Molecular Dynamics of PAMAM Dendrimers

1. Molecular Dynamics of PAMAM Dendrimers Jovan Mijovic and Sanja Ristic (Polytechnic University)and Jose Kenny (University of Perugia, Italy) DMR-0346435 NSF-EC PAMAM (poly(amidoamine)) dendrimers, or “dense star” polymers, represent an exciting new class of macromolecular architecture (Fig.1). Unlike conventional polymers, dendrimers have well defined, highly branched, compartmentalized structure in the nanometer size range and exhibit unique properties which make them promising candidates for many applications, including drug delivery, gene therapy, imaging, sensing, optoelectronics and catalysis. The principal objectives of this study are to conduct an investigation of the dynamics of PAMAM dendrimers by dielectric relaxation spectroscopy (DRS) and dynamic mechanical spectroscopy (DMS). Studies of dynamics probe the motions of molecules in Fig. 2 α γ β 0.09 Permitivitty’’ 0.06 applied fields, such as electric or mechanical, and are crucial for understanding processing and properties of materials. Fig. 1 0.03 -2 1 0 1 2 3 4 5 6 7 log (frequency) Fig. 3 γ 0.1 Two generations of PAMAM dendrimers were investigated by DRS: generation 0 (Fig. 2) and generation 1 (Fig. 3). Both of them have 3 relaxations but there is a difference (Fig 2 vs 3) which we are now trying to relate to their molecular structure. β α 0.08 Permitivitty’’ 0.06 0.04 -2 1 0 1 2 3 4 5 6 7 log (frequency) Structure of dendrimers (Fig.1); Dielectric permittivity in the frequency domain with temperature as a parameter for generation 0 (Fig. 2) and generation 1 (Fig. 3)

2. Dynamics of Nanostructured Systems Jovan Mijovic, Polytechnic University, DMR-0346435 NSF-EC Education: Four Chemical Engineering PhD students: HyungKi Lee (3nd year), Yu Bian (3nd year), Sanja Ristic (2st year), Chetan Khamar (1st year) and four undergraduate students in Chemical and Biological Engineering: Ruel McKenzie (Senior), Anastasija Shytuhina (Junior), Darya Kozlova (Senior) and Qi Ke Chen (Junior) are currently involved in this program. Outreach: Every year our lab accommodates a number of under-represented minority students from New York City high schools under the aegis of the YES (Youth in Engineering and Science) summer program at Polytechnic University. Photo Caption: From left to right: Sanja Ristic, Ruel McKenzie, Yu Bian, HyungKi Lee, Anastasija Shytuhina, Professor Mijovic, Darya Kozlova and Qi Ke Chen. Chetan Khamar is not in the picture.