Potential Functional Material Research Articles

Red-light controlled supramolecular co-assembly transformations of stiff stilbene and donor acceptor stenhouse adduct amphiphiles

Amphiphiles are of great interest in the search of biomimicking supramolecular assembly for their assembling into complex and hierarchical structures in aqueous media across multiple length-scale. Incorporations of photoswitching units into amphiphiles provide a means to control the morphology of the resultant assembled structures by light irradiation, which is non-invasive and generally biocompatible. The use of light to induce morphological changes offers several extra merits, including selective excitation of photoswitches by different wavelengths, high temporal- and spatial-resolution. Macroscopic soft materials assembled from donor-acceptor Stenhouse adducts (DASA) amphiphiles (DA) in aqueous media are generally suffered from absorption peak broadening due to aggregation and requires strong white-light irradiation to induce a morphological change. Herein, we provide a new strategy for the restoration of red-light sensitivity of DA in aqueous medium, which requires a co-assembly system of DA with a six-membered fused ring stiff stilbene amphiphile (6SA). This 6SA:DA co-assembly forms supramolecular structures in both microscopic and macroscopic length-scale. Morphological changes of these supramolecular structures can be fine adjusted with red-light irradiation. The structural design, supramolecular assemblies and co-assemblies, and macroscopic scaffolds of photoresponsive SA and DA could enable potential visible-light controlled soft functional materials with improved biocompatibility and photosensitivity.

Antioxidative and Circadian Rhythm Regulation Effect of Quercus gilva Extract

Herein, water and ethanol extracts were obtained from the leaves, branches, kernels, and pericarp of Quercus gilva and subsequently analyzed for antioxidant activity and circadian rhythm regulation effects. Candidate components that may affect circadian rhythm and antioxidant activity were investigated to discover potential functional materials. Antioxidant activity was analyzed via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity assays, showing that the hot water extract exhibited higher activity than that of the ethanol extract. In particular, the branch extract showed high antioxidant activity. By measuring total contents of polyphenols, flavonoids, and tannins, the hot water branch extract showed the highest concentrations, highlighting their significant contribution to the antioxidant activity. Examination of the circadian rhythm regulation of each extract showed that the ethanol extract exhibited greater impacts on the circadian rhythm amplitude compared to the water extract. The branch ethanol extract induced circadian rhythm amplitude changes via clock gene Bmal1 expression regulation. Determination of 12 phenolic compound concentrations showed that the branch ethanol extract contained many phenolic compounds, including catechin. This suggests that these compounds affected circadian rhythm regulation. In conclusion, the hot water branch extract has potential as an natural antioxidant material, while the corresponding ethanol extract has potential as a functional material for regulating circadian rhythm.

Nanopore Generation in Biodegradable Silk/Magnetic Nanoparticle Membranes by an External Magnetic Field for Implantable Drug Delivery.

Implantable devices for localized and controlled drug release are important, e.g., for therapies of cancer and chronic pain. However, most of the existing active implants are limited by the usage of nonbiodegradable materials; thus, surgery is needed to extract them after the treatment, which leads to secondary damage. Here, we show a fully biodegradable composite membrane made from silk fibroin and magnetic nanoparticles (MNPs). The membrane porosity can be remotely modified by an alternating magnetic field, which opens nanopores by local heating of MNPs in the composite allowing a liquid to diffuse through them. The stability of the silk membrane in water can be prolonged up to several months by increasing its β-sheet content through ethanol annealing. We present the following original findings. (a) Nanopores can be generated inside the silk/MNP composite membrane by exposing it to an external alternating magnetic field. (b) A longer exposure time results in more nanopore sites. (c) The controllable release of rhodamine B dye is achieved by tuning the period of exposure to the magnetic field. The obtained results demonstrate the suitability of the investigated silk/MNP composite membrane as a potential functional material for implantable drug delivery.

Production of Analogs of the Rare Minerals Sampleite and Lavendulan as Potential Functional Materials

Production of Analogs of the Rare Minerals Sampleite and Lavendulan as Potential Functional Materials

Two 1D Anderson-Type Polyoxometalate-Based Metal-Organic Complexes as Bifunctional Heterogeneous Catalysts for CO2 Photoreduction and Sulfur Oxidation.

Sulfur oxides from the combustion of petrol and excessive emissions of carbon dioxide (CO2) are currently the main causes of environmental pollution. Considerable interest has been paid to solving the challenge, and catalytic reactions seem to be the desired choice. Due to the high density of Lewis acid active sites, polyoxometalates are considered to be the ideal choice for these catalytic reactions. Herein, two captivating polyoxometalate-based metal-organic complexes, formulated as [Co(H2O)2DABT]2[CrMo6(OH)5O19] ({Co-CrMo6}) and [Zn(H2O)2DABT]2[CrMo6(OH)5O19] ({Zn-CrMo6}) (DABT = 3,3'-diamino-5,5'-bis(1H-1,2,4-triazole)) were successfully obtained under hydrothermal conditions. The structural analysis demonstrates that {Co-CrMo6} and {Zn-CrMo6} are isostructural with two different transition metal (Co/Zn) ions based on quadridentate Anderson-type [CrMo6(OH)5O19]4- polyanions. A fan-shaped unit of {Co-CrMo6}/{Zn-CrMo6} is linked to generate a one-dimensional (1D) ladder-like structure. Intriguingly, benefitting from rich Co centers with a suitable energy band structure, {Co-CrMo6} displays better photocatalytic activity than {Zn-CrMo6} for converting CO2 into CO, endowing the CO formation of 1935.3 μmol g-1 h-1 with high selectivity. Meanwhile, {Co-CrMo6} also exhibits a satisfactory removal rate of 99% for oxidizing dibenzothiophene at 50 °C, which suggests that {Co-CrMo6} may be utilized as a potential dual functional material with immense prospects in photocatalytic CO2 reduction and sulfur oxidation for the first time.

Green Tea Extract Containing Piper retrofractum Fruit Ameliorates DSS-Induced Colitis via Modulating MicroRNA-21 Expression and NF-κB Activity.

The aim of the present study was to examine the effect of green tea extract containing Piper retrofractum fruit (GTP) on dextran-sulfate-sodium (DSS)-induced colitis, the regulatory mechanisms of microRNA (miR)-21, and the nuclear factor-κB (NF-κB) pathway. Different doses of GTP (50, 100, and 200 mg/kg) were administered orally once daily for 14 days, followed by GTP with 3% DSS for 7 days. Compared with the DSS-treated control, GTP administration alleviated clinical symptoms, including the disease activity index (DAI), colon shortening, and the degree of histological damage. Moreover, GTP suppressed miR-21 expression and NF-κB activity in colon tissue of DSS-induced colitis mice. The mRNA levels of inflammatory mediators, such as tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), were downregulated by GTP. Colonic nitric oxide (NO) and prostaglandin E2 (PGE2) production, and myeloperoxidase (MPO) activity were also lowered by GTP. Taken together, our results revealed that GTP inhibits DSS-induced colonic inflammation by suppressing miR-21 expression and NF-κB activity, suggesting that it may be used as a potential functional material for improving colitis.

Low temperature coefficient of resistance and high conductivity: Enhanced Cu–substituted LaCo0.4Ni0.6O3 ceramics for functional material

The LaCo0.4Ni0.6-yCuyO3 (LCNCu, y = 0.02–0.08) ceramics were prepared and their possibility as a cheap alternative functional material for thick film resistors was studied. Scanning electron microscopy, differential–thermal and thermomechanical analyses showed that the incorporation of Cu2+ lowered the densification temperature and enhanced the compactness of LCNCu ceramics. All of the samples revealed relatively high conductivity. When y < 0.05, both Cu2+ substitution and sintering temperature showed a strong influence on the conductivity of LCNCu ceramics. However, the simulation results indicated that the density of states almost did not change after Cu2+ substitution despite the weakened electron transport. The temperature coefficient of resistance (TCR) gradually decreased with the addition of Cu2+. Low TCR values (absolute values < 300 ppm/°C) and high conductivity were realized for the samples with y ≤ 0.04 sintered at 1200 °C and y = 0.02 sintered at 1225 °C. Consequently, the improved LaCo0.4Ni0.6-yCuyO3 ceramics may be a potential economical functional material for thick film resistors.

Electrical Properties of the Carbon Nanotube-Reinforced Geopolymer Studied by Impedance Spectroscopy.

Geopolymers, recognized as an ecological alternative to cement concrete, are gaining more and more interest from researchers and the construction industry. Due to the registrable electrical conductivity, this material also attracts the interest of other fields of science and industry as a potential functional material. The article discusses the used geopolymer material, created on the basis of metakaolin and waste Cathode Ray Tubes (CRT) glass, reinforced with ultra-long in-house carbon nanotubes (CNT), in the context of its use as a smart material for Structural Health Monitoring. Long in-house made carbon nanotubes were added to enhance the electrical conductivity of the geopolymer. The impedance spectroscopy method was applied to investigate the conductive properties of this material. The paper shows the microscopic and mechanical characteristics of the materials and presents the results of promising impedance spectroscopy tests.

Chitin oligosaccharides alleviate atherosclerosis progress in ApoE-/- mice by regulating lipid metabolism and inhibiting inflammation

Atherosclerosis is driven both by hyperlipidemia and inflammation. Chitin oligosaccharides (NACOS) have shown pharmacological effects on multiple diseases via hypolipidemic and/or anti-inflammatory activities. The present study aims to evaluate whether NACOS treatment can prevent atherosclerosis induced by a high-fat-diet (HFD) in Apolipoprotein E-knockout (ApoE-/-) mice. Results showed that 300 and 900mg/kg b.w./day NACOS supplementation for 14 weeks significantly decreased atherosclerotic lesions up to 45% and 67% in compared with the HFD (P < 0.05), as measured in the valve area of the aortic root. Further, NACOS supplementation significantly reduced the serum hyperlipidemia and circulating proinflammatory cytokines including interleukin-1β, interleukin-6, monocyte chemoattractant protein-1 and tumor necrosis factor-α. NACOS decreased the hepatic Hmgcr to reduce cholesterol synthesis, activated the genes involved in reverse cholesterol transport to enhance cholesterol efflux and excretion, and reduced the intestinal Npc1L1 to lower cholesterol absorption. Additionally, NACOS enhanced cecum short chain fatty acids production and intestinal integrity. Thus, NACOS supplementation ameliorated atherosclerosis via altering lipid metabolism and reducing inflammation. These findings indicate that NACOS may be a potential functional food material for attenuating atherosclerosis development.

Various Dimensional CuI–DPA Coordination Polymers Based on the Same Components for Different Electronic and Photothermal Properties

Constructing varied dimensional coordination polymers (CPs) from the same chemical components is interesting but rare, which holds back to building the relationship between spatial topological structures and properties. Designing ligands with unequal coordination sites is a possible strategy to construct CPs with distinct spatial topologies. Herein, a novel planar ligand 2,7‐di(pyridin‐4‐yl)acridine (DPA) with two kinds of coordination N sites is prepared for coordinating with copper(I) iodide (CuI). 1D‐, 2D‐, and 3D‐CPs (named α‐, β‐, and γ‐CuI–DPA, respectively) are constructed by similar [Cu2I2] dimers and DPA building blocks but different CuI‐to‐DPA ratios. Interconversions among three CPs are verified. According to property characterization and structural analysis, 3D γ‐CuI–DPA with unique chains possesses charge movement pathways for higher electrical conductivity than those of the others. In addition, π–π stacking interactions are observed to play a significant role in promoting nonradiative migration and triggering photothermal conversion. This work presents a set of objects for investigating the structure‐to‐property connection of CPs in conductivity and photothermal conversion, as well as a roadmap for designing potential functional CPs materials in future.

Characterization of Bioactive Colored Materials Produced from Bacterial Cellulose and Bacterial Pigments.

A Bacterial Cellulose (BC) film was developed and characterized as a potential functional bioactive material. BC films, obtained from a microbial consortium of bacteria and yeast species, were functionalized with the bacterial pigment prodigiosin, produced by Serratia plymuthica, and flexirubin-type pigment, from Chryseobacterium shigense, which exhibit a wide range of biological properties. BC was successfully functionalized at 15% over the weight of the fiber at 40 °C during 60 min, and a color strength of 1.00 ± 0.01 was obtained for BC_prodigiosin and 0.38 ± 0.02 for BC_flexirubin-type pigment. Moreover, the BC films showed moderate hydrophilic character following alkaline treatment, which was maintained after both pigments were incorporated. The porosity and mechanical performance of the functionalized BC samples also remained unaffected. Furthermore, the BC samples functionalized with prodigiosin presented antibacterial activity and were able to inhibit the growth of pathogenic bacteria Staphylococcus aureus and Pseudomonas aeruginosa, with inhibition rates of 97.89 ± 0.60% and 85.12 ± 0.17%, respectively, while BC samples functionalized with flexirubin-type pigment exhibited the highest antioxidant activity, at 38.96 ± 0.49%. This research provides an eco-friendly approach to grant BC film-based material with color and advantageous bioactive properties, which can find application in several fields, especially for medical purposes.

TD-carbon: A new face-centered cubic carbon allotrope

A new allotrope with sp - and sp 3 - hybridized bonds has been predicted by first-principles calculations. This allotrope is formed by interweaving the structures of T-carbon and diamond, thus termed TD-carbon. The energy stability, thermodynamic stability and dynamic stability of TD-carbon have been verified through calculating the total energy, ab initio molecular dynamics simulation, and phonon spectra as well as elastic constants, respectively. TD-carbon is a semiconductor with a direct band gap of 2.82 eV and a low density of 0.673 g / cm 3 . Importantly, it absorbs visible light more easily than TiO 2 . These results suggest that TD-carbon is a potential functional material for optoelectronic devices, hydrogen storage and aerospace materials.

Construction of multifunctional NH2-UiO-66 metal organic framework: sensing and photocatalytic degradation of ketorolac tromethamine and tetracycline in aqueous medium.

Existence of pharmaceutical residues in water has endangered environmental pollution worldwide, which makes it ineludible to develop prospective bifunctional materials which not only possess excellent fluorescence behaviour to monitor pharmaceuticals but also exhibit simultaneous photocatalytic removal efficiency. Strengthened by functionalized metal organic framework (MOF) materials, we present here an amine functionalized zirconium-based MOF NH2-UiO-66 which has been successfully synthesized using solvothermal approach. The as prepared MOF was subjected to numerous structural, morphological and compositional characterizations. Interestingly, featured by the excellent fluorescent intensity of MOF modulated by LMCT effect, NH2-UiO-66 was screened to detect pharmaceutical compounds with KTC and TC in aqueous solution. The prepared functionalized MOF showcased excellent sensing platform with magnificent response range (0‒3µM), lower limit of detection (160nM; KTC and 140nM; TC), excellent selectivity and influential anti-interference capability. More importantly, the practical utility of the proposed sensor was further explored for the determination of pharmaceutical drugs in real water samples with suitable recoveries. Simultaneously, the synthesized MOF also exhibited high photocatalytic efficiency towards the removal of KTC and TC under solar light irradiation. The degradation efficiency for KTC and TC was found to be 68.3% and 71.8% within 60 and 280min of solar light, respectively. Moreover, excellent recyclability was demonstrated by the current synthesized system over five cycles. Overall, this study presents a feasible route for the utilization of functionalized MOFs as potential dual functional materials towards the simultaneous detection and degradation of specific pharmaceuticals from aqueous medium.

Research on the application potential of lattice materials based on the cell configuration

Lattice materials are recognized as the most potential functional material, with remarkable periodic and modular characteristics. The 3D models and mechanical models of ECC, BCC, GBCC and BCCxy cells are established. The mechanical properties of different cell configurations under static and dynamic loads are studied by finite element simulation. The results show that the straight-rod dominant cells such as the ECC and GBCC cells have higher equivalent stiffness, and the lattice material composed of that will be provided with better bearing performance. The inclined-rod dominant cells such as the BCC and BCCxy cells have greater strain energy, and the lattice material composed of that will be provided with better buffer and energy absorption. By studying the mechanical properties of different cells, it provides a reference for cells selection and optimization of lattice materials to meet different engineering application requirements.

Sargahydroquinoic acid isolated from Sargassum serratifolium as inhibitor of cellular basophils activation and passive cutaneous anaphylaxis in mice

Basophils and mast cells are characteristic effector cells in allergic reactions. Sargahydorquinoic acid (SHQA), a compound isolated from Sargassum serratifolium (marine alga), possesses various biochemical properties, including potent antioxidant activities. The objective of the present study was to investigate inhibitory effects of SHQA on the activation of human basophilic KU812F cells induced by phorbol myristate acetate and A23187 (PMACI), a calcium ionophore. Furthermore, we confirmed the inhibitory effects of SHQA on the activation of rat basophilic leukemia (RBL)–2H3 cells induced by compound 48/80 (com 48/80), bone marrow-derived mast cells (BMCMCs) induced by anti-dinitrophenyl(DNP)-immunoglobulin E (IgE)/DNP-bovine serum albumin (BSA), DNP/IgE and on the reaction of passive cutaneous anaphylaxis (PCA) mediated by IgE. SHQA reduced PMACI-induced intracellular reactive oxygen species (ROS) and calcium levels. Western blot analysis revealed that SHQA downregulated the activation of ERK, p38, and NF-κB in a dose-dependent manner. Moreover, SHQA suppressed the production and gene expression of various cytokines, including interleukin (IL)-1 β, IL-4, IL-6, and IL-8 in PMACI-induced KU812F cells and IL-4 and tumor necrosis factor (TNF)- α in com 48/80-induced RBL-2H3 cells. It also determined the inhibition of PMACI, com 48/80- and IgE/DNP-induced degranulation by reducing the release of β -hexosaminidase. Furthermore, it attenuated the IgE/DNP-induced PCA reaction in the ears of BALB/c mice. These results suggest that SHQA isolated from S. serratifolium is a potential therapeutic functional food material for inhibiting effector cell activation in allergic reactions and anaphylaxis in animal model.

Facile Synthesis of Graphene Oxide/Titanate Nanotube Composites and Their Application for Cobalt(II) Removal

In this work, the novel graphene oxide/titanate nanotubes (GTNT) composites were synthesized through a facile and high-yield alkaline hydrothermal method. SEM, TEM, XRD, BET, and TGA/DTA were applied to study the morphology and structure of the GTNT composites. The results show that a huge number of titanate nanotubes are closely attached to the graphene sheet structure and overlap each other. This hierarchical morphology endows the GTNT composites with not only the high specific surface area of 236.9 m2/g but also abundant porous structure, both of which are benefit for Co(II) adsorption. The batch adsorption experiments demonstrate that the GTNT composites have a high adsorption capacity and rapid kinetics for Co(II) adsorption (10 min for equilibrium). The adsorption capacity of the GTNT composites reaches 211.1 mg/g. The adsorption kinetics of the GTNT composites fits well to the pseudo-second-order model, while the adsorption isotherm of which fits well to the Langmuir model. The adsorption performance of Co(II) ions on the GTNT composites has a great relationship with the pH value, in the pH range of 1–7, the Co(II) adsorption capacity of the GTNT composites greatly increases with the increase of the pH value. In addition, the effect of coexisting anions on fluoride removal is also investigated. Na+, K+, and Mg2+ ions have shown a negligible effect on the Co(II) adsorption efficiency of the GTNT composites. However, the existences of Cu2+, Cd2+, and Pb2+ ions would clearly have an effect on the Co(II) adsorption of the GTNT composites. The adsorption mechanism is also discussed. It is believed that the GTNT composites can be considered as a potential functional material for removing the radioactive metals containing wastewater.

The Optimization of Extraction Process, Antioxidant, Whitening and Antibacterial Effects of Fengdan Peony Flavonoids.

Flavonoids have important biological activities, such as anti-inflammatory, antibacterial, antioxidant and whitening, which is a potential functional food raw material. However, the biological activity of Fengdan peony flavonoid is not particularly clear. Therefore, in this study, the peony flavonoid was extracted from Fengdan peony seed meal, and the antioxidant, antibacterial and whitening activities of the peony flavonoid were explored. The optimal extraction conditions were methanol concentration of 90%, solid-to-liquid ratio of 1:35 g:mL, temperature of 55 °C and time of 80 min; under these conditions, the yield of Fengdan peony flavonoid could reach 1.205 ± 0.019% (the ratio of the dry mass of rutin to the dry mass of peony seed meal). The clearance of Fengdan peony total flavonoids to 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, hydroxyl radical and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical could reach 75%, 70% and 97%, respectively. Fengdan peony flavonoid could inhibit the growth of the Gram-positive bacteria. The minimal inhibitory concentrations (MICs) of Fengdan peony flavonoid on S. aureus, B. anthracis, B. subtilis and C. perfringens were 0.0293 mg/mL, 0.1172 mg/mL, 0.2344 mg/mL and 7.500 mg/mL, respectively. The inhibition rate of Fengdan peony flavonoid on tyrosinase was 8.53–81.08%. This study intensely illustrated that the antioxidant, whitening and antibacterial activity of Fengdan peony total flavonoids were significant. Fengdan peony total flavonoids have a great possibility of being used as functional food materials.

Characterization of Oleic Acid/CHAPSO Bicellar Mixture Formation via Lipid Transfer.

Oleic acid/3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxypropane sulfonate (OA/CHAPSO) bicellar mixtures are potential functional membrane materials. The lipid transfer during the formation of these bicellar mixtures was evaluated. The OA/CHAPSO bicellar mixture was prepared by mixing a solution of OA vesicles as a source of bilayer membranes with a solution of CHAPSO as a detergent at different composition ratios, x OA (= [OA] / ([OA] + [CHAPSO])). The lipid transfer was evaluated based on the leakage of fluorescent probe molecules, i.e., carboxyl boron-dipyrromethene (BODIPY C12), from the OA bilayer membranes. Mixing the CHAPSO solution with the OA vesicle eliminated the self-quenching of BODIPY C12 because of the leakage of BODIPY C12 molecules. The apparent rate constant of the leakage increased with decrease in x OA to 0.60. However, at x OA ≤ 0.60, the apparent rate constants barely changed. The correlation between the leakage of the BODIPY C12 molecules and the transfer of OA molecules enables the evaluation of the lipid transfer during the OA/CHAPSO bicellar mixture formation through the observation of the self-quenching of BODIPY C12.

Dynamic relaxation characteristics and stress relaxation behavior of Pd-based&lt;sub&gt; &lt;/sub&gt;metallic glass

As a potential functional and structural material, high-entropy metallic glasses have aroused tremendous research interest in condense matter physics and mechanics. The correlation between macroscopic mechanic properties and microstructure heterogeneity of high-entropy metallic glasses is one of the most important scientific issues in glassy solids. In the present research, Pd&lt;sub&gt;42.5&lt;/sub&gt;Cu&lt;sub&gt;30&lt;/sub&gt;Ni&lt;sub&gt;7.5&lt;/sub&gt;P&lt;sub&gt;20&lt;/sub&gt; metallic glass and Pd&lt;sub&gt;20&lt;/sub&gt;Pt&lt;sub&gt;20&lt;/sub&gt;Cu&lt;sub&gt;20&lt;/sub&gt;Ni&lt;sub&gt;20&lt;/sub&gt;P&lt;sub&gt;20&lt;/sub&gt; high-entropy metallic glass are selected as the model alloys. Dynamic mechanical analysis (DMA) and stress relaxation are used to investigate the influences of temperature and physical aging on dynamic mechanical relaxation process and microstructure heterogeneity of the model alloys. The dynamic mechanical analysis results demonstrate that the Pd&lt;sub&gt;42.5&lt;/sub&gt;Cu&lt;sub&gt;30&lt;/sub&gt;Ni&lt;sub&gt;7.5&lt;/sub&gt;P&lt;sub&gt;20&lt;/sub&gt; metallic glass and Pd&lt;sub&gt;20&lt;/sub&gt;Pt&lt;sub&gt;20&lt;/sub&gt;Cu&lt;sub&gt;20&lt;/sub&gt;Ni&lt;sub&gt;20&lt;/sub&gt;P&lt;sub&gt;20&lt;/sub&gt; high-entropy metallic glass both exhibit evident &lt;i&gt;β&lt;/i&gt; relaxation process. In addition, the atomic mobility of model alloys is reduced in these processes, and the &lt;i&gt;β&lt;/i&gt; relaxation shifts toward higher temperatures. In the stress relaxation process, the Gibbs free energy is reduced due to the high configurational entropy. This is the potential reason that high-entropy metallic glass possesses higher activation energy. In parallel, high-entropy metallic glass is more difficult to activate and needs to break through a higher energy barrier. With the increase of physical aging time, the flow unit in high-entropy metallic glass becomes smaller. This also benefits from the high-entropy effects that bring sluggish diffusion into high-entropy metallic glass. The change of activation volume under physical aging of high-entropy metallic glass is less sensitive to stress relaxation than that of metallic glass.

Copper naphthoporphyrin showing enhanced water-solubility by nano-encapsulation and efficient photoacoustic response

ABSTRACT Here, we report the facile synthesis of Cu(II) tetraaryl-tetranaphtoporphyrin CuTNP showing an extremely sharp, intense Q band above 700 nm via retro-Diels-Alder approach. The highly saddled structure of CuTNP was confirmed using X-ray single-crystal diffraction. The optical and magnetic properties of CuTNP, as well as its excellent reversible redox behaviours, were thoroughly examined both experimentally and theoretically. The water-soluble nanocomposites encapsulating CuTNP by bent amphiphilic molecules were successfully developed, which kept the intense Q band of CuTNP in water. The strong photoacoustic response of CuTNP was detected, suggesting its potential as a photoacoustic imaging agent. This work provides metal-coordinated linearly π-extended porphyrins as potential functional materials for future biomedical applications.