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Confined evaporation-induced self-assembly (C-EISA) is a powerful technique to guide disordered nanoparticles into long-range organized structures. Herein, we investigate the C-EISA behavior of 1-butyl-3-vinylimidazolium cation ([VBIm]+) grafted cellulose nanocrystals (CNC-C) in a parallel-plates confined geometry. Interestingly, CNC-C can spontaneously assemble into maze-like patterns with branch dimensions on the micrometer scale and uniformly distributed throughout the confined space, which is completely different from the lamellar self-assembly patterns of unmodified CNCs. Combining in situ observations and microscopic characterization, we speculate that the formation of maze-like patterns originates from the reduction of colloidal stability induced by the grafted imidazolium cations. The electrostatic attraction between CNC-C aggregated bundles and glass substrates acts as anchor points, thereby leading to the unstable motion of the liquid-air menisci during the inward intrusion of air. Due to the physicochemical properties and unique C-EISA behavior, the CNC-C based adhesive can maintain adhesion at temperatures of ca. 200 °C, while rapidly debonding when immersed in water, demonstrating the potential to be used as stimuli-responsive temporary or removable adhesives. Furthermore, the strategy proposed in this work for achieving CNCs patterning is also promising to be extended to other anisotropic rod-shaped nanoparticles. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Constructed a SERS substrate with excellent performance without using noble metals. • Optimized SERS performance by the synergistic effect of perovskite and graphene. • The SERS detection of cTnI was carried out by "reverse"-SERS method. • The processed samples could be stably stored at room temperature. Noble metal has always been used as a preferred base for SERS substrate. However, the preparation cost of such materials is trully high. Therefore, many researchers have begun to search for succedanea which cost were lower. In this work, CsPbBr 3 @ZIF-8 was synthesized by in-situ reduction method and combined with graphene nanosheets to construct a SERS substrate. The SERS performance of this substrate could be further enhanced by the synergistic effect of perovskite quantum dots and graphene. Base on this material, a sensitive SERS strategy composed of CsPbBr 3 @ZIF-8@G, antibody, and Bradford method was developed for the quantitative determination of cardiac troponin I (cTnI) in human serum. It's worth noting that the sensitivity and accuracy of this method could approach the level of other SERS methods using noble metals. The "reverse"-SERS method could improve the uniformity and stability of detection platform obviously. The detection range of this method was 0.01–100 ng/mL, and the estimated detection of limit (LOD) was 4.7 pg/mL. The recovery rate of this method range was between 93.1 % and 104.8 %, and RSD range was between 4.47 % and 7.06 %. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrolysed peptide fragments instead of the whole cardiac troponin I for surface imprinted. • Good Raman signal peaks obtained by staining the peptides with Coomassie Brilliant Blue G-250. • MMIPs could be stored for more than half a year without affecting its adsorption properties. • The materials open wide possibilities for efficient, specific and economic detection of cardiac troponin I. This paper proposes a selective strategy for quantitative detecting cardiac troponin I (cTnI) in clinical serum samples by using Raman spectroscopy combined with magnetic molecularly imprinted polymers (MMIPs). The signature peptide was selected as a template for molecular imprinting due to its chemical stability and small molecular mass. MMIPs were synthetized with the signature peptide as template and methylacrylic acid as monomer in presence of vinyl-modified magnetic particles. MMIPs with high magnetic character and adsorption properties were able to be stained by Coomassie Brilliant Blue G-250 after the target template was specifically captured, which showing a characteristic absorption peak at Raman shift 1610 cm−1. The Raman signal intensity at 1610 cm−1 showed a linear relationship in the 0.01 to 100 ng·mL−1 concentration range. The recovery of cTnI in serum were 92.7–111.2 % with relative standard deviation in the range of 2.51 % to 8.52 %. This paper has important practical application for preliminary rapid detection of cTnI in clinical serum samples. [ABSTRACT FROM AUTHOR]

Janus graphene oxide (GO) usually refers to a unique two-dimensional material with asymmetric surface chemistries on opposite faces of the sheets. Herein, we propose a facile and efficient method to fabricate Janus-like GO (JGO) with a novel asymmetric structure along the faces of the sheets. Unlike the traditional post-synthesis of double-faced Janus GO based on pre-prepared GO, the novel JGO with a randomly distributed asymmetric oxidation structure along the sheet face can be achieved by a simple ultrasonic treatment on partially oxidized graphene. The asymmetric oxidation structure along the sheet face of our Janus GO was confirmed by confocal micro-Raman imaging and analysis of height profiles by atomic force microscopy. Due to the asymmetric oxidation structure, the as-prepared JGO has amphiphilic characteristics, with hydrophilicity on one side of the sheet and hydrophobicity on the other side, leading to an eyelash-like liquid crystal alignment at the oil/water interface. The perpendicular alignment rather than the parallel orientation behavior of GO liquid crystals at the oil/water interface further confirms the asymmetric structure of our JGO along the face graphene sheets. The simple approach and a new class of JGO proposed herein provide a new insight into understanding the asymmetric chemistry of graphene. The facile preparation of Janus GO nanosheets with asymmetric surface chemistries and eyelash-like liquid crystal alignment at the oil/water interface. Image 1 [ABSTRACT FROM AUTHOR]

Bio-inspired citrate-hydroxyapatite (HAP) nanoparticles doped with zinc ions were prepared from mussel shells via a rapid method of ultrasonication and microwave irradiation. It was found that zinc ions can interact with citrate ions in the crystallization process of HAP. The growth of nanocrystals in citrate solution was slower than that in HCl solution. The addition of zinc ions reduced the residue of citrate in the products and increased the crystallinity of HAP. Furthermore, mineral platelets with the length of 29 ± 7 nm and the thickness of 3–5 nm were obtained for Zn/(Zn+Ca) = 5 mol%, which displayed similar morphology with HAP platelets in bone. Moreover, the obtained HAP nanoparticles are promising for use as bone graft materials in biomedical applications. [ABSTRACT FROM AUTHOR]

Solar desalination has been recognized as one of the most promising technologies for solving current freshwater scarcity. However, enhancement of the photothermal conversion efficiency and prohibiting salt crystallization on the top light-absorbing surface are the two major critical challenges for developing highly-efficient and stable solar evaporators. Here, we have discovered that tree roots, often as processing waste when utilizing woods, can serve as a high-efficient solar evaporation device for continuous desalination. The naturally occurring hierarchical structure of tree roots possesses multilevel longitudinal channels from micrometer to millimeter-scale and interconnected porous microstructures, which allows excellent water transport and multidirectional salt exchange, exhibiting a superior anti-salt-accumulation capability even in 21% brine. Together with a mountain-shaped hydrophobic absorber surface obtained from the in situ synthesized Fe 3 O 4 nanoparticles, the designed tree root-based solar evaporator demonstrates an evaporation rate of 1.64 kg m−2 h−1 and ultra-high conversion efficiency of 96% at 1 solar irradiation, rendering it as one of the best performing wood-based solar evaporators. Furthermore, such a high-efficacy, techno-economic and long-term stable seawater desalination platform provided by the architectures of multi-level channel-array in tree root will inspire material scientists and engineers to tailor structurally similar materials from building blocks of broader selections. [Display omitted] • The structural features of tree root make it a "natural choice" for solar evaporation. • Naturally hierarchical structure allows excellent water transport and salt exchange. • Tree root based solar evaporator exhibits superior anti-salt-accumulation property. • A mountain-shaped hydrophobic layer shows extensive and strong light absorption. • An evaporation rate of 1.64 kg m−2 h−1 and conversion efficiency of 96% were obtained. [ABSTRACT FROM AUTHOR]

A biomimetic method was used to prepare hybrid hydroxyapatite (HAP) nanoparticles with chitosan/polyacrylic acid (CS-PAA) nanogel. The morphology, structure, crystallinity, thermal properties and biocompatibility of the obtained hybrid nanogel-HAP nanoparticles have been characterized. In addition, bovine serum albumin (BSA) was used as a model protein to study the loading and release behaviors of the hybrid nanogel-HAP nanoparticles. The results indicated that the obtained HAP nanoparticles were agglomerated and the nanogel could regulate the formation of HAP. When the nanogel concentration decreased, different HAP crystal shapes and agglomerate structures were obtained. The loading amount of BSA reached 67.6 mg/g for the hybrid nanoparticles when the mineral content was 90.4%, which decreased when the nanogel concentration increased. The release profile of BSA was sustained in neutral buffer. Meanwhile, an initial burst release was found at pH 4.5 due to the desorption of BSA from the surface, followed by a slow release. The hemolysis percentage of the hybrid nanoparticles was close to the negative control, and these particles were non-toxic to bone marrow stromal stem cells. The results suggest that these hybrid nanogel-HAP nanoparticles are promising candidate materials for biocompatible drug delivery systems. [ABSTRACT FROM AUTHOR]

In this study, a biomimetic method was used to prepare hydroxyapatite (HAP) and zinc substituted HAP (ZnHAP) nanoparticles, in which silk fibroin was used as template. The morphology of HAP is rod-like, while ZnHAP changes to wrinkled sheets. HAP and ZnHAP nanoparticles were used to coat titanium by EPD with additional chitosan and multiwalled carbon nanotubes. Phase composition, morphology and structure were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared and Raman spectroscopy. The results showed that the composite coatings containing HAP and ZnHAP had homogeneous morphology and good apatite formation ability. The ZnHAP composite coating possessed class 5B adhesive strength using tape test. Furthermore, the ZnHAP composite coating had better corrosion resistance compared to the HAP composite coatings. [ABSTRACT FROM AUTHOR]

Cellulose acetate (CA) nanofibers were deposited on stainless steel plates by electrospinning technique. The composite of hydroxyapatite (HAP) nanoparticles and chitosan (CHI) was coated subsequently by dip-coating. The structure and morphology of the obtained coatings were investigated by Fourier transform infrared spectroscopy and scanning electron microscopy. The stability of the coatings in physiological environment was studied using electrochemical polarization and impedance spectroscopy. The CA nanofibers were embedded in the HAP/CHI coating and the resulted composite film was densely packed and uniform on the substrate. The in vitro biomineralization study of the coated samples immersed in simulated body fluid (SBF) confirmed the formation ability of bone-like apatite layer on the surface of HAP-containing coatings. Furthermore, the coatings could provide corrosion resistance to the stainless steel substrate in SBF. The electrochemical results suggested that the incorporation of CA nanofibers could improve the corrosion resistance of the HAP/CHI coating. Thus, biocompatible CA/HAP/CHI coated metallic implants could be very useful in the long-term stability of the biomedical applications. [ABSTRACT FROM AUTHOR]

Co-assembly of metal ion and cellulose nanocrystals (CNC) is a promising strategy to fabricate novel iridescent CNC materials with advanced applications. By combining ultrasonication pretreatment and vacuum-assisted self-assembly (VASA) technique, a facile and rapid strategy is proposed to prepare the Mn2+-doped carboxylated CNC (C-CNC) iridescent films with multifunctional application. The ultrasonication pretreatment temporarily disassembles the aggregates of C-CNC nanorods caused by the electrostatic interaction between negative charged C-CNC and Mn2+. The subsequent VASA process accelerates the self-assembly of chiral liquid crystals prior to the re-agglomeration of C-CNC by the bridge effect of Mn2+. Furthermore, the as-prepared Mn2+/CNC film exhibits a rapid and visible color change in ammonia atmosphere along with the formation of MnO 2. The reversible change can be realized by the stimulation of reducing agent. The derived MnO 2 /C-CNC composite film displays efficient removal of methylene blue dye in aqueous solution by both of adsorption and degradation procedure. [Display omitted] [ABSTRACT FROM AUTHOR]

Rod-like cellulose nanocrystals (CNCs) show the intriguing liquid crystal self-assembly ability. The understanding of the self-assembly behavior of CNCs is of fundamental importance for constructing cellulose-based functional materials. The presented work explores how the liquid crystal self-assembly behavior of CNCs is affected by the grafted ionic liquids (IL) [VBIm][BF 4 ]. The results demonstrate that the IL modified CNC (CNC-IL) with positive charged form chiral nematic structure in suspensions, which was normally observed in negative charged ones. Significantly, such liquid-crystalline organization can be obtained under much lower concentration (as low as 1.0 wt%) than that of the non-functionalized CNCs prepared from paper pulp (~ 3.0 wt%). Moreover, for CNC-IL concentrations varying from 1.0 to 4.0 wt%, the tactoids (showing obvious fingerprint texture) coexist with the disordered CNC phase, rather than separating into two phases. Unlike original CNCs, the pitch of chiral nematic tactoids increases with increasing concentration of CNC-IL. Our study suggests that the distinct liquid crystal self-assembly behavior of CNC-IL is related to the restricted mobility of CNCs rods due to the increase in CNCs particle size and the high viscosity of CNC-IL suspension as the result of IL surface modification. The study of the liquid crystal assembly behavior of IL modified CNCs provides some new insight to understand the intriguing chiral nematic self-assembly of CNCs and for construction of CNC-IL reinforced nanocomposites. [Display omitted] • It is verified that CNC modified by ionic liquid (CNC-IL) can form chiral nematic tactoids. • CNC-IL can form a chiral nematic phase at a lower concentration than CNC-OSO 3 and not separate into two phases. • Unlike original CNCs, the pitch of chiral nematic tactoids decreases with increasing concentration of CNC-IL. [ABSTRACT FROM AUTHOR]

Solar desalination devices utilizing sustainable solar energy and the abundant resource of seawater has great potential as a response to global freshwater scarcity. Herein, a bilayered solar evaporator was designed and fabricated utilizing a facile paper sheet forming technology, which was composed of cellulose fibers decorated with Fe3O4 nanoparticles as the top absorbent layer and the original cellulose fibers as the bottom supporting substrate. The characterization of the cellulose fibers decorated with Fe3O4 nanoparticles revealed that the in situ formed Fe3O4 nanoparticles were successfully loaded on the fiber surface and presented a unique rough surface, endowing the absorber layer with highly efficient light absorption and photothermal conversion. Moreover, due to its superhydrophilic property, the cellulose fiber-based bottom substrate conferred ultra-speed water transport capability, which could enable an adequate water supply to combat the water loss caused by continuous evaporation on the top layer. With the advantages mentioned above, our designed bilayered paper-based evaporator achieved an evaporation rate ~1.22 kg m−2 h−1 within 10 min under 1 sun irradiation, which was much higher than that of original cellulose cardboard. Based on the simple and scalable manufacture process, the bilayered paper-based evaporator may have great potential as a highly efficient photothermal conversion material for real-world desalination applications. [ABSTRACT FROM AUTHOR]

Solar steam evaporation exhibits great potential in solving the global shortage of freshwater resources. However, salt accumulation at the top photothermal conversion surface has severely limited the desalination efficiency and stability of solar desalination systems. Herein, we demonstrated a nature-inspired salt resistant bilayered evaporator by using a slight delignificated tree root as bottom substrate and decorated graphene oxide layer as the top absorber surface. The naturally design of tree root inherently exists multilevel vertical channels interconnected porous microstructures. This distinctive structure of tree root allows ultra-high-speed water transport capability and rapid multi-directional salt exchange, enabling it to possess anti-salt-accumulation properties for solar steam generation. This designed tree root-based evaporator effectively prevented salt accumulation while maintaining a fast and stable evaporation rate, which exhibited an evaporation rate of 1.60 kg m−2 h−1 with excellent long-term stability in a high-salinity brine (21 wt%) under 1 sun irradiation. Taking the unparalleled advantages, our designed tree root-based evaporator obtained by a facile fabrication method represents a high-efficacy and stable fresh water production platform for practical applications in water purification. [Display omitted] • The unique microstructure of tree root makes it a "natural choice" as solar evaporator. • Natural multiscale channeled structure allows rapid multi-directional salt exchange. • Tree root based solar evaporator exhibits ultra-high-speed water transport capability. • A super-high and stable conversion efficiency of 96.5% was obtained. • This work showed a high-efficacy and long-term stable seawater desalination platform. [ABSTRACT FROM AUTHOR]

• Protective layer suppresses side reactions by separating Zn foil from electrolyte. • The interphase of the PVB and the Cu-Zn provides a fast ion transfer path. • Protected Zn anode shows uniformly deposition with the longevity over 2700 hrs. Aqueous zinc ion batteries (AZIBs) are considered promising for the future large-scale energy storage applications due to their intrinsic high safety, low cost, environmental benignity and competitive energy density. However, the side reactions and dendrite growth of zinc metal anode result in low Coulombic efficiency and inferior cycle stability, which hinders the deployment of AZIBs in large scale applications. Herein, an organic–inorganic composite layer with rapid Zn2+ diffusion path is fabricated on the surface of the zinc metal anode, which is composed of polyvinyl butyral (PVB) and Cu-Zn alloy nanoparticles. The composite layer works as an artificial solid electrolyte interphase (SEI) layer with surface hydrophobic, even Zn2+ flux and low nucleation energy that suppresses Zn dendrite growth and surface H 2 evolution reaction during the repeated zinc deposition/stripping. As a result, the surface protected Zn anode (p-Zn) is very stable over 2700 h in symmetrical cells at 0.5 mA/cm2–0.5 mAh/cm2 condition. The full cell coupled with VO 2 cathode stably cycles 1000 cycles with an average Coulombic efficiency of 99.945% at the current of 1 A/g. Furthermore, p-Zn||VO 2 pouch cells are assembled and achieve more than 330 cycles at the current of 1 A/g with no swelling or leakage of electrolyte. The work presented here provides a simple and feasible strategy for the protection of zinc anodes and has great potential for practical applications. [ABSTRACT FROM AUTHOR]

Nowadays, high performance and functional low-dimensional nanomaterials have been targeted in modern sustainable energy science for diverse potential applications. However, broad applications of emerging nanomaterials such as graphene and biomass nanofillers have suffered from low preparation efficiency, low quality of products, unstable dispersion in matrix. In this study, a 100% yield of low-oxidized graphene/nanocellulose hybrids (LGENC) was prepared by one-pot ball milling. Low-oxidized expanded graphite (LOEG) and microfibrillated cellulose (MFC) were used as precursors for fabricating LGENC by the co-exfoliation strategy. That is, exfoliation of LOEG, nanofibrillation of MFC and their hybridization were simultaneously realized under the shear and collision of balls milling. The concentration of LGENC suspension can be concentrated to 50 mg/mL, which has great potential for 3D printing. A series of characterization identified the hybridization of low-oxidized graphene (LGE) and nanocellulose via hydrophobic and hydrogen bond interaction, and confirmed that the LGE has fewer oxygen functional groups and more complete structure than graphene oxide. Benefiting from the intact structure, the conductivity of LGENC can reach up to ~5800 S/m. In addition, the as-prepared LGENC showed significant potential in reinforcing rubber latex. In general, this study proposes a high-efficiency preparation method for graphene/cellulose hybrid materials with extraordinary properties. [Display omitted] • Co-exfoliation of low-oxidized expanded graphite and microfibrillated cellulose is a simple and efficient way to prepare hybrid nanomaterials. • The concentration of as-prepared LGENC dispersion is as high as 13 mg/mL, which can be further concentrated to 50 mg/mL. • The conductivity of as-prepared LGENC films exhibits obvious anisotropy, and the in-plane conductivity can reach up to ~5800 S/m. • The as-prepared LGENC demonstrated significant reinforcing ability for carbonylated nitrile butadiene rubber. [ABSTRACT FROM AUTHOR]