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!
Transporting spin: A graphene and boron nitride heterostructure creates large spin signals
16.08.2017 | Graphene Flagship
From hot to cold: How to move objects at the nanoscale
10.08.2017 | Scuola Internazionale Superiore di Studi Avanzati
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).
The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
16.08.2017 | Physics and Astronomy
16.08.2017 | Materials Sciences
16.08.2017 | Interdisciplinary Research