A unique chemical imaging tool readily and reliably presents volatile liquids to scientific instruments, according to a team including Pacific Northwest National Laboratory. These instruments require samples be held in a vacuum, which is often incompatible with hydrocarbons and other liquids. Designed and built at PNNL, this one-of-a-kind sample holder continuously pumps the liquid through a gold-coated microfluidic chamber. The extremely narrow channel provides high linear velocity at the detection window and helps overcome the liquids' tendency to vaporize. Instruments access the liquid via an open viewing port. Tests with electron microscopes and mass spectrometers prove the device can operate continuously for up to 8 hours. Further, the device handles complex liquids.
Decision making processes are fundamentally made at regional scales. An integrated approach that accounts for the dynamics of climate, energy, and environmental systems will provide insight into options for how to manage and plan for future resources. In their paper, Dr. Kathy Hibbard and Dr. Anthony Janetos of Pacific Northwest National Laboratory make the case for integrated regional-scale analyses, discussing how regional dynamic interactions between human and natural systems provide insight into mitigation and adaptation strategies, their tradeoffs and consequences, and how these influence the global Earth system.
Fortified with new evidence of particles' true disposition, scientists at Pacific Northwest National Laboratory developed a multi-dimensional modeling framework that predicts their formation and evolution in the atmosphere. Instead of treating secondary organic aerosols (SOAs), created by a mix of natural and human-caused emissions, as liquid-like volatile solutions as has traditionally been done, they modeled them as non-volatile semi-solids. The study is an important step in improving SOA modeling representations based on recent experimental findings of evaporation rates, diffusivity, and viscosity.
From catalysts to cold medicines, molecular-level interactions in liquids are of interest to scientists. Microfluidic devices allow scientists to obtain chemical imaging data by channeling small samples past electron microscopes or spectrometers. The devices hold the sample, and are then fitted into the instrument for analysis. This area of research is quickly growing, according to scientists at Pacific Northwest National Laboratory in their review article published in Microfluidics and Nanofluidics.
An international team, including a Pacific Northwest National Laboratory scientist, used two new techniques to find the viscosity of organic particles produced when alpha-pinene meets ozone. They found that the resulting carbon-containing particles behave like liquids, semi-solids or solids across a range of atmospheric relative humidity conditions. Their research was published in the Proceedings of the National Academy of Sciences. At PNNL, this work was supported through the Aerosol Climate Initiative of the Laboratory Research and Development Program, and used the continuous-flow environmental chamber at the Atmospheric Measurements Laboratory.