Synthesis of Surface-Modified Nanoparticles via Cycloaddition-Reactions

Summary. The surface modification of nanoparticles via azide/alkine-1,3-dipolar cycloaddition-reactions is described. Ligand exchange onto various nanoparticles was monitored by ¹H NMR spectroscopy and formed the basis for the attachment of ligands onto the nanoparticles and their subsequent modification by dipolar cycloaddition reactions. Nanoparticle-surfaces were monitored by binding onto self-assembled monolayers derivatized with matching supramolecular interactions after derivatization.     

展望21世纪的高分子化学

回顾了高分子合成化学方法和高分子材料的发展历史,结合高分子化学的研究现状,展望了２１世纪的高分子化学的发展前景。     

Our Contributions in Nanochemistry for Antibiosis,Electrocatalyst and Energy Storage Materials

This account mainly introduces and reviews our recent progress in three projects: antibacterial nanomaterial, electrocatalyst for detecting and electrode nanomaterial of energy storage device, especially the supercapacitor. Besides, our thought and idea about the design, fabrication and application of corresponding nanomaterials are sketched throughout the whole article in order to reveal the structure‐function relationship and corresponding mechanism. In the end, we tend to attach importance to the bottleneck of nanomaterial's development and put forward our understanding in this field.     

Biomimetic sensor chip monitoring real-time food degradation: correlating chemical deterioration with microbiological status

Abstract  Conventional tests currently in use for the detection and identification of food-borne pathogens and also of microbial food deterioration are time-consuming as they are based on conventional culturing techniques or monitoring environmental conditions like the increase of temperature or change in pH. These parameters do not reflect the real quality of the meat to be tested. The aim of our approach was to create a simple and cheap sensor providing reasonable sensitivity and selectivity to indicate the bacterial infection in real-time monitoring combined with a memory effect that cannot easily be corrupted. Thus, an optical thin film sensor chip was developed able to detect bacterial decay of food through a specific colour change. The design of the sensor relates to the phenomenon of “anomalous absorption”, which can best be described as a thin film enhanced absorption. A metal nanoparticle layer positioned at a well-defined distance to a smooth metal surface shows that the minimum of spectral reflectivity strongly depends on the thickness of the distance layer. This setup represents a special kind of reflection interference filter. In such a sensor setup a biomimetic polymer is integrated, which is degradable by lytic enzymes excreted by microorganisms in food decay. Meat deterioration under controlled conditions is correlated to the amount of enzymes secreted by microorganisms and the bacterial count. Thus, after incubation of the sensor setup with standard meat preparations, the enzymes released from decaying cell material change the thickness of the polymer layer and generate an easily visible colour change. This setup would be useful for integration into meat packaging. Graphical Abstract   M. Barth, U. Bohrn and M. Ibrišimović contributed equally to this work.     

In quest of a systematic framework for unifying and defining nanoscience

This article proposes a systematic framework for unifying and defining nanoscience based on historic first principles and step logic that led to a “central paradigm” (i.e., unifying framework) for traditional elemental/small-molecule chemistry. As such, a Nanomaterials classification roadmap is proposed, which divides all nanomatter into Category I: discrete, well-defined and Category II: statistical, undefined nanoparticles. We consider only Category I, well-defined nanoparticles which are >90% monodisperse as a function of Critical Nanoscale Design Parameters (CNDPs) defined according to: (a) size, (b) shape, (c) surface chemistry, (d) flexibility, and (e) elemental composition. Classified as either hard (H) (i.e., inorganic-based) or soft (S) (i.e., organic-based) categories, these nanoparticles were found to manifest pervasive atom mimicry features that included: (1) a dominance of zero-dimensional (0D) core–shell nanoarchitectures, (2) the ability to self-assemble or chemically bond as discrete, quantized nanounits, and (3) exhibited well-defined nanoscale valencies and stoichiometries reminiscent of atom-based elements. These discrete nanoparticle categories are referred to as hard or soft particle nanoelements. Many examples describing chemical bonding/assembly of these nanoelements have been reported in the literature. We refer to these hard:hard (H-n:H-n), soft:soft (S-n:S-n), or hard:soft (H-n:S-n) nanoelement combinations as nanocompounds. Due to their quantized features, many nanoelement and nanocompound categories are reported to exhibit well-defined nanoperiodic property patterns. These periodic property patterns are dependent on their quantized nanofeatures (CNDPs) and dramatically influence intrinsic physicochemical properties (i.e., melting points, reactivity/self-assembly, sterics, and nanoencapsulation), as well as important functional/performance properties (i.e., magnetic, photonic, electronic, and toxicologic properties). We propose this perspective as a modest first step toward more clearly defining synthetic nanochemistry as well as providing a systematic framework for unifying nanoscience. With further progress, one should anticipate the evolution of future nanoperiodic table(s) suitable for predicting important risk/benefit boundaries in the field of nanoscience. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

Surface Modification and Functionalization of Metal and Metal Oxide Nanoparticles by Organic Ligands

Summary. Metal or metal oxide nanoparticles possess unique features compared to equivalent larger-scale materials. For applications, it is often necessary to stabilize or functionalize such nanoparticles. Thus, modification of the surface of nanoparticles is an important chemical challenge. In this survey, various possibilities are discussed how nanoparticles can be protected by organic ligands and how these ligands can be used to introduce functionalities. The preparative possibilities include grafting of an already functionalized ligand on the nanoparticle surface, exchanging part or all existing ligands on the nanoparticle surface, or grafting of a ligand on a nanoparticle followed by modification by organic chemical reactions.     

新型沸石分子筛主体-纳米客体复合材料研究进展

This paper mainly elaborated the recent developments of the studies on the new type zeolite molecular sieve host-nanoguest composite materials composing of molecular sieve channels or cages encapsulated nanoscale materials from the point of nanochemistry and material science, and the trends of development in this field. As the research of the properties of this kind of materials are going on, it is possible that this kind of host-guest nanocomposite materials will be usd in some fields. such as science and high technology fields. as the new type of optical, electrical and magnetic materials in the level of molecular assembly. This paper contains the following contents: hosts and guests; the sizes and shapes of guests; the optical, electrical and magnetic properties of the materials; the syntheses and characterizations of the materials; the applications of the materials and forecast.