Liquid transport in a confined space can be enhanced via propelling microdroplets. These microdroplets form spontaneously from localized liquid–liquid phase separation as a ternary mixture is diluted by a diffusing poor solvent.
Two types of β nucleating agents (β-NAs), aryl dicarboxylic acid amide (TMB-5) and diphenyl phthalate diamine (NT-C), were adopted to modify the polypropylene (PP)/ethylene propylene diene monomer (EPDM) blends, which were prepared by dynamic-vulcanization technology. Wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) were used to study the crystallization kinetics of PP. Our results showed that the addition of β-NAs can considerably increase the crystallization temperature, and significantly decrease the spherulite size of β-PP (LSUB300/SUB). The Jeziorny analysis showed there were ~82% and ~89% of relative crystallinity generated from the primary crystallization in the composites containing TMB-5 and NT-C, respectively. The crystallization half time (tSUB0.5/SUB) showed that NT-C improved the overall crystallization rate more effectively than TMB-5. In addition, the peaks of the relative crystallization rate curves were shifted towards higher temperature by 14 and 9℃ with the addition of TMB-5 and NT-C, respectively.
Abstract Background YTHDC1, a key m(6)A nuclear reader, plays a crucial role in regulating mRNA splicing, export, and stability. However, the functional significance and regulatory mechanisms of YTHDC1 in inflammatory bowel disease (IBD) remain to be explored. Methods We established a dextran sulfate sodium (DSS)-induced murine colitis model in vivo and LPS/IFN-γ-stimulated macrophage inflammation in vitro. The expression of YTHDC1 was determined. Colocalization of YTHDC1 and macrophages was assayed by immunofluorescence staining. LV-YTHDC1 or shYTHDC1 lentiviruses were applied for YTHDC1 overexpression or inhibition. For NF-κB inhibition, JSH-23 was utilized. The interaction of YTHDC1 and Beclin1 mRNA was determined by RIP, and the m6A modification of Beclin1 was confirmed by MeRIP. Results In DSS-induced colitis and LPS/IFN-γ-treated RAW264.7 macrophages, we observed a significant downregulation of YTHDC1. Overexpression of YTHDC1 resulted in decreased levels of iNOS , CD86 , and IL-6 mRNA, along with inhibited NF-κB activation in LPS/IFN-γ-treated RAW264.7 cells. Conversely, downregulation of YTHDC1 promoted iNOS expression and inhibited autophagy. Additionally, the effect of YTHDC1 knockdown on CD86 and IL-6 mRNA induced by LPS/IFN-γ was abolished by the NF-κB inhibitor JSH-23. Mechanistically, YTHDC1 interacted with Beclin1 mRNA, thereby stabilizing Beclin1 mRNA and enhancing Beclin1 expression and autophagy. These effects ultimately led to the inhibition of NF-κB signaling in LPS/IFN-γ-challenged macrophages. Conclusions YTHDC1 inhibited the macrophage-mediated inflammatory response by stabilizing Beclin1 mRNA, which may be a potential therapeutic target for the treatment of IBD.
The PP/EPDM blends were prepared using dynamical vulcanization. The effects of different plastic/rubber ratios, content of SiO2 on the mechanical properties, thermal conductivity as well as crystallization kinetics were intensively investigated. Our findings showed that the cooling rate of the PP/EPDM blends increased with increasing EPDM content. With the addition of EPDM, the crystallization half time (t1/2) was shortened, suggesting that the existence of EPDM phase was favorable to the improvement on PP nucleation during the cooling period from melt state.
Droplets at solid-liquid interfaces play essential roles in a broad range of fields, such as compartmentalized chemical reactions and conversions, high-throughput analysis and sensing, and super-resolution near-field imaging. Our recent work has focused on understanding and controlling the nanodroplet formation on solid surfaces in ternary liquid mixtures. These surface nanodroplets resemble tiny liquid lenses with a typical height of <1 μm and a volume of subfemtoliters. The solvent exchange is based on the process of displacing a droplet liquid solution by a poor solvent to create a transient oversaturation for droplet formation. A quantitative understanding of growth dynamics of surface nanodroplets in ternary liquid mixtures not only provides insight into the liquid-liquid phase separation induced by solvent addition in general but also has made it possible to control the droplet size well. This review article will summarize our findings in the last ∼5 years from the research with our collaborators. The first part will explain the fundamental aspects that are key to the formation and stability of surface nanodroplets. In the second part, we will highlight the applications of nanodroplets in chemical analysis and functional surface fabrication and finally point out future directions in droplet-based applications.
Abstract Preconcentration is key for detection from an extremely low concentration solution, but requires separation steps from a large volume of samples using extracting solvents. Here, a simple approach is presented for ultrafast and sensitive microanalysis from a tiny volume of aqueous solutions. In this approach, liquid–liquid nanoextraction in an evaporating thin liquid film on a spinning substrate is coupled with quantitative analysis in one step. The approach is exemplified using a liquid mixture comprising a target compound to be analyzed in water, mixed with extractant oil and co‐solvent ethanol. With rapid evaporation of ethanol, nanodroplets of oil form spontaneously in the film. The compounds are highly concentrated by liquid evaporation and meanwhile extracted to nanodroplets. A detection limit of nanomolar to picomolar is demonstrated for fluorescent model compounds in only ≈5 µL of solution with the entire process taking ≈10 s. The combination of nanoextraction and infrared microscopy also enables simultaneous chemical identification. The dynamics of thin film evaporation are revealed using fast imaging. The principle behind this approach is general, providing a powerful technique for fast and sensitive chemical analysis of a vast library of compounds for environment monitoring, national security, early diagnosis, and many other applications.
This paper investigated the thermorheological properties, thermal properties and flame retardant properties of wood-plastic composites (WPCs). With the addition of wood flour (WF), the rheological behavior became complexity. The critical frequency of shear-thinning phenomenon of the melt viscosity was shifted toward lower value. The temperature dependence of elastic modulus, loss modulus became more serious with the addition of WF. The Cole-Cole plot indicated the existence of complex multi-phase structure in the WPC melt. The CONE calorimetry results showed that ammonium polyphosphate (APP) had good flame retardancy through promoting the formation of the intumescent carbon layer. The present study will supply good insight into the optimization of WPC formulation.
The effects of cooling medium temperatures and plastic/rubber ratios on solidification and crystallization kinetics of dynamically-vulcanized polypropylene/ethylene-propylene-diene rubber (PP/EPDM) blends were investigated with the aid of an in-situ measurement technique. The cooling medium temperature heavily influenced the solidification kinetics primarily due to a combination of latent heat liberated from the molten polymer and the heat transferred away via the metallic wall during the cooling period. Interestingly, the parameter C in three-parameter model was not only affected by the material properties, but also by the cooling condition, different from the previous literature. The crystallization kinetics analysis indicated that the effect of EPDM in the blends consisted of both nucleation-promoting effect (low EPDM loading) and steric effect (higher EPDM loading). The present kinetic analysis may be helpful to further studies on improving the product performances for industrial applications.
Microporous carbon was prepared using a novel procedure based on a zinc(Ⅱ)-organic coordination polymer. The polymer was prepared through the coordination interaction of zinc ions with tartaric acid, and then it was introduced into the open networks of resorcinol/formaldehyde (R/F) resol using hydrogen-bonding interactions. The R/F resol and zinc-organic coordination compound system copolymerized to produce an R/F and zinc-organic coordination copolymer. The copolymer was then heat-treated at 950℃ to decompose and evaporate zinc to fabricate microporous carbon materials. The carbon materials possessed relatively regular large micropores, with a specific surface area of up to 1260 m2·g-1 and a total pore volume of 0.63 cm3 ·g-1 . The resultant microporous carbon materials were used as supercapacitor electrodes, exhibiting an equivalent series resistance of 0.46 Ω, and ideal capacitive behavior with a rectangular shape in cyclic voltammograms. Galvanostatic charge/discharge measurements of the carbon materials gave a specific capacitance of 196 F ·g-1 at a current density of 1A·g-1 and 137F·g-1 at a large current density of 10A·g-1 . A high retention of 98% was measured for the long-term cycling stability (～1000 cycles) of the mesoporous carbon. Overall, the microporous carbon materials exhibited very good electrochemical performance. This study highlights the potential of well-designed microporous carbon materials as electrodes for diverse supercapacitor applications.
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