Gaseous emissions from brake wear can form secondary particulate matter.

Road traffic is an important source of urban air pollutants. Due to increasingly strict controls of exhaust emissions from road traffic, their contribution to the total emissions has strongly decreased over time in high-income countries. In contrast, non-exhaust emissions from road vehicles are not yet legislated and now make up the major proportion of road traffic emissions in many countries.

Strong Uptake of Gas-Phase Organic Peroxy Radicals (ROO) by Solid Surfaces Driven by Redox Reactions.

Organic peroxy radicals (ROO) are key oxidants in a wide range of chemical systems such as living organisms, chemical synthesis and polymerization systems, combustion systems, the natural environment, and the Earth's atmosphere. Although surfaces are ubiquitous in all of these systems, the interactions of organic peroxy radicals with these surfaces have not been studied until today because of a lack of adequate detection techniques. In this work, the uptake and reaction of gas-phase organic peroxy radicals (CHOO and i-CHOO) with solid surfaces was studied by monitoring each radical specifically and in real-time with mass spectrometry.

The reaction of organic peroxy radicals with unsaturated compounds controlled by a non-epoxide pathway under atmospheric conditions.

Today, the reactions of gas-phase organic peroxy radicals (RO) with unsaturated Volatile Organic Compounds (VOC) are expected to be negligible at room temperature and ignored in atmospheric chemistry. This assumption is based on combustion studies ( ≥ 360 K), which were the only experimental data available for these reactions until recently. These studies also reported epoxide formation as the only reaction channel.

A new instrument for kinetics and branching ratio studies of gas phase collisional processes at very low temperatures.

A new instrument dedicated to the kinetic study of low-temperature gas phase neutral-neutral reactions, including clustering processes, is presented. It combines a supersonic flow reactor with vacuum ultra-violet synchrotron photoionization time-of-flight mass spectrometry. A photoion-photoelectron coincidence detection scheme has been adopted to optimize the particle counting efficiency.

Product Detection of the CH Radical Reactions with Ammonia and Methyl-Substituted Amines.

Reactions of the methylidyne (CH) radical with ammonia (NH), methylamine (CHNH), dimethylamine ((CH)NH), and trimethylamine ((CH)N) have been investigated under multiple collision conditions at 373 K and 4 Torr. The reaction products are detected by using soft photoionization coupled to orthogonal acceleration time-of-flight mass spectrometry at the Advanced Light Source (ALS) synchrotron. Kinetic traces are employed to discriminate between CH reaction products and products from secondary or slower reactions.