15 research outputs found
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SelfâHealable and Recyclable Tactile Force Sensors with PostâTunable Sensitivity
It is challenging to postâtune the sensitivity of a tactile force sensor. Herein, a facile method is reported to tailor the sensing properties of conductive polymer composites by utilizing the liquidâlike property of dynamic polymer matrix at low strain rates. The idea is demonstrated using dynamic polymer composites (CB/dPDMS) made via evaporationâinduced gelation of the suspending toluene solution of carbon black (CB) and acidâcatalyzed dynamic polydimethylsiloxane (dPDMS). The dPDMS matrices allow CB to redistribute to change the sensitivity of materials at the liquidâlike state, but exhibit typical solidâlike behavior and thus can be used as strain sensors at normal strain rates. It is shown that the gauge factor of the polymer composites can be easily postâtuned from 1.4 to 51.5. In addition, the dynamic polymer matrices also endow the composites with interesting selfâhealing ability and recyclability. Therefore, it is envisioned that this method can be useful in the design of various novel tactile sensing materials for many applications
Tailorable Synthesis of Porous Organic Polymers Decorating Ultrafine Palladium Nanoparticles for Hydrogenation of Olefins
Two 1,2,3-triazolyl-containing porous
organic polymers (CPP-C and
CPP-Y) were readily synthesized through click reaction and Yamamoto
coupling reaction, respectively. The effects of synthetic methods
on the structures and properties of CPP-C and CPP-Y were investigated.
Their chemical compositions are almost identical, but their physical
and texture properties are different from each other. Ultrafine palladium
nanoparticles can be effectively immobilized in the interior cavities
of CPP-C and CPP-Y. The interactions between polymers and palladium
are verified by IR, solid-state NMR, XPS, and EDS. Their catalytic
performances are evaluated by hydrogenation of olefins. Pd@CPP-Y exhibits
higher catalytic activity and recyclability than Pd@CPP-C. Hot filtration
and the three-phase test indicate that hydrogenation functions in
a heterogeneous pathway
SelfâHealable and Recyclable Tactile Force Sensors with PostâTunable Sensitivity
It is challenging to postâtune the sensitivity of a tactile force sensor. Herein, a facile method is reported to tailor the sensing properties of conductive polymer composites by utilizing the liquidâlike property of dynamic polymer matrix at low strain rates. The idea is demonstrated using dynamic polymer composites (CB/dPDMS) made via evaporationâinduced gelation of the suspending toluene solution of carbon black (CB) and acidâcatalyzed dynamic polydimethylsiloxane (dPDMS). The dPDMS matrices allow CB to redistribute to change the sensitivity of materials at the liquidâlike state, but exhibit typical solidâlike behavior and thus can be used as strain sensors at normal strain rates. It is shown that the gauge factor of the polymer composites can be easily postâtuned from 1.4 to 51.5. In addition, the dynamic polymer matrices also endow the composites with interesting selfâhealing ability and recyclability. Therefore, it is envisioned that this method can be useful in the design of various novel tactile sensing materials for many applications
Facile Fabrication of Ultrafine Palladium Nanoparticles with Size- and Location-Control in Click-Based Porous Organic Polymers
Two click-based porous organic polymers (CPP-1 and CPP-2) are readily synthesized through a click reaction. Using CPP-1 and CPP-2 as supports, palladium nanoparticles (NPs) with uniform and dual distributions were prepared through H<sub>2</sub> and NaBH<sub>4</sub> reduction routes, respectively. Ultrafine palladium NPs are effectively immobilized in the interior cavities of polymers. The coordination of 1,2,3-triazolyl to palladium and the confinement effect of polymers on palladium NPs are verified by solid-state <sup>13</sup>C NMR and IR spectra, XPS analyses, EDX mapping, and computational calculation. The steric and electronic properties of polymers have a considerable influence on the interaction between polymers and palladium NPs, as well as the catalytic performances of NPs. The ultrafine palladium NPs with uniform distribution exhibit superior stability and recyclability over palladium NPs with dual distributions and palladium on charcoal in the hydrogenation of nitroarenes, and no obvious agglomeration and loss of catalytic activity were observed after recycling several times. The excellent performances mainly result from synergetic effects between palladium NPs and polymers
Anion-Directed Assemblies of Cationic MetalâOrganic Frameworks Based on 4,4âČ-Bis(1,2,4-triazole): Syntheses, Structures, Luminescent and Anion Exchange Properties
Three cationic metalâorganic
frameworks (MOFs), AgÂ(btr)·âPF<sub>6</sub>·â0.5CH<sub>3</sub>CN (<b>1</b>), Ag<sub>2</sub>(btr)<sub>2</sub>Â(H<sub>2</sub>O)·â2CF<sub>3</sub>SO<sub>3</sub>·âH<sub>2</sub>O (<b>2</b>), and Ag<sub>2</sub>(btr)<sub>2</sub>Â(NO<sub>3</sub>)·âNO<sub>3</sub> (<b>3</b>), were prepared
from reaction of 4,4âČ-bisÂ(1,2,4-triazole) (btr) with silver
salts containing different anions. Complex <b>1</b> is a three-dimensional
(3-D) framework constructed from tetrahedral-shaped nanoscale coordination
cages with PF<sub>6</sub><sup>â</sup> as counteranions. <b>2</b> and <b>3</b> are 3-D architectures containing 1-D
channels, in which charge-balancing CF<sub>3</sub>SO<sub>3</sub><sup>â</sup> and NO<sub>3</sub><sup>â</sup> are located
in their respective channels. Luminescent emission of <b>1</b>â<b>3</b> shows an obvious red shift compared with the
btr ligand. Anion exchange studies show that <b>1</b> is able
to selectively exchange MnO<sub>4</sub><sup>â</sup> in aqueous
solution with a modest capacity of 0.56 mol mol<sup>â1</sup>; the luminescent emission of <b>1</b> is quickly quenched
upon MnO<sub>4</sub><sup>â</sup> exchange
Thermoresponsive Mobile Interfaces with Switchable Wettability, Optical Properties, and Penetrability
Liquid-based mobile
interfaces, in which liquids are being utilized as structural long-term
components, have shown their multifunctionality in materials science,
such as the hydration layer of polyelectrolyte brushes used for artificial
implants, stabilized lubricants for antibiofouling, anti-icing, self-cleaning,
optical control, and so forth. However, these currently available
systems do not usually show a response to environmental stimuli. Here,
we describe a strategy for preparing thermoresponsive mobile interfaces
made from novel silicone-based lubricants that display lower critical
solution temperature and demonstrate their capabilities on controlling
in situ water wetting and dewetting, thermo-gating penetration, and
optical properties. These properties allow the mobile films to form
a kind of erasable recording platforms. We foresee diverse applications
in liquid transport, wetting and adhesion control, and transport switching
Thermoresponsive Mobile Interfaces with Switchable Wettability, Optical Properties, and Penetrability
Liquid-based mobile
interfaces, in which liquids are being utilized as structural long-term
components, have shown their multifunctionality in materials science,
such as the hydration layer of polyelectrolyte brushes used for artificial
implants, stabilized lubricants for antibiofouling, anti-icing, self-cleaning,
optical control, and so forth. However, these currently available
systems do not usually show a response to environmental stimuli. Here,
we describe a strategy for preparing thermoresponsive mobile interfaces
made from novel silicone-based lubricants that display lower critical
solution temperature and demonstrate their capabilities on controlling
in situ water wetting and dewetting, thermo-gating penetration, and
optical properties. These properties allow the mobile films to form
a kind of erasable recording platforms. We foresee diverse applications
in liquid transport, wetting and adhesion control, and transport switching
Growth-Promoting Effects of Zhenqi Granules on Finishing Pigs
Developing nonantibiotic livestock growth promoters attracts intensive interest in the post-antibiotic era. In this study, we investigated the growth-promoting efficacy of Zhenqi granules (ZQ) in pigs and further explored the possible mechanisms by transcriptomics analysis. Weaned piglets (52 days old with an average body weight of 17.92 kg) were fed with diets supplemented with different doses of ZQ (0 g/kg, 1 g/kg, and 2 g/kg) for 30 days and continued observations for an additional 32 days after removing ZQ from the diets. Compared with the control group, the average daily gain, carcass weight, average back fat thickness, and fat meat percentage of the group supplemented with 1 g/kg of ZQ showed a significant increase, and the feed/gain ratio was lower. The group supplemented with 2 g/kg of ZQ also showed a significant increase in average daily gain and average backfat thickness. A transcriptomics analysis revealed that the supplementation of ZQ at 1 g/kg upregulated the expression of genes related to collagen biosynthesis and lipid biosynthesis in skeletal muscle and liver. This effect was primarily through upregulating the mRNA levels of structural proteins and lipid-related enzymes. This study demonstrates the growth-promoting efficacy of ZQ and provides some insights of the mechanism of growth promotion