15-Oct-2019 - Ludwig-Maximilians-Universität München (LMU)

An ultrafast glimpse of the photochemistry of the atmosphere

Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.

The nanocosmos is constantly in motion. All natural processes are ultimately determined by the interplay between radiation and matter. Light strikes particles and induces reactions. By altering the energy states of electrons, it reshuffles atoms and causes molecules to be reconfigured. These processes are significantly accelerated when the reactants are absorbed on the surface of nanoparticles in the atmosphere. This phenomenon is crucial for the photochemistry of the atmosphere and thus has an impact on our health and climate. One of the light-driven molecular processes that takes place on aerosols has now been investigated in detail by researchers led by Professir Matthias Kling and Dr. Boris Bergues at the Laboratory for Attosecond Physics, which is operated jointly by the LMU Munich and the MPQ. The group has developed a new method, called reaction nanoscopy, which makes it possible to study elemental physicochemical transitions on solid interfaces. They have now used it to characterize the reaction of ethanol with water molecules on the surface of glass nanoparticles under the influence of high-intensity laser light.

The researchers irradiated the spherical particles with ultrashort laser pulses, each lasting for a few femtoseconds. A femtosecond is a millionth of a billionth of a second. With the aid of reaction nanoscopy, they were able to record this ultrashort interaction in three dimensions with nanometer resolution. "We have observed the detachment and acceleration of hydrogen ions from molecules on the surface of nanoparticles. The ability to do so forms the basis for the high spatial resolution of our imaging technique," explains Boris Bergues. "Because the technology enables us to determine the exact position on the nanoparticle with the highest reaction yield, we can trace reactions of molecules adsorbed on the surface of aerosols with high spatial resolution", adds Matthias Kling.

Such processes are ubiquitous, especially in the fields of atmospheric physics and astrochemistry. For example, light in our atmosphere interacts with aerosols and their attached molecules, triggering subsequent reactions that may be important for the development of our climate. In the short term, the results obtained with the new analytical procedure by the Munich laser physicists may provide useful insights, especially in the field of atmospheric chemistry.

Facts, background information, dossiers
More about LMU
  • News

    Energy transmission by gold nanoparticles coupled to DNA structures

    Since the inception of the field in 2006, laboratories around the world have been exploring the use of ‘DNA origami’ for the assembly of complex nanostructures. The method is based on DNA strands with defined sequences that interact via localized base pairing. “With the aid of short strands ... more

    Did Darwinian evolution begin before life itself?

    Before life emerged on Earth, many physicochemical processes on our planet were highly chaotic. A plethora of small compounds, and polymers of varying lengths, made up of subunits (such as the bases found in DNA and RNA), were present in every conceivable combination. Before life-like chemi ... more

    Fluorescence microscopy at highest spatial and temporal resolution

    Only a few years ago, an ostensibly fundamental resolution limit in optical microscopy was superseded - a breakthrough which in 2014 led to the Nobel Prize in Chemistry for super-resolution microscopy. Since then, there has been another quantum leap in this area, which has further reduced t ... more

More about MPI für Quantenoptik
  • News

    The next phase of the proton puzzle

    Scientists at the Max Planck Institute of Quantum Optics (MPQ) have succeeded in testing quantum electrodynamics with unprecedented accuracy to 13 decimal places. The new measurement is almost twice as accurate as all previous hydrogen measurements combined and moves science one step closer ... more

    Laser takes pictures of electrons in crystals

    Microscopes of visible light allow us to see tiny objects such living cells and their interior. Yet, they cannot discern how electrons are distributed among atoms in solids. Now researchers around Prof. Eleftherios Goulielmakis of the Extreme Photonics Labs at the University of Rostock and ... more

    Modelling the molecular architecture

    Searching for new substances and developing new techniques in the chemical industry: tasks that are often accelerated using computer simulations of molecules or reactions. But even supercomputers quickly reach their limits. Now researchers at the Max Planck Institute of Quantum Optics in Ga ... more