Search

Astragalus polysaccharide‐containing 3D‐printed scaffold shows great potential in traumatic skin repair. This study aimed to investigate its repairing effect and to combine it with proteomic technology to deeply resolve the related protein expression changes. Thirty SD rats were divided randomly into three groups (n = 10 per group): the sham‐operated group, the model group and the scaffold group. Subsequently, we conducted a comparative analysis on trauma blood perfusion, trauma healing rate, histological changes, the expression of the YAP/TAZ signalling pathway and angiogenesis‐related factors. Additionally, neonatal skin tissues were collected for proteomic analysis. The blood perfusion volume and wound healing recovery in the scaffold group were better than that in the model group (p < 0.05). The protein expression of STAT3, YAP, TAZ and expression of vascular‐related factor A (VEGFA) in the scaffold group was higher than that in the model group (p < 0.05). Proteomic analysis showed that there were 207 differential proteins common to the three groups. Mitochondrial function, immune response, redox response, extracellular gap and ATP metabolic process were the main groups of differential protein changes. Oxidative phosphorylation, metabolic pathway, carbon metabolism, calcium signalling pathway, etc. were the main differential metabolic pathway change groups. Astragalus polysaccharide‐containing 3D‐printed scaffold had certain reversals of protein disorder. The Astragalus polysaccharide‐containing 3D‐printed scaffold may promote the VEGFs by activating the YAP/TAZ signalling pathway with the help of STAT3 into the nucleus, accelerating early angiogenesis of the trauma, correcting the protein disorder of the trauma and ultimately realizing the repair of the wound. [ABSTRACT FROM AUTHOR]

Yield criteria for porous material have been widely used to model the decrease of yield strength caused by porosity during ductile failure which deserves long-term efforts in modelling to remedy the current drawbacks. To improve their accuracy, a method of building yield criteria for porous single crystals based on physics-informed neural networks (PINNs) has been developed, and the newly well-trained yield functions are capable of predicting the yield stress of porous single crystals with different porosity, stress states and crystal orientations. The reliability of the yield functions is guaranteed by the precise datasets generated by the crystal plasticity finite-element method. In particular, through embedding the associated flow rule into the training process, the PINN-based yield function not only achieves higher accuracy in comparison with the analytical methods (e.g. variational nonlinear homogenization or limit analysis) but also avoids the improper appearance of grooves that happens in feed-forward neural networks. The proposed framework enjoys an excellent portability as the yield functions can be rebuilt in the similar non-trivial procedure when new influencing factors must be introduced, which makes us believe in its potential to be extended. [ABSTRACT FROM AUTHOR]

Two reported D‐A‐D monomers based on 3,4‐ethylenedioxythiophene (EDOT) were selected for electrochemical copolymerization to obtain copolymer film, named pRG. Then, a soluble polymer poly[3,4‐ethylenedioxythiophene‐alt‐3,4‐bis([2‐ethylhexyl]oxy)thiophene] (pEA) based on the EDOT derivative was screened out, which is complementary to the absorption trough of the pRG film in visible region and matched with its working potential. The bilayer composite film pRG/pEA was obtained by spinning pEA basement membrane on fluorine doped tin oxide (FTO) coated glass surface, and then in situ electrochemical polymerization of pRG film. Compared to the pRG monolayer film, the bilayer composite film shows a more saturated black color in the neutral state and significant improvement on cyclic stability (only decreased by 1.7% after 250 cycles, while pRG film decreased by 17.1%). The introduction of pEA buffer layer not only achieves the full spectral absorption of the composite film in the visible region, but also significantly improves the cyclic stability of the bilayer composite film. The assembled EC prototype device based on the pRG/pEA composite film exhibits a "black to high transmission" reversible switch. Finally, this method combining electrochemical copolymerization, spin‐coating, lamination and other methods provides a new research idea for designing and preparing black to transmissive electrochromic materials. [ABSTRACT FROM AUTHOR]

A new star‐shaped structure conjugated microporous polymers, poly (2,8,14‐tri[4‐diphenyl‐benzene]‐hexaazatrinaphthylene) (PTPA‐HATN), was designed and in‐situ electrochemically polymerized on the surfaces of FTO electrodes with a directional alignment TiO2 nanorod array to obtain TiO2/PTPA‐HATN core‐shell nanocomposite films. Compared with the PTPA‐HATN film, the TiO2/PTPA‐HATN composite film exhibits higher optical contrast and faster response time, with contrast of 57% at 783 nm, coloring time of 3.62 s and discoloring time of 2.55 s (43%, 4.63 s and 4.77 s for PTPA‐HATN film, respectively). After 400 cycles, the contrast of nanocomposite film decreased by 28%, while the PTPA‐HATN film basically lost its electrochromic properties. A simple three‐layer EC prototype device based on TiO2/PTPA‐HATN nanocomposite film constructed with hydrogel electrolyte clearly shows color changes at different voltages. On the one hand, the formation of core‐shell porous nanostructure of TiO2/PTPA‐HATN composite film provides a larger ion doping/de‐doping interface, shortening the average diffusion length of ions. On the other hand, the large indented polymer‐nanorods contact interface makes it difficult for the polymer to detach from the electrode, thus significantly improving the cyclic stability of the composite film. [ABSTRACT FROM AUTHOR]

The next generation of electrochromic materials are required to be rich in color rendering, offer excellent processability and contribute to environmental protection. Soluble electrochromic polymers (ECPs) can fulfill these requirements. However, a more environmentally friendly water-soluble ECP (WS-ECP) primary color system has not yet been developed. In this work, three novel 3,4-propylenedioxythiophene (ProDOT)-based and colored-to-transmissive ECPs that could be processed from aqueous solutions were designed and synthesized, referred to as WS-ECP-Cyan (WS-ECP-C), WS-ECP-Magenta (WS-ECP-M), and WS-ECP-Yellow (WS-ECP-Y), respectively. All three WS-ECPs exhibit desirable electrochromic properties, including fast switching speed (1.39 s/0.57 s for WS-ECP-Y), appropriate optical contrast (54.4% for WS-ECP-M) and lasting cycle stability (1.5% reduction for WS-ECP-C after 100 cycles) with low driving voltages (<0.8 V). Subsequently, according to the CMY color mixing theory, a range of multilayer films, with the help of the polymer solubility changes (soluble/insoluble) caused by the side chain transformation of WS-ECPs, were formed onto ITO-coated glass through spraying layer by layer (SLbL) to realize full color control. In the same way, all colors in the visible spectrum including black color were also achieved via the co-processing of multicomponent WS-ECPs. The resulting ECP composite films (SLbL or co-processing) showed electrochromic properties comparable to those of WS-ECP-C/M/Y films. The establishment of an environmentally friendly WS-ECP primary color system and two color control methods (SLbL and co-processing) that can realize full color control will strongly promote the application of electrochromic materials in various fields of people's daily life. [ABSTRACT FROM AUTHOR]

Graphene now is one of the most attractive materials in the world. Many countries and institutes are engaged in its functionalization. Combined with the present research situation home and abroad, four different modification methods according to the functional molecules were summed up, which are metals and their oxidation, inorganic molecules, organic molecules and polymer, and then the development of functional modification of graphene, the application and prospect in various fields were introduced. [ABSTRACT FROM AUTHOR]

Silicon (Si), as an ideal anode component for lithium-ion batteries, is susceptible to substantial volume changes, leading to pulverization and excessive electrolyte consumption, ultimately resulting in a rapid decline in the cycle stability. Herein, a new sodium carboxymethyl cellulose-epichlorohydrin (CMC-ECH) binder featuring a three-dimensional (3D) network cross-linked structure is synthesized by a simple ring-opening reaction, which can effectively bond the Si anode through abundant covalent and hydrogen bonds to mitigate its pulverization. Benefitting from the merits of the CMC-ECH binder, the electrochemical performance is significantly enhanced compared to the CMC binder. The CMC-ECH binder is applied to Si anodes, a specific capacity of 1054.2 mAh g -1 can be maintained at 0.2 C following 200 cycles under an elevated Si mass loading of around 1.0 mg cm -2 , and the corresponding capacity retention is 65.6%. In the case of the LiFePO 4 //Si@CMC-ECH full battery, the cycle stability exhibits a substantial enhancement compared with the LiFePO 4 //Si@CMC full battery. Furthermore, the CMC-ECH binder demonstrates compatibility with micron-Si anode materials. Based on the above, we have successfully developed a facilely prepared water-based CMC-ECH binder that is suitable for Si and micron-Si anodes in lithium-ion batteries.

The metastable intermixed composite (MIC) is one of the most popular research topics in the field of energetic materials (EMs). The goal is to invent EMs with tunable reactivity and desired energy content. However, it is very difficult to tune the reactivity of MIC due to its high reactivity and sensitivity caused by enlarged specific surface area and intimate contact between the oxidizers and fuels. Herein, we demonstrated a facile fabrication method that can be used to control the reactivity between the nanoaluminum (n-Al) and poly(tetrafluoroethylene) (PTFE) using an in situ-synthesized polydopamine (PDA) binding layer. It was found that PDA can adhere to both n-Al and PTFE particles, resulting in integrated n-Al@PDA/PTFE MICs. In comparison with traditional n-Al/PTFE MICs, the n-Al@PDA/PTFE showed an increased energy release and reduced sensitivity and more importantly tunable reactivity. By regulating the experimental conditions of coating, the thickness of PDA could be well controlled, which makes the tunable reactivity of n-Al@PDA/PTFE possible. The PDA interfacial layer may increase the preignition reaction (PIR) heat of Al 2 O 3 /PTFE and therefore the overall reaction heat of n-Al/PTFE. It also reveals that the PDA interfacial layer postponed the PIR, leading to an increase in onset thermal decomposition temperature ( T o ). As T o increased, a more complete reaction between PTFE and Al nanoparticles could be achieved.