Seminar


Department of Chemistry
Indian Institute of Technology Delhi

Tuning Nanoparticle Surfaces: From Cluster Induced Assembly to Dynamics at Single Particle Level

Dr. Indranath Chakraborty
Alexander von Humboldt Fellow and Junior Group Leader Center for Hybrid Nanostructure (CHyN) University of Hamburg

Date: January 23rd 2018 (Tuesday)
Time: 4 PM
Venue: Committee Room, Chemistry Department, 6th Floor

Particles in nano dimension have drawn tremendous research interest owing to their tunable optical and photophysical properties.1, 2 As the dimension of a solid becomes smaller (in nanometer range), the ratio of surface atoms increases dramatically. For a 3 nm gold nanoparticle, ~ 50% atoms are on the surface, while for a large bulk material, the surface layer is only a tiny fraction of the total solid. Thus, surfaces play major roles in dictating properties of colloidal nanoparticles.3 Tuning nanoparticles surfaces is very important to introduce new properties to the system such as solubility, self-assembly, sensing, biocompatibility, etc. Here, few such examples were brought in to highlight the importance of surface tuning in developing optoelectronic4 or biocompatible properties along with the understanding of hidden dynamics at the single particle level.5 We have shown how atomically precise nanoclusters can induce unusual bilayer assembly in the TeNW system and how protein can control nanoparticles surfaces to create differently shaped nanoparticles which help to build a model system to understand the particle toxicity. Along with ensemble analysis, we will explain how single nanoparticle spectroscopy reveals the hidden dynamics of a simple galvanic exchange reaction which results out different surface structure.


    References:
  1. M. A. Boles, D. Ling, T. Hyeon and D. V. Talapin, Nat. Mater., 2016, 15, 141-153.
  2. I. Chakraborty and T. Pradeep, Chem. Rev., 2017, 117, 8208-8271.
  3. J. Hühn, C. Carrillo-Carrion, M. G. Soliman, C. Pfeiffer, D. Valdeperez, A. Masood, I. Chakraborty, L. Zhu, M. Gallego, Z. Yue, M. Carril, N. Feliu, A. Escudero, A. M. Alkilany, B. Pelaz, P. del Pino and W. J. Parak, Chem. Mater., 2017, 29, 399-461.
  4. A. Som,# I. Chakraborty,# T. A. Maark,# S. Bhat and T. Pradeep, Adv. Mater., 2016, 28, 2827-2833 (#contributed equally).
  5. J. G. Smith,# I. Chakraborty# and P. K. Jain, Angew. Chem., Int. Ed., 2016, 55, 9979-9983 (#contributed equally).


All are cordially invited to attend.
Convener (Seminars)