Lecture

Nanocrystal Synthesis: Nucleation and Growth

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

In course

ChE-430: Nanomaterials for chemical engineering application

This course provides an overview on nanoparticle synthesis and their use in different energy-related applications. The first part of the course is more fundamental and chemistry oriented. The second part is more applied and chemical engineering oriented. T ...

Description

This lecture by the instructor covers the synthesis of nanocrystals through top-down and bottom-up approaches, focusing on the nucleation and growth mechanisms. It delves into classical and non-classical nucleation theories, discussing the role of monomers, nuclei, and nanocrystals. The lecture explores the factors influencing nucleation rates, such as saturation and temperature, and the size distribution of nanocrystals. Additionally, it explains the chemical reaction mechanisms involved in the synthesis of metal oxides and semiconductors, highlighting the importance of sol-gel reactions and thermal decomposition. In-situ studies using transmission electron microscopy and infrared spectroscopy are presented to corroborate the non-classical growth of nanocrystals.

Instructor

Raffaella Buonsanti

Teaching & PhD PhD Students Riya Gupta, Jennifer Calderon Mora, Coline Boulanger, Moritz Tritschler, Marco Fabbiano, Seyedmohamadjavad Chabok, Hugh Andrew Warkentin Past EPFL PhD Students Chethana Janardhana Gadiyar, Seryio Saris, Valeria Mantella, Seyedehbehnaz Varandili, Pranit Srinivas Iyengar, Yannick Thomas Guntern, Jan Vávra, Laia Castilla Amorós, Valery Okatenko, Ona Segura Lecina, Ludovic Emile Frédy Zaza, Petru Pasquale Albertini Courses Introduction to chemical engineering Laboratory Works

Official source

Related concepts (32)

Nucleation

In thermodynamics, nucleation is the first step in the formation of either a new thermodynamic phase or structure via self-assembly or self-organization within a substance or mixture. Nucleation is typically defined to be the process that determines how long an observer has to wait before the new phase or self-organized structure appears. For example, if a volume of water is cooled (at atmospheric pressure) below 0 °C, it will tend to freeze into ice, but volumes of water cooled only a few degrees below 0 °C often stay completely free of ice for long periods (supercooling).

Infrared spectroscopy

Infrared spectroscopy (IR spectroscopy or vibrational spectroscopy) is the measurement of the interaction of infrared radiation with matter by absorption, emission, or reflection. It is used to study and identify chemical substances or functional groups in solid, liquid, or gaseous forms. It can be used to characterize new materials or identify and verify known and unknown samples. The method or technique of infrared spectroscopy is conducted with an instrument called an infrared spectrometer (or spectrophotometer) which produces an infrared spectrum.

Near-infrared spectroscopy

Near-infrared spectroscopy (NIRS) is a spectroscopic method that uses the near-infrared region of the electromagnetic spectrum (from 780 nm to 2500 nm). Typical applications include medical and physiological diagnostics and research including blood sugar, pulse oximetry, functional neuroimaging, sports medicine, elite sports training, ergonomics, rehabilitation, neonatal research, brain computer interface, urology (bladder contraction), and neurology (neurovascular coupling).

Scanning transmission electron microscopy

A scanning transmission electron microscope (STEM) is a type of transmission electron microscope (TEM). Pronunciation is [stɛm] or [ɛsti:i:ɛm]. As with a conventional transmission electron microscope (CTEM), images are formed by electrons passing through a sufficiently thin specimen. However, unlike CTEM, in STEM the electron beam is focused to a fine spot (with the typical spot size 0.05 – 0.2 nm) which is then scanned over the sample in a raster illumination system constructed so that the sample is illuminated at each point with the beam parallel to the optical axis.

Reaction mechanism

In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical reaction occurs. A chemical mechanism is a theoretical conjecture that tries to describe in detail what takes place at each stage of an overall chemical reaction. The detailed steps of a reaction are not observable in most cases. The conjectured mechanism is chosen because it is thermodynamically feasible and has experimental support in isolated intermediates (see next section) or other quantitative and qualitative characteristics of the reaction.

Related lectures (64)

Homogeneous Catalysis Basics

Introduces the basics of homogeneous catalysis, focusing on reaction mechanisms and catalyst design.

Chemical Reactions: Affinity and Osmosis

Explores chemical potential, affinity, and osmosis in chemical reactions, emphasizing reaction progress over time.

Scanning Electron Microscopy: Signals and Detectors

Covers the principles of Scanning Electron Microscopy, including SEM signals, detectors, and energy spectrum of electrons, as well as the efficiency of X-ray generation.

Chemical Equilibrium: Principles and Applications

Explores chemical equilibrium principles, including Le Châtelier's Principle and equilibrium constants, and discusses the influence of temperature, pressure, and concentration on equilibrium shifts.

Chemical Kinetics: Reaction Rates