2 research outputs found
Hydrophobic-Sheath Segregated Macromolecular Fluorophores: Colloidal Nanoparticles of Polycaprolactone-Grafted Conjugated Polymers with Bright Far-Red/Near-Infrared Emission for Biological Imaging
This article describes molecular
design, synthesis and characterization
of colloidal nanoparticles containing polycaprolactone-grafted conjugated
polymers that exhibit strong far red/near-infrared (FR/NIR) fluorescence
for bioimaging. Specifically, we synthesized two kinds of conjugated
polymer bottle brushes (PFTB<sup>out</sup>-<i>g</i>-PCL
and PFTB<sup>in</sup>-<i>g</i>-PCL) with different positions
of the hexyl groups on the thiophene rings. A synthetic amphiphilic
block copolymer PCL-<i>b</i>-POEGMA was employed as surfactants
to encapsulate PFTB-<i>g</i>-PCL polymers into colloidal
nanoparticles (denoted as “nanoREDs”) in aqueous media.
The chain length of the PCL side chains in PFTB-<i>g</i>-PCL played a critical role in determining the fluorescence properties
in both bulk solid states and the colloidal nanoparticles. Compared
to semiconducting polymer dots (Pdots) composed of PFTB<sup>out</sup> without grafted PCL, nanoRED<sup>out</sup> showed at least four
times higher fluorescence quantum yield (∼20%) and a broader
emission band centered at 635 nm. We further demonstrated the application
of this new class of nanoREDs for effective labeling of L929 cells
and HeLa cancer cells with good biocompatibility. This strategy of
hydrophobic-sheath segregated macromolecular fluorophores is expected
to be applicable to a broad range of conjugated polymers with tunable
optical properties for applications such as bioimaging
Monomer Symmetry-Regulated Defect Engineering: In Situ Preparation of Functionalized Covalent Organic Frameworks for Highly Efficient Capture and Separation of Carbon Dioxide
Developing
crystalline porous materials with highly efficient CO2 selective
adsorption capacity is one of the key challenges
to carbon capture and storage (CCS). In current studies, much more
attention has been paid to the crystalline and porous properties of
crystalline porous materials for CCS, while the defects, which are
unavoidable and ubiquitous, are relatively neglected. Herein, for
the first time, we propose a monomer-symmetry regulation strategy
for directional defect release to achieve in situ functionalization
of COFs while exposing uniformly distributed defect-aldehyde groups
as functionalization sites for selective CO2 capture. The
regulated defective COFs possess high crystallinity, good structural
stability, and a large number of organized and functionalized aldehyde
sites, which exhibit one of the highest selective separation values
of all COF sorbing materials in CO2/N2 selective
adsorption (128.9 cm3/g at 273 K and 1 bar, selectivity:
45.8 from IAST). This work not only provides a new strategy for defect
regulation and in situ functionalization of COFs but also provides
a valuable approach in the design and preparation of new adsorbents
for CO2 adsorption and CO2/N2 selective
separation