Most high-performance Tröger’s
base (TB) polymers for gas separation membranes are from mixed diamine
isomers, and the configuration differences in the polymer chain packing
that arise from these isomers are still unknown. Herein three triptycene-containing
Tröger’s-base-based polymers, CTTB (from pure Trip-2,6-diamine),
MTTB (from pure Trip-2,7-diamine), and ITTB (from 50/50 Trip-2,6-diamine/Trip-2,7-diamine
mixed regioisomers), were successfully synthesized and fully characterized.
All polymers exhibited high thermal stability and rigidity, a large
Brunauer–Emmett–Teller surface area, and distinct microporosity
(pores <20 Å). ITTB showed the largest pores (ITTB (6.25 Å) > MTTB (6.15 Å) > CTTB (5.68 Å)) and pore-size
distributions (ITTB (6.14–8.0 Å) > CTTB
(5.48–7.0 Å) > MTTB (6.09–6.90 Å)). MTTB
and
CTTB showed outstanding H2/CH4, H2/N2, and O2/N2 separation performance
that successfully surpassed the 2015 trade-off curves, better than
those of the most recently reported state-of-the-art gas separation
membranes and ITTB, due to their more uniform polymer main chain arrangement.
This result shed light on the future high-performance gas separation
polymer designs.
A novel fluorinated triptycene-derived ladder PIM (DFTTB) showed an unprecedented O2/N2 selectivity of 10.1 and O2 permeability of 137 barrer at −30 °C that provides new opportunities for low temperature air separation applications.
Intelligent control
over the handedness of circularly polarized
luminescence (CPL) is of special significance in smart optoelectronics,
information storage, and data encryption; however, it still remains
a great challenge to rationally design a CPL material that displays
reversible handedness inversion without changing the system composition.
Herein, we show this comes true by coupling the two scenarios of Harata–Kodaka’s
rule on the same supramolecular platform of crystalline microtubes
self-assembled from surfactant–cyclodextrin host–guest
complexes. Upon coassembling a linear dye with its electronic transition
dipole moment outside of the cavity of β-CyD, the chirality
transfer from the induced chirality of SDS in the SDS@2β-CyD
microtubes to the dye generates left-handed CPL at room temperature.
Upon elevating temperature, the dye forms inclusion complex with β-CyD,
so that right-handed CPL is induced because the polar group of the
dye is outside of the cavity of β-CyD. This process is completely
reversible. We envision that host–guest chemistry would be
very promising in creating smart CPL inversion materials for a vast
number of applications.
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