Engineering Nano/Microscale Chiral Self‑Assembly in 3D Printed Constructs

Helical hierarchy found in biomolecules like cellulose,chitin,and collagen underpins the remarkable mechanical strength and vibrant colors observed in living organisms.This study advances the integration of helical/chiral assembly and 3D printing technology,providing precise spatial control over chiral nano/microstructures of rod-shaped colloidal nanoparticles in intricate geometries.We designed reactive chiral inks based on cellulose nanocrystal(CNC)suspensions and acrylamide monomers,enabling the chiral assembly at nano/microscale,beyond the resolution seen in printed materials.We employed a range of complementary techniques including Orthogonal Superposition rheometry and in situ rheo-optic measurements under steady shear rate conditions.These techniques help us to understand the nature of the nonlinear flow behavior of the chiral inks,and directly probe the flow-induced microstructural dynamics and phase transitions at constant shear rates,as well as their post-flow relaxation.Furthermore,we analyzed the photo-curing process to identify key parameters affecting gelation kinetics and structural integrity of the printed object within the supporting bath.These insights into the interplay between the chiral inks self-assembly dynamics,3D printing flow kinematics and photopolymerization kinetics provide a roadmap to direct the out-of-equilibrium arrangement of CNC particles in the 3D printed filaments,ranging from uniform nematic to 3D concentric chiral structures with controlled pitch length,as well as random orientation of chiral domains.Our biomimetic approach can pave the way for the creation of materials with superior mechanical properties or programable photonic responses that arise from 3D nano/microstructure and can be translated into larger scale 3D printed designs.

Preparation and Characterization of SrTiO_3 Thin Film on Functional Organic Self-Assembled Monolayers

SrTiO3 thin film was successfully prepared on the functionalized organic self-assembled monolayers（SAMs） by the Liquid Phase Deposition（LPD） method.The as-prepared samples were characterized by X-ray diffraction（XRD）,atomic force microscope（AFM）,scanning electron microscopy（SEM） and metallographic microscope.Measurement of contact angle showed that the hydrophobe substrate was changed into hydrophile by UV irradiation.AFM photographs of octadecyl-trichloro-silane self-assembled monolayer（OTS-SAM） surface approved that UV irradiation did change the morphology of OTS monolayer and provided evidence for the conversion of hydrophilic characteristic.Photographs of Metallographic Microscope showed that OTS-SAM had an active effect on the deposition of SrTiO3 thin film.XRD and SEM indicated that the thin film was of pure cubic phase SrTiO3 and composed of nanosized grains with a size in the range of 100-500 nm.The formation mechanism of the SrTiO3 film was proposed.

Simultaneous Determination of Dopamine and Uric Acid at 2-Amino-5-mercapto-[1, 3, 4]triazole Self-assembled Monolayers Gold Electrode

A newly synthesized reagent 2-amino-5-mercapto-[1, 3, 4]triazole (MATZ) has been usedto fabricate self-assembled monolayers (SAMs) on gold electrode for the first time. The SAMselectrode was characterized by electrochemical methods and scanning electronic microscopy (SEM),the SAMs electrode can be used to determinate dopamine (DA) and uric acid (UA) simultaneouslywith a detection limit of 8×10-7 mol/L for DA and 1×10-6 mol/L for UA respectively. The SAMscan also be used to detect the contents of DA and UA in synthetic urine sample with satisfactoryresults.

Plasma Triggered Grain Coalescence for Self-Assembly of 3D Nanostructures

Grain coalescence has been applied in many areas of nanofabrication technology, including modification of thinfilm properties, nanowelding, and self-assembly of nanostructures. However, very few systematic studies of selfassembly using the grain coalescence, especially for threedimensional(3D) nanostructures, exist at present. Here, we investigate the mechanism of plasma triggered grain coalescence to achieve the precise control of nanoscale phase and morphology of the grain coalescence induced by exothermic energy. Exothermic energy is generated through etching a silicon substrate via application of plasma. By tuning the plasma power and the flow rates of reactive gases, different etching rates and profiles can be achieved, resulting in various morphologies of grain coalescence. Balancing the isotropic/anisotropic substrate etching profile and the etching rate makes it possible to simultaneously release 2D nanostructures from the substrate and induce enough surface tension force,generated by grain coalescence, to form 3D nanostructures.Diverse morphologies of 3D nanostructures have been obtained by the grain coalescence, and a strategy to achieve self-assembly, resulting in desired 3D nanostructures, has been proposed and demonstrated.

Fluorescence spectra of colloidal self-assembled CdSe nano-wire on substrate of porous Al2O3/Au nanoparticles

We present a self-assembly method to prepare array nano-wires of colloidal CdSe quantum dots on a substrate of porous Al2 O3 film modified by gold nanoparticles. The photoluminescence(PL) spectra of nanowires are in situ measured by using a scanning near-field optical microscopy(SNOM) probe tip with 100-nm aperture on the scanning near-field optical microscope. The results show that the binding sites from the edge of porous Al2 O3 nanopores are combined with the carboxyl of CdSe quantum dots’ surface to form an array of CdSe nanowires in the process of losing background solvent because of the gold nanoparticles filling the nano-holes of porous Al2 O3 film. Compared with the area of nonself-assembled nano-wire, the fluorescence on the Al2 O3/Au/CdSe interface is significantly enhanced in the self-assembly nano-wire regions due to the electron transfer conductor effect of the gold nanoparticles’ surface. In addition, its full width at half maximum(FWHM) is also obviously widened. The method of enhancing fluorescence and energy transfer can widely be applied to photodetector, photocatalysis, optical display, optical sensing, and biomedical imaging, and so on.

Oriented Organization of Poly(3-Hexylthiophene)for Efficient and Stable Antimony Sulfide Solar Cells

Poly(3-hexylthiophene)(P3HT),as a traditional organic hole-transporting material(HTM),is widely used in thin-film solar cells due to its high charge mobility and good thermal stability.However,the P3HT films obtained by the traditional method are amorphous,which is unfavorable to hole extraction and transport.Here,a low-toxicity solvent 1,2,4-trimethylbenzene(TMB)was used as the solvent instead of the commonly used halogen solvent chlorobenzene(CB)to dissolve P3HT.Thus,the self-assembled nanofibrous P3HT film was prepared and applied as HTM in the newly emerged Sb_(2)S_(3)solar cells.According to the density functional theory calculations,the interface contact between TMB-P3HT and Sb_(2)S_(3)was enhanced via the bonding interaction of S in P3HT and Sb in Sb_(2)S_(3).Through transient absorption spectroscopy characterization,the enhanced interface contact improves the charge extraction ability of TMB-P3HT when compared to the CB-P3HT film.Thus,the TMB-P3HT-based Sb_(2)S_(3)solar cell delivers a power conversion efficiency of 6.21%,which is 9.7%higher than that of the CB-P3HT-based device.Furthermore,the dopant-free TMB-P3HT-based Sb_(2)S_(3)devices exhibit excellent environmental stability compared with Spiro-OMeTAD-based devices.This work demonstrates that the application of P3HT and the solvent engineering of HTM are applicable strategies for developing Sb_(2)S_(3)solar cells with high efficiency and stability.

Innovation leading development:a glimpse into three-dimensional bioprinting in Israel

Three-dimensional(3D)printing has attracted increasing research interest as an emerging manufacturing technology for devel-oping sophisticated and exquisite architecture through hierarchical printing.It has also been employed in various advanced industrial areas.The development of intelligent biomedical engineering has raised the requirements for 3D printing,such as flexible manufacturing processes and technologies,biocompatible constituents,and alternative bioproducts.However,state-of-the-art 3D printing mainly involves inorganics or polymers and generally focuses on traditional industrial fields,thus severely limiting applications demanding biocompatibility and biodegradability.In this regard,peptide architectonics,which are self-assembled by programmed amino acid sequences that can be flexibly functionalized,have shown promising potential as bioinspired inks for 3D printing.Therefore,the combination of 3D printing and peptide self-assembly poten-tially opens up an alternative avenue of 3D bioprinting for diverse advanced applications.Israel,a small but innovative nation,has significantly contributed to 3D bioprinting in terms of scientific studies,marketization,and peptide architectonics,including modulations and applications,and ranks as a leading area in the 3D bioprinting field.This review summarizes the recent progress in 3D bioprinting in Israel,focusing on scientific studies on printable components,soft devices,and tissue engineering.This paper further delves into the manufacture of industrial products,such as artificial meats and bioinspired supramolecular architectures,and the mechanisms,physicochemical properties,and applications of peptide self-assembly.Undoubtedly,Israel contributes significantly to the field of 3D bioprinting and should thus be appropriately recognized.

Ultra-stable CsPbBr3 Perovskite Nanosheets for X-Ray Imaging Screen

Wet chemistry methods,including hot-injection and precipitation methods,have emerged as major synthetic routes for high-quality perovskite nanocrystals in backlit display and scintillation applications.However,low chemical yield hinders their upscale production for practical use.Meanwhile,the labile nature of halide-based perovskite poses a major challenge for long-term storage of perovskite nanocrystals.Herein,we report a green synthesis at room temperature for gram-scale production of CsPbBr3 nanosheets with minimum use of solvent,saving over 95% of the solvent for the unity mass nanocrystal production.The perovskite colloid exhibits record stability upon long-term storage for up to 8 months,preserving a photoluminescence quantum yield of 63% in solid state.Importantly,the colloidal nanosheets show self-assembly behavior upon slow solidification,generating a crack-free thin film in a large area.The uniform film was then demonstrated as an efficient scintillation screen for X-ray imaging.Our findings bring a scalable tool for synthesis of high-quality perovskite nanocrystals,which may inspire the industrial optoelectronic application of large-area perovskite film.

Drying-Mediated Self-Assembly of Graphene for Inkjet Printing of High-Rate Micro-supercapacitors

Scalable fabrication of high-rate micro-supercapacitors(MSCs)is highly desired for on-chip integration of energy storage components.By virtue of the special self-assembly behavior of 2D materials during drying thin films of their liquid dispersion,a new inkjet printing technique of passivated graphene micro-flakes is developed to directly print MSCs with 3D networked porous microstructure.The presence of macroscale through-thickness pores provides fast ion transport pathways and improves the rate capability of the devices even with solid-state electrolytes.During multiple-pass printing,the porous microstructure effectively absorbs the successively printed inks,allowing full printing of 3D structured MSCs comprising multiple vertically stacked cycles of current collectors,electrodes,and sold-state electrolytes.The all-solid-state heterogeneous 3D MSCs exhibit excellent vertical scalability and high areal energy density and power density,evidently outperforming the MSCs fabricated through general printing techniques.

Ti_(3)C_(2) MXene co-catalyst assembled with mesoporous TiO_(2) for boosting photocatalytic activity of methyl orange degradation and hydrogen production

Photocatalytic degradation and hydrogen production using solar energy through semiconductor photocatalysts are deemed to be a powerful approach for solving environmental and energy crisis.However,the biggest challenge in photocatalysis is the efficient separation of photo-induced carriers.To this end,we report that the mesoporous TiO_(2)nanoparticles are anchored on highly conductive Ti_(3)C_(2)MXene co-catalyst by electrostatic self-assembly strategy.The constructed mesoporous TiO_(2)/Ti_(3)C_(2)composites display that the mesoporous TiO_(2)nanoparticles are uniformly distributed on the surface of layer structured Ti_(3)C_(2)nanosheets.More importantly,the as-obtained mesoporous TiO_(2)/Ti_(3)C_(2)composites reveal the significantly enhanced light absorption performance,photo-induced carriers separation and transfer ability,thus boosting the photocatalytic activity.The photocatalytic methyl orange degradation efficiency of mesoporous TiO_(2)/Ti_(3)C_(2)composite with an optimized Ti_(3)C_(2)content(3 wt%)can reach 99.6%within 40 min.The capture experiments of active species confirm that the·O_(2)-and·OH play major role in photocatalytic degradation process.Furthermore,the optimized mesoporous TiO_(2)/Ti_(3)C_(2)composite also shows an excellent photocatalytic H2 production rate of 218.85μmol g^(-1)h^(-1),resulting in a 5.6 times activity as compared with the pristine mesoporous TiO_(2)nanoparticles.This study demonstrates that the MXene family materials can be applied as highly efficient noble-metal-free co-catalysts in the field of photocatalysis.

Gap-plasmon of Fe3O4@Ag Core-shell Nanostructures for Highly Enhanced Fluorescence Detection of Rhodamine B

A novel gap-plasmon of Fe3O4@Ag core-shell nanoparticles for surface enhanced fluorescence detection of Rhodamine B（RB） was developed. Fe3O4@Ag core-shell nanostructures with Ag shell and Fe3O4 core were synthetized by self-assembled method with the assistance of 3-mercaptopropyl trimethoxy silane（MPTS）. To study the RB fluorescence enhanced by gap-plasmon, the fluorescence properties of RB on the substrates with different nanogap densities were systematically investigated, and the results showed that the fluorescence intensity of RB on Fe3O4@Ag core-shell NPs substrate was much stronger than that on bare glass substrate, and the fluorescence intensity was further improved by using multilayer Fe3O4@Ag core-shell NPs substrate which had higher nanogap density. Different from the mechanism that is based on the maximum overlap of the surface plasmon resonance（SPR） band and emission band, the mechanism of the fluorescence enhancement in our work is based on the localized surface plasmon（LSP） and the gap plasmon near-field coupling with the Fe3O4@Ag core-shell NPs. Besides, the detection limit obtained was as low as 1×10^（-7） mol/L, and the Fe3O4@Ag core-shell NPs substrate had high selectivity for RB fluorophores. It was demonstrated that the Fe3O4@Ag core-shell NPs substrate had activity, good stability, and selectivity for fluorescence detection of RB. And the detection of RB by the surface plasmon enhanced fluorescence was more convenient and rapid than the traditional detection methods in previous works.

Ordered SrTiO_3 Nanoripples Induced by Focused Ion Beam

Ordered nanoripples on the niobium-doped SrTiO_3 surfaces were fabricated through focused ion beam bombardment. The surface morphology of the SrTiO_3 nanoripples was characterized using in situ focused ion beam/scanning electron microscopy. The well-aligned SrTiO_3 nanostructures were obtained under optimized ion irradiation conditions. The characteristic wavelength was measured as about 210 nm for different ion beam currents. The relationship between the ion irradiation time and current and SrTiO_3 surface morphology was analyzed. The presented method will be an effective supplement for fabrication of SrTiO_3 nanostructures that can be used for ferroelectric and electronic applications.

Self-Assembled Monolayer of Mixed Gold and Nickel Nanoparticles

Forming a monolayer of mixed nickel and gold nanoparticles through self-assembly via simple solution processing constitutes an important step toward inexpensive nanoparticle-based carbon nanofiber growth.In this work,mixed gold and nickel nanoparticles were anchored on the silicon wafer using self-assembled monolayers(SAMs)as a template.SAMs of 3-mercaptopropyl trimethoxysilane(MPTS-SAMs)were formed on silicon wafer,with the exposed thiol functionality providing ligand exchange sites to form the mixed monolayer of nickel and gold nanoparticles via a two-step sequential soaking approach.The densities of the nickel and gold nanoparticles on the surface can be varied by adjusting the soaking sequence.

Behavior of Self-assembled Mn（Ⅲ）/Mn（Ⅱ）-NEtz Conjugate on Different Support Observed by AFM-SNOM

Et3N （Mn^Ⅱ-triethylamine） complex conjugated with binuclear Mn^Ⅲ-hydroxide, Mn2（OH）3Cl and similar manganese complex with Et2NH （diethylamine） self-assembled in aqueous solutions have been investigated by simultaneous AFM （atomic force microscopy） and SNOM （scanning near-field optical microscopy） in thin layers prepared on mica and PET （polyethylene terephthalate） The size of the particles after crystallization of the precipitated former conjugate was controlled with XRD （X-ray diffraction）. It is found that the conjugate self-assembling produces the smallest grains with the diameter of 65 ± 7.5 nm measured at contact with the support. This particle size matches the crystallite size of 44.2 nm found by XRD for the conjugate taking into account the particles deformation under the contact with the support. The self-assembly of the smallest particles in solution has produced non-transparent for light core observed on mica with the size varied between 300 to 400 nm. The latter occurs due to hydrophobic interactions since no core of the former conjugate has been found on hydrophobic PET surface. No submicroscopic core is also found in the case of similar conjugate with Mn^Ⅱ-Et2NH complex on PET film and mica both.

Surface Dissociation Properties of Short Chain Carboxyl Mercaptan Self-Assembled Monolayers by Impedance Titration

Impedance titration was used to determine the surface dissociation characteristics of short-chain carboxyl mercaptan self-assembled monolayers （SAMs）. Based on the change of the cyclic voltammetric peak current and the charge-transfer resistance, which was related to pH value of the solution, the surface pKa of mercaptoacetic acid（MA）, 3-mercaptopropionic acid（MPA） and ω-mercaptohexanic acid（MHA） self-assembled membranes, with ionic strength being 0.1 mol/L, were determined to be 5.20, 4.80, 7.40, respectively. In addition, factors such as time needed for assembling, structure of monolayers and ionic strength, which effected the surface pKa, were studied as well. Such surface pKa shifts were sufficiently explained by interactions between interfacial molecules and hydrophobicity.

Asymmetric Mesoporous Carbon Microparticles by 3D-Confined Self-Assembly of Block Copolymer/Homopolymer Blends and Selective Carbonization

Shape control of mesoporous carbon microparticles(MCMPs)is of critical importance;in particular,asymmetric shapes that can yield unique properties have attracted significant attention.However,the tailored synthesis of asymmetric MCMPs with ordered structures remains challenging.Herein,we report a facile route to prepare asymmetric MCMPs by dynamic neutral interface-guided 3D-confined self-assembly(3D-CSA)of block copolymer/homopolymer(BCP/hP)blends,followed by a self-templated selective direct carbonization strategy.BCP/h P Janus microparticles with ordered hierarchical mesostructures were prepared with emulsion solvent evaporation-induced 3D-CSA.The continuous phase of BCP domains was then crosslinked.Composite asymmetric MCMPs are successfully generated after selective carbonization of the crosslinked continuous phase.This method allows tuning the shape of MCMPs easily by varying the blending ratio of BCP/h P.The composite asymmetric MCMPs combine the advantages of asymmetric shape,ordered structure,high specific surface area,chemical inertness and thermal stability and could provide great possibilities for applications in catalysis,drug delivery,energy conversion and storage.

3D ball-type self-assemble CeO_(2) nanostructure produced by facile hydrothermal strategy for catalytic wet air oxidation of N,N-dimethylformamide

CeO_(2)plays an important role in heterogeneous catalysis,and its performance is highly dependent on the oxygen vacancies and surface defects,which can be easily tuned by manipulating the particle dimensions and morphology.In this article,we report a facile strategy to synthesize a new type of CeO_(2)with modified surface property which can improve its ability to active oxygen.The obtained ball-type 3D selfassemble CeO_(2)(M-CeO_(2)) is composed of large amounts of small 1D crystals which are stro ngly connected with each other.Detailed characterizations confirm its morphology,particle size and improved reducibility with abundant fraction of Ce^(3+)and more surface active oxygen when compared with CeO_(2)-nanorods and CeO_(2)-nanocubes.In the catalytic wet air oxidation(CWAO)of N,N-dimethylfo rmamide,the total organic carbon(TOC)and total nitrogen(TN)conversion of M-CeO_(2)at 180℃in 3 h are 68%and 46%,respectively,which are higher than that of CeO_(2)-nanorods and CeO_(2)-nanocubes.Besides,M-CeO_(2) presents the lowest activation energy,which is related to its modified surface property.The good stability with consecutive four reactions of M-CeO_(2)in catalytic reactions suggests its potential application in CWAO processes for industrial wastewater treatment.

Magnetic NiFe_(2)O_(4)@FeNi_(3)core-shell nanospheres derived from FeNi-LDH precursor anchoring on rGO nanosheets for enhanced electromagnetic wave absorption

Graphene has been extensively utilized in the domain of electromagnetic wave(EMW)absorption ma-terials because of its excellent electrical conductivity.However,the inferior impedance matching per-formance and the single loss mechanism vastly restrict the application.Hence,it’s an effective strat-egy to solve these issues by introducing magnetic components.Notably,layer double hydroxide(LDH)is an appropriate template to obtain magnetic component materials.Considering that ferromagnetic met-als such as Fe,Co,Ni,and their corresponding metal oxides are usually treated as magnetic compo-nents which are promising candidates for EMW absorption materials.Therefore,in this work,a FeNi-layered double hydroxide-reduced graphene oxide(FeNi-LDH-rGO)aerogel was synthesized through a series of processes such as electrostatic self-assembly,hydrothermal,freeze-drying,and annealing.The magnetic NiFe_(2)O_(4)@FeNi_(3)core-shell nanospheres were obtained from FeNi-LDH precursor,anchoring on rGO nanosheets after the annealing treatment.Furthermore,the effects of different mass ratios of LDH to GO as well as different annealing temperatures of LDH-rGO aerogel on the EMW absorption prop-erty and impedance matching performance were explored.As a consequence,the fabricated ultralight 600LDH-rGO 2:1 aerogel shows a broad effective absorption bandwidth(EAB)of 7.04 GHz at a thickness of 2.3 mm with a low filling content of only 6 wt%and a low density of 4.4 mg/cm^(3).In conclusion,the synthetic LDH-rGO aerogels offer an effective strategy for preparing EMW absorption materials that own three-dimensional porous network structure and unique magnetic NiFe_(2)O_(4)@FeNi_(3)core-shell struc-ture nanospheres.

Hydrothermal Self-assembly Synthesis of Mn3O4Reduced Graphene Oxide Hydrogel and Its High Electrochemical Performance for Supercapacitors

In the present work Mn3O4/reduced graphene oxide hydrogel （Mn3O4-rGOH） with three dimensional （3D） networks was fabricated by a hydrothermal self-assembly route. The morphology, composition, and microstructure of the as-obtained samples were characterized using powder X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, thermogravimetry analysis （TG）, atomic absorption spectrometry （AAS）, field emission scanning electron microscopy （FESEM） and transmission electron microscope （TEM）. Moreover, the electrochemical behaviors were evaluated by cyclic voltammogram （CV）, galvanostatic charge-discharge and electrochemical impedance spectroscopy （EIS）. The test results indicated that the hydrogel with 6.9% Mn3O4 achieved specific capacitance of 148 F.g^-1 at a specific current of 1 A.g^-1, and showed excellent cycling stabilily with no decay after 1200 cycles. In addition, its specific capacitance could retain 70% even at 20 A.g^- 1 in comparison with that at 1 A.g ^-1 and the operating window was up to 1.8 V in a neutral electrolyte.

11B 3Q MAS NMR Study on Glucose-Responsive Micelles Self-assembled from PEG-b-P(AA-co-AAPBA)

Phenylboronic acid (PBA) based glucose-responsive materials have attracted great interests in recent years for developing insulin delivery systems.It is desired to obtain PBA based materials that can response to glucose under physiological pH and understand the mechanism.By using 11B triple-quantum magic-angle spinning nuclear magnetic resonance (11B 3Q MAS NMR) measurements,the glucose-responsive mechanism of micelles self-assembled from poly(ethylene glycol)-b-ploy(acrylic acid-co-acrylamidophenylboronic acid) PEG-b-P(AA-co-AAPBA) is deeply investigated.Different configurations of phenylboronic acid during various steps of glucose-responsive behaviors are clearly analyzed in the 11B 3Q MAS NMR spectra and coordination between carboxyl and PBA is confirmed.By increasing the AA units in PEG-b-P(AA-co-AAPBA),the carboxyl can coordinate with PBA moieties and cause the glucose-responsiveness of micelles even in the weak acid environment.