Halogenated Antimonene: One‐Step Synthesis,Structural Simulation,Tunable Electronic and Photoresponse Property

Surface functionalization is considered to be an effective and versatile strategy to tailor intrinsic electronic and optoelectronic properties of 2D materials. In this work, surface‐decorated few‐layer antimonene is synthesized by a one‐step electrochemical exfoliation and synchronous halogenation method in halogen‐containing an ionic liquid–based electrolyte at room temperature. The prepared halogenated antimonene nanosheets are composed of oxygen‐ and halogen‐decorated amorphous and crystalline domains. The structural reconstructions and evolutions of halogenated antimonene are further revealed by ab initio molecular dynamics simulations and first‐principles calculations. The band structures and optical properties of antimonene can be tailored after amorphization and surface functionalization, depending on the reactivity of different halogens. The photoresponse performance of the halogenated antimonene is further evaluated by photoelectrochemical measurement. Exhibiting self‐powered photoresponse behavior, their photocurrent density increases with the increases of external bias potential and light intensity. This work proposes a new idea of tuning the optoelectronic properties of 2D materials by synchronous halogenation in the facile one‐step electrochemical synthesis process. Benefiting from this facile synthesis procedure, the halogenation of antimonene may shed light on chemical functionalization of other 2D materials for electronic and optoelectronic applications.     

Asymmmetric Diamino Functionalization of Nanotubes Assisted by BOC Protection and Their Epoxy Nanocomposites

Homogenous dispersion and strong interfacial bonding are prerequisites for taking full advantage of the mechanical properties of nanotubes in a composite. In order to simultaneously achieve both conditions, a highly efficient and mechanically non‐destructive functionalization of nanotubes is developed. With fluoronanotubes as the precursor, asymmetric diamine molecules, N‐BOC‐1,6‐diaminohexane, are used to replace fluorines on the wall of fluoronanotubes and construct covalent bonding to the surface of the nanotubes. A BOC de‐protection reaction is conducted and the resulting exposed amino groups create strong covalent bonds with the matrix in the course of epoxy ring‐opening etherification and curing chemical reactions. In comparison with the conventional functionalization based on symmetric diamine molecules, the functionalized nanotubes derived from the BOC‐protected diamine molecule are more dispersed within the epoxy matrix. Dynamic mechanical analysis shows that the functionalized nanotubes have better crosslinking with the matrix. The composites reinforced by the nanotubes demonstrate improvement in various mechanical properties. The Young’s Modulus, ultimate tensile strength, and storage modulus of composites loaded with 0.5 wt% functionalized nanotubes are enhanced by 30%, 25%, and 10%, respectively, compared with the neat epoxy. The increase of the glass transition temperature, as much as 10 °C, makes the composites suited for engineering applications under higher temperatures. The new functionalization method allows for an competitive enhancement in the composite performance in use of relatively low cost raw nanotubes at a small loading level. The reinforcement mechanism of the functionalized nanotubes in the epoxy resin is discussed.     

Nanoarchitecturing of Activated Carbon: Facile Strategy for Chemical Functionalization of the Surface of Activated Carbon

Nanoarchitecturing of carbon nanospheres onto the surface of activated carbon (AC) gives birth to a new composite carbon material that features a hierarchical structure with macro‐ and nanometer dimensions of the respective carbon components and exhibits a remarkably enhanced adsorption capability for heavy‐metal ions ( and Fe³⁺) from aqueous solution as compared to AC. Thus, we first propose that nanoarchitecturing of AC can be utilized not only as a flexible method for the synthesis of novel, hybrid, nanostructured composite carbon materials but also as a new and “green‐route” strategy for functionalization of the surface of AC in an effective manner. Hence, there is scope for a possible new concept in the functionalization of industrial AC for specific applications.     

Infrared Aluminum Metamaterial Perfect Absorbers for Plasmon‐Enhanced Infrared Spectroscopy

Matured surface chemistry and excellent chemical stability have enabled gold to become the material‐of‐choice for plasmonic sensing in both visible and infrared wavelength range. Here, successful surface functionalization of metamaterials made from a low‐cost abundant plasmonic material, aluminum, with phosphonic acid and subsequent detection of the C?O vibration mode via surface‐enhanced infrared absorption spectroscopy is demonstrated. The metamaterial consists of infrared perfect absorbers fabricated by colloidal lithography. Near perfect absorption is achieved at resonance wavelengths, which can be readily tuned by changing the diameters of the Al disk resonators, enabling excellent overlapping with the molecular vibration. Separately, the detection of a physically adsorbed protein layer on the Al metamaterial is also demonstrated. Surface functionalization with phosphonic acid provides various functional groups to the Al surfaces. Combined with tunable metamaterials, the work herein opens up great opportunities for Al‐based plasmonic nanostructures for biochemical sensing applications.     

Simultaneous Reduction and Surface Functionalization of Graphene Oxide by Mussel‐Inspired Chemistry

This study presents a method of simultaneous reduction and surface functionalization of graphene oxide by a one‐step poly(norepinephrine) functionalization. The pH‐induced aqueous functionalization of graphene oxide by poly(norepinephrine), a catecholamine polymer inspired by the robust adhesion of marine mussels, chemically reduced and functionalized graphene oxide. Moreover, the polymerized norepinephrine (pNor) layer provided multifunctionality on the reduced graphene oxide that includes surface‐initiated polymerization and spontaneous metallic nanoparticle formation. This facile surface modification strategy can be a useful platform for graphene‐based nano‐composites.     

Tetrakis‐(4‐thiyphenyl)methane: Origin of a Reversible 3D‐Homopolymer

The efficient syntheses of tetrakis(thiophenol)methane and of a new poly(disulfide) hyper‐crosslinked polymer based on the former monomer are described. Controlled de‐polymerization as well as surface post‐functionalization are successfully conducted on this novel material. Direct prove of post‐functionalization is obtained through solid‐state fluorescence emission spectroscopy, and the number of unreacted thiol‐functions on the surface of the polymeric material is indirectly quantified by de‐polymerization of the post‐functionalized material.     

Nanopatterning of Anionic Nanoparticles based on Magnetic Prussian‐Blue Analogues

Prussian‐blue analogues (PBA) are a family of molecule‐based magnetic compounds of general formula A_xM_y[M’(CN)₆]_z, whose magnetic properties can be tuned by an external stimulus. This tunability makes PBA good candidates for their integration into new electronic or spintronic devices. As a previous step to accomplish this integration, PBA need to be deposited onto surfaces in controllable ways and if possible into specific positions on the surface. Even though the study of PBA has traditionally been limited to bulk, lately they have also been processed as nanoparticles (NPs). Here an efficient approach is presented for the accurate deposition and organization of PBA‐NPs of different sizes (from ～6 to ～25 nm) over silicon surfaces. The approach used in this work, relies on a combination of surface functionalization with local oxidation nanolithography (LON) and uses electrostatic interactions between PBA‐NPs and a charged self‐assembled monolayer patterned on specific parts of the silicon surface. By using atomic force microscopy (AFM), magnetometry, infrared spectroscopy (IR) and auger electron spectroscopy (AES) we show that the deposition process does not affect NPs properties. In addition, we present a study on the evolution of AFM nanolithographed SiO₂ patterns under sonication.     

Fabrication and Surface Functionalization of Nanoporous Gold by Electrochemical Alloying/Dealloying of Au–Zn in an Ionic Liquid,and the Self‐Assembly of L‐Cysteine Monolayers

This paper describes a totally electrochemical process for the fabrication and functionalization of high‐surface‐area, nanoporous gold films. The fabrication process involves the electrodeposition of a binary gold–zinc alloy at gold wires, followed by subsequent electrochemical dealloying of the less noble component zinc from the surface. Both the deposition and dealloying steps are conducted in a single low‐temperature bath of 40.0–60.0 mol‐% zinc chloride–1‐ethyl‐3‐methylimidazolium chloride ionic liquid at 120 °C without using any other corrosive acids or bases. The porous structure and morphology of the nanostructured gold film could be controlled by electrochemical variation of the composition of the Au–Zn surface alloy. It is demonstrated that the nanoporous gold surface can be successfully functionalized with self‐assembled monolayers of L ‐cysteine. Such functionalization greatly improves the utility of the nanoporous gold, as is demonstrated in the sensitive and selective determination of Cu(II ).     

Rapid and Facile Microwave‐Assisted Surface Chemistry for Functionalized Microarray Slides

This report describes a rapid and facile method for surface functionalization and ligand patterning of glass slides based on microwave‐assisted synthesis and a microarraying robot. The optimized reaction enables surface modification 42‐times faster than conventional techniques and includes a carboxylated self‐assembled monolayer, polyethylene glycol linkers of varying length, and stable amide bonds to small molecule, peptide, or protein ligands to be screened for binding to living cells. Customized slide racks that permit functionalization of 100 slides at a time to produce a cost‐efficient, highly reproducible batch process. Ligand spots can be positioned on the glass slides precisely using a microarraying robot, and spot size adjusted for any desired application. Using this system, live cell binding to a variety of ligands is demonstrate and PEG linker length is optimized. Taken together, the technology we describe should enable high‐throughput screening of disease‐specific ligands that bind to living cells.     

Composite Colloidal Gels Made of Bisphosphonate‐Functionalized Gelatin and Bioactive Glass Particles for Regeneration of Osteoporotic Bone Defects

Injectable composite colloidal gels are developed for regeneration of osteoporotic bone defects through a bottom‐up assembly from bisphosphonate‐functionalized gelatin and bioactive glass particles. Upon bisphosphonate functionalization, gelatin nanoparticles show superior adhesion toward bioactive glass particles, resulting in elastic composite gels. By tuning their composition, these composite colloidal gels combine mechanical robustness with self‐healing ability. The composite colloidal gels support cell proliferation and differentiation in vitro without requiring any osteogenic supplement. In vivo evaluation of the composite colloidal gels reveals their capacity to support the regeneration of osteoporotic bone defects. Furthermore, the bisphosphonate modification of gelatin induces a therapeutic effect on the peri‐implantation region by enhancing the bone density of the osteoporotic bone tissue. Consequently, these composite colloidal gels offer new therapeutic opportunities for treatment of osteoporotic bone defects.     

Functionalized Nanostructures with Liquid‐Like Behavior: Expanding the Gallery of Available Nanostructures

Recently, we have developed a novel family of functionalized nanostructures that exhibit liquid‐like behavior in the absence of solvents and preserve their nanostructure in the liquid state. The gallery of nanostructures developed so far includes functionalized silica and magnetic iron oxide nanoparticles, layer‐like organosilicate nanoparticles, polyoxometalate clusters, and organic–inorganic hybrid networks. In an effort to demonstrate the wider applicability of this concept and to provide a deeper insight into this class of materials, the present work cites additional paradigms of functionalized nanostructures with similar behavior as above. In one case, surface functionalization of anatase nanoparticles (TiO₂, an inorganic nanostructure) with a quaternary ammonium organosilane leads to ionically modified nanoparticles that, when electrostatically combined with a poly(ethylene glycol) (PEG)‐tailed sulfonate anion, exhibit liquid‐like behavior in the absence of solvents. In a different but quite interesting case of a bionanostructure, ion‐exchange functionalization of a DNA oligonucleotide with a PEG‐tailed quaternary ammonium cation leads to an easily separable liquid derivative with attractive features. These examples show the versatility of this concept over a range of nanostructures.     

Bandgap Engineering in OH‐Functionalized Silicon Nanocrystals: Interplay between Surface Functionalization and Quantum Confinement

In this work, a systematic first‐principles study of the quasi‐band structure of silicon nanocrystals (Si‐NCs) is provided, focusing on bandgap engineering by combining quantum confinement of the electronic states with OH surface‐functionalization. A mapping between the bandgap, Si‐NC diameter, and the degree of hydroxide coverage is provided, which can be used as a guideline for bandgap engineering. Complementary to first‐principles calculations, the photoluminescence (PL) wavelength of Si‐NCs in the quantum‐confinement regime is measured with well‐defined diameters between 1 and 4 nm. The Si‐NCs are prepared by means of a microplasma technique, which allows a surfactant‐free engineering of the Si‐NCs surface with OH groups. The microplasma treatment technique allows us to gradually change the degree of OH coverage, enabling us, in turn, to gradually shift the emitted light in the PL spectra by up to 100 nm to longer wavelengths. The first‐principles calculations are consistent with the experimentally observed dependence of the wavelengths on the OH coverage and show that the PL redshift is determined by the charge transfer between the Si‐NC and the functional groups, while on the other hand surface strain plays only a minor part.     

Porous Silicon Nanodiscs for Targeted Drug Delivery

There is a strong demand for techniques that allow the fabrication of biocompatible porous nanoparticles for drug delivery applications. In this work, a new method to fabricate size‐ and shape‐controlled porous silicon (pSi) nanodiscs is described. The process relies on a combination of colloidal lithography and metal‐assisted chemical etching. Height and diameter of the pSi nanodiscs can be easily adjusted. The nanodiscs are degradable in physiological milieu and are nontoxic to mammalian cells. In order to highlight the potential of the pSi nanodiscs in drug delivery, an in vitro investigation that involved loading of nanodiscs with the anticancer agent camptothecin and functionalization of the nanodisc periphery with an antibody that targets receptors on the surface of neuroblastoma cells is carried out. The thus‐prepared nanocarriers are found to selectively attach to and kill cancer cells.     

Implementing Thermometry on Silicon Surfaces Functionalized by Lanthanide‐Doped Self‐Assembled Polymer Monolayers

The thermal gradients generated at submicrometer scale by the millions of transistors contained in integrated circuits are becoming the key limiting factor for device integration in micro‐ and nanoelectronics. Noncontact thermometric techniques with high‐spatial resolution are, thus, essential for noninvasive off‐chip characterization and heat management on Si surfaces. Here, the first ratiometric luminescent molecular thermometer implemented in a self‐assembled polymer monolayer functionalized Si surface is reported. The functionalization of Si surfaces with luminescent thermometers constitutes a proof‐of‐concept that foretells a wide range of applications in Si‐based micro‐ and nanostructures. The thermometric functionalization of the Si surface with Tb³⁺ and Eu³⁺ complexes leads to a thermal sensitivity up to 1.43% K^?1, a cycle–recycle reliability of 98.6%, and a temperature uncertainty of less than 0.3 K. The functionalized surface presents reversible bistability that can be used as an optically active molecular demultiplexer.     

The Art of Integrated Functionalization: Super Stable Black Phosphorus Achieved through Metal‐Organic Framework Coating

Black phosphorus (BP) is a promising 2D nanomaterial with a great potential in various areas, while its intrinsic instability greatly suppresses practical applications, particularly under harsh conditions (e.g., high temperature). Herein, BP functionalization with Al ion is achieved in an integrated manner through MIL‐53 metal‐organic framework (MOF) coating, which greatly improves both ambient and thermal stability of BP. For the obtained MIL‐53 coated BP (BP@MIL‐53), abundant Al ion within MIL‐53 interacts with the lone pair electrons of BP, and subsequently decreases the BP surface electron density, reducing the reactivity of BP toward O₂ and H₂O. The MOF growth crosslinks the Al ion on the BP surface, and achieves integrated functionalization to withstand the detachment of individual Al ion from the BP surface. The noncovalent bond of BP? Al and highly porous structure of MIL‐53 preserve the physical/chemical properties of BP to the maximum, and render BP@MIL‐53 with super‐stability. This functionalization strategy extends the applications of BP based devices under high temperature conditions. As a proof of concept, BP@MIL‐53 is further utilized as a NO₂ gas sensor under relatively high operating temperatures. The BP@MIL‐53 sensor exhibits fast response, outstanding selectivity, and high recovery dynamic process in contrast to bare BP sensor.     

Dual Functionalization of Liquid‐Exfoliated Semiconducting 2H‐MoS2 with Lanthanide Complexes Bearing Magnetic and Luminescence Properties

Liquid exfoliated, atomically thin semiconducting transition metal dichalcogenides (TMDs), as inorganic equivalents of graphene, have attracted great interest due to their distinctive physical, optoelectronic, and chemical properties. Functionalization of 2D TMDs brings new prospects for applications in optoelectronics, quantum technologies, catalysis, and medicine. In this report, dual functionalization of 2D semiconducting 2H‐MoS₂ nanosheets through simultaneous incorporation of magnetic and luminescent properties is demonstrated. A facile method is proposed for tuning the properties of the TDM semiconductors and accessing multimodal platforms, consisting in covalent grafting of lanthanide complexes onto the surface of 2D TMDs. Dual functionalization of liquid‐exfoliated MoS₂ nanosheets is demonstrated simultaneously with both europium (III) and gadolinium (III) complexes to form a colloidally stable luminescent (with millisecond lifetimes) and paramagnetic MoS₂‐based nanohybrid material. This work is the first example of transition metal dichalcogenide nanosheets functionalized with preformed lanthanide complexes. These findings open new prospects for covalent functionalization of TMDs with molecular species bearing specific functionalities as a means to tune the optoelectronic properties of the semiconductors, in order to create advanced materials and devices with a wide range of functionalities.     

Carbon Fiber–Bismaleimide Composites Filled with Nickel‐Coated Single‐Walled Carbon Nanotubes for Lightning‐Strike Protection

Multifunctional carbon fiber composites are imperative for next‐generation lightweight aircraft structures. However, lightning‐strike protection is a feature that is lacking in many modern carbon fiber high‐temperature polymer systems, due to their high electrical resistivity. This work presents a study on processing, materials optimization, and property development of high‐temperature bismaleimide (BMI)–carbon fiber composites filled with nickel‐coated single‐walled carbon nanotubes (Ni‐SWNTs) based on three key factors: i) dispersion of Ni‐SWNTs, ii) their surface coverage on the carbon plies and, iii) the composite surface resistivity. Atomic force microscopy analysis revealed that coating purified SWNTs with nickel enabled improved dispersion which resulted in uniform surface coverage on the carbon plies. The electrical resistivity of the baseline composite system was reduced by ten orders of magnitude by the addition of 4 wt% Ni‐SWNTs (calculated with respect to the weight of a single carbon ply). Ni‐SWNT–filled composites showed a reduced amount of damage to simulated lightning strike compared to their unfilled counterparts, as indicated by the minimal carbon fiber pull‐out.     

Rational Synthesis of Large‐Area Periodic Chemical Gradients for the Manipulation of Liquid Droplets and Gas Bubbles

Synthetic approaches based on the patterned deposition of volatile molecules from the vapor phase are used extensively in the creation of surface‐chemical gradients; however, the ability to generate diffusion‐controlled 1D and 2D gradients from multiple sources remains a challenge. The current work reports a one‐step approach to the synthesis of continuous and periodic chemical gradients with simple and intricate geometries using multiple sources within custom reaction chambers. Specifically, this approach provides precise, simultaneous control over the physicochemical conditions (e.g., concentration, evaporation rate, and direction of diffusion flux of the chemical moieties) and the geometrical parameters (e.g., size, shape, and position) during surface functionalization, thus enabling materials with predictable surface‐chemical gradients applicable to the manipulation and/or organization of liquid droplets and that can generate assemblies of functional solids (e.g., silver nanoparticles) that are transferrable via stamping. These surfaces can be useful to various fields, for example, molecular diagnostics and microfabrication. Furthermore, this work extends the application of these surfaces to the precise placement and manipulation of gas bubbles that can have potential use in, for example, controlling bubble nucleation in processes designed to manage heat transfer.     

Facile Methods to Coat Polystyrene and Silica Colloids with Metal

To avoid the complex core surface functionalization or pretreatment that is necessary in order to coat latex and silica colloids with a uniform, complete metal shell, the solvent‐assisted route has been explored to prepare a complete metal (Ag or Au) shell with controlled thickness on polystyrene (PS) colloids and the electroless plating approach, based on electrostatic attraction, has been explored to prepare a complete silver shell with controlled thickness on silica colloids. Without any additional surface treatment, the as‐prepared complex core–shell colloids can be crystallized directly into long‐range‐ordered structures with photonic bandgaps, as reported here for the first time. These ordered structures may find potential applications as substrates or physical systems for the enhancement of Raman scattering studies, besides applications as photonic crystals. The optical plasmon resonance of the composite core–shell colloids changes with metal shell thickness, the wavelength varying over hundreds of nanometers. Our coating routes are facile and versatile, and can be extended to coat PS and silica colloids with any other metal whose ion or complex can be reduced in solution.     

Biomimetic Architectures for the Impedimetric Discrimination of Influenza Virus Phenotypes

Rapid discrimination of avian vs. human phenotypes of emerging influenza A virus isolates with pandemic potential is an important issue in pathogenesis and epidemiology studies of the infection. In this work, functional architectures are tailored on the surface of a gold electrode, introducing receptor molecules as a sensing entity that mimics those found in the membrane of target cells of the influenza A virus and with the aim of developing an impedimetric‐based detector for influenza A virus phenotyping. In a bottom‐up approach, the artificial receptors are built by sequential assembly of a 1‐octanethiol/octyl‐galactoside hybrid bilayer, followed by an enzyme‐mediated functionalization of the terminal galactoside groups with sialic acid molecules. The detection mechanism relies hence on the specific affinity between the sialic acid‐galactose receptor moieties anchored on the modified electrode surface and the hemagglutinin (HA) viral surface protein. By using the appropriate type of sialyltransferase enzyme, sialylation of galactose residues is made through α‐2,3 or α‐2,6 linkages. This permits the envisaged impedimetric detector to discriminate rapidly between avian vs. human strains of influenza A virus with the absence of elaborate sample preparation steps. In contrast to immunosensors based on antibodies as bioreceptor, the sialylated modified gold electrode is also able to distinguish among influenza phenotypes, which could make the here presented detector a reagentless, label‐free diagnostic device for influenza phenotyping.