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Polyelectrolyte nanogel consisting of charged network is a prospective platform for developing nanoreactor due to their integrated features of both polyelectrolyte and hydrogel. In this work, cationic poly (methacrylatoethyl trimethyl ammonium chloride) (PMETAC) nanogels with regulated size (30–82 nm) and crosslinking degree (10–50%), has been synthesized by Electrostatic Assembly Directed Polymerization (EADP) method and applied to load gold nanoparticles (AuNPs). Based on the typical reduction reaction of 4-nitrophenol (4-NP), the catalytic performance of the constructed nanoreactor was examined by studying their kinetic process, where the loaded AuNPs exhibited dependent activity on crosslinking degree of nanogels, while independent catalytic activity on nanogel size. Our results validate that, polyelectrolyte nanogels are capable of loading metal NPs and regulating their catalytic performance, therefore demonstrates potential for developing functional nanoreactors. [ABSTRACT FROM AUTHOR]

The combination of nanofluids and micro-texture is an established method to improve the tribological properties of TiC-based ceramics (TC). Due to the limitations of nature and function, the mono-type nanoparticle is limited for improvement in lubrication, heat transfer and other aspects. In this study, a new nanofluid based on magnetic Fe3O4 nanoparticles loaded with multi-walled carbon nanotubes (CNTs) was developed by the co-precipitation method as a lubricant to improve the thermal and tribological properties. Firstly, the surfactant with the best adaptability to Fe3O4@CNTs was selected by a visible spectrophotometer to prepare nanofluids with different volumetric concentrations. Then, the micron-grooves were prepared on the tool surface by laser micromachining technology. The tribological properties and contact angles were measured by the ball-on-disc friction method and angle measurement method, respectively. The results show that compared with the traditional water-based cutting fluid and TC, the contact angle, coefficient of friction, and flashpoint temperature of 0.5 vol% Fe3O4@CNTs nanolubricants and textured TiC-based ceramics (TTC) were reduced by 29.17%, 44.69% and 48.28%. The lubrication and heat dissipation mechanism of Fe3O4@CNTs nanofluids on the surface of TTC were also revealed. [ABSTRACT FROM AUTHOR]

The asymmetric tool wear caused by the tool runout significantly affects the cutting force in micro-milling. In this study, an improved cutting force model considering asymmetric tool wear is constructed for predicting the micro-milling force. Firstly, by analyzing the effect of asymmetric tool wear on uncut chip thickness (UCT), shear/ploughing force, and friction force in the flank wear region, the analytical micro-milling force model considering asymmetric tool wear is derived. Secondly, the multiple parameters in the model are determined by the proposed laser measurement, wear image detection, and mechanical parameter identification methods. Finally, the cutting force and tool wear experiments are designed to validate the proposed model. Experimental results show that the established cutting force model improves the accuracy of cutting force prediction by 6.36% compared with the conventional cutting force model without considering the asymmetric wear. [ABSTRACT FROM AUTHOR]

Transport coefficients, such as the diffusion coefficient and shear viscosity, are important material properties that are calculated in computer simulations. In this study, the criterion for the accurate estimation of viscosity, as an example of transport coefficients, is determined by using the Green-Kubo formula without fitting any analytic forms for the stress decay function. The related algorithm is given by the estimation of the viscosities of polyethylene oxide solutions by using a molecular dynamics simulation for testing. The algorithm can be used in the simulations of complex systems with a long tail of correlations typically found in macromolecular and biological simulation systems. [Display omitted] ● A universal approach for estimating transport coefficients without fitting any analytic forms. ● Criterion for determining the accurate integration cutoff time using the Green-Kubo formula. ● Simple and robust computational handling procedure for systems with multiple modes of correlation times. ● Pecise and reliable results in the fluctuation-based equilibrium simulation method. [ABSTRACT FROM AUTHOR]

With the rapid growth of the aerospace, automotive and biomedical industries, the demand for hard-cutting materials such as titanium alloy has increased sharply. Severe friction and material adhesion exist between tool-chip contact interfaces are the challenges in machining titanium alloy. To solve these problems, the rake face of uncoated cutting tool was textured with micro-groove parallel to the main cutting edge by Nd: YAG laser (named TP). And, cutting tools without laser surface texturing (named NT) were also employed for comparison. Two different coolants were also applied. Nanofluids (named NC) were proposed as a coolant for milling titanium alloy, and conventional cutting fluids (named CC) were also used as a comparison. Then, series of experiments were carried out to investigate the coupling effects of micro-textures and nanofluids (TP + NC) on cutting performance of milling tools at various cutting conditions. Results obtained in this research indicated a dramatic reduction in cutting force of up to 38.4% and 27.75% of surface roughness and 63.3% of tool wear rate (TWR) in TP + NC when compared with NT + CC cutting condition. In addition, the mechanisms for the coupling effects of micro-textures and nanofluids were also revealed. [ABSTRACT FROM AUTHOR]

High-speed cutting technology has become the main direction of development of machinery manufacturing industry; however, the excessive temperature and sharp tool wear have greatly restricted the improvement of drilling speed. To reduce the cutting temperature and alleviate the severe friction and wear of the tool/chip and tool/workpiece interface, micro-groove textures were fabricated on the rake face and flank face of the carbide internal cooling twist drills by an Nd:YAG laser. Thus, two developed cutting tools were fabricated: (1) the internal cooling twist drills with textured rake-face (TF) and (2) the internal cooling twist drills with textured flank-face (TB). High-speed drilling experiments were carried out on Ti6Al4V using these developed tools, and the resulting friction and wear data were compared with those from the conventional one (NT). Results obtained in this work demonstrated the feasibility of fabricating micro-groove textures on internal cooling tool to improve the high-speed cutting performance. Moreover, the mechanisms for the effects of micro-textures fabricated on rake face and flank face were different. The micro-groove textures fabricated on the rake face can significantly increase the degree of chip curling, reduce the contact length at the tool/chip interface, and improve the chip breaking ability; while, the internal cooling abilities were significantly enhanced by the micro-textures fabricated on the flank face; thus, the effects on decreasing the drilling force and improving the anti-adhesive and abrasive wear properties were achieved. [ABSTRACT FROM AUTHOR]

Development of a high performance molecular fluorescence sensor from natural products for metal ions selective detection is also a great challenge. Herein, catechine-dopamine (C-DA) as a fluorescence sensor, was designed for Cu(II) and Hg(II) selective detection in 100% aqueous solution. C-DA with high fluorescence quantum yield of 10.93% was rapidly synthesized from the reaction between two natural phenols, catechine and dopamine, by a simple one-pot organic solvent free approach. Based on fluorescence “on-off”, C-DA could linearly detect the Cu(II) and Hg(II) concentrations in a range of 75 nM - 10 μM and 0.25 μM - 8 μM, respectively, and realized the Cu(II) and Hg(II) determination in tap water samples. Moreover, C-DA exhibited strong affinity to Cu(II) and Hg(II) among 15 kinds of metal ions and 9 kinds of anions. The association constants of C-DA-Cu(II) and C-DA-Hg(II) were respectively calculated as 3.21 × 10 4  M -1 and 3.05 × 10 4  M -1 . Interestingly, although both Cu(II) and Hg(II) formed 1:1 complex to C-DA, they bond to C-DA in a different manner. Cu(II) firstly oxidized the catechol hydroxyl to quinone and was reduced to Cu(I), and then Cu(I) chelated with quinone. Nevertheless, Hg(II) straightly bonded to catechol hydroxyl. [ABSTRACT FROM AUTHOR]

In this paper, we investigated the effects of multi-scale textures on improving the adhesion of PVD TiAlN coating-carbide substrate composites, which is crucial for tribological applications. The substrate pre-treatments were conducted using a nanosecond laser and a femtosecond laser to produce three types of surface textures: (i) micro-scale textures, (ii) nano-scale textures and (iii) micro/nano-scale textures. Characterization tests such as variable depth scratch tests and ball-on-disk wear tests were performed to evaluate the coating adhesiveness as well as the tribological behavior of the PVD TiAlN coatings deposited on the multi-scale textured substrates. The results revealed that the adhesion of three textured TiAlN coatings was greatly improved over that of the untextured one and that anti-adhesive wear properties of TiAlN coatings against AISI 316 stainless steel were significantly improved by using laser substrate pre-treatment. Moreover, the type of surface textures had a profound effect on the adhesive strength and tribological properties of the pre-treated samples. In the experiment, the micro/nano-scale texture was the most effective in providing a mechanical locking of the coatings on the substrate, a matching chemical property between substrate and coating materials, and a high active substrate surface, thus increasing the critical load of the coatings. [ABSTRACT FROM AUTHOR]

This work investigated how particlesoftness can influence theinitial adhesive capture of submicrometer colloidal particles fromflow onto collecting surfaces. The study focused on the case dominatedby potential attractions at the particle periphery (rather than, forinstance, steric stabilization, requiring entropically costly deformationsto access shorter-range van der Waals attractions.) The particles,“spherical polyelectrolyte brushes” with diameters inthe range of 150–200 nm depending on the ionic strength, consistedof a polystyrene core and a corona of grafted poly(acrylic acid) chains,producing a relatively thick (20–40 nm) negative brushy layer.The adhesion of these particles was studied on electrostatically heterogeneouscollecting surfaces: negatively charged substrates carrying flat polycationicpatches made by irreversibly adsorbing the poly-l-lysine(PLL) polyelectrolyte. Variation in the amount of adsorbed PLL changedthe net collector charge from completely negatively charged (repulsive)to positively charged (attractive). Adjustments in ionic strengthvaried the range of the electrostatic interactions. Comparing capturekinetics of soft brushy particles to those of similarly sized andsimilarly charged silica particles revealed nearly identical particlecapture kinetics over the full range of collecting surface compositionsat high ionic strengths. Even though the brushy particles containedan average of 5 vol % PAA in the brushy shell, with the rest beingwater under these conditions, their capture was indistinguishablefrom that of similarly charged rigid spheres. The brushy particleswere, however, considerably less adherent at low ionic strengths wherethe brush was more extended, suggesting an influence of particle deformabilityor reduced interfacial charge. These findings, that the short timeadhesion of brushy particles can resemble that of rigid particles,suggest that for bacteria and cell capture, modeling the cells asrigid particles can, in some instances, be a good approximation. [ABSTRACT FROM AUTHOR]

• Effect of magnetic field on derivative cutting of textured tool is studied. • Infiltration mechanism of Fe 3 O 4 nanofluid under magnetic field is presented. • The mechanism between micro-texture and friction is revealed. Laser texturing of cutting tool is a promising surface modification method for improving the machinability and form accuracy of the machined workpieces in the precision machining of difficult-to-machine material. However, the blocking of micro-textures by the cutting chips, i.e., derivative cutting, usually occurs because of the severe friction between the tool and chip, which can hinder the effectiveness of micro-textures prepared on the rake face of the cutting tool. To address this issue, an external magnetic field was superimposed on the micro-textured tools in order to promote the infiltration of magnetic nanofluid into the micro-textured tool-chip interface, and the possible mechanisms for the effect of magnetic field on the inhibition of derivative cutting caused by the micro-textures was for the first time revealed in this research. Herein, the cutting of 316 L stainless steel with the micro-textured tools was performed under the magnetic field, and the effect of different parameters of magnetic fields on the machining characteristic of micro-textured tools (TT) under Fe 3 O 4 nanofluid (MNF) lubrication condition was investigated. The results reveal that the MNF could be effectively migrated into the micro-textured tool-chip interface in presence of the external magnetic field, and consequently the degree of derivative cutting caused by the micro-textured tools was effectively suppressed. Thus, the machining characteristic of TT tools was gradually improved with increasing the magnetic field strength from 300 to 1200 Gs. Besides, infiltration mechanism of MNF at the micro-textured tool-chip interface under different parameters of magnetic fields were discussed. [ABSTRACT FROM AUTHOR]

To improve the bonding strength of diamond-like carbon film (DLC) on Ti6Al4V alloy (TA) substrate, the effect of texturing, carburizing and their combination was investigated. The different surface treatments were carried out on the Ti6Al4V substrate surface by laser texturing and carburizing before the deposition of DLC coatings. Thus, three different DLC coated samples were prepared: 1. DLC coatings with a laser textured substrate, named TDLC; 2. DLC coatings with a laser carburized substrate, named CDLC; 3. DLC coatings with a hybrid laser textured and carburized substrate, named TCDLC. Meanwhile, the only mechanical polished DLC coatings (ODLC) were also prepared for comparison. The adhesion and tribological performance of different DLC coatings were evaluated by using variable depth nano-scratch tests and ball-on-disk wear tests. Among the four kinds of DLC coatings with different surface treatments, the bonding strength of hybrid pretreated coatings (TCDLC: 12.25 N) were highest compared with other three samples (ODLC: 5.73 N; TDLC: 8.72 N; CDLC: 9.28 N). The coupling of the mechanical-physical-chemical effects accompanying laser texturing and carburizing reaction can enhance the wettability and specific surface area of the Ti6Al4V substrate surface, thereby providing a mechanical self-locking and matching chemical property between the Ti6Al4V substrate and DLC coatings. • A hybrid pre-processing method of laser texturing and carburizing was proposed. • The combined treated DLC coated sample presented the best coatings adhesion. • Matching chemical property between Ti6Al4V substrate and DLC coatings was obtained. [ABSTRACT FROM AUTHOR]

Stimuli-responsive nanoparticles have attracted considerableinterest due to their enormous potential applications. In this paper,nanosized bifunctional spherical polyelectrolyte brushes (BSPBs) wereprepared through grafting random copolymer chains from N-isopropylacrylamide (NIPA) and acrylic acid (AA) onto polystyrenecore by photoemulsion polymerization. The pH- and thermo-responsesof the BSPB with different ratio of NIPA and AA were investigatedby dynamic light scattering. Atomic force microscopy (AFM) was employedto in situ monitor the pH response of the morphology and surface adhesionof BSPB as well as to visualize BSPB individually or as monolayerin air and liquid. The brush-like shell was illegible in electronmicroscopy images but clearly observed in AFM images. The resultsdemonstrated that AFM was a powerful tool for in situ observing thestimulus-response of brushes on the surface of nanoparticles. [ABSTRACT FROM AUTHOR]

Abstract: The rheology of modified poly(acrylic acid) (PAA) solutions can be tuned by controlling the inclusion interactions between α-cyclodextrins and alkyl hydrophobes. We demonstrate three modes of control: (1) using free cyclodextrins (CD) to displace hydrophobe–hydrophobe association in hydrophobically modified poly(acrylic acid) (HMPAA) polymers—which reduces fluid viscosity, (2) using competitive inclusion interactions where stronger SDS:CD binding can be used to ‘unmask’ CD:hydropobe inclusion interactions—which increases viscosity, and (3) employing HMPAA inclusion interactions with CD groups grafted to PAA chains (CDPAA)—which produces higher viscosities than purely hydrophobic association systems at the same concentration. The inclusion association between alkyl side-group in HMPAA and CD, either free or grafted onto PAA, obeys a 1-to-1 stoichiometry at low polymer concentrations (<1wt%). In contrast to purely hydrophobically associating polymers, the CD:hydrophobe interaction is only binary, and, therefore, these associated networks should be ideal model systems to test theoretical predictions for associative fluids. [Copyright &y& Elsevier]

[Display omitted] • An automatic single-liquid-slug oscillatory flow platform for kinetic study. • A miniaturize baffled photo-reactor for oscillation of a liquid slug. • Significantly less material, time and labor consumption. • Deeper understanding of the photocatalytic singlet oxygen oxidation mechanism. Herein, an automatic single-liquid-slug oscillatory flow platform was established for the kinetic investigation of photochemical reactions. Reaction parameters including concentration, reaction time, light intensity, pressure, and temperature were controlled precisely in an automatic manner, and the reaction outcomes were obtained accurately via, integration of an online HPLC. With the reaction kinetics measurement performed for the photocatalytic oxidation of citronellol by Ru(bpy) 3 Cl 2 at a volume scale of 50 μL, it was demonstrated that the single-liquid-slug oscillatory flow method was capable of achieving material and time savings of 70 % and 38 % respectively as compared to the conventional batch method, and of 80 % and 62 % respectively as compared to the continuous flow method. The four reaction orders manifesting the effects of the substrate concentration, photocatalyst concentration, light intensity, and oxygen pressure, respectively, were attained as well as the photoreaction rate constant. Furthermore, the kinetic data obtained under a series of temperatures also shed light on the photoreaction mechanism which exhibited a relationship between the photoreaction rate constant and temperature that deviated from the Arrhenius law. The approach developed in this work is especially useful for the kinetic studies of photoreactions with relatively slower intrinsic reaction kinetics, achieving a more resource-efficient practice with higher repeatability and accuracy. [ABSTRACT FROM AUTHOR]

Inspired by human skin, soft sensors that are capable of sensing various external signals have been an active area of research. However, the vast majority of the developed soft sensors still lag far behind human skin in terms of multimodal sensing capability. Herein, this work reports on a multimodal soft sensor that can decouple thermal and mechanical signals. The sensor is made of poly(ethylene glycol) gel (PEGgel) containing ionic liquid, which is stretchable and transparent and shows decent strain and temperature sensing performances. Importantly, analysis of the ion relaxation dynamics shows that the charge relaxation time and capacitance change of the sensor are independently sensitive to the variations of temperature and mechanical deformation, respectively. By measuring the charge relaxation time and capacitance, the thermal and mechanical signals detected by the PEGgel sensor can be nicely decoupled without signal interference. Such a multimodal soft sensor may serve as a starting point for the development of lifelike soft sensors for high‐tech applications in a variety of fields such as soft robotics, the internet of things, and human–machine interaction. [ABSTRACT FROM AUTHOR]

[Display omitted] Supramolecular self-assembly is ubiquitous in living system and is usually controlled to proceed in time and space through sophisticated reaction–diffusion processes, underpinning various vital cellular functions. In this contribution, we demonstrate how spatiotemporal self-assembly of supramolecular hydrogels can be realized through a simple reaction–diffusion-mediated transient transduction of pH signal. In the reaction–diffusion system, a relatively faster diffusion of acid followed by delayed enzymatic production and diffusion of base from the opposite site enables a transient transduction of pH signal in the substrate. By coupling such reaction–diffusion system with pH-sensitive gelators, dynamic supramolecular hydrogels with tunable lifetimes are formed at defined locations. The hydrogel fibers show interesting dynamic growing behaviors under the regulation of transient pH signal, reminiscent of their biological counterpart. We further demonstrate a proof-of-concept application of the developed methodology for dynamic information encoding in a soft substrate. We envision that this work may provide a potent approach to enable transient transduction of various chemical signals for the construction of new colloidal materials with the capability to evolve their structures and functionalities in time and space. [ABSTRACT FROM AUTHOR]

[Display omitted] The introduction of heteroatoms into hollow carbon spheres is imperative for enhancing catalytic activity. Consequently, we investigated the utilization of nitrogen–oxygen(N/O) co-doped hollow carbon (C)/silica (SiO 2) nanospheres (N x C@mSiO 2), which have a large internal volume and a nano-constrained environment that limits metal aggregation and loss, making them a potential candidate. In this study, we demonstrate the synthesis of nitrogen–oxygen (N/O) co-doped hollow carbon spheres using resorcinol and formaldehyde as carbon precursors, covered with silica, and encapsulated with palladium nanoparticles (NPs) in situ. The N/O co-doping process introduced defects on the surface of the internal C structure, which acted as active sites and facilitated substrate adsorption. Subsequent treatment with hydrogen peroxide (H 2 O 2) introduced numerous carboxyl groups onto the C structure, increasing the catalytic environment as acid auxiliaries. The carboxyl group is present in the carbon structure, as determined calculations based on by density functional theory, reduces the adsorption energy of acetylene, thereby promoting its adsorption and enrichment. Furthermore, H 2 O 2 -treatment enhanced the oxygen defects in the carbon structure, improving the dispersion of Pd NPs and defect structure. The Pd/N x C@mSiO 2 -H 2 O 2 catalysts demonstrated outstanding performance in the acetylene dialkoxycarbonylation reaction, showcasing high selectivity towards 1,4-dicarboxylate (>93 %) and remarkable acetylene conversion (>92 %). Notably, the catalyst exhibited exceptional selectivity and durability throughout the reaction. [ABSTRACT FROM AUTHOR]

• Controllable preparation of micro-texture is achieved by IBE-assisted laser. • Effect of IBE/laser pretreating on adhesion of PVD tool coatings is studied. • The profile evolution mechanism of the micro-textures was investigated. The micro-texture fabricated on the substrate surface of coatings is an established method for enhancing the Physical Vapor Deposition (PVD) coatings adhesion. Currently, laser micromachining is widely used to prepare the micro/nano-texture. Nevertheless, it has a problem of low processing accuracy, such as irregular texture edges and irregular protrusions inside the textures. Here, we propose an ion beam etching (IBE)-assisted laser machining approach to fabricate micro-texture, and the effect of IBE/laser textures on the PVD coatings adhesion is revealed for the first time. The profile evolution mechanism of the micro-textures on the cemented carbide during etching process was investigated. By IBE-assisted laser machining, a ring-shaped microholes array with high precision and controllability was fabricated on the cemented carbide substrate surface. Then, the textured substrates were coated with TiAlN materials using cathode arc-evaporation technique. The scratch tests and dry wear tests on the coatings with the textured substrates were carried out, demonstrating that the IBE/laser textured coatings exhibited higher adhesive strength compared to that of the untextured and laser textured ones. Thus, the IBE-assisted laser machining shows a great potential in the preparation of high precision micro-textures for enhancing PVD coatings adhesion. [ABSTRACT FROM AUTHOR]

In this study, the coupling effect of magnetic nanofluids and micro-textures under magnetic field on the tribological properties of uncoated tool is revealed for the first time. The micro-scale grooves parallel to the main cutting edge were fabricated on the tool rake face by laser processing (named TP), and for comparison the tools without surface texturing (named NT) were also prepared. Magnetic nanofluids with a solid content of 30% (named MN) were prepared as coolant for machining the workpiece, and the conventional cutting fluids (named CC) were also prepared for a comparison. At the same time, the magnetic nanofluids were applied to the cutting area by a novel machining setup, then the turning tests were accomplished to study the coupling effect of micro-texture and magnetic nanofluids (TP + MN) under different magnetic field strengths. The analysis of obtained results (cutting forces, surface roughness of workpiece after turning and tool wear) proves the advantages of the magnetic nanofluids and micro-texture under the magnetic field. In these experiments, under the highest magnetic field strength (40 kA/m), TP + MN has 48.6% lower cutting force and 49.1% lower surface roughness of machined workpiece compared to that of NT + CC. Additionally, the mechanism for the coupling effect of micro-textured tool and magnetic nanofluids under magnetic field wasalso revealed. [ABSTRACT FROM AUTHOR]

• Uniform nanoripple structure is fabricated by combined plasma/laser technique. • Effect of plasma/laser pretreating on adhesion of hard-soft coatings is studied. • Physical and chemical bonding between coating and textured substrate is studied. This research reveals for the first time, how different surface pretreatments (including mechanical polishing, plasma etching, femtosecond laser texturing, and plasma-assisted femtosecond laser texturing) on the PVD hard coatings impact the physical and chemical bonding between PVD soft and hard coatings and its resulting properties. Therefore, the as-deposited TiAlN coatings were served as substrates for the following pretreatments and the deposition of WS 2 soft coatings. The scratch tests and dry wear tests were carried out to investigate the adhesion and tribological performance of these WS 2 /TiAlN soft/hard composite coated samples. Results show that uniform and periodic nano-textures are fabricated on the TiAlN coatings surface by the plasma-assisted laser texturing, which results in high compressive stress and increased surface activity. Thus, the critical load of WS 2 coatings deposited on the plasma-assisted laser textured TiAlN substrates (F N = 46 N) exhibits higher values in comparison with the WS 2 coatings deposited on untreated TiAlN substrate (F N = 28 N). And, an obviously increasing in wear life of WS 2 coatings from 2400 s to 5200 s is achieved by plasma-assisted laser texturing. Additionally, the growth mode of WS 2 coatings deposited on the plasma-assisted laser pretreated TiAlN substrare is changed from Volmer–Weber model to Stranski–Krastanov model. [ABSTRACT FROM AUTHOR]

Nanosized spherical polyelectrolyte brushes (SPBs) are ideal candidates for the preparation of nanometal catalysts, protein separation, and medical diagnostics. Until now, SPBs have been synthesized by photo-emulsion polymerization in a batch reactor, which remains challenging to scale up. This paper reports a successful continuous preparation of SPBs by photo-emulsion polymerization in a self-made microreactor. The effects of residence time, monomer concentration, and feed ratios on the conversion of monomers and SPB structures are systematically investigated by dynamic lighting scattering and transmission electron microscopy. Poly(acrylic acid) (PAA) SPBs obtained in a microreactor exhibiting a narrow size distribution with a short reaction time are very effective in inhibiting the calcium carbonate scale and are comparable to those produced in a batch reactor. This work confirms the feasibility of continuous preparation and scaled-up production of SPBs. [ABSTRACT FROM AUTHOR]

In cancer therapy, the selective targeting of cancer cells while avoiding side effects to normal cells is still full of challenges. Here, we developed dual‐functionalized crescent microgels, which selectively captured and killed lung cancer cells in situ without killing other cells. Crescent microgels with the inner surface of the cavity functionalized with antibody and containing glucose oxidase (GOX) in the gel matrix have been produced in a microfluidic device. These microgels presented high affinity and good selectivity to lung cancer cells and retained them inside the cavities for extended periods of time. Exposing the crescent hydrogels to physiological concentrations of glucose leads to the production of a locally high concentration of H2O2 inside the microgels' cavities, due to the catalytic action by GOX inside the gel matrix, which selectively killed 90 % cancer cells entrapped in the microgel cavities without killing the cells outside. Our strategy to create synergy between different functions by incorporating them in a single microgel presents a novel approach to therapeutic systems, with potentially broad applications in smart materials, bioengineering and biomedical fields. [ABSTRACT FROM AUTHOR]

In cancer therapy, the selective targeting of cancer cells while avoiding side effects to normal cells is still full of challenges. Here, we developed dual‐functionalized crescent microgels, which selectively captured and killed lung cancer cells in situ without killing other cells. Crescent microgels with the inner surface of the cavity functionalized with antibody and containing glucose oxidase (GOX) in the gel matrix have been produced in a microfluidic device. These microgels presented high affinity and good selectivity to lung cancer cells and retained them inside the cavities for extended periods of time. Exposing the crescent hydrogels to physiological concentrations of glucose leads to the production of a locally high concentration of H2O2 inside the microgels' cavities, due to the catalytic action by GOX inside the gel matrix, which selectively killed 90 % cancer cells entrapped in the microgel cavities without killing the cells outside. Our strategy to create synergy between different functions by incorporating them in a single microgel presents a novel approach to therapeutic systems, with potentially broad applications in smart materials, bioengineering and biomedical fields. [ABSTRACT FROM AUTHOR]

Poly(acrylic acid) (PAA) has recently attracted great interest in various fields, including in biomedical applications. This work compares the aqueous behaviors of two kinds of PAA in different environments. We compared free PAA (PAAfree) in an aqueous solution with PAA confined to a polystyrene nanoparticle surface (PAAconf.). The dissociation behaviors of PAA in both environments were systematically studied under various conditions, including differing ionic strengths, molecular weights of PAA, and PAA grafting density by using pH titration assays. The two key parameters concerning dissociation behaviors were obtained, namely, the degree of dissociation (α) and the dissociation constant (pKa). The results showed that the pKa was a little higher for PAAconf. than for PAAfree due to the Donnan effect. The pKa decreased with increasing ionic strength for both PAA cases due to the weakening of hydrogen bonding and the acceleration of dissociation by counterions. PAAfree with a lower molecular weight and PAAconf. with a higher grafting density showed smaller pKas, both indicating stronger dissociation abilities. To clarify this, the electromobility and zeta potential of each case were also measured, and the results confirmed the difference. Finally, bovine serum albumin (BSA) was used as a model protein to study protein-PAA interactions based on their aqueous behaviors. This work furthers our understanding of PAA behaviors in various environments and conditions, shed light on both the structural design capabilities of PAA and its further applications as a functional material. [ABSTRACT FROM AUTHOR]

Living organisms are capable of dynamically changing their structures for adaptive functions through sophisticated reaction‐diffusion processes. Here we show how active supramolecular hydrogels with programmable lifetimes and macroscopic structures can be created by relying on a simple reaction‐diffusion strategy. Two hydrogel precursors (poly(acrylic acid) PAA/CaCl2 and Na2CO3) diffuse from different locations and generate amorphous calcium carbonate (ACC) nanoparticles at the diffusional fronts, leading to the formation of hydrogel structures driven by electrostatic interactions between PAA and ACC nanoparticles. Interestingly, the formed hydrogels are capable of autonomously disintegrating over time because of a delayed influx of electrostatic‐interaction inhibitors (NaCl). The hydrogel growth process is well explained by a reaction‐diffusion model which offers a theoretical means to program the dynamic growth of structured hydrogels. Furthermore, we demonstrate a conceptual access to dynamic information storage in soft materials using the developed reaction‐diffusion strategy. This work may serve as a starting point for the development of life‐like materials with adaptive structures and functionalities. [ABSTRACT FROM AUTHOR]

Living organisms are capable of dynamically changing their structures for adaptive functions through sophisticated reaction‐diffusion processes. Here we show how active supramolecular hydrogels with programmable lifetimes and macroscopic structures can be created by relying on a simple reaction‐diffusion strategy. Two hydrogel precursors (poly(acrylic acid) PAA/CaCl2 and Na2CO3) diffuse from different locations and generate amorphous calcium carbonate (ACC) nanoparticles at the diffusional fronts, leading to the formation of hydrogel structures driven by electrostatic interactions between PAA and ACC nanoparticles. Interestingly, the formed hydrogels are capable of autonomously disintegrating over time because of a delayed influx of electrostatic‐interaction inhibitors (NaCl). The hydrogel growth process is well explained by a reaction‐diffusion model which offers a theoretical means to program the dynamic growth of structured hydrogels. Furthermore, we demonstrate a conceptual access to dynamic information storage in soft materials using the developed reaction‐diffusion strategy. This work may serve as a starting point for the development of life‐like materials with adaptive structures and functionalities. [ABSTRACT FROM AUTHOR]

The biosafety and degradability of nanocarriers have always been an important factor restricting their entry into the clinic. In this work, a new nano-system was prepared by coating the photothermal effect of dopamine-doped mesoporous silica nanoparticles with carboxymethyl chitin through electrostatic interaction, and is further anchored with folic acid on the surface for targeted delivery of anti-cancer the drug doxorubicin (DOX). The nano-system (DOX@PDA/MSN-CMCS-FA) is simply modified CMCS after being loaded with DOX and has good dispersibility, and the drug loading is 10.6%. In vitro release studies have shown that the release rate of PDA/MSN-CMCS-FA is 40% in pH 5.5. Effective degradation is debris in 14 d acidic environments. Due to the anti-infrared photothermal effects of PDA doping and DOX chemotherapy, the semi-lethal concentration (IC50) of nanoparticles (NPS) was 14.95 μg/mL, which can inhibit tumor cell growth by photochemical synergistic treatment, and have certain degradation performance. [ABSTRACT FROM AUTHOR]

Collecting water from the air could alleviate freshwater shortages in arid regions such as remote and inland areas. However, it is challenging to prepare adsorption materials that have high adsorption and desorption performance using straightforward synthesis routes for water harvesting applications. In this paper, a polydopamine (PDA)@Sodium polyacrylamide carboxymethyl cellulose (PAM-CMCNa)-calcium chloride (CaCl2) composite aerogel (PDCA) with a vertical channel was prepared by salt template method and photopolymerization for atmospheric water collection (AWH). The designed vertical channel promotes the rapid transport of water molecules from the atmosphere to the interior of the hydrogel through capillary action. During this process, the hydrogel further expands to prevent the leakage of the internal salt solution, which effectively improves the water vapor adsorption and desorption by hydrogel. Experimental results showed that the hydrogel can absorb 2.78 g/g of water at 90% relative humidity (RH), where 56.3% of the captured water can be desorbed within 60 min of exposure under 1.0 sun light intensity. After 10 adsorption-desorption cycles, the PDCA still possesses excellent water sorption performance. The indoor water collection test showed that the water collection performance reached 2.143 kg/kg day at 90% RH and 25°C adsorption for 12 h and desorption for 6 h. The proposed method for the preparation of PDCA composites can achieve high water harvesting performance over a wide humidity range to enable solar-driven clean water production in remote areas. [ABSTRACT FROM AUTHOR]

Both carbon dioxide‐ (CO2) and biomass‐based molecules have recently been regarded as renewable, abundant, environmentally benign, and attractive carbon feedstocks for organic synthesis. Therefore, a mild and efficient method for the synthesis of 1,3‐oxazolidin‐2‐ones was developed through a “green” four‐component coupling reaction by using CO2, biomass‐based aldehydes such as furfural and 5‐hydroxymethylfurfural (HMF), terminal aromatic alkynes, and primary aliphatic amines with copper iodide as a catalyst. 24 Furyl‐substituted 1,3‐oxazolidin‐2‐ones were obtained in 29–84 % yield from the four‐component coupling reaction. Moreover, the coupling reaction was applicable to the syntheses of furyl‐containing bisoxazolidinone and polyoxazolidinone under mild conditions. [ABSTRACT FROM AUTHOR]

Metal nanoparticles are widely used in catalysis. Loading metal nanoparticles into polymer brushes has aroused wide attention, but regulation of catalytic performance still needs to be improved. The novel diblock polymer brushes, polystyrene@sodium polystyrene sulfonate-b-poly (N-isopropylacrylamide) (PSV@PSS-b-PNIPA) and PSV@PNIPA-b-PSS with reversed block sequence, were prepared by surface initiated photoiniferter-mediated polymerization (SI-PIMP) and used as nanoreactors to load silver nanoparticles (AgNPs). The block sequence caused the difference of conformation and further affected the catalytic performance. PSV@PNIPA-b-PSS@Ag was found to be able to control the amount of AgNPs exposed to external reactant of 4-nitrophenol at different temperatures to achieve regulation of the reaction rate due to the hydrogen bonds and further physical crosslinking between PNIPA and PSS. [ABSTRACT FROM AUTHOR]

Functionally graded materials (FGMs) are a promising engineering material, which is highly desirable in extreme environments of aerospace, nuclear, and bio-implants. Although the surface accuracy and quality of 3D-printed Ni–Fe FGMs can meet most application scenarios, it still requires post-cutting treatment especially in nuclear industry. The FGMs, with the gradient of mechanical property, are a new type of difficult-to-cut material. However, no ready-made post milling process can be referred. The poor-machined surface quality induced by excessive tool wear still cannot be handled even with textured tool under minimum quantity lubrication (MQL). In this paper, the mechanical properties and machinability of the Ni–Fe FGMs as well as its 5 isotropic component 304LxIN625y were firstly studied and correlated. Then, two milling parameter selection strategies were proposed by minimum milling force and by minimum surface roughness, corresponding to strategy I and strategy II. The results show that tool breakage occurs in bottom cutting edge when strategy I is adopted. On the contrary, strategy II can reduce tool major flank wear 40.1% by forming an elastohydrodynamic lubrication between bottom cutting edge and the machined surface, which is a prospective method to solve the tool failure during milling of 3D-printed Ni–Fe FGMs. [ABSTRACT FROM AUTHOR]

Substantial efforts are directed into exploring the structure-properties relationships of photoluminescent Carbon dots (C-dots). This study unravels a resculpting mechanism in C-dots that is triggered by electrochemical etching and proceeds via extensive surface oxidation and carbon–carbon breakage. The process results in the gradual shrinkage of the nanoparticles and can enhance the quantum yield by more than half order of magnitude compared to the untreated analogues. [ABSTRACT FROM AUTHOR]

In this study, we reported a novel Ag/AgCl loaded N-doped carbon composite photocatalyst (Ag/AgCl/NC) which was fabricated by a facile and green method. The composite was prepared only by two simple steps. Firstly, the Ag/N-doped carbon (Ag/NC) was prepared by one-step hydrothermal treatment; during this progress the environmentally benign and renewable natural chitosan was used as not only reducer and stabilizer, but also as a nitrogen source and carbon source. Secondly, Ag/AgCl/NC composite was synthesized via in situ oxidation reaction by adding FeCl. The Ag/AgCl/NC composite was characterized using X-ray diffraction, transmission electronic microscopy, energy dispersive X-ray spectra, UV-visible diffused reflectance spectra, X-ray photoelectron spectroscopy and nitrogen adsorption-desorption measurements, respectively. The obtained Ag/AgCl/NC composite exhibited a superior photocatalytic activity and stability for the degradation of rhodamine B (RhB) under visible light irradiation. [ABSTRACT FROM AUTHOR]

Ultrafine magnetic nanoparticles (MNP, 1.4–5.8 nm) were generated within a nanoreactor of spherical polyelectrolyte brushes (SPB). SPB consist of a solid polystyrene (PS) core and densely grafted poly(acrylic acid) (PAA) chains. Due to strong chemical coordination between carboxyl groups in PAA and MNP surfaces, the obtained magnetic spherical polyelectrolyte brushes (MSPB) kept excellent stability and maintained pH sensitivity. The magnetic properties of MSPB were confirmed by a vibrating sample magnetometer (VSM). The size and the size dispersion of MNP can be modulated by varying adding sequences (conventional coprecipitation or reverse coprecipitation), or nanoreactor structure (with or without crosslinking). MNP content in MSPB could be adjusted by multicycle reactions. This new strategy makes it possible to synthesize ultrafine inorganic nanoparticles with tunable size in SPB. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOF) are of great potential for molecular separation, but the ligand rotation flexibility makes them remain challenging in the construction of fixed nanochannels for precise sieving. Here we report an electrostatic‐anchoring strategy to fix the rotation of 2‐methylimidazole (2‐MIM) ligand in ZIF‐8. Electrostatic inducer trifluoroacetate anchored at and blocked the six‐membered windows of ZIF‐8, and meanwhile induced the positive 2‐MIM rotated from initial 49° to 68°, thus opening neighbored four‐membered windows with a constant size of 3.4 Å. The obtained ZIF‐8 significantly enhanced the CO2/N2 adsorption selectivity from 14.02 to 332.86. Further membrane‐based separation exhibited an outstanding CO2/N2 selectivity of up to 137 with a desired permeability of 286 Barrer, which exceeded the 2019 upper bound. This strategy provides a new inspiration for fixing the ligand rotation in soft MOF for desired precise molecular sieving. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOF) are of great potential for molecular separation, but the ligand rotation flexibility makes them remain challenging in the construction of fixed nanochannels for precise sieving. Here we report an electrostatic‐anchoring strategy to fix the rotation of 2‐methylimidazole (2‐MIM) ligand in ZIF‐8. Electrostatic inducer trifluoroacetate anchored at and blocked the six‐membered windows of ZIF‐8, and meanwhile induced the positive 2‐MIM rotated from initial 49° to 68°, thus opening neighbored four‐membered windows with a constant size of 3.4 Å. The obtained ZIF‐8 significantly enhanced the CO2/N2 adsorption selectivity from 14.02 to 332.86. Further membrane‐based separation exhibited an outstanding CO2/N2 selectivity of up to 137 with a desired permeability of 286 Barrer, which exceeded the 2019 upper bound. This strategy provides a new inspiration for fixing the ligand rotation in soft MOF for desired precise molecular sieving. [ABSTRACT FROM AUTHOR]

The morphology and overall electronic structure of the metal-organic framework (MOF) can be regulated by introducing non-noble metal elements so that it has higher electrocatalytic oxygen evolution reaction (OER) activity but does not change the stability of MOF itself. Herein, we report a series of self-supporting ZnFe bimetallic MOF electrocatalysts on foam nickel (NF) substrates using a simple one-step solvothermal strategy. The morphology evolution process and electronic structure of the Zn2+/Fe3+ molar ratio from 0.25 to 0.75 are systematically investigated. It is worth noting that the overpotentials of ZnFe-BDC-0.75 in alkaline freshwater electrolyte and natural seawater electrolyte are 292 mV and 308 mV (100 mA cm−2), respectively. This work emphasizes the significance of tailoring the electronic microstructure of bimetallic MOFs for efficient OER activity in alkaline and seawater. [Display omitted] • The introduction of Zn2+ influences the morphology evolution of ZnFe-BDC. • ZnFe-BDC-0.75 has excellent OER activity in simulated seawater. • ZnFe-BDC-0.75 has excellent corrosion resistance to Cl− in simulated seawater. • ZnFe-BDC-0.75 has excellent OER activity in natural seawater. [ABSTRACT FROM AUTHOR]

Porous Organic Cages (POCs) with tunable tailoring chemistry properties and polymer‐like processing conditions are of great potential for molecular selective membranes, but it remains challenging in the assembly of high crystalline POCs with regular nanochannels for effective molecular sieving. Here we report an electrostatic‐induced crystal‐rearrangement strategy for the design of a POC membrane with heterostructure. Due to electrostatic attraction, ionic liquid molecules induced cage molecules to rearrange into a sub‐10 nm uniform and defect‐free crystal layer, which displayed competitive CO2 separation performance. The optimized hetero‐structured membrane exhibited an attractive CO2/N2 separation selectivity of over 130, which was superior to the state‐of‐the‐art membranes, accompanied with excellent long‐term and thermal shock stability. This strategy provides a new inspiration for the preparation of crystal‐rearranged membranes with regular channels for gas molecule sieving. [ABSTRACT FROM AUTHOR]

Porous Organic Cages (POCs) with tunable tailoring chemistry properties and polymer‐like processing conditions are of great potential for molecular selective membranes, but it remains challenging in the assembly of high crystalline POCs with regular nanochannels for effective molecular sieving. Here we report an electrostatic‐induced crystal‐rearrangement strategy for the design of a POC membrane with heterostructure. Due to electrostatic attraction, ionic liquid molecules induced cage molecules to rearrange into a sub‐10 nm uniform and defect‐free crystal layer, which displayed competitive CO2 separation performance. The optimized hetero‐structured membrane exhibited an attractive CO2/N2 separation selectivity of over 130, which was superior to the state‐of‐the‐art membranes, accompanied with excellent long‐term and thermal shock stability. This strategy provides a new inspiration for the preparation of crystal‐rearranged membranes with regular channels for gas molecule sieving. [ABSTRACT FROM AUTHOR]

Carboxymethyl Ficoll (CM-Ficoll) has attracted wide attention in various areas such as cell isolation and pharmaceutical slow-release. However, the preparation especially the precise control of carboxymethyl degree of CM-Ficoll remains a challenge. In this work, the preparation of CM-Ficoll was investigated systematically. The substitution degree of hydroxyl groups by carboxymethyl ones in Ficoll was found to be easily controlled by feed ratio, temperature and reaction time. More interestingly, it is found that the CM-Ficoll has significant scale inhibition performance for against calcium carbonate (CaCO3) during water treatment. The scale inhibition performance can be modulated by changing the substitution degree of CM-Ficoll. The possible inhibition mechanism of CM-Ficoll against CaCO3 is the combination of lattice distortion, chelation and dispersion. This work demonstrated that CM-Ficoll should be a promising eco-friendly and cost-effective scale inhibitors for water treatments. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cyclodextrin was successfully covalently grafted to the surface of titanium dioxide. • Introduction of cyclodextrin improved the photocatalytic performance of titanium dioxide. • This modification increased the degradation efficiency of methyl bromide by 2.7 times. A photocatalytic system based on the cooperative effect of β-cyclodextrin (β-CD) was established. Here, β-CDs were covalently grafted onto the surface of TiO 2 nanoparticles through hexamethylene diisocyanate bonds. The structure and photocatalytic properties of the resulting photocatalysts were characterized by various analytical methods. This modification resulted in a 2.7-fold improvement in the degradation efficiency of the pure TiO 2 for methylene blue (MB) and showed good stability in cyclic degradation experiments. [ABSTRACT FROM AUTHOR]

The unpredictable release behavior of metal nanoparticles/metal ions from metal nanoparticle-loaded hydrogels, without a suitable in situ detection method, is resulting in serious cytotoxicity. To optimize the preparation and design of antibacterial hydrogels for in situ detection of metal nanoparticles, an in-situ detection platform based on the fluorescence signal change caused by the potential surface energy transfer of silver nanoparticles (AgNPs) and carbon dots (CD) through silver mirror reaction and Schiff base reaction was established. The antimicrobial test results show that the composite antimicrobial hydrogel, with lower dosages of AgNPs and CD, exhibited a higher inhibition rate of 99.1 % against E. coli and 99.8 % against S. aureus compared to the single antimicrobial component. This suggests a potential synergistic antimicrobial activity. Furthermore, the fluorescence detection platform was established with a difference of <3 μg between detected values and actual values over a period of 72 h. This demonstrates the excellent in situ detection capability of the hydrogel in antimicrobial-related applications. [Display omitted] • The energy transfer within the hydrogels enables in-situ monitoring of the dynamic release behavior of silver nanoparticles. • Schiff base bond, hydrogen bonds, and electrostatic interactions collectively enhance the network structure of hydrogels. • Silver nanoparticles were prepared through the silver mirror reaction without the use of chemical reductants or surfactants. [ABSTRACT FROM AUTHOR]

The healing of severe skin injury is a complicated process and the development of hydrogel dressing with antibacterial and stimuli responsive abilities is necessary. Recently, reduced graphene oxide (RGO) has been widely used in hydrogel dressings due to its good conductivity and photothermal effects. However, there still exist some problems in the fabrication of RGO‐modified hydrogels, especially in the green preparation and dispersion process of RGO. In this work, macromolecular carboxymethyl chitosan (CMCS) is chosen as the reducing agent for the green preparation of RGO. Hydrogels with antibacterial and stimulus‐responsive properties are constructed via Schiff base condensation between CMCS and oxidized pectin (OP). Over 95% cell viability is observed, which is critical for medical applications. RGO endows the hydrogels with relatively good conductivity, self‐healing properties, and mechanical strength. The diameters of bacteriostasis circle of the hydrogel for Escherichia coli and Staphylococcus aureus increase by 0.2 and 0.8 cm respectively after exposure to NIR for 5 min, resulting from the photothermal antibacterial properties of the hydrogel provided by RGO. This study provides guidance for the design and application of multifunctional wound dressing. [ABSTRACT FROM AUTHOR]

Metal coordination-driven nanocomplexes are known to be responsive to physiologically relevant stimuli such as pH, redox, temperature or light, making them well-suited for antitumor drug delivery. The ever-growing demand for such nanocomplexes necessitates the design of a scalable approach for their production. In this study, we demonstrate a novel coordination self-assembly strategy, termed flash nanocomplexation (FNC), which is rapid and efficient for the fabrication of drug-loaded nanoparticles (NPs) in a continuous manner. Based on this strategy, biocompatible chitosan (CS) and Cu2+ can be regarded anchors to moor the antitumor drug (curcumin, Cur) through coordination, resulting in curcumin-loaded chitosan nanocomplex (Cur-loaded CS nanocomplex) with a narrow size distribution (PDI < 0.124) and high drug loading (up to 41.75%). Owing to the excellent stability of Cur-loaded CS nanocomplex at neutral conditions (>50 days), premature Cur leakage was limited to lower than 1.5%, and pH-responsive drug release behavior was realized in acidic tumor microenvironments. An upscaled manufacture of Cur-loaded CS nanocomplex is demonstrated with continuous FNC, which shows an unprecedented method toward practical applications of nanomedicine for tumor therapy. Furthermore, intracellular uptake study and cytotoxicity experiments toward H1299 cells demonstrates the satisfied anticancer efficacy of the Cur-loaded CS nanocomplex. These results confirm that coordination-driven FNC is an effective method that enables the rapid and scalable fabrication of antitumor drugs. [ABSTRACT FROM AUTHOR]

Polyion complex (PIC) vesicles have attracted considerable attention as soft yet functional delivery vehicles. However, most of the PIC vesicles suffer from insufficient stability and functionality which hinder their applications. Herein, a new type of PIC vesicles obtained by co‐assembly of neutral‐cationic diblock copolymers with a supramolecular coordination polyelectrolyte is reported. The latter exhibits tunable structures and properties that endows regulated stability and functionalities of the vesicles. With lanthanide‐based coordination polymers, PIC vesicles are constructed with not only enhanced stability against salt, but also tunable fluorescent or magnetic properties associated with particular Ln3+ ions. Moreover, the vesicle lumen is applied to load PEGlated indocyanine green as a model photothermal transduction agent. The designed vesicles finally display high stability, good biocompatibility, and efficient photothermal conversion, and therefore behave well for thermal ablation of both tumor cells and tumor in mice. The well‐regulated stability and functions of the PIC vesicles are assigned the adaptive structure and properties of the supramolecular coordination polyelectrolytes, which hardly be achieved with conventional covalent polyelectrolytes. This study therefore demonstrates a facile strategy to regulate the stability and function of PIC vesicles, and shall be inspirational for developing novel vesicular materials for potential biomedical applications. [ABSTRACT FROM AUTHOR]

Traditional surface-to-surface contact heterojunctions suffer from poor stability and low electron-hole separation efficiency, which has become a crucial limiting the further improvement of photocatalytic property. Therefore, improving the combination of heterogeneous materials will become a new attempt. In this work, a novel lattice embedded ZnO@TiO 2 (B) nanoflowers was prepared by combining electrodeposition method combined with hot solvent method. The hetero interface of the ZnO@TiO 2 (B) nanoflowers is distributed in the phase of TiO 2 (B), which drives high-efficiency charge separation. The sample Zn:Ti 1:4 has the highest photocatalytic property, and the H 2 generation efficiency under the full spectrum is 1.695 mmol g−1 h−1, which is 3.5 times that of TiO 2 (B). After 36 h cycle stability test, its stability is as high as 90%. According to results, the possible mechanism of ZnO@TiO 2 (B) photocatalytic hydrogen production is proposed. These findings may provide new strategies for the preparation of high-efficiency heterojunction photocatalysts with special structures. In this work, a novel lattice embedded ZnO@TiO 2 (B) nanoflowers was prepared by combining electrodeposition method combined with hot solvent method. Different from the traditional surface-to-surface contact type-II heterojunction, the hetero interface of the ZnO@TiO 2 (B) nanoflowers is distributed in the phase of TiO 2 (B), which drives high-efficiency charge separation. The results show that the photocatalytic efficiency and photostability of TiO 2 (B) nanoflowers has been improved after adding ZnO. [Display omitted] • Dissolution process of the ZnO nanorods makes the broken ZnO nanocrystals embed in the TiO 2 (B) lattice. • The hetero interfaces of the ZnO@TiO 2 (B) heterojunction are distributed in the bulk phase of TiO 2 (B). • More hetero interfaces promote the transfer of carriers and inhibit the recombination of electron-hole pairs. • Excellent cycling stability: the H 2 generation efficiency of 1.695 mmol h−1 g−1 maintained 90% after 36 h. [ABSTRACT FROM AUTHOR]

Based on a new designed tris-ligand L 3 (BTA-DPA 3), complex supramolecular fibers are prepared through a coordination-induced self-assembly. Upon mixing metal ion and L 3 ligand, the coordination constructs an assembled subunit which further stack into supramolecular fibers based on the strong H-bonding of BTA core. Varying metal ions hardly disturbs the fiber formation and structure, while enables introducing different functionalities from the metal ions. The study demonstrates a novel strategy for constructing supramolecular materials with hierarchical structures and functionalities. [Display omitted] In the quest for large but well-controlled supramolecular structures, the discotic benzene-1,3,5-tricarboxamide (BTA) has received quite some attention, because it can form hydrogen-bonded stacks that can be regarded as supramolecular polymers of which the single BTA molecule is the monomer. In this report, we consider a more complex BTA-based supramolecular polymer, namely one that is built up from supramolecular 'monomers'. We design a tris-ligand L 3 consisting of a BTA core carrying three dipicolinic acid (DPA) groups. L 3 itself is too small to form polymers, but in the presence of appropriate metal ions, each L 3 can form three coordination bonds and so form (L 3) n clusters that are large enough to stack successfully: at an appropriate metal dose, long and stable filaments with a cross-sectional diameter of 12 nm appear. We monitor the growth process by UV–vis spectroscopy and light scattering, and use small angle X-ray scattering (SAXS), TEM as well as molecular simulation to confirm the filamentous structure of the fibers and determine their dimensions. The formation and structure of the fiber are very similar for various transition metal ions, which enables introducing different functionalities, e.g., magnetic relaxivity, by proper choice of the metal ions. Hence, we obtain a doubly supramolecular polymer, connected axially by hydrogen bonds, and radially by coordination bonds. Not only does this realize a higher level of complexity, but it also allows to easily introduce and vary metal-derived functionalities. [ABSTRACT FROM AUTHOR]

Associations of amphiphiles assume their various morphologies according to the so‐called packing parameter under thermodynamic control. However, one may raise the question of whether polymers can always relax fast enough to obey thermodynamic control, and how this may be checked. Here, a case of polyion complex (PIC) assemblies where the morphology appears to be subject to kinetic control is discussed. Poly (ethylene oxide)‐b‐(styrene sulfonate) block copolymers are combined with cationic PAMAM dendrimers of various generations (2–7). The PEO‐PSS diblocks, and the corresponding PSS‐PEO‐PSS triblocks should have nearly identical packing parameters, but surprisingly creat different assemblies, namely core‐shell micelles and vesicles, respectively. Moreover, the micelles are very stable against added salt, whereas the vesicles are not only much more sensitive to added salt, but also appear to exchange matter on relevant time scales. The small and largely quenched early‐stage precursor complexes are responsible for the morphological and dynamic differences, implying that kinetic control may also be a way to obtain particles with well‐defined and useful properties. The exciting new finding that triblocks produce more "active" vesicles will hopefully trigger the exploration of more pathways, and so learn how to tune PICsomes toward specific applications. [ABSTRACT FROM AUTHOR]

Assembly of amine-terminated PAMAM dendrimer with PSS n - b -PEO 45 diblock leads to stable and well-defined PIC vesicles that can tolerate not only different PSS block lengths but also dendrimer generations from 2 to 7. As a consequence, hierarchical dendrimer-based PIC vesicles with multiple compartments, namely the dendrimer cavity and the vesicle lumen are obtained. [Display omitted] Hierarchical dendrimer-based polyion complex (PIC) vesicles with multiple compartments have attracted considerable attention as functional delivery vehicles and nano-carriers. Formation of these vesicles relies on the electrostatic assembly of asymmetric polyelectrolytes, namely branched dendrimers with linear polyion-neutral diblock copolymers. However, successful incorporation of dendrimers in vesicle lamellae is challenging due to the compact structure of dendrimers, and therefore, vesicles reported so far are prepared mainly with low generation dendrimers which lack the cavity required for carrier functions. Here, we present a new assembly combination of amine-terminated dendrimer polyamidoamine (PAMAM) with polyion-neutral diblock copolymer poly (styrene sulphonate- b -ethylene oxide) (PSS- b -PEO). The strong charge interaction between the building blocks leads to stable and well-defined PIC vesicles that can tolerate not only different PSS block lengths but, more importantly, also different dendrimer generations from 2 to 7. As a consequence, high generation dendrimers with a cavity can be packed in the vesicle wall, and one obtains hierarchical PIC vesicles with multiple compartments, namely the dendrimer cavity for loading small hydrophobic cargo, and the vesicle lumen for encapsulating hydrophilic macromolecules. Our study demonstrates that combining proper building blocks enables to manipulate the charge interactions, which is essential for controlling the dendrimer packing and the formation of PIC vesicles. These findings should be helpful for understanding the assembly of asymmetric (linear / branched) polyelectrolyte complexes, as well as for designing new hierarchical PIC vesicles for controlled delivery of multiple active substances. [ABSTRACT FROM AUTHOR]

Significant progress has been made in the application of nanoparticle drug carriers in the treatment of cancer. However, the clearance of nanoparticles by the reticuloendothelial system limits their circulation time and tumor cell targeting, reducing the effectiveness of drug delivery. Herein, we construct a bionic core–shell nanostructure by using a "Trojan horse" strategy. The constructed biotin (bio)-modified red blood cell membrane (RBCm)-coated mesoporous silica nanoparticle (MSN) drug carrier (Bio-RBCm@MSN–DOX) exhibits excellent stability, high efficiency of drug encapsulation, and resistance to elimination by immune cells. Therefore, Bio-RBCm@MSN–DOX is a sustained drug delivery system (SDDS) that prolongs circulation and enhances the effective drug release time. The ability to target HeLa cells increased about 4.64 times and the phagocytic efficiency of macrophages decreased by 2.55 times. The composite core–shell structure developed here can serve as a multifunctional drug carrier system, which can become a novel candidate for "circulating target-therapy" carriers. [ABSTRACT FROM AUTHOR]