Radiation curable materials – principles and new perspectives

Increasing environmental concerns and the ensuing legislation to cut emissions of volatile organic compounds (VOCs) have been major driving forces behind the development of radiation cured coatings over the past 25 years. Today radiation cured coatings are known for their good overall performance and their excellent resistance against chemical and physical surface damages. Advanced photoinitiator systems allow the light stabilisation of UV‐curable formulations and the outdoor application of the coating. The rapid curing, combined with the possibility of immediate processing of the coated objects opens the way for radiation curing – in 100%‐, water based‐, and dual cure systems as well as for radiation curable powder coatings – for a wide variety of application.     

Capillary electrophoresis and herbicide analysis: Present and future perspectives

The aim of this article is to provide an overview on the potential of the CE–herbicides binomial. To this end, the methods proposed so far are discussed: their characteristics, types of samples and analytes to which the methods have been applied, sample preparation steps, if required (e.g. cleanup–preconcentration, derivatization steps), and type of detection in each case. Also, the methods are compared with counterparts based on LC, when appropriate. The role of MS detection in present and future analytical research in this field (both for identification and quantitation) are commented. The foreseeable and desirable trends in analysis of herbicides are also outlined in the light of the present trends in metabolomics as a way of knowing the pathways, the intermediate and final degradation products that can influence the crops and the food chain of humans and other animals, as a result.     

Platinum—alkynyl and —alkyne complexes: old systems with new chemical and physical perspectives

The chemistry of alkynyl and alkyne ligands in platinum complexes of different oxidation states is described. The review focuses on the synthetic aspects of mono- and polynuclear compounds and on the reactivity of σ-alkynyl and π-alkyne species in different stoichiometric reactions such as insertion, addition of nucleophiles and electrophiles, rearrangements and isomerization processes and also some catalytic additions of heteroatoms (B, Si, S) across the CC triple bond. The relevant features of polynuclear complexes bearing the CC group in dendrimers and organometallic polymers are briefly reported.     

Supramolecular chemistry — Molecular information and the design of supramolecular materials

Molecular information expressed through molecular recognition events provides means for directing the spontaneous formation of supramolecular species from complementary components. It may allow the design and engineering of supramolecular materials, in particular of liquid crystalline and of polymeric nature. Thus, supramolecular mesophases have been obtained from molecular recognition-induced association of suitable subunits. The self-assembly of complementary ditopic components generates liquid crystalline “polymers” of supramolecular nature; it takes place by a progressive growth revealed by electron microscopy: from nuclei, to filaments, to tree-like species, to strings and fibers that present helicity induced by the chirality of the subunits. A rich variety of structures and properties may be expected to result from the blending of supramolecular chemistry with polymer chemistry and materials science.     

Present situation of food irradiation in South America and the regulatory perspectives for Brazil

This presentation shows the main aspects of the Brazilian and Argentinean regulations on food irradiation, the current situation in each country and the perspectives for legislation in Brazil     

可生物降解聚合物的现状及生物降解性研究

综述了可生物降解聚合物的现状及发展、影响生物降解性的因素和生物降解性的评价方法。     

Present status and future trends in biological and environmental reference materials in China

Summary The present status of biological and environmental reference materials (BERMs) is summarized, including the institutions involved in the preparation, certification and approval of BERMs, types, analysis, homogeneity, stability and role in analytical practice. The future perspectives on the BERMs in China are also briefly discussed.     

Food irradiation—past, present and future

A review is presented of historical developments, the present situation, and expected future developments in the field of food irradiation. Acceptance of the process in different parts of the world is not uniform. In the USA and in some other countries where health authorities actively encourage the use of this technology, commercial application has greatly advanced in recent years. In contrast, progress in the European Union is still slow.     

Synthesis and properties of new aromatic polyimides — Polymeric materials for light-emitting and liquid-crystal displays

New aromatic diamines containing π-conjugated heterocyclic rings were synthesized, which emit blue light in the photoluminescence. Using these new monomers, soluble poly(amic acid)s were prepared by the polycondensations with pyromellitamic dianhydride, and thermally converted to the polyimides in films which emit intense blue-light. These polyimides are considered as potential candidate materials for fabricating optoelectronic devices which emit blue light. In addition, new poly(m-phenylene 4,4′-oxydiphthalimide)s containing various side chains were synthesized. For these polyimides, thermal properties were investigated with considering the chain flexibility of polymer backbone as well as the spacer and biphenyl mesogen end group in the side chains. In particular, these polyimides exhibited excellent performance in the rubbing process and the controlling of both the alignment and the pretilt of liquid-crystal (LC) molecules in the LC cell. This might be attributed mainly to a strong interaction between the biphenyl mesogen end group in the side chains and the mesogen unit of LC molecules.