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A multi-stimuli responsive fluorophore, named NBDNI, was developed by constructing a 1,8-naphthalimide derivative in which a rotatable electron-donating N,N-dimethylaniline group attached to its 4-position. This molecular structure endowed NBDNI with aggregate-induced emission (AIE) and twisted intramolecular charge transfer (TICT) properties, enabling remarkable fluorescence changes in response to multiple external stimuli: (i) sensitivity to polarity in various solvent systems and polymer matrix; (ii) significant fluorescence response and excellent linearity towards temperature changes in solution; (iii) distinct switch of fluorescence color upon acid and base treatments; (iv) reversible mechanochromism behavior in the solid state. Moreover, the mechanisms underlying the aforementioned stimuli-responsive phenomena have been proposed based on comprehensive systematic measurements. Furthermore, preliminary applications such as fluorescence thermometry and acid/base test paper have been demonstrated. This research will bring about new opportunities for the development of novel stimuli-responsive luminescent materials. [ABSTRACT FROM AUTHOR]

Thermal conductivity silicone gel with low permeability and high filling was prepared by 200 mPa·s (PDMS-Vi200) and 500 mPa·s (PDMS-Vi500) as silicone oil, 0.05 wt% hydrogen silicone oil (PDMS-H) as cross-linking agent, and 5 µm (A0-05), 20 µm (A0-20) and 40 µm (A0-40) spherical A12O3 added with different ratios as heat conduction filler. The effects of spherical A12O3 and viscosity of PDMS-Vi on viscosity of adhesive and the maximum filling were studied. The effects of γ-mercaptotrimethoxysilane (KH590) on the thermal conductivity of silicone gel, as well as viscosity of PDMS-Vi, ratios of Si-H to Si-Vi and filling amount on the hardness, density, thermal conductivity and mechanical strength of silicone gel. The influence of the type and proportion of aluminua complex ligand on the anti oil permeability and heat resistance of silicone gel was studied. The results show that the thermal conductive silicone gel has been prepared by vinyl-terminated silicone oil, 0.05 wt% hydrogen silicone oil as the crosslinking agent, and spherical A12O3 with different particle sizes as filler. U-sing silicone oil with different viscosity as the base oil, 0.05 wt% hydrogen silicone oil as the crosslinking agent, and spherical A1203 with different particle sizes as the composite thermal conductive filler, thermal conductive silicone gel with low permeability and high filling has been prepared. When using 20 µm spherical A12O3 with a uniform particle size, there is no obvious increase on viscosity of the gel and the maximum filling is up to 1500 phr. The appropriate amount of KH590 (2.00 wt%) effectively improves the thermal conductivity of the silicone gel. When PDMS-Vi200 is used as silicone oil, the ratio of Si-H to Si-Vi is 0.8:1, A0-20 is used as thermal conductivity filler (600 phr), silicone gel has better performance, with Shore 00 hardness of 67, density of 1.83 g/cm3, thermal conductivity of 3.69 W/(m·K) and tensile strength of 1.95 MPa. The thermal conductivity of thermal conductive silicone gel prepared with different particle sizes is higher than that with one particle size, and when the mass ratio of A0-20 to A0-05 is 2/1, the silicone gel has a better thermal conductivity of 4.7233 W/(m·K). Due to the surface silanization of spherical A12O3, winding of silicone oil and hydrogen bonding effects of sulfhydryl groups with residual double bonds, it can significantly improve the permeability and heat resistance of silicone gel. Moreover, the silicone gel prepared by A0-20 to A0-05(mass ratio of 2/1) has better anti oil permeability and heat resistance, the oil permeability ratio is 1.0476, 5 wt% weight loss temperature of 331 t and the residual mass fraction of 89.10% at 700 °C. [ABSTRACT FROM AUTHOR]

Cobalt complexes have previously been reported to exhibit high faradaic efficiency in reducing CO2 to CO. Herein, we synthesized capsule-like cobalt–polypyridine diamine complexes [Co(L1)](BF4)2 (1) and [Co(L2) (CH3CN)](BF4)2 (2) as catalysts for the electrocatalytic reduction of CO2. Under catalytic conditions, complexes 1 and 2 demonstrated the electrocatalytic reduction of CO2 to CO in the presence or absence of CH3OH as a proton source. Experimental and computational studies revealed that complexes 1 and 2 undergo two consecutive reversible one-electron reductions on the cobalt core, followed by the addition of CO2 to form a metallocarboxylate intermediate [CoII(L)–CO22−]0. This crucial reaction intermediate, which governs the catalytic cycle, was successfully detected using high resolution mass spectrometry (HRMS). In situ Fourier-transform infrared spectrometer (FTIR) analysis showed that methanol can enhance the rate of carbon–oxygen bond cleavage of the metallocarboxylate intermediate. DFT studies on [CoII(L)–CO22−]0 have suggested that the doubly reduced species attacks CO2 on the C atom through the dz2 orbital, while the interaction with CO2 is further stabilized by the π interaction between the metal dxz or dxz orbital with p orbitals on the O atoms. Further reductions generate a metal carbonyl intermediate [CoI(L)–CO]+, which ultimately releases CO. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations were performed on CaO-MgO-Al2O3-SiO2 (CMAS) diopside glass ceramics (GCs) to study the effect of nanocrystal on glass and the effect of chemical composition on mechanical properties. Under tensile loading, the GCs demonstrated that the strength lay between its glass and ceramic counterparts and maintained considerable ductility. Moreover, high Mg/Ca ion ratios are conductive to both the strength and ductility of GCs. In addition, Al ions should be avoided as far as possible since they would promote fracture. After analyzing the shear strain and displacement vector map for ion structures, we found that the presence of nanocrystal in glass changes the original deformation pattern and led to the deformation concentration surrounding the nanocrystal. A high Mg/Ca ion ratio would make the deformation more homogeneous, while a high Ca/Mg ion ratio would aggregate the deformation in the glass region near the nanocrystal. The existence of Al ions near the interface between glass and crystal would promote the formation of voids. [ABSTRACT FROM AUTHOR]

A silicone-modified waterborne polyurethane emulsion (Si-WPU) was prepared by carbon dioxide binary alcohol (PPC), polypropylene glycol, poly-1,4-butylene adipate glycol, 4-methyl-m-phenylene diisocyanate, 2,2-bis(hydroxymethyl)propionic acid, N- [3-(trimethoxysilyl)propyl] ethylenediamine (KH 792) and triethylamine as the main raw materials. The influence of R(the mole ratio of isocyanate to hydroxyl group), the type and content of soft chain segment as well as the amount of KH 792 on the appearance, particle size and stability of Si-WPU emulsion were studied. The influence of mechanical strength, adhesion, water absorption, water contact angle and heat resistance of the cured Si-WPU film was also systematically studied. The results showed that when R was 1. 67, PPC was the soft-chain segment with an addition volume of 75wt%, and KH 792 was 3. 5wt%, Si-WPU emulsion was pan-blue with low viscosity, low particle size and good stability, i. e., the viscosity was 313 mPa·s and particle size was 213 nm. In addition, the Si-WPU film showed better comprehensive performance, with hardness of 2 H, tensile strength of 53. 83 MPa, fracture elongation of 1 465%, adhesion grade of 4B, water contact angle of 93. 5° and water absorption rate of 2. 65%. A novel preparation route has been provided for high-performance and environmentally friendly waterborne polyurethane coating. [ABSTRACT FROM AUTHOR]

The chemical composition of shaddock mainly includes polyphenols, proteins and polysaccharides. However, polysaccharides from shaddock materials have received much less consideration than polyphenols (Fellers et al., 1990). Herein the chemical compositions, α-glucosidase and α-amylase inhibitory activities of crude polysaccharides from the endodermis of shaddock were investigated. The exopolysaccharides (EPS) exhibited a broad and intense peak at 3300-3400 cm-1 that characterized the absorption of the hydroxyl group, and one weak C-H band at around 2941.3 cm-1 in the IR spectrum. The content of neutral sugars in EPS was determined as 37.16%. The content of acidic sugar in EPS was determined as 33.71%. EPS exhibited the highest content of neutral sugar. The content of proteins in EPS was 5.75%. The content of polyphenols was 6.52%. The EPS mainly consisted of four types of polysaccharides with molecular weights of 110 kD, 68 kD, 31 kD and 12 kD. The crude EPS showed significantly higher inhibitory effects on α-glucosidase and α-amylase (inhibition to 74.12% and 86.59%, respectively).

Expression of concern for 'Designing novel morphologies of L -cysteine surface capped 2D covellite (CuS) nanoplates to study the effect of CuS morphologies on dye degradation rate under visible light' by Shahid Iqbal et al., CrystEngComm, 2020, 22, 4162–4173, https://doi.org/10.1039/D0CE00421A. [ABSTRACT FROM AUTHOR]

There has been a lot of interest in the manufacture of stable, high-efficiency photocatalysts. In this study, initially Cr doped ZnFe2O4 nanoparticles (NPs) were made via surfactant-assisted hydrothermal technique. Then Cr-ZnFe2O4 NPs were modified by incorporating S-g-C3N4 to enhance their photocatalytic efficiency. The morphological, structural, and bonding aspects were analyzed by XRD, FTIR, and SEM techniques. The photocatalytic efficiency of the functional Cr-ZnFe2O4/S-g-C3N4 (ZFG) heterostructure photocatalysts was examined against MB under sunlight. The produced ZFG-50 composite has the best photocatalytic performance, which is 2.4 and 3.5 times better than that of ZnFe2O4 and S-g-C3N4, respectively. Experiments revealed that the enhanced photocatalytic activity of the ZFG nanocomposite was caused by a more effective transfer and separation of photo-induced charges. The ZFG photocatalyst can use sunlight for treating polluted water, and the proposed modification of ZnFe2O4 using Cr and S-g-C3N4 is efficient, affordable, and environmentally benign. Under visible light, Gram-positive and Gram-negative bacteria were employed to ZFG-50 NCs' antimicrobial activity. These ZFG-50 NCs also exhibit excellent antibacterial potential. [ABSTRACT FROM AUTHOR]

Currently, organic dyes and other environmental contaminants are focal areas of research, with considerable interest in the production of stable, high-efficiency, and eco-friendly photocatalysts to eliminate these contaminants. In the present work, bismuth-doped zinc ferrite (Bi-ZnFe2O4) nanoparticles (NPs) and bismuth-doped zinc ferrites supported on sulfur-doped graphitic carbon nitride (Bi-ZnFe2O4/S-g-C3N4) (BZFG) photocatalysts were synthesized via a hydrothermal process. SEM, XRD, and FTIR techniques were used to examine the morphological, structural, and bonding characteristics of the synthesized photocatalysts. The photocatalytic competence of the functional BZFG nanocomposites (NCs) was studied against MB under sunlight. The influence of Bi (0.5, 1, 3, 5, 7, 9, and 11 wt.%) doping on the photocatalytic performance of ZnFe2O4 was verified, and the 9%Bi-ZnFe2O4 nanoparticles exhibited the maximum MB degradation. Then, 9%Bi-ZnFe2O4 NPs were homogenized with varying amounts of S-g-C3N4 (10, 30, 50, 60, and 70 wt.%) to further enhance the photocatalytic performance of BZFG NCs. The fabricated Bi-ZnFe2O4/30%S-g-C3N4 (BZFG-30) composite outperformed ZnFe2O4, S-g-C3N4 and other BZFG NCs in terms of photocatalytic performance. The enriched photocatalytic performance of the BZFG NCs might be ascribed to a more efficient transfer and separation of photo-induced charges due to synergic effects at the Bi-ZnFe2O4/S-g-C3N4 interconnection. The proposed modification of ZnFe2O4 using Bi and S-g-C3N4 is effective, inexpensive, and environmentally safe. [ABSTRACT FROM AUTHOR]