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Solar energy is the most abundant energy resource on earth. Unfortunately, only a very small portion of the solar radiation can be utilized by current light-harvesting materials, thus leading to the poor utilization efficiency of solar energy. In this regard, aggregation-induced emission luminogens (AIEgens) have demonstrated versatile properties that can enhance energy conversion and potentially revolutionize solar utilization systems. AIEgens with great processability can selectively absorb radiation across multiple spectral regions and transform solar energy into longer-wavelength light, heat, or alternative forms of energy. These processes can considerably enhance the solar energy utilization performance by either developing light-harvesting systems based on AIEgens or hybridizing modern light-harvesting systems with AIE technology. In this Perspective, based on material properties, we highlight different functions of AIEgens related to solar light utilization, including sunlight transformation, chemical conversion, and thermal conversion.

Interfacial heating is the most obvious feature that distinguishes the novel solar driven interfacial heating from the traditional solar heating technology, and it is also a key factor in promoting solar energy utilization and vapor generation performance. However, the inherent trade-off between water supply and the interfacial heating performance of photothermal materials has rarely been investigated. Herein, an all-in-one designed bilayer evaporator consisting of a top solar absorber (Fe

The upgrade project of the Beijing Electron Positron Collider (BEPCII) is a high-current electron–positron collider with beam intensity close to 1A. The RF system plays an important role in providing energy for the beam, compressing the beam length and maintaining beam lifetime. Once the RF system shuts down the RF power for various reasons, the accelerator will stop working. In order to determine which reason causes the RF trip, a new RF trip diagnostic system was built based on the NI PXI system. The new RF trip diagnostic system is used to collect the data of the forward power, reflected power, cavity voltage, and beam current in a period of time before and after the RF trip event happens. The system uses LabVIEW as the control software, which conducts I/Q sampling of down-converted RF signals directly, then calculates the amplitude and phase of each RF signal, and plots the change curve. The data and figures are stored in the disk and MySQL database. The change curve can be replotted by the data browser which developed by the Python or PHP language. Through the analysis of the RF trip data and figures that produced by the new RF trip system, it can be clear whether the RF trip is caused by the RF system, so as to locate the reason of the RF trip more quickly and improve the reliability and stability of the machine operation.

Background Integrase inhibitors (INIs)-based antiretroviral therapies (ART) are more recommended than efavirenz (EFV)-based ART for people living with HIV/AIDS (PLWHA). Yet, the advantage of integrase inhibitors in treating TB/HIV coinfection is uncertain. Therefore, the objective of this systematic review is to evaluate the effects and safety of INIs- versus EFV-based ART in TB/HIV coinfection, and demonstrate the feasibility of the regimens. Methods Four electronic databases were systematically searched through September 2020. Fixed-effects models were used to calculate pooled effect size for all outcomes. The primary outcomes were virologic suppression and bacteriology suppression for INIs- versus EFV-based ART. Secondary outcomes included CD4+ cell counts change from baseline, adherence and safety. Results Three trials (including 672 TB/HIV patients) were eligible. ART combining INIs and EFV had similar effects for all outcomes, with none of the point estimates argued against the INIs-based ART on TB/HIV patients. Compared to EFV-based ART as the reference group, the RR was 0.94 (95% CI 0.85 to 1.05) for virologic suppression, 1.00 (95% CI 0.95 to 1.05) for bacteriology suppression, 0.98 (95% CI 0.95 to 1.01) for adherence. The mean difference in CD4+ cell counts increase between the two groups was 14.23 cells/μl (95% CI 0− 6.40 to 34.86). With regard to safety (adverse events, drug-related adverse events, discontinuation for drugs, grade 3–4 adverse events, IRIS (grade 3–4), and death), INIs-based regimen was broadly similar to EFV-based regimens. The analytical results in all sub-analyses of raltegravir- (RAL) and dolutegravir (DTG) -based ART were valid. Conclusion This meta-analysis demonstrates similar efficacy and safety of INIs-based ART compared with EFV-based ART. This finding supports INIs-based ART as a first-line treatment in TB/HIV patients. The conclusions presented here still await further validation owing to insufficient data.

A digital low level radio frequency (DLLRF) system has been developed to replace the old analog LLRF and operated stably at BEPCII east RF station in the past two years. The RF stabilities required for BEPCII are ± 1% in magnitude and ± 1 degree in phase. These are satisfied both by the new DLLRF and the old analog LLRF. Yet, the DLLRF did not improve the RF stabilities so much as expected, especially when the beam current was high in collision mode. The purpose is to improve the RF stabilities further and meet the requirements by the upgraded BEPCII project (BEPC3). A disturbance observer based (DOB) controller to suppress the noise was developed and tested with beam at BEPCII RF system. The DOB controller works and the RF stabilities with beam may be improved from ± 1% to less than ± 0.5% in magnitude and from ± 1 degree to less than ± 0.5 degrees in phase.

A new and simple colorimetric receptor 1 was prepared easily by one-step condensation of 3-acetyl-4-hydroxycoumarin and 8-aminoquinoline. Its absorbance at λ 296 nm significantly increased upon addition of Fe3+ with a turn-on mode. Furthermore, turn-off sensing happened when F– was added to the 1–Fe3+ complex formed in situ. The 1–Fe3+ complex showed high selectivity and low detection limit toward F– ion. Free Schiff base 1 was then given off for recognition Fe3+ again. The reversible “off-on-off” sensing occurred upon sequential addition of Fe3+ and F–.

Hydrogels have drawn extensive attention due to their unique physical and biological properties. However, the relatively low mechanical strength and poor processability of hydrogels limit their applications. Especially, the emerging 3D printing technology for nontoxic hydrogels requires proper formability and controllable mechanical behaviors. In this study, a new strategy to construct a novel double-network biocompatible hydrogel from poly(ethylene glycol) diacrylate (PEGDA) and short-chain chitosan (CS) via ionic-covalent cross-linking is by a two-step method involving UV curing followed by immersion in an anionic solution. The CS-based ionic network and PEGDA-based covalent network as well as the hydrogen bonds between them jointly induce excellent mechanical properties, which can be regulated by changing the PEGDA/CS content and ionic cross-linking time. Compared with conventional hydrogels, this mechanically optimized hydrogel exhibits a superior elastic modulus (3.84 ± 0.4 MPa), higher tensile strength (7.23 ± 0.2 MPa), and higher tensile strain (162 ± 7%). Notably, its excellent printing capability through the citrate anionic solution adjustment enables 3D printing with precision, flexibility, and a complex inner structure by extrusion in air at room temperature. In addition, a number of citrate ions existed in the ionic network, giving the hydrogels good electrical conductivity. Therefore, this printable, conductive, and tough hydrogel exhibits potential for vascular engineering, cartilage tissue engineering, and wearable device applications.

Visualization of immunocyte-microbe interaction is of great importance to reveal the physiological role and working mechanism of innate and adaptive immune system. The lack of rapid and stable microbial labeling platform and insufficient understanding of macrophage-microbe interaction may delay precautions that could be made. In this contribution, a clickable AIEgen, CDPP-NCS, containing a cationic pyridinium moiety for targeting bacteria and an isothiocyanate moiety for covalently bonding with amine groups, is successfully developed. With the advantages of excellent photostability and rapid bioconjugation with amine groups on the bacterial envelope, the processes of macrophage-bacterium interactions with subcellular resolution has been successfully captured using this clickable AIE probe. Therefore, the new clickable AIEgen is a powerful tool to study the interaction between cell and bacterium.

The reactive and stable catalysts for the oxygen reduction reaction are highly desirable for low temperature fuel cells. The commercial oxygen reduction reaction electrocatalysts generally reply on noble metal based nanomaterials, which suffer from inherent cost and selectivity issues. At present, it still remains challenge for designing efficient non-noble metal-based oxygen reduction reaction electrocatalysts. Herein, we successfully synthesize Co nanoparticles supported on three-dimensionally N-doped holey graphene aerogels hybrids by the high-temperature calcination of the graphene aerogels-polyallylamine-CoII hybrids. The component optimized hybrids show the excellent electrocatalytic activity for oxygen reduction reaction in alkaline media, which is comparable to commercial Pt/C electrocatalyst. Meanwhile, the hybrids also show eminent tolerance for CO and methanol, attributing to their excellent oxygen reduction reaction selectivity. The three-dimensionally interconnected structure of graphene aerogels, N-doping, uniform dispersion and high crystallinity of Co nanoparticles, and holey structure of graphene contribute to the striking oxygen reduction reaction activity of hybrids.

openaire: EC/H2020/796280/EU//CADOACCFAP The unique antibacterial characteristics of Ag nanomaterials offer a wide potential range of applications, but achieving rapid and durable antibacterial efficacy is challenging. This is because the speed and durability of the antibacterial function make conflicting demands on the structural design: the former requires the direct exposure of Ag to the surrounding environment, whereas the durability requires Ag to be protected from the environment. To overcome this incompatibility, we synthesize sandwich-structured polydopamine shells decorated both internally and externally with Ag nanoparticles, which exhibit prompt and lasting bioactivity in applications. These shells are biocompatible and can be used in vivo to counter bacterial infection caused by methicillin-resistant Staphylococcus aureus superbugs and to inhibit biofilm formation. This work represents a new paradigm for the design of composite materials with enhanced antibacterial properties.

Olivine-type LiFexMn1-xPO4/C cathode materials are of great interest for lithium-ion batteries because of their higher lithium ion intercalation potential compared with that of LiFePO4. Two types of LiFe0.5Mn0.5PO4/C nanorods with different sizes and crystal structures were synthesized through a facile glycol-based solvothermal process with different precursor feeding sequences. The microstructural investigation revealed that the size and structure of the LiFe0.5Mn0.5PO4 nanorods can be tuned by nucleation and crystal growth rates of the intermediate precipitates, which can be controlled by precursor feeding sequence. The LiFe0.5Mn0.5PO4 nanorods obtained through the first feeding sequence (a solution of transition metal salts was added dropwise into the solution mixture of LiOH and H3PO4) exhibited less exposure of the (010) crystal faces and had bigger sizes compared with those of the LiFe0.5Mn0.5PO4 nanorods obtained through the second feeding sequence (a LiOH solution was added dropwise into the solution mixture of H3PO4 and transition metal salts). Electrochemical investigations indicated that the LiFe0.5Mn0.5PO4 nanorods obtained through the second feeding sequence showed substantially improved electrochemical performance, in which the discharge capacities reached 157 and 119 mAh g−1 at 0.2 and 5 C, respectively. Furthermore, a capacity retention of 89% was obtained after 500 cycles at 1 C, demonstrating excellent cyclic stability.

The clean-up of oil spills is a worldwide challenge for the prevention of serious environmental pollution. Therefore, it is imperative to develop materials for oil-spill cleanup that have high absorption/separation capacity, good selectivity, controlled collection and easy recyclability. Here, we present a facile and low-cost approach for fabricating magnetic, durable, and superhydrophobic carbon sponges. The resultant carbon sponges feature fast magnetic response, excellent superhydrophobicity/superoleophilicity, high chemical resistance, environmental stability and mechanical durability, as well as high oil/water separation efficiency and oil absorbency. More importantly, given the magnetically controllable property endowed by magnetic particles to superhydrophobic carbon sponges, which act as magnetically controlled “smart absorbents”, the carbon sponges can therefore controllably and selectively adsorb oils from oil-water mixtures. Thus, our strategy may open up a new avenue for developing magnetic responsive intelligent oil sorbent materials suitable for practical applications in the fields of water remediation, oil spill clean-up and oil recovery.

Surface-enhanced Raman scattering (SERS) allows for label-free detection of analyte molecules with high sensitivity, but it is still vastly challenged for the detection of ultra-highly diluted analyte solutions in practice, e.g., femtomolar concentrates, 10−15 M. Here, we report a facile approach for the fabrication of hierarchical superhydrophobic melamine-formaldehyde/Ag (MF/Ag) nanocomposite array substrates, applicable for ultra-highly sensitive SERS detection of biological analytes at very low concentrations up to femtomolar levels. Hierarchical superhydrophobic MF/Ag nanocomposite arrays are synthesized by integrating colloidal lithography at the air-liquid interface and in-situ interfacial reactions. These substrates can confine analyte molecules within the localized sensing regions, so as to effectively prevent the random spread of analyte molecules. In this way, these substrates are able to detect dopamine with a detection limit of 10-15 M, and with a SERS enhancement factor (EF) as high as 3.21 × 1010. The substrates are durable and the SERS results are reproducible. For practical demonstration, these superhydrophobic SERS-active substrates are also applied for detecting proteins, lysozyme and hemoglobin at low concentrates. This work presents a straightforward way to synthesize the hierarchical superhydrophobic SERS-active substrates with superior sensitivity and long-term reproducibility, with rational modification, which might merit the practical SERS applications in detection of drug and pollutants in extremely dilute environments.

It is of great significance to timely, accurately, and effectively monitor land use/cover in city regions for the reasonable development and utilization of urban land resources. The remotely sensed dynamic monitoring of Land use/land cover (LULC) in rapidly developing city regions has increasingly depended on remote-sensing data at high temporal and spatial resolutions. However, due to the influence of revisiting periods and weather, it is difficult to acquire enough time-series images with high quality at both high temporal and spatial resolution from the same sensor. In this paper we used the temporal-spatial fusion model ESTARFM (Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model) to blend Landsat8 and MODIS data and obtain time-series Landsat8 images. Then, land cover information is extracted using an object-based classification method. In this study, the proposed method is validated by a case study of the Changsha City. The results show that the overall accuracy and Kappa coefficient were 94.38% and 0.88, respectively, and the user/producer accuracies of vegetation types were all over 85%. Our approach provides an accurate and efficient technical method for the effective extraction of land use/cover information in the highly heterogeneous regions.

BackgroundCases with coronavirus disease 2019 (COVID-19) emigrated from Wuhan escalated the risk of spreading in other cities. This report focused on the outside-Wuhan patients to assess the transmission and clinical characteristics of this illness.MethodsContact investigation was conducted on each patient who admitted to the assigned hospitals in Hunan Province (geographically adjacent to Wuhan) from Jan 22, 2020 to Feb 12, 2020. Demographic, clinical, laboratory and radiological characteristics, medication therapy and outcomes were collected and analyzed. Patients were confirmed by PCR test.ResultsOf the 104 patients, 48 (46.15%) were imported cases and 56 (53.85%) were indigenous cases; 93 (89.42%) had a definite contact history with infections. Family clusters were the major body of patients. Transmission along the chain of 3 “generations” was observed. Mean age was 43 (rang, 8-84) years (including 3 children) and 49 (47.12%) were male. Most patients had typical symptoms, 5 asymptomatic infections were found and 2 of them infected their relatives. The median incubation period was 6 (rang, 1-32) days, of 8 patients ranged from 18 to 32 days. Just 9 of 16 severe patients required ICU care. Until Feb 12, 2020, 40 (38.46%) discharged and 1 (0.96%) died. For the antiviral treatment, 80 (76.92%) patients received traditional Chinese medicine therapy.ConclusionsFamily but not community transmission occupied the main body of infections in the two centers. Asymptomatic transmission demonstrated here warned us that it may bring more risk to the spread of COVID-19. The incubation period of 8 patients exceeded 14 days.

Developing robust and inexpensive non-noble metal based anode electrocatalysts is highly desirable for alkaline direct methanol fuel cells (ADMFCs). Herein, we successfully develop a facile self-template synthetic strategy for gram-grade porous NiO nanotubes (NTs) by pyrolyzing a nanorod-like Ni-dimethylglyoxime complex. The pyrolysis temperature highly correlates with the morphology and crystallinity of NiO NTs. The optimal NiO NTs exhibit a large electrochemically active surface area, a fast catalytic kinetics, and a small charge transfer resistance, which induce an outstanding electrocatalytic activity for the methanol oxidation reaction (MOR). Compared with conventional NiO nanoparticles, NiO NTs achieve a 11.5-fold increase in mass activity at 1.5 V for the MOR due to nanotubal morphology and abundant non-vacancy defects on the NiO NT surface. Moreover, NiO NTs have a higher electrocatalytic activity for the intermediates of the MOR (such as formaldehyde and formate) than conventional NiO nanoparticles, which also contribute to MOR activity enhancement. Given the facile synthesis and enhanced electrocatalytic performance, NiO NTs may be promising anode electrocatalysts for ADMFCs.

A facile and environmentally friendly approach was proposed to decorate Ag nanoparticles on melamine-formaldehyde (MF) colloidal particles (MF/Ag composite microspheres). In this approach, monodisperse MF colloidal particles were prepared via a two-step organic sol-gel process and served as the active templates for the decoration of Ag nanoparticles. Then, the [Ag(NH3)2]+ ions as the Ag precursors can be adsorbed onto the surfaces of the MF colloidal particles and were in situ reduced into metallic Ag nanoparticles, forming MF/Ag composite microspheres. During this synthesis, neither presurface activation nor extra reductants were necessary. These MF/Ag composite microspheres can be used as the surface-enhanced Raman scattering (SERS) active substrates for the trace detection of organic compounds, e.g., 4-aminobenzenethiol (4-ABT) and penicillin G sodium. Furthermore, these MF/Ag composite microspheres also showed excellent antibacterial activities against both Escherichia coli (E. coli, gram-negative bacteria) and Staphylococcus aureus (S. aureus, gram-positive bacteria).

Spinel-type Li4Ti5O12 has peculiar advantages in ultralong cyclic lifespan and high safety. However, its intrinsic low electrical conductivity strongly restricts its applications. Self-assembled mesoporous Li4Ti5O12/C hollow spheres have been obtained through an aerosol pathway, in which the mesoporous shells consist of Li4Ti5O12 nanoparticles embedded in amorphous carbon. Electrochemical performance of the mesoporous Li4Ti5O12/C hollow spheres has been evaluated, which demonstrate their excellent cyclic capacity, stability and rate capability for high power-density and long lifespan lithium-ion batteries. The initial reversible capacity reaches 164.3 mAh g−1 at 0.5 C, which is 93.9% or 98.3% of the theoretical capacity with or without carbon content. The capacity fading rate of each cycle is as low as 0.012%. A self-assembly mechanism of the mesoporous Li4Ti5O12/C hollow spheres has been proposed, which is expected to be beneficial for self-assembling hollow spherical structures with applications in batteries.

Hierarchical one-dimensional (1D) hollow nanostructures have attracted intense research attention due to their unique structures that may be capable of many promising applications. Here, we report a facile and effective strategy to prepare nickel silicate nanotubes (NiSNTs). Using this approach, mesoporous SiO2 nanorods served as sacrificial templates for a simple hydrothermal process to prepare NiSNTs via a self-template route. The obtained NiSNTs preserve the tubular hierarchical morphology and hollow interior structures, which confer the NiSNTs with high surface areas and large pore volumes. These features point to NiSNTs as superior candidates for efficiently adsorbing heavy metal ions and organic dyes in wastewater. Moreover, NiSNTs can also serve as both supports and nickel sources, forming nickel silicate/nickel nanocomposite tubes (NiSNTs/Ni) via in situ reduction of NiSNTs under hydrothermal conditions. The addition of nickel precursors and surface pre-activation are therefore unnecessary. The NiSNTs/Ni exhibit efficient and recyclable catalytic properties when used for the reduction of 4-nitrophenol (4-NP). With a rational adaption, we believe this synthetic strategy can be extended to fabricate multifunctional one-dimensional hollow nanostructures with diverse compositions and morphologies, which may be useful for environmental protection, catalysis, energy and many other important domains.

Blind image deconvolution is a highly ill-posed problem. As a generalization of the well known Weiner filter, the existing iterative Weiner filter (IWF) method for blind image deconvolution is unstable and suffers from serious ringing artifacts. To overcome these drawbacks, in this paper, we propose two novel regularized iterative Weiner filter methods. We assume that both the latent image and the convolution kernel can be estimated by applying two different filters on the observed image. To estimate the filters, we propose to minimize energy functionals combined by the mean square errors with some regularization terms. Both H 1 and total variation (TV) regularization are considered. By applying alternating minimization method and operator splitting technique, we derive iterative algorithms for each regularization method. The proposed methods are effective for blind deconvolution of Gaussian blurred images which is widely observed in real applications such as microscopic images. Numerical experimental results on both synthetic images and real microscopic images are presented. The comparisons show that the proposed regularized algorithms perform better than the closely related state-of-the-art methods in terms of peak signal-to-noise ratio (PSNR) and visual quality.

Engineering hollow particles with high complexity in their morphology or composition is highly desirable for both fundamental studies and practical applications. Here, we combine mussel-inspired polydopamine (PDA) chemistry with template-assisted and hydrothermal approaches to explore a general approach for engineering hollow PDA colloidal composite particles with tunable complexities in terms of particle geometry, shell architecture and chemical composition. PDA coating and hydrothermal treatment are carried out sequentially in the same environment, which not only simplifies the experimental procedure but also avoids the use of hazardous core-removers. This approach is generally applicable to a wide variety of colloidal templates irrespective of their shape, material and structure, allowing the void structure and geometry (spherical void, yolk-shell, multi-shells and non-spherical cavity) to be controlled. The surface of the PDA shell provides a versatile platform for a number of secondary reactions (e.g., electroless metallization, superhydrophobic modification, Michael addition and nanoparticle decoration). Consequently, tuning the exterior or interior of the hollow PDA shell with various functional materials offers a range of potential uses in superhydrophobic surfaces, catalysis, photocatalysis and surface-enhanced Raman spectrum sensing.

Surface-enhanced Raman scattering (SERS) sensor allows for fingerprinting and label-free molecular detection with a high sensitivity, but the simple fabrication of SERS active substrates with a well-control over the SERS performance, e.g. an ultra-high sensitivity, superior reproducibility and long-term stability remain a great challenge. Here, we introduce an easy strategy for synthesizing polydopamine-Ag microbowl/nanoparticle array (PDA-Ag MNA) substrates with a tunable superhydrophobic surface, applicable for ultra-highly sensitive SERS detection. First, the periodically dented PDA films are prepared by polymerizing dopamine onto 2D polystyrene colloidal crystals formed at the liquid/air interface, and followed with an in-situ reduction of Ag ions to Ag nanoparticles after removing polystyrene. The surface morphology, i.e. microbowl/nanoparticle structure, is well-controlled, therefore, allowing that the SERS activity of the substrate is under control. Inspired by the superhydrophobic hierarchical surface of the rose petals, this analogous MNA surface is subsequently endowed to be superhydrophobic. This way, the SERS detection of ultra-dilute solute (10−14 M) can be achieved by concentrating analytes within a localized region. Moreover, this substrate also shows a superior reproducibility in result and durability in use. This strategy exhibits a realistic paradigm for further improving the sensitivity of the SERS technique.

Hierarchical Ni(OH)2 nanotubes with ultrathin nanoflakes were successfully synthesized by a self-sacrificial template via a facile solvothermal method. The as-prepared Ni(OH)2 nanotubes exhibit a high specific capacitance of 1319 F g-1 at 3 A g-1, and retain 700 F g-1 (79.3% of the initial capacitance) at 5 A g-1 after 7000 cycles.

We combine the active surface of polydopamine (PDA) with the biomimetic mineralization of CaCO3 to obtain the macroscopically continuous CaCO3 films under mild conditions. In this approach, the organic matrices were adhesive PDA coatings, which were dip-coated on silicon wafers by the self-polymerization of dopamine in an alkaline aqueous solution (pH 8.5). The inorganic layers were CaCO3 films, which were formed in a CaCl2 solution in the presence of poly(acrylic acid) (PAA) via a CO2 diffusion method. During the biomimetic mineralization, amorphous calcium carbonate (ACC) was formed on PDA matrices with the help of PAA, which, subsequently, was transformed into a flat continuous calcite film on the PDA matrices. As the mineralization time increased, a new layer of CaCO3 crystals was formed over the calcite and, as a result, led to continuous CaCO3 films with rough surfaces. The thicknesses of CaCO3 films can be controlled by tuning the mineralization time. Our approach may provide a simple, yet efficient way for the preparation of macroscopically continuous organic–inorganic composite CaCO3 films under mild conditions. Moreover, superhydrophobic surfaces can be successfully achieved via a hydrophobic modification of the rough CaCO3 films, which make them suitable candidates for a variety of superhydrophobic applications, such as self-cleaning surfaces or anticorrosion, antiadhesive coatings.

The currently available superhydrophobic coating techniques that utilize mussel-inspired polydopamine coating to construct hierarchical superhydrophobic structures require multiply procedures and are time-consuming processes. Here, we propose an ultrasound-accelerated strategy to various commercial sponges with hierarchically structured superhydrophobic surfaces by briefly submerging sponges into a slightly alkaline aqueous mixture comprising dopamine hydrochloride (DA) and dodecyltrimethoxysilane (DTMS) under ultrasound. The ultrasound is found significantly accelerate the hierarchical surface structures from PDA, while only minorly influences the hydrolysis of DTMS that hydrophobically modifies the surface of PDA. As a result, the hierarchical superhydrophobic surfaces are formed within 25 min. In addition, the superhydrophobicity of the surface can be recovered by repeating this ultrasound-assisted process, provided that the superhydrophobic feature is vanished or lost during their use in a harsh environment. These superhydrophobic sponges are superior materials for oil collection from water, in a durably robust, efficient and recyclable manner with multi-life span. This strategy presents a rather high efficient and time-saving process for constructing/recovering hierarchical superhydrophobic surfaces, which may be useful for the rapid engineering commercial materials with restorable superhydrophobic surfaces.

Synthesis of hollow colloidal particles with a well-defined structure in a single step is challenging and highly desired for numerous applications. We propose a simple and productive approach to synthesize hierarchical nickel hydroxidenitrate hollow colloidal particles (NiHNHCP) with tunable structure and property via a one-pot manner for the application in supercapacitor. In this approach, the formation of the NiHN shells and the dissolution of the melamine-formaldehyde (MF) template particles occur simultaneously and successively under a solvothermal condition with time. It is found that the nickel precursors can protonate the solvent, declining the pH and further causing the dissolution of the MF particles. Meanwhile, the nickel precursors transform into NiHN nanosheets that self-assemble into hierarchical shells exclusively at the surface of the MF particles. With the reactions proceeding, the NiHNHCP are yielded ultimately. These NiHNHCP are characterized with superior electrochemical performance, making them practically useful in the application of supercapacitor.

It is imperative to develop efficient and environmentally friendly oil-spill cleanup materials to solve the problems raised by frequent oil spillages and industrial discharge of organic solvents. Here, we present a bioinspired one-step construction of hierarchical superhydrophobic surfaces on various commercial porous materials by immersing the materials into an alkaline aqueous mixture consisting of dopamine (DA) and dodecyltrimethoxysilane (DTMS). The self-polymerization of DA constructs the bumpy surfaces, while the DTMS coatings enhance the hydrophobicity of the surfaces. The combined use of both results in the hierarchical superhydrophobic surfaces. This surface modification of porous materials allows them as the potential candidates for collecting a wide variety of oils/organic solvents from water in a highly efficient, recyclable, and durable way. This approach proposes a general, yet green path for constructing superhydrophobic surfaces, which can be further adapted to prepare economic oil/organic solvents absorbents applied in the fields of oil/water separation, wastewater remediation, and organics recovery.

The use of polymer particles as organic templates for producing inorganic materials is an intriguing approach, because it offers the synthetic feasibility of organic–inorganic hybrid materials which may promise a variety of interesting applications. Here, inspired by mussel-adhesion phenomena in nature, we combined the use of the active surface of polydopamine (PDA) with biomimetic mineralization of hydroxyapatite (HAP) to synthesize a novel HAP-based, organic–inorganic hybrid material. Monodisperse micro-sized polystyrene (PS) particles were first prepared as inert polymer templates via dispersion polymerization, which, subsequently, were coated with PDA through the self-polymerization of dopamine in a weakly alkaline aqueous environment (pH = 8.5). This chemical modification activated the inert surface of PS particles to become bioactive. Thus, these synthesized PS/PDA composite particles were ideal templates for the biomimetic mineralization of HAP when they were incubated in a simulated body fluid (SBF) solution in aid of the biocompatible PDA layer. During the PDA-assisted biomimetic mineralization, the PDA layer interacted with the mineral ions introduced, and anchored the mineralization of HAP exclusively onto the surfaces of the composite particles. The detailed structures and morphologies of HAP-based hybrid materials (PS/PDA/HAP hybrid materials) were characterized. These HAP-based hybrid materials did not show a significant in vitro cytotoxicity against HeLa cells, indicating their potential biocapacity for drug delivery, protein and gene transfer, and as coating materials for bioimplants or as the injectable scaffold materials in bone tissue engineering for defect filling and regeneration.

Inspired by nature, we combine the easy decoration of polydopamine with the attractive biomimetic silification to develop a facile synthetic route toward raspberry-like nanocomposite particles, and further lead to the superhydrophobic and superoleophilic surfaces by mimicking the lotus leaf surface structures in the usage of these particles. In this approach, monodisperse polystyrene (PS) particles are used as the template particles, and then, follows with a subsequent polydopamine (PDA) coating step through the self-polymerization of dopamine in a weakly alkaline aqueous environment (pH = 8.5). The obtained core–shell PS/PDA particles are used as the active substrates for the biomimetic silification under the ambient conditions, allowing a well-controlled synthesis of raspberry-like PS/SiO2 nanocomposite particles with a tunable surface roughness. Upon adjusting the concentration of silica precursor, the surface geometry and the coverage degree of silica nanoparticles of PS/PDA composite particles can be easily tailored. The whole procedure is carried out in a mild environment, no intricate instruments or toxic reagents are involved. In addition, these raspberry-like PS/SiO2 nanocomposite particles self-assemble onto the glass slides driven by capillary force during drying, forming a hierarchical dual-sized rough structure, which is analogous to the surface morphology of lotus leaf in nature. Making full use of this hierarchical surface, superhydrophobic and superoleophilic surfaces can be successfully achieved via a rational surface modification of this lotus leaf-like surface structure. The superhydrophobic performances can be readily adjusted by varying the scale ratio of the micro/nano surface structures.