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Converting solar energy to evaporative energy to obtain clean water has been intensively studied. However, the efficiency of the reported solar evaporators remains limited, and their construction is complex and challenging to control. Here, we report a facile method for constructing efficient solar evaporators by utilizing a thin-layer, highly concentrated polyelectrolyte solution as the evaporation layer. Under an electric field, a single layer of polyelectrolyte–shelled micelles is grafted onto a hydrogel surface, controllably and stably modifying highly concentrated polyelectrolyte chains on the outermost surface. These chains, with their low chemical potential, efficiently absorb water to form the evaporation layer. Theoretical calculations indicate that the water molecules in the evaporation layer possess high energy as the hydrogen bonds between them are significantly disrupted, thus minimizing the evaporation energy. Consequently, for simulated seawater and under 1 kW m–2irradiation, the as-prepared evaporator without a photothermal component achieves a high evaporation rate of 3.74 kg m–2h–1(1.5 times the highest nonphotothermal hydrogels) and that with photothermal particles β-Ti3O5reaches a record-breaking value (6.92 kg m–2h–1). Remarkably, the ion rejection ratio is as high as 99.97% due to repulsion from the positively charged polyelectrolyte.

This review article discusses the challenges of particle assembly and proposes coassembly of synthetic particles with heterogeneous assembling components as a promising solution. Particle assembly using particles as building blocks offers access to superstructural and highly functional materials. However, the rigidity and preorganized structures of particles limit their ability to contact and fuse, making particle self-assembly kinetically and/or thermodynamically unfavorable. Co-assembly of synthetic particles with synthetic/bioderived macromolecules and/or particles bearing complementary surficial chemistries provides efficient pathways to overcome these barriers, enabling the attainment of regular superstructural and highly functional materials. The review focuses on strategies and future perspectives for coassembly of synthetic particles with heterogeneous assembly components, which include block copolymers, DNA, proteins, and particles bearing different surficial chemistries. Co-assembly systems and their potential applications are reviewed. The article also discusses the challenges and future needs in the field of coassembly of synthetic nanoparticles with heterogeneous assembly components.

ABSTRACTBackgroundTo evaluate the effectiveness of varicella vaccine (VarV) as post-exposure prophylaxis (PEP) among children during varicella outbreaks.Material and MethodsA comprehensive literature search was performed in PubMed, Embase, Web of Science, SinoMed, Wanfang and CNKI. Relevant outcomes included the incidence of varicella. Pooled estimates were calculated using a fixed-effects or random-effects model according to the heterogeneity among studies.ResultsA total of 15 studies with 7,474 children that received one or two dosages of VarV as PEP and 183,827 children who received no VarV were included in the meta-analysis. In total, one-dose and two-dose VarV as PEP had 43% (95% confidence interval (CI):27%, 55%) and 60% (95%CI: 35%, 75%) efficacy, respectively. When PEP was applied within 3 days, the pooled VarV as PEP for prevention of varicella was 80% (95%CI: 68%, 88%); when PEP was administered beyond 3 days, the pooled VarV as PEP for the prevention of varicella was 50% (95%CI: 11%, 72%). If the PEP was implemented with a coverage of more than 80%, the VarV could prevent 82% of varicella cases from occurring (95%CI: 15%, 96%); if the PEP covered a maximum of 80% of the susceptible cases, the VarV could prevent 65% of varicella cases from occurring (95%CI: 50%, 76%).ConclusionThe two-dose VarV had better efficacy than one-dose VarV in the control of varicella outbreaks, especially if PEP was applied within 3 days of an outbreak and in conjunction with a high coverage rate ≥80%.

Optimizing electrode materials performance and improving the energy density of supercapacitors is a hot research topic. The complex hollow sphere structure material, as a supercapacitor electrode material, provides more redox active sites and volume expansion space during the electrochemical energy storage process, which has the potential to assemble high performance supercapacitors. Herein, a novel nickel cobalt sulfide and carbon nanotube composite are successfully prepared by the Kirkendall effect. The yolk–shell-structured nickel cobalt sulfide and carbon nanotube composite exhibits superior electrochemical performance as the positive electrode of the hybrid supercapacitor. The hybrid supercapacitor has a specific capacity of 603 C g–1at 1 A g–1, and the capacity retention rate is as high as 67.4% from 1 to 15 A g–1. Moreover, the assembled hybrid supercapacitor has an energy density of 45.35 Wh kg–1. After 8000 cycles, the capacitance retention rate is 91.33%, and the columbic efficiency is 96.15%. Its excellent electrochemical performance is mainly attributed to the excellent conductivity of carbon nanotubes as the supporting skeleton and conducting network, which effectively inhibits the aggregation of nanospheres, exposes more active sites, and facilitates the rapid transmission of ions/electrons, thereby obtaining high specific capacity and rate performance.

Structures impact the performance of nanocatalysts, but optimizing them by altering their structures is tedious and restricted. We present a strategy using “high energy” polymeric composite micelles as precursors to produce variously structured nanocatalysts in a simple, temporally controlled manner. By incubating core–shell spherical micelles of poly(ethylene glycol)-b-poly(4-vinylpyridine) with a molybdate hydrate complexable with poly(4-vinylpyridine), the molybdates cross-link and enlarge the confined poly(4-vinylpyridine) core, producing “high-energy” and “crosslinking-locked” polymeric composite micelles. Properly increasing the temperature weakens the cross-linking and releases the energy at a suitable rate, facilitating the stepwise transition of the polymeric composite micelles into various structures. Cooling the system at specific phases generates worm-like, flower-like, and clustered structures that further develop into molybdenum phosphide (MoP) nanoworms, nanoflowers, and nanoclusters, respectively. MoP nanoworms demonstrate the highest efficiency as nanoelectrocatalysts for hydrogen evolution, surpassing previously reported MoP-based catalysts and even commercial Pt/C catalysts in high current density regions.

In reported experimental studies, DNA/polymer self-assemblies are usually kinetically trapped, leading to the encapsulation and irregular collapse of DNA chains within the resultant assemblies. In striking contrast, eukaryotic cells use tetrasome-to-nucleosome pathways to escape possible kinetic trapping for the formation of well-defined 10 nm chromatin fibers. Here, we report a novel pathway for DNA and amphiphilic diblock copolymer self-assembly inspired by the tetrasome pathway with highly controllable kinetics. The polymer is an A-b-B diblock copolymer with a hydrophilic and noninteractive block A and a hydrophobic and interactive block B. Below the critical water content for the micellization, B blocks wrap the backbone of a DNA chain by weak electrostatic interactions to form a linear DNA/polymer complex. With a gradual increase in the water content, the diblock copolymer unimers in the bulk solution tend to aggregate on the linear DNA/polymer complex, which induces the originally wrapped DNA chain, to change its conformation to wrap around the polymer aggregate, guiding and tailoring the self-assembly. Highly controllable kinetics is achieved via the reduced DNA/polymer electrostatic interactions and the high dynamics of the polymer chains in the system. DNA/polymer self-assembly leads to tailorable and morphologically pure core–shell nanofibers. Compared to the DNA/micelle self-assembly pathway described in our previous study, the present self-assembly pathway exhibits advantages for the fabrication of flexible nanofibers with lengths in micrometers and the potential for unique applications in preparing not only 2D networks at extremely low percolation thresholds but also chemiresistors with large on/off current ratios.

We report a facile and versatile method for fabrication of multiheteroatom-doped hierarchically porous carbon with a large specific surface area, using the 3D network constructed by ZIF-8 coated wormlike micelles as template. The uniform and highly pure wormlike micelles developed in our laboratory is essential, because they not only are responsible for the formation of hierarchical porosity, but also play as a versatile platform for multiheteroatoms doping. In a primary experiment, S, N, B, and P heteroatoms were doped conveniently and the resultant porous carbons have the excellent oxygen reduction reaction performance comparable to the commercial 20% Pt/C.

In this work, a novel cube-shaped cationic lipid based on the imidazolium salt of polyhedral oligomeric silsesquioxane (POSS) was complexed with double-stranded DNA. Because of the negative spontaneous curvature of the cationic POSS imidazolium lipid, an inverted hexagonal phase resulted above the melting point of POSS crystals. Depending on the competition between the crystallization of POSS molecules and the negative spontaneous curvature of cationic POSS imidazolium lipids, different self-assembled phase morphologies were obtained. A lamellar phase was obtained when the POSS crystallization was relatively slow. When the POSS crystallization was fast, an inverted hexagonal phase was obtained with POSS lamellar crystals grown in the interstitials of DNA cylinders. On the basis of a circular dichroism study, double-stranded DNA adopted the B-form helical conformation in the inverted hexagonal phase, whereas the helical conformation was largely destroyed in the lamellar phase.

Techniques to acquire chiral information from molecules are essential for deciphering important biological processes and improving the performance of industrial chiral materials. Herein, we report novel supramolecular gelators that enable widely accessible chiral supramolecular organogels for simple naked-eye enantiodifferentiation of specific enantiomers (left- or right-handedness) for wide-range substances. The supramolecular gelators featuring multiple hydrogen-bonding sites and large π-π conjugated groups are produced by complexing commercially available chiral tartaric acids and achiral 1-naphthylmethylamine. The highly polar and insoluble acid-amine complexes drive the aggregation of the supramolecular gelators, which further form chiral nanofibers due to chirality transfer from tartaric acid to the supramolecular nanofibers through multiple hydrogen-bonding between the hydroxyl groups of chiral tartaric acids and π-π stacking between 1-naphthylmethylamine molecules. At high concentrations, physical crosslinking of the chiral nanofibers creates a chiral gel structure that facilitates interactions between its chirally and non-covalently associated components and enantiomers, making the gel system particularly sensitive to specific types of enantiomers. Consequently, sensitive naked-eye detection of specific enantiomers of diverse substances is achieved viaobserving “gel-to-micelle” transitions, which occurs when the enantiomers generate complexes that disrupt chirality transfer in the co-assembly and destroy the hierarchical structures.

Mechanical responsiveness in many plants is produced by helical organizations of cellulose microfibrils. However, simple mimicry of these naturally occurring helical structures does not produce artificial materials with the desired tunable actuations. Here, we show that actuating fibres that respond to solvent and vapour stimuli can be created through the hierarchical and helical assembly of aligned carbon nanotubes. Primary fibres consisting of helical assemblies of multiwalled carbon nanotubes are twisted together to form the helical actuating fibres. The nanoscale gaps between the nanotubes and micrometre-scale gaps among the primary fibres contribute to the rapid response and large actuation stroke of the actuating fibres. The compact coils allow the actuating fibre to rotate reversibly. We show that these fibres, which are lightweight, flexible and strong, are suitable for a variety of applications such as energy-harvesting generators, deformable sensing springs and smart textiles.

In this study, tadpole-like single chain polymer nanoparticles (TSCPNs) were efficiently synthesized by intramolecularly cross-linking P4VP block of commercial block polymer of PMMA2250-b-P4VP286in N,N-dimethylformamide using propargyl bromide as cross-linking agent. The intramolecular cross-linking reaction led to the production of TSCPNs with a linear tail and a cross-linked head. The as-prepared TSCPNs were then applied as emulsifier to stabilize water in chlorobenzene emulsion, and an extremely stabilized water in oil (W/O) emulsion was generated at a low TSCPNs concentration. The TSCPNs concentration was as low as 0.0075 wt % versus total weight of water and chlorobenzene for emulsion formation. The emulsifying performance of TSCPNs was better than that of low molecular surfactant, such as Span-80. The generated W/O emulsion provided an ideal medium for the reduction of oil-soluble p-nitroanisole by water-soluble sulfide to p-anisidine, an effective contact problem between the two reactants with different solubility was well solved through interfacial reaction.

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Not just a pretty structure: Water‐dispersible hybrid nanotubes were used as a desymmetrization tool to prepare Janus nanoparticles consisting of a hydrophobic sphere with water‐soluble polymer chains grafted on one side (see picture). The Janus micelles undergo self‐assembly to form supermicelles with a flowerlike morphology in which the constituent Janus particles are the “petals”.

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Frechet‐type benzyl ether dendrons of second and third generations with a carboxyl group (G2, G3) at the apex site could attach to poly(4‐vinylpyridine) (PVP), forming hydrogen‐bonded dendronized polymers (HB denpols) in their common solvent, chloroform. The HB denpols show unique self‐assembly behavior, forming vesicles in the common solvent under ultrasonic treatment. The structure and morphology of the vesicles were characterized by dynamic light scattering (DLS), static light scattering (SLS), SEM, TEM, and AFM. The size of the vesicles decreases and the thickness of the vascular membrane increases as the molar ratio of Gx/PVP increases. The hydrogen bonding, π–π aromatic stacking of the dendrons, and the considerable difference in architecture between the dendron Gxand PVP are the main factors facilitating the assembly of the HB denpols in the common solvent.

Summary:Soluble carbon nanotubes were prepared by treating SWNTs with sec‐butyllithium and subsequently using the generated carbanions as the initiator to graft PtBA and PtBA‐b‐PMMA onto the surface of SWNTs. The anionic polymerization initiated by SWNTs‐bearing carbanions not only provides a powerful strategy for functionalizing SWNTs but also gives us knowledge of the sidewall chemistry of SWNTs. The results indicate that a carbanion born on SWNTs behaves like an anionic initiator with high steric hindrance.

Based on our long‐term research on interpolymer complexation due to hydrogen bonding, we proposed several novel self‐assembly approaches to polymeric micelles with regular structures. Differing from micelles of block and graft copolymers, our micelles don't have any chemical bonds between the core and shell. In addition, some of these approaches have been proved to be effective to fabricate hollow aggregates.

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Chloromethyl groups were introduced into the polystyrene (PS) blocks of hydrogenated poly(styrene-block-butadiene-block-styrene) (SEBS) via Friedel–Crafts reaction. The product (SEBS-CH2Cl) formed spherical micelles with PS corona and hydrogenated PB core in THF/ethanol (10/9, v/v). Then, the polystyrene corona carrying CH2Cl groups was cross-linked by amination with 1,6-hexanediamine as a cross linker. The shell cross-linked micelles showed spherical core-shell structure and were stable in solution, which was verified by DLS in solution and by TEM in the solid state.

This article demonstrates the applicability of the algorithm of grid search to the determination of Mark–Houwink (MH) parameters. In the existing methods, the determination of MH parameters involves the use of linear or nonlinear regression. In the cases of using the algorithm of grid search to solve the linear regression problem for the determination of MH parameters, the values of the MH parameters obtained by the grid search method are the same as those obtained by the linear regression method, while in the cases when some nonlinear regression methods have to be used in the existing methods, using the algorithm of grid search can determine the parameters much more easily and accurately than using any nonlinear regression methods. In addition, the grid search method is very easy to understand and execute, and the accuracy of the results can be exhibited by the value of the least‐square function. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 481–487, 2000

Nanocrystalline TiO2 was prepared by the sol-gel method, and raw gelatin and its modified samples crosslinked with formaldehyde acted as dispersers in this method. Transmission electron microscope and X-ray diffractometer measurements showed, using modified gelatin samples, the prepared TiO2 nanocrystals have smaller particle size and more homogeneous particle distribution at the same calcining temperature. Following Fourier transform IR spectroscope analysis, the dispersion mechanism is considered to be through the bonding of TiO(NO3)2 · H2O with the peptide chains of gelatin by a hydrogen bond. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2569–2574, 1999

Abstract: A novel anti-condensation ship coating is discussed, and equipment designed for evaluating the performance of the coating quantitatively is described. An isobutylene-anhydride based copolymer was synthesized and used as a water-absorbing resin instead of a starch-based water-absorbing resin currently used in the coatings. Expanded perlite was used as the heat insulation material. The optimum formulation was determined to be titanium dioxide powder 5.1 g (8.26%); perlite 12 g (19.44%); zeolite 13 g (21.06%); water-absorbing resin 3 g (4.86%); tributyl-phosphate 0.3 g (0.49%); emulsifier OP-10 0.3 g (0.49%); and styrene-acrylate copolymer emulsion 28 g (45.38%).

Polymerization of 4,4'-bismaleimidediphenyl methane and N-phenylmaleimide was conducted in dimethyl formamide, catalyzed by nanocrystalline titania. The monomers and polymers involved were characterized with infrared spectroscopy, ¹H-NMR, and ¹³C-NMR, respectively. The mechanism of the catalyzed polymerization was discussed as well. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 665–669, 1999

AbstractThis paper describes the method of a phase-alternating composite π pulse sequences, in which the subroutines are programed instead of the previously reported “IMSL” library DUNSJ to solve the non-linear least square problems, being used to minimize the pulse angles with respect to resonance off-set. The main program and subroutines were carried out on a personal computer. It is found that the results from the new program were in agreement with that reported in the reference being obtained from IBM/3600 computer and the present method is more effeciant than other existing pulse sequences.

AbstractSimulated annealing algorithm (SAA) was applied to locate the global minimum of a non-linear least square function for spectra fitting. The resolution of methylene region of two 13C-NMR spectra of polystyrene was implemented successfully with this method. Compared with the existing methods, this technique has important advantages in two respects: one is that the resulting resolution of spectra with this method have lesser dependence on the initial values of the parameters inputted to start the optimization of the least square function; the other is that it provides the possibility to determine the peaks which cannot be recognized by the observation. With this technique, some possible error arising from the observation can be avoided.

In this paper, hyperbranched PDOPA polyester with precise structure was synthesized by thermal polycondensation. PDOPA showed good solubility, degradability, and biocompatibility. Functional polymers based on PDOPA were prepared by reactions of amine groups in PDOPA with pyrenecarboxylic acid and polylactide, respectively. Wide applications of the PDOPA polyester are expected after modified with functional groups.

We report here the preparation of PEO-b-P2VPH–S2O82−micelles and their reversible multi-responsive behavior.

Polymeric hollow nanospheres with stabilized structure have been realized by self-assembly of crosslinkable rigid poly(amic acid) ester (PAE) oligomer and coil-like poly(4-vinylpyridine) (PVPy) via hydrogen bonding in their common solvent and subsequent photo-crosslinking of the PAE.

If acetone or 2‐propanone react with benzyl alcohol, besides the desired mono olefin the bis olefin is formed as well.

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