Self-Assembled Film of Tb^(3+) and Poly(3- Thiophene Acetic Acid) via Layer-by-Layer Complexation Technique and Its Photoluminescence

The layer by layer complexation technique of polymer and metal ion was successfully utilized to fabricate the ultrathin multilayer film of poly(3 thiophene acetic acid (PTAA) and Tb 3+ ion by dipping the substrates alternatively in polymer and Tb 3+ ion aqueous solutions. UV-vis measurement revealed that the absorbance has linearity with the bilayer number from layer to layer and the X ray photoelectron spectrum (XPS) confirmed the existence of Tb 3+ ion. The pH of both the polymer and TbCl 3 solutions influence the thickness dramatically while the concentration of the solutions is not so sensitive. The luminescent spectrum of the complex film shows the characteristic emission of Tb 3+ ion as well as the ligand indicating the formation of the complex.

Stability Behaviour of Monolayer Tetraether Lipids on the Amino-Silanised Silicon Wafer: Comparative Study between Langmuir-Blodgett Monolayers with Self-Assembled Monolayers

This study investigated the stability behaviour of molecular monolayer symmetric chemically modified tetraether lipids caldarchaeol-PO4 on the amino-silanised silicon wafer using Langmuir-Blodgett films, Self Assembling Monolayers (SAMs), ellipsometry, and atomic force microscopy (AFM). The monolayers of caldarchaeol-PO4 were stable on the solid surface amino-silanised silicon wafer. The organizations of molecular monolayers caldarchaeol-PO4 by Langmuir-Blodgett method and SAMs have been analyzed. The surface of pressure in Langmuir-Blodgett processing is carried out monolayers caldarchaeol-PO4 more flat island inhomogeneous. Another method of monolayers caldarchaeol-PO4 by SAMs is showed a large flat domain. Monolayers caldarchaeol-PO4 by Langmuir-Blodgett method seems to be stable and chemically resistant after washing with organic solvent and an additional treatment ultrasonification with various thickness lipids arround 2 nm to 6 nm. Conversely, monolayer caldarchaeol-PO4 by SAMs appears fewer than monolayers caldarchaeol-PO4 by Langmuir-Blodgett method, the thickness of various from 1 nm to 3 nm.

Self-assembled interlayer aiming at the stability of NiOx based perovskite solar cells

Inorganic NiO_(x) based inverted structure perovskite solar cells (PSCs) is reported to be more stable than that with the organic hole transport materials.In this work,NiO_(x)/MAPbI_(3) interface chemical reaction induced instability of perovskite is unveiled:Ni^(3+) and I^(-) exhibit redox reactions and deprotonation of MA^(+) happens,which result in interface defects and perovskite lattice deformation.Thus the defective interface accelerates the degradation of perovskite by defect pathways from the bottom interface to the perovskite surface contacting H_(2)O/O_(2).Self-assembled interlayer of NH_(2)^(-)end silane on NiO_(x)separates the reactive NiO_(x)and MAPbI_(3),tunes the interface energy states by–NH_(2) end group.As a result,the PSC based on the silane treated NiO_(x)achieves enhanced PCE of 20.1%with decent stability under environmental and extreme conditions (high temperature,high humidity,light infiltration).Our work highlights the interface chemical problem induced PSC instability and a simple interface modification to achieve the stable PSCs.

Studies on the Electron Transfer Centers of Amino Oxidase Immobilized on Self-Asembly Monolayer Using Electrochemical Methods

The direct electron transfer of amino oxidase on electrode surface based on self assembly technique occurs at 505 mV( vs . Ag/AgCl), indicating that copper atoms are the electron transfer centers and catalytic centers of amino oxidase.

Preparation of Nano-porous Materials(Ⅰ) by Polymerization of Amphiphile Self-assemblies

The polymerization of amphiphilic self assemblies is a promising method to synthesize nano structured materials with novel properties. These materials have many attractive features for their application in biomedical area and materials science, such as catalysis, separation, surface modification, and therapeutics areas. A general review on the polymerization of lipids and surfactant self assemblies to amphiphilic self assemblies is given in this paper with 49 references. The polymerization and the subsequently resulted structure of lipids in different morphologies are summarized. The polymerization of polymerizable surfactants(surfmers) in emulsion and liquid crystalline phases are also discussed. The potential application of new nano porous materials is briefly described.

Surface-enhanced Raman scattering properties of highly ordered self-assemblies of gold nanorods with different aspect ratios

Gold nanorods with aspect ratios of from 1 （particles） to 31.6 were synthesized by the seed-mediated method and packed in a highly ordered structure on a large scale on silicon substrates through capillary force induced self-assembly behaviour during solvent evaporation. The gold nanorod surface exhibits a strong enhancing effect on Raman scattering spectroscopy. The enhancement of Raman scattering for two model molecules （2-naphthalenethiol and rhodamine 6C） is about 5-6 orders of magnitude. By changing the aspect ratio of the Au nanorods, we found that the enhancement factors decreased with the increase of aspect ratios. The observed Raman scattering enhancement is strong and should be ascribed to the surface plasmon coupling between closely packed nanorods, which may result in huge local electromagnetic field enhancements in those confined junctions.

Design and Self-assembly of a Novel Tetranuclear Zinc(Ⅱ) Complex via Reaction of 1,3-Thiazolidine-2-thione(tzdtH) with Zn(NO_ 3)_ 2

The self-assembly of clusters in inorganic systems is an interesting subject. The self-assembly of big molecules has been well established in biological systems. In addition, the coordination chemistry of metal-sulfur-nitrogen cluster complexes has been a very active and attracting field for many years as a result of the novelty and versatility of the crystal structures and reactivities of such clusters, as well as their potential applications as the models for the active sites in non-heme proteins. At the same time, there is currently considerable interest in the formation of metal complexes with heterocyclic ligands because of the diverse characteristics of ligands and their consequential wide range of applications.

Preparation of Nano-porous Materials(Ⅱ) by Cross-linking of Amphiphilic Self-assemblies

Amphiphilic block copolymers can exhibit rich and complex morphologies in aqueous solutions, but these structures are usually delicate, easily disturbed by composition change or temperature change. In this work, the use of different methods to cross link block copolymer self assemblies in the presence of a selective solvent and to stabilize the structures is reviewed. In addition, the cross linking reaction kinetics of block copolymer amphiphilic self assemblies is briefly discussed.

Plasmonic rhenium trioxide self-assembled microtubes for highly sensitive, stable and reproducible surface-enhanced Raman spectroscopy detection

Compared with noble metals, improving the sensitivity of semiconducting surface-enhanced Raman scattering(SERS) substrates is of great significance to their fundamental research and practical application of Raman spectroscopy. Herein, a simple chemical method is developed to synthesize a rhenium trioxide(ReO_(3)) microtubes assembled with highly crystalline nanoparticles. The ReO_(3) microtubes show a strong and well-defined surface plasmon resonance(SPR) behavior in visible region, which is rare for non-noble metals. As a low-cost SERS substrate, the plasmonic ReO_(3) microtubes exhibit a Raman enhancement factor of 8.9×10^(5) and a lowest detection limit of 1.0×10^(-9) mol/L for phenolic pollutants. Moreover, these ReO_(3) microtubule SERS substrates show excellent chemical stability and can resist the corrosion of strong acids and bases.

Flexible multiterminal photoelectronic neurotransistors based on self‐assembled rubber semiconductors for spatiotemporal information processing

A significant step toward constructing high‐efficiency neuromorphic systems is the electronic emulation of advanced synaptic functions of the human brain.While previous studies have focused on mimicking the basic functions of synapses using single‐gate transistors,multigate transistors offer an opportunity to simulate more complex and advanced memory‐forming behaviors in biological synapses.In this study,a simple and general method is used to assemble rubber semiconductors into suspended two‐phase composite films that are transferred to the surface of the ion‐conducting membrane to fabricate flexible multiterminal photoelectronic neurotransistors.The suspended ion conductive film is used as the gate dielectrics and supporting substrate.The prepared devices exhibit excellent electrical stability and mechanical flexibility after being bent.Basic photoelectronic synaptic behavior and pulse‐dependent plasticity are emulated.Furthermore,the device realizes the spatiotemporally integrated electrical and optical stimuli to mimic spatiotemporal information processing.This study provides a promising direction for constructing more complex spiking neural networks and more powerful neuromorphic systems with brain‐like dynamic spatiotemporal processing functions.

pH-Sensitive Wettability Induced by Topological and Chemical Transition on the Self Assembled Surface of Block Copolymer

pH-sensitive wettability of polystyrene-b-poly（4-vinylpyridine） （PS-b-P4VP） self assembled films, exhibiting superoleophobicity under water and hydrophilicity at low pH value, and oleophobicity under water and hydrophobicity at neutral condition, has been realized. The wettability properties resulted from the surface topological and chemical transition, which were confirmed by in situ AFM measurements under water at different pH. At low pH, P4VP chains, which were confined in the hexagonal-packed nanodomains, got protonated into a swollen state, while at high pH, P4VP chains were deprotonated into a collapsed state. The reversible protonation/deprotonation procedure on the molecular scale leads to surface topological and chemical transition, thereby pH-sensitive wettability.

Highly Oriented ZnO Rod Arrays on Si Substrates from Aqueous Solution

Ordered zinc oxide （ZnO） rod arrays with very high orientation were fabricated on Si substrates by using a solution method. The substrate surfaces were functionalized by Self-Assembly Monolayers （SAMs）. In the very early growth stage, the oriented ZnO crystals had already grown, which appeared to be the main reason why ZnO nanorods showed very high orientation. The un-dense and un-uniform SAMs provided a surface that was heterogeneous to ZnO nucleation. Consequently, highly oriented ZnO rods were selectively grown on the ＂coin-like＂ SAM-uncovered regions. The route developed here can provide some helpful information to control the nucleation and orientation of ZnO in aqueous solution. Also, the site-selective growth mechanisms can indicate a clue to grow patterned highly oriented ZnO nanorod arrays by the organic template.

Self‐assembled fullerene(C60)‐pentacene superstructures for photodetectors

Fullerene assembling with specific donor molecules would yield multi-functional metamaterials via the collective behavior,wherein linear acenes are widely used as donor molecules to construct the charge‐transfer heterojunction structure with fullerene.However,they are generally prepared by vacuum deposition due to the insoluble property of high‐performance linear acenes molecules in common solvents,which makes the construction of fullerene with insoluble donor molecules still be a big challenge in the solution‐processed method.To this end,chemical modification provides an effective solution‐processed strategy to construct donor and acceptor systems.Here,the C60‐pentacene is assembled into controllable flower‐like superstructures by the surface grafting method.It is found that the nanofeatures of the microflowers could be regulated by temperature,resulting in dense‐flakes morphology at room temperature and loose flakes at high temperatures.Furthermore,the dense‐flakes microflowers structures with less mass but better crystalline structure exhibit better optoelectronic properties.Our results reveal an effective control on the nanofeatures of the self‐assembled fullerenes complex super-structures and their role for the optoelectronic performance,which may promote the exploring of fullerene superstructures as photodetectors.

NOVEL SYNTHESIS OF LONG MULTI-BLOCK HETEROPOLYMER CHAINS WITH AN ORDERED SEQUENCE AND CONTROLLABLE BLOCK LENGTHS

It had very long been a dream in polymer science to synthesize long multi-block polymer chains with an orderedchain sequence and controllable block lengths. Using ionic or living free radical polymerization or furnishing each end ofpolymer blocks with a reactive functional group, one can only prepare heteropolymer chains with few long blocks, such asdiblock and triblock copolymers. The most plausible result so far was a pentablock copolymer. Recently, using a combinationof polymer physics and synthetic chemistry, we have invented self-assembly assisted polycondensation (SAAP). Thiscommunication reports the results of using this novel. method to connect 10-100 triblock polymer chains together to formlong multi-block heteropolymer chains with an ordered sequence and controllable block lengths.

Growth in solution of hooked Ni–Fe fibers by oriented rotation and attachment approaches

Inspired by the curved branches of fractal trees, hooked Ni–Fe fibers were grown in situ in Ni–Fe composite coatings on a spheroidal graphite cast iron substrate. These hooked Ni–Fe fibers exhibited inclination angles of about 39°, which was in accordance with the theoretical prediction of 37°. Ni–Fe nanostructures self-assembled to form dendrites and evolved into hooked fibers by an oriented attachment reaction. The orientation rotation of Ni–Fe nanostructures played an important role in the growth of curved hooked Ni–Fe fibers. During sliding wear tests, the volume loss of the spheroidal graphite cast iron substrate was 2.2 times as large as that of the Ni–Fe coating reinforced by hooked fibers. The good load-transferring ability of hooked Ni–Fe fibers led to an improvement in their wear properties during wear tests.

Optical limiting behavior of nano-gold self-assembled multi-wall carbon nanotube

The optical limiting behaviors of nano-gold self-assembled multi-wall carbon nanotube (MWNT) were experimentally investigated at 532 and 1064 nm, respectively. The comparison of the limiting performances between carbon nanotube suspension, C60 solution, and carbon black suspension (CBS) was performed. The results show that the optical limiting characteristic of nano-gold self-assembled MWNT is better than those of C60 and CBS. The mechanisms of the optical limiting for the samples were discussed.

Controlled Deposition of HAp Mimicking Tooth Enamel

Chemical compositions and mierosturcture of mature human tooth enamel were investigated by XRD , FTIR and SEM to further understand the characteristics of tooth enamel. In order to obtain apatite crystals chemically and structurally similar to those in tooth enamel, biomimetic way was employed. Self-assembled monolyers terminated with-SO3 H groups were used as deposition substrates and 1.5 SBF （ the concentrations of Ca^2＋ and PO4^3- ions 1.5 times ttum those in simulated body fluid ） with and without 5 ppm F^- were used as soaking medium. The XRD and FTIR results showed that both the deposited fluoride-substituted hydroxyapatite （ F-HAp ） crystals in 1.5 SBF with F^- and hydroxyapatite （ HAp ） crystals in 1.5 SBF were carbonate-contain ing, mimicking human tooth enamel in chemical compositions. The SEM photos showed that needle-like F-HAp crystals had large aspect ratios and grew in bundles, which were similar to the crystals in human tooth enomel. The results provide available information on dental restoration.

Self-assembled Synthesis of 3D CuO Flocculus-like Nanosheet-based Hierarchical Nanostructures

A simple, surfactant-free, and environmentally benign method has been developed to synthesize a novel 3D flocculus-like CuO hierarchical nanostructure self-assembled with 2D nanosheet as building blocks. Detailed proofs demonstrate that the overall synthetic process underwent the dehydration and re-crystallization of precursor Cu（OH）2 nanowires, and the subsequent two-step oriented attachment. In addition, 3D butterfly-like and flower-like CuO nanostructures consisted of 2D nanosheets could be obtained by adjusting the concentration of NaOH（cNaoH） in the solution. CNaOH played a key role in tailoring the thickness of the nanosheets and changing the morphology of the product. This report may be helpful to constructing fine-tune hierarchical CuO nanostructures under basic conditions.

Electrostatic Self-Assembled Multilayers from Side Chain Azo Polyelectrolytes

Photoresponsive behavior and self assembly properties of three side chain azo polyelectrolytes, poly (2 (4 phenylazophenoxy) ethanol co acrylic acid) (PPAPE), poly (2 (4 (4′ nitrophenylazo) phenoxy) ethanol co acrylic acid) (PNAPE), and poly (2 (4 (4′ ethoxyphenylazo) phenoxy) ethanol co acrylic acid) (PEAPE), were studied. These polyelectrolytes with different degrees of functionalization of azo chromophores were fabricated into nano composite multilayers using two types of dipping solutions through a layer by layer electrostatic self assembling process. Results show that the ratio between tetrahydrofuran (THF) and H 2O significantly influences the photoresponsive behavior of PNAPE in THF H 2O mixture. The THF H 2O dipping solution, used in this work for self assembly of hydrophobic polyelectrolytes, is proved to be as applicable as aqueous dipping solution for normal self assembly of hydrophobic polyelectrolytes. However, significant differences in the multilayer growth between the two systems were also observed, which resulted from the remarkable difference of the existing forms of the polyelectrolytes in these two dipping solutions.

Self-assembly Behavior of Metal Halide Perovskite Nanocrystals

The self-assembled metal halide perovskite(MHP)nanocrystal superlattices have attracted many researchers due to their exceptional optical and electrical properties.The bottom-up self-assembly can be facile to generate ideal and periodic structures.The superlattices’stability can be improved and the photoluminescence lifetime can be extended by an order of magnitude.However,due to lack of a comprehensive and systematic understanding of the internal interactions on self-assembled processes now,superlattices cannot be obtained controllably and play full use of their advantages.Therefore,gaining a deep insight of interaction forces about self-assemblies is the premise of designing and controlling the degree of self-assembly so as to prepare ideal materials.In this review,the definitions and functions of driving forces including van der Waals forces,electrostatic interactions and hydrogen bonds are discussed.Subsequently,we aim to explore the dominant factors affecting the driving forces,which can make a difference in the process of MHP self-assembly.Based on current researches,we emphasize on three aspects−the core of nanocrystals,surface ligands and solvents−to clarify their critical roles in controlling the driving forces.Finally,the outlooks and perspectives of how to facilitate the MHP self-assembly and their application on blue light emitting diodes are discussed.