Synthesis of Biomorphic ZrO2-CeO2 Nanostructures by Silkworm Silk Template

A simple and green technique has been developed to prepare hierarchical biomorphic ZrO2- CeO2, using silkworm silk as the template. Different from traditional immersion technics, the whole synthesis process depends more on the restriction or direction functions of the silkworm silk template. The analytic results showed that ZrO2-CeO2 exhibited a well-crystallized hierarchically interwoven hollow fiber structure with 16-28 μm in diameter. The grain size of the sample calcined at 800 ℃ was about 14 nm. Consequently, the interwoven meshwork at three dimensions is formed due to the direction of biotemplate. The action mechanism is summarily discussed here. It may bring the biomorphic ZrO2-CeO2 nanomaterials with hierarchical interwoven structures to more applications, such as catalysts.

Carbon as a hard template for nano material catalysts

As one of the naturally abundant elements, carbon can present in different molecular structures （allotropes） and thus lead to various physi- cal/chemical properties of carbon-based materials which have found wide applications in a variety of fields including electrochemistry, optical, adsorption and catalysis, etc. On the other hand, its different allotropes also endow carbon-based materials with various morphostructures, which have been recently explored to prepare oxides and zeolites/zeotypes with tailored structures. In this review, we mainly summarize the recent advances in using carbon materials as hard templates to synthesize structural materials. Specifically, we focus on the development in the synthetic strategies, such as endotemplating, exotemplating approaches and using carbon materials as chemical reagents for the synthesis of metal carbides or nitrides, with an emphasis laid on the control of morphostructure. Meanwhile, the applications of the obtained materials will be highlighted, especially, in the field of heterogeneous catalysis where enhanced performances have been achieved with the materials derived from carbon-templated methods.

CONCERTED H-BONDING TEMPLATE SYNTHESIS OF AN ORDERED LADDER POLYSILSESQUIOXANE

A novel soluble regular ladder poly（benzoyl-3-aminopropyl） silsesquioxane （LPBAS） was facilely prepared under effective assistance of concerted H-bonding self-assembly of amido groups of side chains and silanol groups, respectively, of a new template monomer [1,3-bis（benzoyl-3-aminopropyl）-1,1,3,3-tetraethoxydisiloxane] （M）. The ordered ladder structure of LPBAS is manifested in： （1） the presence of two Bragg peaks representing the ladder width （d） and ladder thickness （t） in X-ray diffraction （XRD） pattern; （2） narrow base-line width （w = 6） of resonance absorption for -CH2SiO3/2 moiety in 29Si-NMR and （3） high glass transition temperature Tg = 1 12℃ in differential scanning calorimetry （DSC） analysis.

Shape-controllable Synthesis of Functional Nanomaterials on DNA Templates

DNA nanotechnology enables precise organization of nanoscale objects with extraordinarily structural programmability.Self-assembled DNA nanostructures possess a lot of interesting features,such as designable size and shape,and structural addressability at nanometer scale.Taking advantage of these properties,DNA nanostructures could work as templates or molds for the controllable synthesis of functional nanomaterials,such as organic macromolecules,metallic or inorganic nonmetallic nanomaterials.In this review,we summarize the recent progress in the shape-controllable synthesis of functional nanomaterials on DNA templates.The potential application fields of these nanomaterials are also discussed.

H-bonding template-directed synthesis of a complete m-PDA-bridged ladder polyhydrosiloxane (OLPHS)

A highly ordered m-phenylenediimino-bridged ladder polyhydrosiloxane （abbr. OLPHS） with Mn = 1.24 × 10^4 was synthesized stoichiometric hydrolysis and dehydrochlorination condensation reaction between Si-Cl and Si-OH bonds. The complete ladder structure of OLPHS has been confirmed by the following three data. Two characteristic Bragg＇s peaks representing the ladder width （w = 0.94 nm） and ladder thickness （t = 0.42 nm） were observed in XRD analysis, which are consistent with those calculated by molecular simulation. The very sharp absorption with a small half-peak width （w1/2 = 0.5 ppm） for [（-HN）HSiO2/2]n moiety of OLPHS in ^29Si NMR spectrum indicated presence of the complete ladder structure. As collateral evidence, a higher glass transition temperature （Tg = 105 ℃） is also recorded in the DSC measurement, implying the high stiffness of ladder chain of OLPHS.

Natural nanomaterial as hard template for scalable synthesizing holey carbon naonsheet/nanotube with in-plane and out-of-plane pores for electrochemical energy storage

Tuning porous structure of carbon nanomaterials has been found to be important for their performance enhancement in electrochemical energy storage applications. In this work we employed a natural nanomaterial kaolinite, which is abundant and cheap, as hard template to synthesis porous carbon nanomaterial. By tuning the structure of hard template kaolinite, we have achieved a template directed formation of holey carbon nanosheet/nanotube materials. This carbon nanomaterials with hierarchical in-plane and out-of-plane pores have shown electrochemical energy storage capacity of 286 F/g（equal to 314 F/cm^3） at 0.1 A/g and 85 F/g（equal to 93 F/cm^3） at 100 A/g, which is comparable to variety of reported carbon based electrochemical energy storage electrode materials.

Solution-phase synthesis of nanomaterials at low temperature

This paper reviews the solution-phase synthesis of nanoparticles via some routes at low temperatures, such as room temperature route, wave-assisted synthesis (γ-irradiation route and sonochemical route), directly heating at low temperatures, and hydrothermal/solvothermal methods. A number of strategies were developed to control the shape, the size, as well as the dispersion of nanostructures. Using diethylamine or n-butylamine as solvent, semiconductor nanorods were yielded. By the hydrothermal treatment of amorphous colloids, Bi2S3 nanorods and Se nanowires were obtained. CdS nanowires were prepared in the presence of polyacrylamide. ZnS nanowires were obtained using liquid crystal. The polymer poly (vinyl acetate) tubule acted as both nanoreactor and template for the CdSe nanowire growth. Assisted by the surfactant of sodium dodecyl benzenesulfonate (SDBS), nickel nanobelts were synthesized. In addition, Ag nanowires, Te nanotubes and ZnO nanorod arrays could be prepared without adding any additives or templates.

Adaptive iron-based magnetic nanomaterials of high performance for biomedical applications

With unique physicochemical properties and biological effects,magnetic nanomaterials(MNMs)play a crucial role in the biomedical field.In particular,magnetic iron oxide nanoparticles(MIONPs)are approved by the United States Food and Drug Administration(FDA)for clinical applications at present due to their low toxicity,biocompatibility,and biodegradability.Despite the unarguable effectiveness,massive space for improving such materials'performance still needs to be filled.Recently,many efforts have been devoted to improving the preparation methods based on the materials'biosafety.Besides,researchers have successfully.regulated the performance of magnetic nanoparticles(MNPs)by changing their sizes,morphologies,compositions;or by.aggregating as-synthesized MNPs in an orderly arrangement to meet various clinical requirements.The rise of cloud computing and artificial intelligence techniques provides novel ways for fast material characterization,automated data analysis,and mechanism demonstration.In this review,we summarized the studies that focused on the preparation routes and performance regulations of high-quality MNPs,and their special properties applied in biomedical detection,diagnosis,and treatment.At the same time,the future.development of MNMs was also discussed.

A General and Programmable Synthesis of Graphene-Based Composite Aerogels by a Melamine-Sponge-Templated Hydrothermal Process

Three-dimensional(3D)graphene networks are performance boosters for functional nanostructures in energy-related fields.Although tremendous intriguing nanostructures-decorated 3D graphene networks have been realized,on-demand decoration of nanostructures in the specified position of interest within the whole 3D graphene skeleton is still out of reach,shedding limitations on constructing more sophisticated components with programmable structures which offer enormous potential for the enhancement of performance and exploration of new functions.Here,we report the melamine-sponge(MS)-templated hydrothermal method capable of realizing reduced graphene oxide(RGO)-nanostructure composite aerogels with programmable structures and compositions.The key of this method is using the MS template to preset the structures of choice through programmable solution-processed immobilization of graphene oxide(GO)and nanostructures.Remarkably,the hydrothermal treatment simultaneously removed the MS template and reduced the GO networks without changing the preset structures.We showcased nine typical RGO-nanostructures composite aerogels to demonstrate the versatility of the MS-templated hydrothermal method.

Templated self-assembly of Au-TiO_2 binary nanoparticles-nanotubes

In this work, we developed a templated self-assembly approach to fabricate self-supporting Au/TiO2 binary nanoparticles-nanotubes （NPNTs） for the first time. The stable Au/TiO2 nanoparticles colloids were pre-synthesized and then deposited onto an AAO template, following by a mild calcination process. Au/TiO2 binary NPNTs can be achieved after removing the AAO template by NaOH solution. In addition, Au/TiO2 NPNTs with different thicknesses and size distributions could be achieved by tailoring the process parameters, such as the molar ratio of AuNPs to TiO2NPs, deposition modes and calcinations conditions. Therefore, these findings made controllable formation of Au/TiO2 NPNTs attractive for promising fabrication methodologies of metal/metal oxides NPNTs.

DNA Directed Self-Assembly of Fluorescent Colloidal Semiconductor Quantum Dots and Plasmonic Metal Nanoparticles Heterogeneous Nanomaterials

The exciton-plasmon interaction between fluorescent colloidal semiconductor quantum dots and plasmonic metal nanoparticles may lead to emission quenching or enhancement of quantum dots, which have potential appli- cations in renewable energy, nanophotonics, and biosensing. Semiconductor quantum dots and metal nanoparticles hybrids with controlled geometry, distance, and stoichiometry are crucial for the potential applications. While DNA nanotechnology, based on Watson-Crick base-pairing interactions between two single-stranded DNAs, has provided unique opportunities to generate fully programmable, functional metal nanoparticles and semiconductor quantum dots hybrid nanomaterials, and offers precisely control over the spacing, orientation, and chirality of the compo- nents. This review provides the highlights of the recent progresses in DNA directed self-assembly of colloidal sem- iconductor quantum dots and metallic nanoparticles heterogeneous nanomaterials. We also discuss the challenges and the trends in DNA directed self-assembly of semiconductor quantum dots and metallic nanoparticles hybrid nanomaterials.

Polymer-virus core-shell structures prepared via co-assembly and template synthesis methods

Bionanoparticles(BNPs),consisting of virus and virus-like assemblies,have attracted much attention in the biomedical field for their applications such as imaging and targeted drug delivery,owing to their well-defined structures and well-controlled chemistries.BNPs-based core-shell structures provide a unique system for the investigation of biological interactions such as protein-protein and protein-carbohydrate interactions.However,it is still a challenge to prepare the BNPs-based core-shell structures.Herein,we describe(i) co-assembly method and(ii) template synthesis method in the development of polymer-BNPs core-shell structures.These two methods can be divided into three different systems.In system A,different polymers including poly(2-vinylpyridine)(P2VP),poly(4-vinylpyridine)(P4VP) and poly(ε-caprolactone)-block-poly(2-vinylpyridine)(PCL-b-P2VP) can form a raspberry-like structure with BNPs.In system B,polystyrene(PS) spheres end capped with free amine and BNPs can form a core-shell structure.In System C,layer-by-layer(LBL) method is used to prepare positive charged PS particles,which can be used as a template to form the core-shell structures with BNPs.These two methods may open a new way for preparing novel protein-based functional materials for potential applications in the biomedical field.

Facile Template-free Synthesis of Carbonated Hydroxyapatite Spheres in Aqueous Solution

Prickly carbonated hydroxyapatite（CHAp） spheres were obtained via a facile template-free self-assembly method with Na2HPO4 and self-made cubic CaCO3 as reactants. X-ray diffraction results of the product revealed CHAp with high crystallinity could be successfully prepared in a short reaction time. A nucleation mechanism was proposed according to the results of characterizing the resultant powders and analyzing the growth process. It shows that the self-made CaCO3 particles play an important role in the template-free synthesis of prickly spheres.

A comparative study of assembly and disassembly process of dimeric and monomeric cyanine dyes with DNA templates

Cyanine dyes have attracted more and more interest due to their controllable assembly and disassembly process with biomolecular templates. The self-assembly of cyanine dye not only depend on the environment, but also on their structures. Here, we report assembly and disassembly of two cyanine dyes,a dimeric cyaine dye(TC-P4) and its corresponding monomer(TC). In PBS, these dyes could form aggregates. The parallel c-myc G-quadruplex as a template causes the transformation of TC-P4 from Haggregates to dimer and monomer; while duplex and single-stranded DNAs could not. The interaction between these DNAs motifs and TC could all induce the appearance of monomer band. Parallel c-myc Gquadruplex could enhance the fluorescence intensity of TC-P4 and TC. The self-assembly and disassembly of TC and TC-P4 could be regulated and used as probes for G-quadruplex recognition from duplex and single-stranded DNAs in solution.

Orientated-assembly of rod-like silica particles based on sandwich structure from the superhydrophobic template and the superhydrophilic substrates

The paper demonstrated a facile approach for the orientated assembly of the rod-like silica particles by sandwich structure from the combined effect of superhydrophobic template and the superhydrophilic substrates. The rod-like particles can be arranged in ring-like, square-like and etc from the confined effect of the template, which will produce an important insight for the oriented assembly ofanisotropic particles and the development of the novel functional materials and devices.

Copper nanomaterials and assemblies for soft electronics

Soft electronics that can simultaneously offer electronic functions and the capability to be deformed into arbitrary shapes are becoming increasingly important for wearable and bio-implanted applications.The past decade has witnessed tremendous progress in this field with a myriad of achievements in the preparation of soft electronic conductors,semiconductors,and dielectrics.Among these materials,copper-based soft electronic materials have attracted considerable attention for their use in flexible or stretchable electrodes or interconnecting circuits due to their low cost and abundance with excellent optical,electrical and mechanical properties.In this review,we summarize the recent progress on these materials with the detailed discussions of the synthesis of copper nanomaterials,approaches for their assemblies,strategies to resist the ambient corrosion,and their applications in various fields including flexible electrodes,sensors,and other soft devices.We conclude our discussions with perspectives on the remaining challenges to make copper soft conductors available for more widespread applications.

An Overview of Molecular Packing Mode in Two-Dimensional Organic Nanomaterials via Supramolecular Assembly

Two-dimensional(2D)organic nanomaterials are attracting increasing research interest and expected to be the ideal candidate for futureproofed flexible electronics and biotechnologies.Owing to the complex molecular structures and multiple intermolecular interactions in organic systems,deeper understanding of rational molecular design and assembly principles is urgently required.In this review,a collection of molecular packing mode in the 2D organic nanomaterials via supramolecular assembly is presented,so as to help explicit the relationship among molecular structures,supramolecular interactions and molecular packing motifs in 2D assembly systems.We also provide a rational and accessible schematic model to demonstrate several typical kinds of molecular packing motifs for the prediction of the 2D morphology.

Self-assembly low dimensional inorganic/organic heterojunction nanomaterials

One dimensional inorganic/organic heterojunction nanomaterials have gained extensive attention in materials science because of their outstanding optical and electrical properties. Strong interactions between the inorganic and organic units can lead to novel or improved physical or chemical performance relative to that of the individual components, realizing synergistic ("1+1>2") performance. It is of great scientific significance for the development of basic scientific research: Understanding and interpretation the law of molecular self-assemble, controlling the self-assemble of low dimensional molecular aggregation with high ordered degree in large area through tailoring the molecular structure and the interaction forces, understanding the synergy drive mechanism produced by the weak interactions between the molecular aggregations then optimizing the original function through the hybrid/ heterojunction self-assemble. In this paper, we discuss the synthetic methods for preparing heterojunctions incorporating diverse components and their potential applications in the fields of electronics and optics.

Peptoid-based hierarchically-structured biomimetic nanomaterials: Synthesis, characterization and applications

Peptoids(or poly-N-substituted glycines)are a promising class of bioinspired sequence-defined polymers due to their highly efficient synthesis,high chemical stability,enzyme hydrolysis resistance,and biocompatibility.By tuning the side chain chemistry of peptoids,it allows for precise control over sequences and achieving a large side-chain diversity.Due to these unique features,in the last several years,many amphiphilic peptoids were designed as highly tunable building blocks for the preparation of biomimetic nanomaterials with well-defined hierarchical structures and desired functionalities.Herein,we provide an overview of the recent achievements in this area by dividing them into the following three aspects.First,mica-and silica-templated peptoid selfassembly are summarized.The presence of inorganic substrates provides the guarantee of investigating their selfassembly mechanisms and interactions between peptoids and substrates using nanoscale characterization techniques,particularly in situ atomic force microscopy(AFM)and AFMbased dynamic force spectroscopy(AFM-DFS).Second,solution-phase self-assembly of peptoids into nanotubes and nanosheets is presented,as well as their self-repair properties.Third,the applications of peptoid-based nanomaterials are outlined,including the construction of catalytic nanomaterials as a template and cytosolic delivery as cargoes.

Mechanical force-induced assembly of one-dimensional nanomaterials

There have been intensive and continuous research efforts in large-scale controlled assembly of one-dimensional(1D)nanomaterials,since this is the most effective and promising route toward advanced functional systems including integrated nano-circuits and flexible electronic devices.To date,numerous assembly approaches have been reported,showing considerable progresses in developing a variety of 1D nanomaterial assemblies and integrated systems with outstanding performance.However,obstacles and challenges remain ahead.Here,in this review,we summarize most widely studied assembly approaches such as Langmuir-Blodgett technique,substrate release/stretching,substrate rubbing and blown bubble films,depending on three types of external forces:compressive,tensile and shear forces.We highlight the important roles of these mechanical forces in aligning 1D nanomaterials such as semiconducting nanowires and carbon nanotubes,and discuss each approach on their effectiveness in achieving high-degree alignment,distinct characteristics and major limitations.Finally,we point out possible research directions in this field including rational control on the orientation,density and registration,toward scale-up and cost-effective manufacturing,as well as novel assembled systems based on 1D heterojunctions and hybrid structures.