Advances in Design and Self-Assembly of Functionalized LB Films and Supramolecular Gels

The recent progress in functionalized LB films and supramolecular gels varies and occupies various fields. Self-assembly technique is playing an important role in preparing well-defined multilevel nanostructures and the functionalized nanomaterials with the designed and controlled properties. In this chapter, various kinds of functionalized LB films and supramolecular gels, including gold nanoparticles, inorganic-organic hybrid composites, and graphene oxide nanocomposites, have been demonstrated and analyzed. We show main research contributions in recent years in two sections: preparation and self-assembly of some functionalized LB films and preparation and self-assembly of some functionalized supramolecular gels. The above research work may give the potential perspective for the design and preparation of new self-assembly nanomaterials. Future research on preparation of LB films and supramolecular gels will depend on the novel applications and special nanostructures in order to produce novel functional nanomaterials and devices

Preparation of Functionalized Graphene and Gold Nanocomposites – Self-assembly and Catalytic Properties

Nanocomposites and nanomaterials have been attracting more attention in various fields. Nanocomposites can be prepared with a variety of special physical, thermal, and other unique properties. They have better properties than conventional microscale composites and can be synthesized using simple and inexpensive techniques. A composite material consists of an assemblage of two materials of different natures completing and allowing us to obtain a material of which the set of performance characteristics is greater than that of the components taken separately. In our recent research, some functionalized nanocomposites and nanomaterials have been prepared and investigated. In addition, some of the analytical methods, theoretical treatments, and synthetic tools, which are being applied in the area of self-assembly and supramolecular chemistry, will be highlighted. In this chapter, we summarize our main research contributions in recent years in two sections: (1) preparation and catalytic properties of some functionalized graphene nanocomposites; (2) preparation and catalytic properties of some functionalized gold nanocomposites. These works not only provided important inspirations for developing graphene-hybridized materials but also opened new possibilities to improve the photocatalytic activity of photocatalyst

Preparation and Self-assembly of Functionalized Nanocomposites and Nanomaterials – Relationship Between Structures and Properties

The recent progress in nanocomposites and nanomaterials is varied and occupies various fields. Nanocomposites can be prepared with a variety of special physical, thermal, and other unique properties. On the other hand, self-assembly technique is playing an important role in preparing well-defined multilevel nanostructures and the functionalized surface with the designed and controlled properties. In this chapter, various kinds of nanocomposites including gold nanoparticles, inorganic-organic hybrid composites, graphene oxide nanocomposites, and supramolecular gels via functionalized imide amphiphiles/binary mixtures have all been investigated and analyzed. We summarize main research contributions in recent years in three sections: preparation and self-assembly of some functionalized hybrid nanostructures; preparation and self-assembly of some graphene oxide nanocomposites; preparation and self-assembly of supramolecular gels based on some functionalized imide amphiphiles/binary mixtures. The above work may give the potential perspective for the design and fabrication of nanomaterials and composites. New nanocomposites and nanomaterials are emerging as sensitive study platforms based on unique optical and electrical properties. Future research on preparation of nanocomposites and nanomaterials will depend on the less-expensive processes in order to produce low-cost nanomaterials and devices

Facile Preparation of Silver Halide Nanoparticles as Visible Light Photocatalysts

In this study, highly efficient silver halide (AgX)-based photocatalysts were successfully fabricated using a facile and template-free direct-precipitation method. AgX nanoparticles, which included silver chloride (AgCl), silver bromide (AgBr) and silver iodide (AgI), were synthesized using different potassium halides and silver acetate as reactive sources. The size distribution of the AgX nanoparticles was determined by the reaction time and ratio of the reagents, which were monitored by UV-vis spectra. The as-prepared AgX nanoparticles exhibited different photocatalytic properties. This shows the differences for the photodegradation of methyl orange and Congo red dyes. In addition, the AgCl nanoparticle-based photocatalyst exhibited the best photocatalytic property among all three types of AgX nanoparticles that are discussed in this study. Therefore, it is a good candidate for removing organic pollutants

Single-Step Synthesis of LaMnO3/MWCNT Nanocomposites and Their Photocatalytic Activities

Composites of the nano‐sized perovskite‐type oxide of LaMnO3 and multi‐walled carbon nanotubes (MWCNTs) were synthesized in a single step using the sol‐gel method. Their photocatalytic activities for the degradation of various water‐soluble dyes under visible light were evaluated. The prepared samples were characterized by thermogravimetry analysis, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, photoluminescence spectroscopy and UV‐vis diffused spectroscopy. Results showed that LaMnO3 nanoparticles grew on the surface of MWCNTs with a grain size of around 20 nm. Photocatalysis measurements revealed that the LaMnO3/MWCNT nanocomposites had greater photocatalytic activities than pure LaMnO3 nanoparticles, and the mass percentage of MWCNTs showed that 9.4% possessed the highest photocatalytic activity. These results indicate that LaMnO3/MWCNT nanocomposites are promising candidates as highly effective photocatalysts

The Application of Resonance-Enhanced Multiphoton Ionization Technique in Gas Chromatography Mass Spectrometry

Gas chromatography resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (GC/REMPI-TOFMS) using a nanosecond laser has been applied to analyze the 16 polycyclic aromatic hydrocarbons (PAHs). The excited-state lifetime, absorption characters, and energy of electronic states of the 16 PAHs were investigated to optimize the ionization yield. A river water sample pretreated by means of solid phase extraction was analyzed to evaluate the performance of the analytical instrument. The results suggested that REMPI is superior to electron impact ionization method for soft ionization and suppresses the background signal due to aliphatic hydrocarbons. Thus, GC/REMPI-TOFMS is a more reliable method for the determination of PAHs present in the environment

Multifunctional antimicrobial biometallohydrogels based on amino acid coordinated self-assembly

There is a real need for new antibiotics against self‐evolving bacteria. One option is to use biofriendly broad‐spectrum and mechanically tunable antimicrobial hydrogels that can combat multidrug‐resistant microbes. Whilst appealing, there are currently limited options. Herein, broad‐spectrum antimicrobial biometallohydrogels based on the self‐assembly and local mineralization of Ag+‐coordinated Fmoc‐amino acids are reported. Such biometallohydrogels have the advantages of localized delivery and sustained release, reduced drug dosage and toxicity yet improved bioavailability, prolonged drug effect, and tunable mechanical strength. Furthermore, they can directly interact with the cell walls and membrane, resulting in the detachment of the plasma membrane and leakage of the cytoplasm. This leads to cell death, triggering a significant antibacterial effect against both Gram‐negative (Escherichia coli) and Gram‐positive (Staphylococcus aureus) bacteria in cells and mice. This study paves the way for developing a multifunctional integration platform based on simple biomolecules coordinated self‐assembly toward a broad range of biomedical applications

Self-Assembly, Interfacial Nanostructure, and Supramolecular Chirality of the Langmuir-Blodgett Films of Some Schiff Base Derivatives without Alkyl Chain

A special naphthyl-containing Schiff base derivative, , -bis(2-hydroxy-1-naphthylidene)-1,2-phenylenediamine, was synthesized, and its coordination with various metal ions in situ at the air/water interface has been investigated. Although the ligand contains no alkyl chain, it can be spread on water surface. When metal ions existed in the subphase, an interfacial coordination between the ligand and different metal ions occurred in the spreading film, while different Nanostructures were fabricated in the monolayers. Interestingly to note that among various metal ions, only the in situ coordination-induced Cu(II)-complex film showed supramolecular chirality, although the multilayer films from the ligand or preformed complex are achiral. The chirality of the in situ Cu(II)-coordinated Langmuir film was developed due to the special distorted coordination reaction and the spatial limitation at the air/water interface. A possible organization mechanism at the air/water interface was suggested

Preparation of Iron-nickel Alloy Nanostructures via Two Cationic Pyridinium Derivatives as Soft Templates

In this paper, crystalline iron-nickel alloy nanostructures were successfully prepared from two cationic pyridinium derivatives as soft templates in solution. The crystal structure and micrograph of FeNi alloy nanostructures were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy, and the content was confirmed by energy-dispersive spectrometry. The results indicated that the as-prepared nanostructures showed slightly different diameter ranges with the change of cationic pyridinium derivatives on the surface. The experimental data indicated that the adsorption of cationic pyridinium compounds on the surface of particles reduces the surface charge, leading to an isotropic distribution of the residual surface charges. The magnetic behaviours of as-prepared FeNi alloy nanostructures exhibited disparate behaviours, which could be attributed to their grain sizes and distinctive structures. The present work may give some insight into the synthesis and character of new alloy nanomaterials with special nanostructures using new soft templates