2 research outputs found
âJacketingâ Effect Liquid Crystalline Polymer with Perylenediimide as Side Chain: Synthesis, Liquid Crystalline Phase, and Photovoltaic Performances
All polymer solar
cells (all-PSCs) is one of the important emerging renewable energy
technologies. In this work, we use âjacketingâ effect
liquid crystalline polymer (LCP) with perylenediimide as side chain
to fabricate all-PSCs. First, polyÂ(2,5-bisÂ{[6-(4-alkoxy-4âČ-perylenediimide)-6-hexyl]Âoxycarbonyl}Âstyrene)
(abbreviated as PPDCS) is successfully synthesized via chain polymerization.
The resultant polymer PPDCS forms stable smectic C (SmC) structure
until decomposition. The electrochemical experiment indicates PPDCS
shows deep LUMO energy level of â3.81 eV, thus, the nonconjugated
PPDCS can be employed as acceptor materials to build all-PSCs. Atomic
force microscopy (AFM) experiments show that the PBT7/PPDCS blend
film forms a bicontinuous network-domains and the resultant film shows
extensive absorption spectrum (300â800 nm) on UVâvis
spectra. All-PSCs device fabricated by PTB7/PPDCS presents the best
power conversion efficiency (PCE) of 1.23% after optimization, where
the short-circuit current density (<i>J</i><sub>sc</sub>) is 4.34 mA cm<sup>â2</sup>, an open-circuit voltage (<i>V</i><sub>oc</sub>) is 0.65 V, and a fill factor (FF) is 0.37.
This work suggests that the nonconjugated LCP shows potential application
for solar cell
Alignment Control of Nematic Liquid Crystal using Gold Nanoparticles Grafted by the Liquid Crystalline Polymer with Azobenzene Mesogens as the Side Chains
The gold nanoparticles
highly grafted by a liquid crystalline polymer
(LCP) with azobenzene mesogens as the side chain (denoted as Au@TE-PAzo
NPs) are successfully designed and synthesized by the two-phase BrustâSchiffrin
method. The chemical structures of the monomer and polymer ligands
have been confirmed by nuclear magnetic resonance, and the molecular
weight of the polymer is determined by gel permeation chromatography.
The combined analysis of transmission electron microscopy and thermogravimetric
analysis shows that the size of the nanoparticles is 2.5(±0.4)
nm and the content of the gold in the Au@TE-PAzo NPs is ca. 17.58%.
The resultant Au@TE-PAzo NPs can well disperse in the nematic LC of
5CB. The well-dispersed mixture with appropriate doping concentrations
can automatically form a perfect homeotropic alignment in the LC cell.
The homeotropic alignment is attributed to the brush formed by Au@TE-PAzo
NPs on the substrate, wherein the Au@TE-PAzo NPs gradually diffuse
onto the substrate from the mixture. On the contrary, the pure side
chain LCPs cannot yield vertical alignment of 5CB, which indicates
that the alignment of 5CB is ascribed to the synergistic interaction
of the nanoparticles and the grafted LCPs. Moreover, Au@TE-PAzo NPs
show excellent film-forming property on account of their periphery
of high densely grafted LCPs, which can form uniform thin film by
spin-coating. The resultant thin film also can prompt the automatical
vertical alignment of the nematic 5CB. Further, upon alternative irradiation
of UV and visible light, the alignment of 5CB reversibly switches
between vertical and random orientation because of the transâcis
photoisomerization of the azobenzene group on the periphery of Au@TE-PAzo
NPs. These experimental results suggest that this kind of nanoparticles
can be potentially applied in constructing the remote-controllable
optical devices