A new flexible material changes its porous nature when exposed to light
Researchers at Kyoto University's Institute for Integrated Cell-Material Sciences (iCeMS) and the University of Tokyo have developed a light-responsive crystalline material that overcomes challenges faced in previous studies.
Photochromic molecules change their electronic states or chemical structures, when exposed to light. They can play key roles in the development of 'photoresponsive' materials that could be used in delivery systems for controlled drug release, or to develop dynamic scaffolds for tissue engineering, among other applications. But so far, their use with solid materials has proven challenging because the materials have been too rigid to allow repeatable and reversible changes.
Susumu Kitagawa of iCeMS, Hiroshi Sato of the University of Tokyo, and their colleagues, prepared a flexible porous crystal composed of a photoresponsive dithienylethene derivative, zinc ions (Zn2+), and 1,4-benenzenedicarboxylate.
The 'porous coordination polymer' consisted of two-dimensional sheets connected by pillars of photoresponsive molecules, which created a three-dimensional, entangled framework. The researchers compare the entwined components to twisted metal wire and string puzzles.
Due to the flexible nature of the entangled framework, the channels changed shape when exposed to light. The distance between the two layers shrank upon ultraviolet irradiation then expanded when lit by visible light.
The researchers tested the material's ability to uptake carbon dioxide (CO2). When the material was not irradiated, it adsorbed up to 136 millilitres (ml) of CO2. When exposed to ultraviolet light, the pores shrank, decreasing CO2 adsorption to 108 ml. When then exposed to visible light, CO2 absorption rose again to 129 ml. It then decreased to 96 ml upon re-exposure to ultraviolet light.
The polymer's entangled framework enables these reversible and repeatable CO2 absorption changes; it gives room for the photoresponsive molecules to transform while allowing them to release their strain into the flexible material.
Preliminary tests indicated that the porous crystal could also adsorb other gases, such as nitrogen, at various temperatures, but more detailed investigation is required.
"Our strategy will grant access to a new dimension of porous compounds as platforms for various photochemical conversions and the photomodulation of porous properties," conclude the researchers in their study, published in the journal Nature Communications.
The paper "Flexible interlocked porous frameworks allow quantitative photoisomerization in a crystalline solid appeared on July 24, 2017 in Nature Communications, with doi: 10.1038/s41467-017-00122-5.
The Institute for Integrated Cell-Material Sciences (iCeMS) at Kyoto University in Japan aims to advance the integration of cell and material sciences, both traditionally strong fields at the university, in a uniquely innovative global research environment. iCeMS combines the biosciences, chemistry, materials science and physics to create materials for mesoscopic cell control and cell-inspired materials. Such developments hold promise for significant advances in medicine, pharmaceutical studies, the environment and industry. http://www.
Izumi Mindy Takamiya | idw - Informationsdienst Wissenschaft
3D inks that can be erased selectively
16.08.2018 | Karlsruher Institut für Technologie (KIT)
Designing Nanocrystals for more efficient Optoelectronics
16.08.2018 | Max-Planck-Institut für Eisenforschung GmbH
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
16.08.2018 | Life Sciences
16.08.2018 | Earth Sciences
16.08.2018 | Life Sciences