, 48, 2030;Langmuir
2008, 24, 1318; Langmuir 2009, 25, 6627; Langmuir 2009, 25, 10002;Langmuir 2010, 26,
13773;J. Am. Chem. Soc. 2011, 133, 3226;Langmuir 2012, 28, 960;Langmuir 2013, 29,