Daniel K. Schwartz
Professor
ECCH 103B
(303) 735-0240
daniel.schwartz@colorado.edu
Curriculum Vitae
Education:
Ph. D. in Physics, Harvard University (1991)
A.B. summa cum laude in Chemistry and Physics, Harvard University (1984)
Awards:
•2008-Boulder Faculty Assembly Award for Excellence in Research
•1999 Camille Dreyfus Teacher-Scholar Award (1999)
•1998 NSF/CAREER Award (1998)
•1997-1999 Mortarboard Honor Society Salute for Excellence in Teaching (3 times, 1997-99)
•1994 Camille & Henry Dreyfus Foundation New Faculty Award (1994)
Selected Publications:
•Siwar Trabelsi, Shishan Zhang, Zhongcheng Zhang, T. Randall Lee, Daniel K. Schwartz,
Langmuir
25, 8056-8061 (2009) “
•Andrei Honciuc, Denver Jn. Baptiste, Ian P. Campbell, and Daniel K. Schwartz, Langmuir 25, 7389-
7392 (2009) ““Solvent Dependence of the Activation Energy of Attachment determined by Single Molecule
Observations of Surfactant Adsorption””
•Andrew D. Price, Jordi Ignés-Mullol, Thomas E. Furtak, Yu-an Lo, Stephanie M. Malone, and
Daniel K. Schwartz, Soft Matter, 5, 2252-2260 (2009) ““Liquid Crystal Anchoring Transformations Induced by Phase Transitions of a Photoisomerizable
Surfactant at the Nematic/Aqueous Interface””
•Andrei Honciuc, Daniel K. Schwartz, J. Am. Chem. Soc. 131, 5973-5979 (2009) ““Probing Hydrophobic Interactions using Trajectories of Amphiphilic Molecules at a Hydrophobic/Water
Interface””
•Andrei Honciuc, Denver Jn. Baptiste, Daniel K. Schwartz, Langmuir 25, 4339-4342 (2009) ““Hydrophobic Interaction Microscopy: Mapping the Solid/ Liquid Interface using Amphiphilic Probe
Molecules””
•Steve T. Marshall, Daniel K. Schwartz, J. William Medlin, Sensors and Actuators B: Chemical 136,
315-319 (2009) ““Selective Acetylene Detection Through Surface Modification of Metal-Insulator-Semiconductor Sensors
with Alkanethiolate Monolayers””
•Siwar Trabelsi, Shishan Zhang, Zhongcheng Zhang, T. Randall Lee, Daniel K. Schwartz, Soft Matter
5, 750-758 (2009), ““Semi-fluorinated Phosphonic Acids Form Stable Nanoscale Clusters in Langmuir-Blodgett and Self-
Assembled Monolayers””
Research Interests:
Interfacial phenomena, Molecular thin films, Nanoscale surface structures, Biomolecules at interfaces
Fundamentals and applications of self-assembled monolayers:
Fundamental growth processes of self-assembled monolayers (SAMs), ultra-thin molecular films adsorbed from solution on solid surfaces, are studied using single molecule fluorescence microscopy, atomic force microscopy, and spectroscopic techniques. These monolayers represent a versatile coating technology with applications in biocompatibility, nanotechnology, biosensors, corrosion resistance, and molecular electronics. We have demonstrated that many of these systems form via an "islanding" mechanism, in which 2D aggregates of adsorbate molecules nucleate, grow, and coalesce on the substrate (see figure). These processes are elegantly described by kinetic models originally created to explain vapor phase growth of semiconductor films in high vacuum. We are continuing these fundamental investigations in an effort to develop a generalized understanding of monolayer growth so that this technology will become applicable to a wider variety of substrate materials. Technological applications of current interest in our group include self-organized strategies for the creation of nano-patterned surfaces (the fabrication of molecular "dots" and "lines"), chemical modification of bone-implant materials (e.g. titanium alloys) for optimized bone growth and adherence, and development of novel surfaces for liquid crystal alignment.
Biomolecules at interfaces:
Biomacromolecules, like proteins and DNA, interact in complex ways at interfaces. We are studying the structural changes that occur when proteins adsorb at solid surfaces and at the air/water interface using a combination of interfacial rheology, atomic force microscopy, and infrared spectroscopy. We are particularly interested in understanding how intramolecular structural changes (e.g. protein unfolding) affects intermolecular interactions such as aggregation and the formation of interfacial gels. This has applications in a number of areas, including the stability of pharmaceutical proteins as well as food colloids. We are also interested in the ways in which molecular monolayers at interfaces are modified by specific molecular recognition, such as protein-ligand binding or DNA hybridization. Our research in this area is motivated by the prospect of developing novel bio-sensing strategies.
Phase behavior and rheology of Langmuir monolayers:
The organization and transport of molecules at fluid/fluid interfaces are directly related to the stability and dynamics of foams and emulsions. These systems are also important models for cell membranes and are of fundamental interest because of their quasi-two dimensional character. We use specialized optical microscopy techniques (fluorescence and Brewster angle microscopy) to study the complicated phase behavior of monolayers at the air/water interface. We also combine microscopy with novel interfacial rheometric techniques to explore how interfacial flow is related to the monolayer structure (e.g. the molecular orientation). In monolayers of small molecules (i.e. fatty acids), we have discovered a rich variety of shear-driven effects, ranging from continuous molecular "tumbling" to "avalanches" of molecular orientation.
