Application issue of anthraquinonoid vat dyes on inherently flame-resistant fabrics

The vat dyeing process of specific fabrics with protective, inherently fire retardant properties that have a high content of aramid fibres in their composition, is presented. The research was performed on fabric samples that differ in raw material composition and aramid content. The samples were dyed in raw form (group 1) as well as after pretreatment with alkaline scouring (group 2). Measured limiting oxygen index (LOI) values showed that the selected fabrics meet the properties of inherently fire retardant fabrics. Dyeing was performed with Indanthren® Olive Green HB (manufactured by DyStar) vat dye, in exhaustion process, with a bath ratio of 1:30. The dye concentration was 3%, and sodium-hydrosulphite (Na₂S₂O₄) was used as a reducing agent. The colouristic analyses were performed based on spectrophotometric measurement and results interpretation according to CIELab system. The evaluation of primary tactile properties was performed which show an increase of smoothness and softness after scouring and dyeing. Also, wash fastness as well as light fastness tests have shown satisfactory fastness properties.     

Laser-Induced,Green and Biocompatible Paper-Based Devices for Circular Electronics

The growing usage and consumption of electronics-integrated items into the daily routine has raised concerns on the disposal and proper recycling of these components. Here, a fully sustainable and green technology for the fabrication of different electronics on fruit-waste derived paper substrate, is reported. The process relies on the carbonization of the topmost surface of different cellulose-based substrates, derived from apple-, kiwi-, and grape-based processes, by a CO₂ laser. By optimizing the lasing parameters, electronic devices, such as capacitors, biosensors, and electrodes for food monitoring as well as heart and respiration activity analysis, are realized. Biocompatibility tests on fruit-based cellulose reveal no shortcoming for on-skin applications. The employment of such natural and plastic-free substrate allows twofold strategies for electronics recycling. As a first approach, device dissolution is achieved at room temperature within 40 days, revealing transient behavior in natural solution and leaving no harmful residuals. Alternatively, the cellulose-based electronics is reintroduced in nature, as possible support for plant seeding and growth or even soil amendment. These results demonstrate the realization of green, low-cost and circular electronics, with possible applications in smart agriculture and the Internet-of-Thing, with no waste creation and zero or even positive impact on the ecosystem.     

Light‐induced cooperative electron–proton transfer in hydrogen‐bonded networks of N,N‐diaryl substituted 1,4‐bisimines and meso‐1,2‐diaryl‐1,2‐ethanediols

The 1:1 cocrystallization of 1,4‐diaryl‐1,4‐bisimines (Ar–CHN–CH₂‐)₂ 4 – 11 and substituted meso‐1,2‐diaryl‐1,2‐ethanediols 1 – 3 leads to supramolecular structures in which the diol is hydrogen bonded by one of its hydroxy groups to an imine nitrogen atom of a 1,4‐bisimine. The second functionality in each molecule leads to the generation of ladderlike polymeric structures where each molecule of the diol is linked to two molecules of the 1,4‐bisimine and vice versa. If the diol carries electron donor groups in the aromatic residue and the 1,4‐bisimine correspondingly acceptor groups, then charge transfer interactions are observed. The excited CT complex which corresponds to a radical ion pair is stabilized by migration of a proton of a hydroxy group to the nitrogen atom of an imino group. This is supported by the appearance of a N–H vibration in the IR spectra. The reorganization is also accompanied by changes in the UV/Vis spectra and by the generation of paramagnetism in the crystalline material. The results represent a type of photochromism which has its origin in a light‐induced cooperative electron–proton transfer. The photochromism is thermally reversible.     

Stereolithographic 3D Printing of Ceramics: Challenges and Opportunities for Structural Integrity

This article reviews the current activities at the Montanuniversität Leoben on the design, processing, and characterization of 3D printed advanced ceramics using the lithography-based manufacturing technology. An overview of the challenges and the opportunities offered to improve the mechanical properties of printing ceramics is given. Their brittle failure is analyzed within the framework of linear elastic fracture mechanics, considering specific aspects of additive manufacturing. Several issues associated with the printing process are addressed, such as surface quality, geometry control, influence of printing directions, as well as the need to establish testing protocols for 3D printed parts. Based on the layer-by-layer capabilities of the stereolithographic process, bio-inspired material design concepts are discussed aiming to enhance the mechanical resistance of 3D-printed ceramics. By tailoring the layer architecture and microstructure of the parts, high strength and fracture resistance may be achieved.     

Validation and Uncertainty Assessment of a Software-Integrated Workflow for pH Calculations

Accurate pH calculations are essential for scientists across different disciplines to design optimal reactor solutions, but they can be arduous to calculate for complex acid-base solutions. Visual Water is a powerful software tool that provides accurate pH calculations with automated mathematical uncertainty analysis. Its workflow is presented and validated using acids and bases, showing a deviation of < 0.2 pH units between measured and calculated pH values. This highlights the software's reliability, which can help to simplify the work of non-experts in water chemistry.     

Investigation of transformation products of selected veterinary drugs generated by electrochemistry,microsomal assays,hydrolysis & photolysis

The knowledge of transformation pathways and transformation products of veterinary drugs is important for health, food and environmental matters. Residues (original veterinary drug and transformation products) are found in food products of animal origin and also in the environment (e.g., soil or surface water). Several transformation processes can alter the original veterinary drug, ranging from biotransformation in living organism to environmental degradation processes like photolysis, hydrolysis, or microbial processes. In this thesis, four veterinary drugs were investigated, three ionophore antibiotics Monensin, Salinomycin and Lasalocid and the macrocyclic lactone Moxidectin. Ionophore antibiotics are mainly used to cure and prevent coccidiosis in poultry especially prophylactic in broiler farming. Moxidectin is an antiparasitic drug and is used for the treatment of internal and external parasites in food- producing and companion animals. The main objective of this work was the usage of different laboratory approaches to generate and identify transformation products. The identification was conducted using high-resolution mass spectrometry (HR-MS). A major focus was put on the application of electrochemistry for simulation of transformation processes. The electrochemical reactor, equipped with a three-electrode flow-through cell, enabled the oxidation or reduction by applying a potential. Derived transformation products were analyzed by online coupling of the electrochemical reactor and a HR-MS and offline by liquid chromatography (LC) combined with HR-MS. The main modification reaction of the identified transformation products was different for each investigated veterinary drug. Monensin was showing decarboxylation and demethylation as main modification reactions, for Salinomycin mostly decarbonylation was occurring and for Lasalocid methylation was prevalent. For Moxidectin I observed oxidation (hydroxylation) reaction and adduct formation with solvent. In general, for salinomycin and Lasalocid more transient transformation products (online measurement) than stable transformation products (offline measurements) were detected. In contrast, the number of transformation products using online and offline measurements were identical for monensin and moxidectin. As a complementary approach, metabolism tests with rat or human liver microsomes were made for the ionophore antibiotics. Monensin was investigated by using rat liver microsomes and identified transformation products were based on decarboxylation and demethylation. Salinomycin and Lasalocid were converted by human and rat liver microsomes. For both substances were more transformation products found by using human liver microsomes. The transformation products of the rat liver microsome conversion were redundant, the transformation products were also found at the human liver microsome assay. Oxidation (hydroxylation) was found to be the main modification reaction for both. In addition, a frequent ion-exchange between sodium and potassium was identified. The last two experiments were performed for one substance each, the hydrolysis of monensin and the photolysis of moxidectin was investigated. The transformation products of the pH- dependent hydrolysis were based on ring-opening and dehydration. Moxidectin formed several transformation products by irradiation with UV-C light and main modification reactions were isomeric changes, (de-)hydration and changes of the methoxime moiety. In summary, transformation products of the four investigated veterinary drugs were generated by the different laboratory approaches. Most of the identified transformation products were identified for the first time. The resulting findings provide an understanding for clarifying the transformation behavior.     

Structure and Properties of Cocrystals of Phenazine and Fumaric‐, 2,3‐Dihydroxyfumaric‐, and Oxalic Acid

Phenazine and the dicarboxylic acids fumaric‐, 2,3‐ dihydroxyfumaric‐, and oxalic acid form 1 : 1 cocrystals. X‐ray analysis shows that the molecules are arranged as linear tapes, mainly held together by strong O‐H…︁N and weak C(sp ²)‐H…︁O hydrogen bonds. Individual molecules form staples which are surrounded by staples of the other molecules. The angle between neighbouring tapes varies from ca. 90° in the cocrystal of phenazine and fumaric acid to ca. 70° in the co‐crystal of phenazine and 2,3‐dihydroxyfumaric acid, and ca. 25° in the cocrystal of phenazine and oxalic acid. The molecules assume an offset face‐to‐face arrangement in individual phenazine staples. Negligible π‐stacking is observed in the cocrystals of phenazine with fumaric‐ and 2,3‐dihydroxyfumaric acid. The absence of the CC double bond as spacer in oxalic acid leads to appreciable π‐overlap of phenazine molecules in the cocrystal. As a consequence, the latter cocrystal displays special properties. An irreversible lightinduced electron transfer generates initially singlet and triplet biradicals with the unpaired electrons positioned on neighbouring phenazine molecules. Partially, the electrons are transformed to magnetically independent electrons which show strong exchange narrowing in the e.p.r. spectrum at temperatures > 0 °C. The proposed model is supported by UV/Vis‐e. s.r.‐, and SQUID measurements.