Researchers detect a new molecule in space

New research has revealed the presence of a previously unknown molecule in space. The open-access paper describing it, "Rotational Spectrum and First Interstellar Detection of 2-Methoxyethanol Using ALMA Observations of NGC 6334I," was published in the April 12 issue of The Astrophysical Journal Letters.

Researchers worked to assemble a puzzle comprised of pieces collected from across the globe, extending beyond MIT to France, Florida, Virginia, and Copenhagen, to achieve this exciting discovery.

To detect new molecules in space, researchers first must have an idea of what molecule they want to look for, then they can record its spectrum in the lab here on Earth, and then finally they look for that spectrum in space using telescopes.

To detect this molecule using radio telescope observations, the group first needed to measure and analyze its rotational spectrum on Earth. The researchers combined experiments from the University of Lille (Lille, France), the New College of Florida (Sarasota, Florida), and the McGuire lab at MIT to measure this spectrum over a broadband region of frequencies ranging from the microwave to sub-millimeter wave regimes (approximately 8 to 500 gigahertz).

The data gleaned from these measurements permitted a search for the molecule using Atacama Large Millimeter/submillimeter Array (ALMA) observations toward two separate star-forming regions: NGC 6334I and IRAS 16293-2422B. Members of the group analyzed these telescope observations alongside researchers at the National Radio Astronomy Observatory (Charlottesville, Virginia) and the University of Copenhagen, Denmark.

Ultimately, they observed 25 rotational lines of 2-methoxyethanol that lined up with the molecular signal observed toward NGC 6334I (the barcode matched), thus resulting in a secure detection of 2-methoxyethanol in this source.This allowed them to then derive physical parameters of the molecule toward NGC 6334I, such as its abundance and excitation temperature. It also enabled an investigation of the possible chemical formation pathways from known interstellar precursors.
Molecular discoveries like this one help the researchers to better understand the development of molecular complexity in space during the star formation process. 2-methoxyethanol, which contains 13 atoms, is quite large for interstellar standards—as of 2021, only six species larger than 13 atoms were detected outside the solar system, many by this research group, and all of them existing as ringed structures.
Continued observations of large molecules and subsequent derivations of their abundances allows scientists to advance our knowledge of how efficiently large molecules can form and by which specific reactions they may be produced.

Zachary T. P. Fried et al, Rotational Spectrum and First Interstellar Detection of 2-methoxyethanol Using ALMA Observations of NGC 6334I, The Astrophysical Journal Letters (2024). DOI: 10.3847/2041-8213/ad37ff

Laser-treated cork absorbs oil for carbon-neutral ocean cleanup

Oil spills are deadly disasters for ocean ecosystems. They can have lasting impacts on fish and marine mammals for decades and wreak havoc on coastal forests, coral reefs, and the surrounding land. Chemical dispersants are often used to break down oil, but they often increase toxicity in the process.

In Applied Physics Letters, researchers  published their work using laser treatments to transform ordinary cork  into a powerful tool for treating oil spills.

They wanted to create a nontoxic, effective oil cleanup solution using materials with a low carbon footprint, but their decision to try cork resulted from a surprising discovery.

In a different laser experiment, they accidentally found that the wettability of the cork processed using a laser changed significantly, gaining superhydrophobic (water-repelling) and superoleophilic (oil-attracting) properties. After appropriately adjusting the processing parameters, the surface of the cork became very dark, which made them realize that it might be an excellent material for photothermal conversion.

Combining these results with the eco-friendly, recyclable advantages of cork, they thought of using it for marine oil spill cleanup.

Cork comes from the bark of cork oak trees, which can live for hundreds of years. These trees can be harvested about every seven years, making cork a renewable material. When the bark is removed, the trees amplify their biological activity to replace it and increase their carbon storage, so harvesting cork helps mitigate carbon emissions. Part 1

The authors tested variations of a fast-pulsing laser treatment to achieve the optimal balance of characteristics in the cork that can be achieved at low cost.

They closely examined nanoscopic structural changes and measured the ratio of oxygen and carbon in the material, changes in the angles with which water and oil contact the surface, and the material's light wave absorption, reflection, and emission across the spectrum to determine its durability after multiple cycles of warming and cooling.

The photothermal properties endowed in cork through this laser processing allow the cork to warm quickly in the sun. The deep grooves also increase the surface area exposed to sunlight, so the cork can be warmed by just a little sunlight in 10–15 seconds. This energy is used to heat up spilled oil, lowering its viscosity and making it easier to collect. In experiments, the laser-treated cork collected oil out of water within two minutes.

The laser treatments not only help to better absorb oil, but also work to keep water out.
When the cork undergoes a fast-pulsing laser treatment, its surface microstructure becomes rougher. This micro- to nano-level roughness enhances hydrophobicity.

As a result, the cork collects the oil without absorbing water, so the oil can be extracted from the cork and possibly even reused.

Femtosecond laser structured black superhydrophobic cork for efficient solar-driven cleanup of crude oil, Applied Physics Letters (2024). DOI: 10.1063/5.0199291

Part 2