The sponges of the future will do more than clean house.
Created by chemists at the University at Buffalo and Penn State Hazleton, this sponge-like crystal contains many pores that change shape when exposed to ultraviolet (UV) light. In addition, the normally colorless crystal (left) blushes in the presence of UV light, turning red (right). Credit: Ian M. Walton
Picture this, for example: Doctors use a tiny sponge to soak up a drug and deliver it directly to a tumor. Chemists at a manufacturing plant use another to trap and store unwanted gases.
These technologies are what University at Buffalo Assistant Professor of Chemistry Jason Benedict, PhD, had in mind when he led the design of a new material called UBMOF-1. The material — a metal-organic framework, or “MOF” — is a hole-filled crystal that could act as a sponge, capturing molecules of specific sizes and shapes in its pores.
The crystal’s pores change shape when hit by ultraviolet light. This is important because changing the pore structure is one way to control which compounds can enter or exit the pores. You could, for instance, soak up a chemical and then alter the pore size to prevent it from escaping. Secure storage is useful in applications like drug delivery, where “you don’t want the chemicals to come out until they get where they need to be,” Benedict says.
The crystal also changes color in response to ultraviolet light, going from colorless to red. This suggests that the material’s electronic properties are shifting, which could affect the types of chemical compounds that are attracted into the pores.
Benedict’s team reported on the creation of the UBMOF on Jan. 22 in the journal Chemical Communications. The paper’s coauthors include chemists from UB and Penn State Hazleton.
“MOFs are like molecular sponges — they’re crystals that have pores,” Benedict said.
“Typically, they are these passive materials: They’re static. You synthesize them, and that’s the end of the road,” he added. “What we’re trying to do is to take these passive materials and make them active, so that when you apply a stimulus like light, you can make them change their chemical properties, including the shape of their pores.”
Benedict is a member of UB’s New York State Center of Excellence in Materials Informatics, which the university launched in 2012 to advance the study of new materials that could improve life for future generations.
To force UBMOF-1 respond to ultraviolet light, Benedict and colleagues used some clever synthetic chemistry.
MOF crystals are made from two types of parts — metal nodes and organic rods — and the researchers attached a light-responsive chemical group called a diarylethene to the organic component of their material.
Diarylethene is special because it houses a ring of atoms that is normally open but shuts when exposed to ultraviolet light.
In the UBMOF, the diarylethene borders the crystal’s pores, which means the pores change shape when the diarylethene does.
The next step in the research is to determine how, exactly, the structure of the holes is changing, and to see if there’s a way to get the holes to revert to their original shape.
Rods containing diarylethene can be forced back into the “open” configuration with white light, but this tactic only works when the rods are alone. Once they’re inserted into the crystal, the diarylethene rings stay stubbornly closed in the presence of white light.
Media Contact InformationCharlotte Hsu
Charlotte Hsu | EurekAlert!
Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern
20.07.2018 | Princeton University
Relax, just break it
20.07.2018 | DOE/Argonne National Laboratory
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences