Researchers at the Institute for Integrated
Cell-Material Sciences (iCeMS) in Japan have demonstrated an on/off switching
behaviour in a coordination polymer crystal.
Coordination polymer crystals are inorganic and
organic hybrid materials. They are known for their structural and functional
diversity and their ability to conduct protons.
Proton conduction is a form of electrical conduction
in which positive hydrogen ions (H+) carry the charge instead of electrons. It
plays a key role in powering photosynthesis in plants and could be used to
develop better fuel cells.
A team of researchers led by Satoshi Horike and Susumu
Kitagawa synthesized a coordination polymer (CP) by reacting zinc oxide,
phosphoric acid and imidazole in ethyl alcohol at room temperature. The CP was
then melted and triflic acid was added. The resultant mixture was then cooled
and recrystallized. This 'acid doping' of the CP significantly enhanced its
proton conductivity.
The team melted their original CP again and instead
added the 'photoacid' pyranine. Photoacids are molecules that become more
acidic upon absorption of light. After cooling the material, its now
recrystallized form was exposed to light and its proton conductivity improved.
When the light was turned off, its conductivity decreased and returned to its
original state. This change could be switched on and off over several
consecutive cycles of light exposure.
Acid doping of the CP resulted in minimal structural
change with overall enhancement of proton conductivity. Doping the CP with
photoacid gave the researchers on-demand external control of the ionic current
in the material.
"This is the first demonstration of utilization
of the melting state for CP functionalization," conclude the researchers
in their study published in the journal Angewandte Chemie. Their melt-doping
strategy could potentially be extended to synthesize a new class of
proton-conducting solids that can be used in non-volatile memory technologies,
ionics-based transistors, and light-induced ionic/electric current circuits.
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.
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Journal Reference:
- Sanjog S. Nagarkar, Satoshi Horike, Tomoya Itakura, Benjamin Le Ouay, Aude Demessence, Masahiko Tsujimoto, Susumu Kitagawa. Enhanced and Optically Switchable Proton Conductivity in a Melting Coordination Polymer Crystal. Angewandte Chemie International Edition, 2017; 56 (18): 4976 DOI: 10.1002/anie.201700962
I still do not understand about acid doping. Can you explain briefly about acid doping?
BalasHapusreacting zinc oxide, phosphoric acid and imidazole in ethyl alcohol at room temperature. The CP was then melted and triflic acid was added. The resultant mixture was then cooled and recrystallized. This 'acid doping' of the CP significantly enhanced its proton conductivity.
HapusThe team melted their original CP again and instead added the 'photoacid' pyranine. Photoacids are molecules that become more acidic upon absorption of light. After cooling the material, its now recrystallized form was exposed to light and its proton conductivity improved. When the light was turned off, its conductivity decreased and returned to its original state. This change could be switched on and off over several consecutive cycles of light exposure.
Acid doping of the CP resulted in minimal structural change with overall enhancement of proton conductivity.
Give an example of photoacid in daily life!
BalasHapusPhotoacids are molecules that become more acidic upon absorption of light.so,photoacid there in photosynthesis.
HapusWhat are the benefit from Coordination polymer crystals ?
BalasHapusCoordination polymer crystals are inorganic and organic hybrid materials. They are known for their structural and functional diversity and their ability to conduct protons.
BalasHapusWhat elements can experience proton induction?
BalasHapusall elements, because elements Composed atoms.
HapusAtoms are the smallest part of an element that still has the properties of that element. The atom consists of nuclei (nuclei) and electrons. The atomic nucleus is the center of an atom consisting of protons and neutrons
what is the coordination polymer
BalasHapusWhy the resultant mixture was then cooled and recrystallized?
BalasHapus