Design von pulverförmigen und granularen Waschmitteln

In the last fifty years, powder and granular detergents have been significantly improved in performance and ecology: more concentrated (less chemicals), biodegradable surfactants, no phosphates, reduced water and energy consumption. The use of optimized enzymes and bleaching boosters enables lowered wash temperatures and the removal of natural stains. The production of solid detergents runs either in spray towers without and with compaction step, or in a non‐tower agglomeration plant. The latest generation of granulation with an integrated mill for simultaneous drying and grinding allows the production of spherical particles, which can be adjusted (small or large, heavy or light). Future formulations will enable lower washing temperatures.     

Dynamic behavior of nanometer-scale amorphous intergranular film in silicon nitride by in situ high-resolution transmission electron microscopy

We report about the dynamic behavior of a nanometer-scale amorphous intergranular film (IGF) in a Si₃N₄ ceramic by an in situ heating experiment in a high-resolution transmission electron microscopy (HRTEM). During the experiment the IGF gradually vanishes at 820 °C accompanied by the formation of crystal planes within the IGF. The IGF reappears after cooling back to room temperature. The results cannot be explained within the framework of a force balance model. We argue that the dynamic behavior of the IGF in our experiment originates from the open system observed.     

Synthesis and characterisation of poly(distyrylbenzene-block-hexa(ethylene oxide)) and its fluorinated analogue—two new block copolymers and their application in electroluminescent devices

Two new soluble block copolymers are reported in which chromophores and hexa(ethylene oxide) units alternate along the polymer backbone. In polymer 1 the chromophore was the distyrylbenzene unit. The polymer was synthesised via the Wittig reaction and the ionisation potential of 5.4±0.2 eV was measured by cyclic voltammetry and photoelectron spectroscopy. Polymer 1 showed a high solid-state photoluminescence efficiency (34%) and was used to make efficient (0.5 cd/A) light emitting diodes (LEDs). Polymer 1 was also used in light emitting cells; these showed luminescence in reverse bias and a reduced turn-on voltage compared to the LEDs. Polymer 2, in which the chromophore was dodecafluoro-distryrylbenzene, was prepared via the Horner-Wittig reaction and showed an ionisation potential of 6.25±0.15 eV and a solid-state photoluminescence efficiency of 17%. It was used as electron-conducting layer in a LED but failed to give significant electroluminescence. The optical energy gap for both polymers was 3.0 eV.     

Enantioselective Organocatalytic Michael Addition of Cyclobutanones to Nitroalkenes

Synthetic applications of cyclobutanones other than ring expansion and fragmentation reactions are rare. Herein, highly efficient diastereo‐ and enantioselective organocatalytic Michael additions of 2‐substituted cyclobutanone derivatives to nitroalkenes are reported allowing the stereocontrolled creation of ‘all‐carbon’ quaternary centers. The approach relies on both the use of Brønsted base/hydrogen‐bond donor bifunctional organocatalysts, and importantly, the specific stabilization and activation of cyclobutanone with a secondary amide moiety. The reaction was found to nicely accommodate a broad scope of substrates, allowing the control of up to three contiguous stereogenic centers. This work has opened new synthetic opportunities.     

Vorkalkulation chemischer Anlagen

The economic analysis of processes allows a market orientation and prioritization of development projects. First of all, a preliminary costing takes place by estimating the investment costs. Basis for calculation is a complete process flow diagram with mass and energy balances for a layout of the process steps, performed in the standard material AISI 316Ti. Costs of other materials can be calculated with factors from a table, that of the other sizes and capacities by degression exponents. The preliminary costing is exemplified. The investment is the basis for the subsequent calculation of production costs.     

SkaSim – Skalierbare HPC‐Software für molekulare Simulationen in der chemischen Industrie

This article outlines advances in molecular modeling and simulation using massively parallel high‐performance computers (HPC). In the SkaSim project, partners from the HPC community collaborated with users from science and industry. The aim was to optimize the prediction of thermodynamic property data in terms of efficiency, quality and reliability using HPC methods. In this context, various topics were dealt with: atomistic simulation of homogeneous gas bubble formation, surface tension of classical fluids and ionic liquids, multicriteria optimization of molecular models, the development of the molecular simulation codes ls1 mardyn and ms2, atomistic simulation of gas separation processes, molecular membrane structure generators, transport resistors and the evaluation of predictive property data models based on specific mixture types.     

用伪并行遗传/模拟退火算法进行多流股换热器网络综合的研究

The multi-stream heat exchanger network synthesis (HENS) problem can be formulated as a mixed integer nonlinear programming model according to Yee et al. Its nonconvexity nature leads to existence of more than one optimum and computational difficulty for traditional algorithms to find the global optimum. Compared with deterministic algorithms, evolutionary computation provides a promising approach to tackle this problem. In this paper, a mathematical model of multi-stream heat exchangers network synthesis problem is setup. Different from the assumption of isothermal mixing of stream splits and thus linearity constraints of Yee et al., non-isothermal mixing is supported. As a consequence, nonlinear constraints are resulted and nonconvexity of the objective function is added. To solve the mathematical model, an algorithm named GA/SA (parallel genetic/simulated annealing algorithm) is detailed for application to the multi-stream heat exchanger network synthesis problem. The performance of the proposed approach is demonstrated with three examples and the obtained solutions indicate the presented approach is effective for multi-stream HENS.     

Chemistry of Leichhardt's Grasshopper, Petasida ephippigera, and its Host Plants, Pityrodia jamesii, P. ternifolia, and P. pungens

Investigation of the strikingly aposematic Leichhardt's grasshopper revealed a number of host-plant-derived components. Chemical study of the three known host plants revealed a diverse array of components. Pityrodia ternifolia and P. pungens contain predominantly sesquiterpenes and sesquiterpene glycosides and P. jamesii is rich in cineole, dihydrochalcones, chalcones, and monoterpene glycosides. Feces from grasshoppers feeding on P. jamesii contain a mixture of hydroxycineoles, of which 3-hydroxycineole is the predominant isomer (68%). No evidence for previously suspected "alkaloidal" toxins was found in either the insect or host plant.     

Chemical model for short-term induction in quaking aspen (Populus tremuloides) foliage against herbivores

Simulated large aspen tortrix (Choristoneura conflictana) herbivory of quaking aspen (Populus tremuloides) induces significant increases in concentrations of two phenol glycosides, salicortin and tremulacin, in leaves within 24 hr. Crushing of leaf tissue, as must occur when aspen leaves are eaten by chewing insects such as the large aspen tortrix, results in conversion of salicortin and tremulacin to 6-hydroxy-2-cyclohexenone (6-HCH). Salicortin, tremulacin, 6-HCH, and its degradation product, catechol, are all toxic to the large aspen tortrix when fed on an artificial diet. These damage-induced chemical changes provide a plausible mechanism for short-term resistance induced in aspen leaves by insect herbivory.     

Vilsmeier–Haack–Arnold formylations of aliphatic substrates with N-chloromethylene-N,N-dimethylammonium salts

The classical electrophilic substitution of activated aromatics with the Vilsmeier–Haack reagent N-chloromethylen-N,N-dimethylammonium chloride (Schemes 1 and 2) has been more recently extended to a great variety of aliphatic substrates, mainly due to the work of Arnold. In this review, a collection of representative examples for these henceforth called Vilsmeier–Haack–Arnold (VHA) formylation reaction of aliphatics is given: the reaction of polymethine cyanines, merocyanines, and other vinylogous iminium salts with the VHA reagent gives, after hydrolysis of the primary substitution products, trialdehydes such as triformylmethane (Scheme 3); VHA reaction with ene-diamines and diene-diamines yields N,N-dialkylaminomalonaldehydes and tetraaldehydes such as 1,1,2,2-tetraformylethane, respectively (Schemes 4 and 5); aldehyde acetals, enol ethers, and carboxylic acids deliver with VHA reagents 2-substituted malonaldehydes (Scheme 6), and α-amino acids give derivatives of the unstable aminomalonaldehyde (Scheme 7); alkenes and polyenes react with VHA reagents to give α,β-unsaturated or higher vinylogous aldehydes (Schemes 8 and 9), and alkenes with donor substituents yield alkylidene-malonaldehydes (Scheme 10); enolizable methyl and methylene ketones produce with VHA reagents 3-chlorovinylaldehydes (Scheme 11). Eventually, the VHA reagent can be used for the intermediate preparation of nucleophilic amino-chlorocarbenes (Scheme 12).