DECHEMA

About: DECHEMA is a nonprofit organization based out in Frankfurt am Main, Germany. It is known for research contribution in the topics: Corrosion & Oxide. The organization has 756 authors who have published 1307 publications receiving 25693 citations.

Influence of bacterial exopolymers on cell adhesion of Desulfovibrio vulgaris on high alloyed steel: Corrosion inhibition by extracellular polymeric substances (EPS)

Abstract: Extracellular polymeric substances (EPS) were studied with regard to their potential application as inhibitors of biocorrosion. EPS that have been isolated from biofilms of sulphate-reducing bacteria (SRB) were adsorbed on samples of high alloyed steel (type 1.4301) at different temperatures. The samples were exposed to SRB containing solution and afterwards analysed by fluorescence microscopy (FM). The results show that the EPS form an incomplete layer and lead to a smaller amount of cell adhesion when compared to pure surfaces. The results are discussed with regard to the application of EPS for the prevention of biofilm formation.

Activity and long-term stability of PEDOT as Pt catalyst support for the DMFC anode

Abstract: The feasibility of using poly(3,4-ethylenedioxythiophene) (PEDOT) as Pt catalyst support for direct methanol fuel cell (DMFC) anodes was investigated. Measurements with freshly prepared Pt-PEDOT/C electrodes showed poor activity for methanol oxidation in a half-cell and a DMFC. A substantial enhancement in that activity was evident after either electrochemical over-oxidation of PEDOT or long-time storage of the Pt-PEDOT/C gas diffusion electrode (GDE) in air. Both procedures led to a reorganization and increase in porosity of the reaction layer, which obviously contributed to better methanol accessibility to Pt catalyst active centres. The effects of electrochemical activation and long-time storage in air on the morphology and elementary composition of the Pt-PEDOT layer were investigated by means of Hg porosimetry and SEM/EDAX. It was found that the increase in porosity was due to degradation of PEDOT characterized by a significant depletion of sulphur and oxygen in the conducting polymer matrix.

A Holistic Approach to Model the Kinetics of Photocatalytic Reactions

Abstract: Understanding and modeling kinetics is an essential part of the optimization and implementation of chemical reactions. In the case of photocatalytic reactions this is mostly done one-dimensionally, i.e., only considering the effect of one parameter at the same time. However, as discussed in this study, many of the relevant reaction parameters have mutual interdependencies that call for a holistic multi-dimensional approach to accurately model and understand their influence. Such an approach is described herein, and all the relevant equations given so that researchers can readily implement it to analyze and model their reactions.

Biological purification of exhaust air using fixed bacterial monocultures

Abstract: This paper presents the results of basic investigations on reactions and process engineering in the biological purification of exhaust air in a trickle-bed reactor. The biocatalysts used were pollutant-specific bacterial monocultures, which were immobilized on various carriers. By using different pollutants (e.g. acetone, propionaldehyde, naphthalene and toluence, crude gas concentrations: 5–35 ppm), the effect of the water solubility of the gaseous substances on separation efficiency was studied. Furthermore, a combination of monocultures was used for degradation of a mixture of pollutants. The results show that, with suitable combinations of bacteria, pollutants and carriers, conversions of more than 80% at a space velocity of about 1000-1 can be achieved by this method.