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 intramolecular 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-assembly.
Recent Publications:
 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, 14438.