Light Induced Processes In Optically Tweezed Aerosol Droplets

Aerosols play a critical role in a broad range of scientific disciplines, such as atmospheric chemistry and physics, combustion science, drug delivery and human health. This thesis explores the fundamentals of a new technique for capturing single or multiple particles using light, and for characterising these particles by Raman or fluorescence spectroscopy. The outcome of this research represents a significant development in optical manipulation techniques, specifically in optical tweezing. These findings can be applied to studies of the mass accommodation of gas-phase water molecules adsorbing onto a water surface. Not only is this a fundamental process of interest to physical chemists, but it is important for understanding the role of aerosol particles in the atmosphere, including their ability to become cloud droplets. This new strategy for investigating aerosol dynamics is fundamental in helping us understand the indirect effect of aerosols on the climate.

Atmospheric aerosols are an important and a highly complex component of the Earth’s atmosphere that alter the radiative forcing and the chemical composition of the gas phase. These effects have impacts on local air quality and the global climate. Atmospheric Aerosol Chemistry outlines research findings to date in aerosol chemistry and advances in analytical tools used in laboratory settings for studying their surface and bulk reactivity.

This volume is a collection of review articles by scientists who have pioneered many of the recent advances in studies of the optical effects of small particles. The book begins with a review of the multitude of sharp dielectric resonances which exist in all optical spectra as a result of particle size and shape. Latest advances in absorption and fluorescence spectroscopy of a single particle and/or an ensemble of particles are also discussed, as well as advances in the energy transfer mechanisms for molecules embedded in the particle. The effects of laser-induced heating on a single particle are reviewed in terms of the hydrodynamics and thermodynamics of the liquid droplet and its ambient gas surrounding. The limits of applying bulk optical constants to small particles which lie between the bulk substance and the quantum-sized substance are also presented.

It has been thirty years since one of the authors (EJD) began a collaboration with Professor Milton Kerker at Clarkson University in Potsdam, New York using light scattering methods to study aerosol processes. The development of a relatively short-lived commercial particle levitator based on a modification of the Millikan oil drop experiment attracted their attention and led the author to the study of single droplets and solid microparticles by levitation methods. The early work on measurements of droplet evaporation rates using light scattering techniques to determine the size slowly expanded and diversified as better instrumentation was developed, and faster computers made it possible to perform Mie theory light scattering calculations with ease. Several milestones can be identified in the progress of single microparticle studies. The first is the introduction of the electrodynamic balance, which provided more robust trapping of a particle. The electrodynamic levitator, which has played an important role in atomic and molecular ion spectroscopy, leading to the Nobel Prize in Physics in 1989 shared by Wolfgang Paul of Bonn University and Hans Dehmelt of the University of Washington, was easily adapted to trap microparticles. Simultaneously, improvements in detectors for acquiring and storing light scattering data and theoretical and experimental studies of the interesting optical properties of microspheres, especially the work on morphology dependent resonances by Arthur Ashkin at the Bell Laboratories, Richard Chang, from Yale University, and Tony Campillo from the Naval Research Laboratories in Washington D. C.

This book highlights cutting-edge research in surface plasmons, discussing the different types and providing a comprehensive overview of their applications. Surface plasmons (SPs) receive special attention in nanoscience and nanotechnology due to their unique optical, electrical, magnetic, and catalytic properties when operating at the nanoscale. The excitation of SPs in metal nanostructures enables the manipulation of light beyond the diffraction limit, which can be utilized for enhancing and tailoring light-matter interactions and developing ultra-compact high-performance nanophotonic devices for various applications. With clear and understandable illustrations, tables, and descriptions, this book provides physicists, materials scientists, chemists, engineers, and their students with a fundamental understanding of surface plasmons and device applications as a basis for future developments.

In Optical Nano and Micro Actuator Technology, leading engineers, material scientists, chemists, physicists, laser scientists, and manufacturing specialists offer an in-depth, wide-ranging look at the fundamental and unique characteristics of light-driven optical actuators. They discuss how light can initiate physical movement and control a variety of mechanisms that perform mechanical work at the micro- and nanoscale. The book begins with the scientific background necessary for understanding light-driven systems, discussing the nature of light and the interaction between light and NEMS/MEMS devices. It then covers innovative optical actuator technologies that have been developed for many applications. The book examines photoresponsive materials that enable the design of optically driven structures and mechanisms and describes specific light-driven technologies that permit the manipulation of micro- and nanoscale objects. It also explores applications in optofluidics, bioMEMS and biophotonics, medical device design, and micromachine control. Inspiring the next generation of scientists and engineers to advance light-driven technologies, this book gives readers a solid grounding in this emerging interdisciplinary area. It thoroughly explains the scientific language and fundamental principles, provides a holistic view of optical nano and micro actuator systems, and illustrates current and potential applications of light-driven systems.

Physical Chemistry of Gas-Liquid Interfaces, the first volume in the Developments in Physical & Theoretical Chemistry series, addresses the physical chemistry of gas transport and reactions across liquid surfaces. Gas–liquid interfaces are all around us, especially within atmospheric systems such as sea spry aerosols, cloud droplets, and the surface of the ocean. Because the reaction environment at liquid surfaces is completely unlike bulk gas or bulk liquid, chemists must readjust their conceptual framework when entering this field. This book provides the necessary background in thermodynamics and computational and experimental techniques for scientists to obtain a thorough understanding of the physical chemistry of liquid surfaces in complex, real-world environments. Provides an interdisciplinary view of the chemical dynamics of liquid surfaces, making the content of specific use to physical chemists and atmospheric scientists Features 100 figures and illustrations to underscore key concepts and aid in retention for young scientists in industry and graduate students in the classroom Helps scientists who are transitioning to this field by offering the appropriate thermodynamic background and surveying the current state of research