Nanomaterials can store all kinds of things, including energy, drugs and other cargo
A team of chemists led by Northwestern University’s William Dichtel has cooked up something big: The scientists created an entirely new type of nanomaterial and watched it form in real time — a chemistry first.
“Our work sets the stage for researchers interested in studying the fundamental properties of interesting materials and applied systems, such as solar cells, batteries, sensors, paints and drug delivery systems,” said Dichtel, the Robert L. Letsinger Professor of Chemistry at the Weinberg College of Arts and Sciences. “The findings have enormous implications for how chemists and materials scientists think about nanotechnology and their science in general.”
The researchers made covalent organic frameworks (COFs) that are stable — a major advancement. These strong, stiff polymers with an abundance of tiny pores are suitable for storing all kinds of things, including energy, drugs and other cargo. But what limits COFs from realizing these applications is that they are usually prepared as powdery substances that can’t be processed into useful forms.
In this study, the nanoparticles stay suspended in a liquid “ink,” creating a new nanomaterial called a COF colloid. This structure allows the unique materials to be processed into useful forms, such as films of arbitrary size and thickness.
Also, for the first time, the chemists demonstrated that the “cooking,” or heating up, of the ingredients for the nanomaterial can take place inside the imaging tool itself, in this case a powerful microscope called a transmission electron microscope. With this new technique, Dichtel and his team could investigate how molecules come together to form COF colloids.
The field of covalent organic frameworks is only a decade old, and much needs to be learned about how the porous polymers form and how to keep them stable. Dichtel is a leader in the young field, focused on bringing unprecedented functionality and improved stability to COFs.
The study, titled “Colloidal Covalent Organic Frameworks,” was published last week in the journal ACS Central Science. Dichtel is a corresponding author of the study.
The COF colloids are nanoparticles (approximately 50 nanometers in diameter, roughly the size of a virus) made from any number of building blocks in a predictable way. The COF colloids also feature small pores, whose size, shape and chemical groups can be designed precisely. (Each pore is approximately 2.5 nanometers wide, big enough to hold a variety of cargo.)
“This is about as close to useful ‘molecular LEGOs’ as I’ve seen,” Dichtel said. “Being able to keep these materials stable in solution is a major step forward towards taking advantage of their unique combination of properties.”
For the study, Dichtel teamed up with Nathan C. Gianneschi at the University of California, San Diego, who has developed cutting-edge analysis techniques. Gianneschi, a professor of chemistry and biochemistry, is also a corresponding author of the paper.
Dichtel and Gianneschi developed a new way to watch COF colloids form inside a transmission electron microscope, another major advancement.
The inability to observe reactions as they occur using electron microscopy has been a major limitation, Gianneschi said. Usually samples have to be dried or frozen to use this technique. The microscopy in this study opens the door to a new dimension: allowing scientists to initiate and observe materials as they form in real time.
“This is something that is routine on the macroscale, of course, but has eluded chemists, biologists and physicists at the nanoscale,” Gianneschi said.
Receive an email update when we add a new COVALENT ORGANIC FRAMEWORKS article.
The Latest on: Colloidal covalent organic frameworks
via Google News
The Latest on: Colloidal covalent organic frameworks
- Magnetic field alignment of stable proton-conducting channels in an electrolyte membrane on February 19, 2019 at 2:35 am
The approach opens up a wide variety of other possible systems beyond membranes with aligned proton-conducting channels, such as conductive metal organic frameworks and covalent organic frameworks. We ... […]
- Superior photocatalysts—covalent, crystalline triazine frameworks on August 21, 2018 at 8:02 am
They are especially good photocatalysts for the production of hydrogen by splitting water with solar energy: covalent organic frameworks based on triazines. For this application, the frameworks need t... […]
- New Competition for MOFs: Scientists Make Stronger COFs on August 1, 2018 at 9:38 am
Hollow molecular structures known as COFs (covalent organic frameworks), which could serve as selective filters or containers for other substances and have many other potential uses, also tend to suff... […]
- Covalent Organic Frameworks on July 9, 2018 at 6:47 am
Hold that thought, though: can you name another crystalline organic substance that’s assembled from a framework of covalent bonds? The problem is assembling the framework. If you picture the process d... […]
- ChemRxiv Holiday Reading List on December 18, 2017 at 10:32 am
and for good reason — the manuscript describes how William Dichtel and co-workers at Northwestern University have taken their insights into 2D covalent organic framework (COF) growth mechanisms and us... […]
- The atom, the molecule, and the covalent organic framework on March 2, 2017 at 10:43 am
Covalent molecular frameworks are crystalline microporous materials assembled from organic molecules through strong covalent bonds in a process termed reticular synthesis. Diercks and Yaghi review dev... […]
- Chemists cook up new nanomaterial and imaging method on January 20, 2017 at 2:59 am
The study, titled "Colloidal Covalent Organic Frameworks," was published last week in the journal ACS Central Science. Dichtel is a corresponding author of the study. The COF colloids are nanoparticle... […]
- Best of both worlds: Team proposes novel energy storage model on August 31, 2016 at 1:26 pm
The technology – based on a covalent organic framework (COF) infused with an electronically conducting polymer thin film – could benefit numerous technologies including automotive, by speeding up the ... […]
- These Are the First Materials to Ever Be Woven at the Molecular Level on January 22, 2016 at 4:00 pm
An international collaboration led by scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the University of California Berkeley, has woven the first three-dimension... […]
via Bing News