B.A. (Carleton College, 1983)
Ph.D. (University of Illinois, 1990)
Postdoctoral Fellow (U. California,Berkeley, 1990-1992)
Email: Linda.Reven [at] McGill.CA
Lab: Otto Maass 430
Lab Phone: 514-398-8228
Web Page: http://www.reven-group.mcgill.ca
- Chemical Physics
- Materials Chemistry
Our research concerns the assembly of nanomaterials into organized, stimuli-responsive structures, assisted by solid-state NMR characterization. Below are the three main areas that we are currently pursuing:
Patchy Nanoparticles (NPs). Polymer-based "patchy nanoparticles” are particles with at least one well defined patch to allow directional interactions with other particles or surfaces. Patchy particles are of interest for photonic colloidal crystals, multi-compartmental drug delivery agents and catalysts. Obstacles include a lack of large-scale preparations and suitable characterization tools. Theoretical studies of NPs with mixed polymer shells predict phase separated coronas that provide soft, deformable “patches”. We have developed a facile ligand exchange method to produce NPs with mixed polymer brushes and characterized the nanophase separation by NMR. Controlled assembly of patchy NPs into hierarchical superstructures will be tested by varying the NP size and shape and the ratios and chain lengths of the polymer ligands.
Polymer Functionalized NPs in Liquid Crystals (LCs). This topic merges two areas of expertise of my group, polymer functionalized NPs and NP-liquid crystal dispersions. The main goal is develop suitable polymer ligands to replace custom-synthesized mesogenic ligands typically used to form stable NP-LC dispersions, combining the advantages of polymer and NP additives to LCs. NP dopants can enhance LC electro-optical properties and conversely LCs can template NPs into regular spatial structures. LC-polymer blends are widely used for display applications but the LC-polymer interface remains poorly understood. Theoretical/experimental studies of LC-polymer blends, followed by studies of the same polymers tethered to NPs, will examine the chain conformation and dynamics to understand the molecular level polymer-LC interactions.
Tuning NP Properties via Surface Chemistry. A third topic focuses on the effect of the surface chemistry on the properties of inorganic NPs. Since the surface atoms make up a significant fraction of a NP, the ligand shell composition can determine the NP structure. Lead halide perovskites are a promising new class of semiconductor nanocrystals (NCs). Before these NCs can be used for solar cells or opto-electronic devices, an effective surface chemistry is needed to prevent degradation from moisture, light or heat. Another new nanomaterial, ferroelectric BaTiO3 (BTO) nanocubes, are being studied to understand why it remains ferroelectric down to sizes smaller than theoretical predictions, critical for non-volatile memory and other applications. NMR experiments will allow detection of surface reconstruction by ligand exchange reactions as well as matching of ligands to specific surface binding sites.