CRC-colloquia

Scientific colloquia of the Collaborative Research Centre CRC 1585 MultiTrans is a great platform (open to the public) where invited speakers, lead scientists in their respective fields, present new findings of the transport phenomena in nanoscale confinement, functional structured materials and related areas. Each colloquium is divided into a lecture and a following question session.

Friday, 17 May 2024
10:30 o'clock ZOOM and Lecture Hall: H18, NWII

Prof. Thalappil Pradeep, Indian Institute of Technology Madras (IITM), Chennai, India

Matter in Confinement: Atomically Precise Clusters and Microdroplets

Research in the recent past has resulted in a large number of nanoparticles whose properties depend on the number and spatial arrangement of their constituent atoms. This distinct atom-dependence of properties is particularly noticeable in ligand protected atomically precise clusters of noble metals, which I will refer to as nanomolecules in this lecture. They show unusual properties such as luminescence in the visible and near-infrared regions. Their molecule-like behavior is evident from their atom- and structure conserving-chemical reactions. Several clusters, which are archetypal nanoparticles, Ag₂₅(SR)₁₈ and Au₂₅(SR)₁₈ (-SR = alkyl/aryl thiolate) have been used for such reactions. Despite their geometric robustness and electronic stability, reactions between them in solution at room temperature produce alloys Ag_mAu_n(SR)₁₈ (m+n = 25), keeping their M₂₅(SR)₁₈ composition, structure and topology intact. We captured one of the earliest events of the process, namely the formation of the dianionic adduct, [Ag₂₅Au₂₅(SR)₃₆]^2-, by electrospray ionization mass spectrometry. Numerous new ‘molecules’ of this kind have been synthesised in the recent past and they are being taken to practical applications. This work is closely connected to the mission of “clean water for all using advanced materials”. Glimpses of this work will also be presented.

Work in the recent past has shown that new phenomena occur in microdroplets of common solvents. Often, these are related to reaction acceleration. Our work has shown that unusual materials can be synthesized using microdroplets in millisecond timescales. I will illustrate this with various examples involving nanoparticles, functional materials and devices. I will conclude the presentation with an outline of our most recent work on the spontaneous weathering of minerals forming nanoparticles in charged water microdroplets.

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Prof. T. Pradeep

Prof. Denis Morineau - Liquids under Nanoscale Confinement: How Different are they?Hide

Monday, 05 February 2024
12:00 o'clock ZOOM and Lecture Hall: H18, NWII

Prof. Denis Morineau, Institute of Physics of Rennes, CNRS, University of Rennes, France

Liquids under Nanoscale Confinement: How Different are they?

Spatially confined fluids in nanometer-sized geometry exhibit unique fundamental properties that have no equivalent in corresponding bulk systems. In order to illustrate this statement, I will present an overview of studies we have conducted the recent years on different types of liquids, including binary mixtures, water and aqueous solutions, when confined in carefully designed nanoporous materials.The impacts of confinement on their thermodynamics, structure and dynamics over a wide range of time scales will be discussed based on the combination of experimental and numerical methods, encompassing temporal and spatial windows that range from the molecular to the macroscopic scales.

Snapshot of a microphase separated binary liquid confined in a silica pore Hide

Snapshot of a microphase separated binary liquid confined in a silica pore