Chitosan obtained from black soldier fly larval cuticles expands the value chain and is effective as a biocontrol agent to combat plant pathogens.

The industrial use of certain insects, such as the black soldier fly (BSF, Hermetia illucens), has become a burgeoning way of converting residual biomass into a valuable source of biomolecules for the feed and food industry. Here, the integration of a valuable step as an upcycling technology using biological waste from the 5th instar BSF larvae processing as a source of bioactive chitosan was explored. The goal is to pave the way for sustainable chitosan production from insect-based resources in addition to proteins, lipids, and fertilizers.

A Simple Preparation of Crosslinked, Highly Alkaline Diallyldimethylammonium Hydroxide Hydrogel Particles via Inverse Static Anion Exchange.

Highly alkaline hydrogels are gaining increasing attention in building materials research. Specifically, cationic alkaline hydrogels based on diallyldimethylammonium hydroxide (DADMAOH) as the monomer have been effectively used to seal water-bearing cracks or serve as coupling media for electrochemical chloride extraction. However, the residual halogen content and challenges in scaling up monomer production have hindered broader application.

Hydrolytic Stability of Crosslinked, Highly Alkaline Diallyldimethylammonium Hydroxide Hydrogels.

The aim of this study was to evaluate the persistence of alkaline hydrogels based on a common (,'-methylenebisacrylamide, BIS) and three recently published tetraallyl crosslinkers. Such hydrogels have been shown to be suitable materials for the rehabilitation of cementitious materials. Of the four crosslinkers under investigation, ,,','-tetraallylpiperazinium dibromide decomposed quickly in 1 m KOH solution and was not considered further.

Multivalent Allylammonium-Based Cross-Linkers for the Synthesis of Homogeneous, Highly Swelling Diallyldimethylammonium Chloride Hydrogels.

,-methylenebisacrylamide (BIS) is a very popular cross-linker for the radical polymerisation in water. It is highly reactive but prone to alkaline hydrolysis and suffers from a low solubility. This study shows that with slow polymerising systems such as ,-diallyldimethylammonium chloride, only inhomogeneous networks are formed.

Poultry Feather Waste as Bio-Based Cross-Linking Additive for Ethylene Propylene Diene Rubber.

Most rubbers used today rely on sulphur as a cross-linking agent and carbon black from fossil resources to modify the mechanical properties. A very promising substitute can be found in natural keratins such as feathers. These are not only tough, but also contain a relevant amount of sulphur in the form of disulphide bridges.

Autogenous Cross-Linking of Recycled Keratin from Poultry-Feather Waste to Hydrogels for Plant-Growth Media.

The global rise in atmospheric temperature is leading to an increasing spread of semi-arid and arid regions and is accompanied by a deterioration of arable land. Polymers can help in a number of ways, but they must not be a burden to the environment. In this context, we present herein a method by which goose feathers, representative of keratin waste in general, can be transformed into hydrogels for use as a plant growth medium.

Protein Hydrolysates from Biogenic Waste as an Ecological Flame Retarder and Binder for Fiberboards.

The increasing demand for sustainable building materials requires alternative flame retarders, which have superior sustainability to those previously used. In this respect, we present our initial results with protein hydrolysates made from poultry-feather waste for the preparation of flame-retardant fiberboards. Impregnated wood fibers show a significantly decreased decomposition rate in the region between 300 and 450 °C, as measured by thermogravimetric analysis.

Influence of Environmental Factors on the Swelling Capacities of Superabsorbent Polymers Used in Concrete.

Superabsorbent polymers (SAP) are of major interest as materials to control the cement hydration process. The swelling behavior of the SAPs significantly influences the performance of the resulting concrete by slowly releasing polymer-bound water in order to maintain a consistent / value. A round-robin test conducted by the RILEM Technical Committee 260-RSC showed that the same batch of polymer can lead to large deviations in concrete performance and this was assumed to originate in different storage conditions of the SAP.

CT texture analysis compared to Positron Emission Tomography (PET) and mutational status in resected melanoma metastases.

Purpose: To evaluate the potential of CT texture analysis parameters and metabolic characteristics of melanoma metastases in F- FDG PET/CT to predict relevant mutations of tumour cells for targeted therapy in metastatic melanoma patients in correlation with histopathologic specimen.

Material And Methods: 66 melanoma patients, examined with contrast-enhanced F-FDG PET/CT before scheduled metastasectomy without any prior systemic therapy, were included in this single-centre retrospective analysis under IRB waiver. The largest, resected metastasis in each patient was assessed with CT texture analysis and semiquantitative F-FDG PET parameters.

Sorption-active transparent films based on chitosan.

In this paper we describe the preparation of alkanoic acid-based aqueous chitosan solutions, which show no sign of acid-catalysed depolymerisation over time - something commonly accompanying other preparation methods. Longer chitosan chains have previously been shown to exhibit more advantageous biological activities, and constant viscosities are essential for consistent quality in biomedical applications. Avoiding acid-catalysed depolymerisation requires careful control of the stoichiometry between the free amino groups of chitosan and the appropriate solubilising acid.

Preparation and characterisation of highly alkaline hydrogels for the re-alkalisation of carbonated cementitious materials.

Highly alkaline hydrogels that allow the restoration of alkaline buffer in cementitious materials can be obtained from diallyldimethylammonium hydroxide. The latter must be prepared in dilute solutions and polymerised at ambient temperatures in order to avoid decomposition. Using methacrylamide as a neutral co-monomer capable of forming hydrogen bonds, the rheological properties of the gels can be adjusted over a wide range; e.

Interfacial properties of emulsions stabilized with surfactant and nonsurfactant coated boehmite nanoparticles.

The properties of emulsions stabilized with surface-modified boehmite particles of 26 and 8 nm in diameter have been investigated. The surface-modified particles were prepared by mixing aqueous dispersions of cationic boehmite particles with aqueous solutions of the surfactant p-dodecylbenzenesulfonic acid (DBSA) or the nonsurfactant p-toluenesulfonic acid (TSA). For the 26 nm particles, interfacial tension measurements indicate that p-dodecylbenzenesulfonic acid partitions between the particle surface and the oil-water interface, while p-toluenesulfonic acid remains on the particle surface.

Current-dependent anisotropic conductivity of locally assembled silver nanoparticles in hybrid polymer films.

The electrical behaviour of hybrid poly(ethylene terephthalate) films containing localised, percolating networks of silver nanoparticles separated by pure polymer is studied. The films resemble an array of parallel wires in the submicron range and, thus, exhibit anisotropic conductivity. In the high-conductivity direction at low amplitudes, the films show Ohmic behaviour, while at moderate voltage, non-linearity and a decreasing resistance is observed.

ZnO nanoparticle-containing emulsions for transparent, hydrophobic UV-absorbent films.

A simple method for the preparation of thin, zinc oxide nanoparticle-containing films showing high UV absorption, high transmittance in the visible range (>88%), and water repellence with contact angles of 120 degrees is presented. The films are coated from an emulsion containing the hydrophobic polymer and the nanoparticles. This emulsion was prepared by mixing commercial o/w emulsions used for hydrophobic coatings on textiles with ZnO nanoparticle-containing o/w emulsions.

Temperature-dependent colloidal stability of hydrophobic nanoparticles caused by surfactant adsorption/desorption and depletion flocculation.

Nanoparticles coated with self-assembled dodecyltrimethylammonium bromide shells are shown to undergo colloidal destabilization at higher temperatures. This is caused by two different mechanisms depending on the surfactant concentration. Up to a surfactant concentration of 55 mM, the surfactant micelles dissolve before the breakdown of the dispersion.

Colloidal stability of hydrophobic nanoparticles in ionic surfactant solutions: definition of the critical dispersion concentration.

The dispersion stability diagrams of hydrophobic boehmite nanoparticles in aqueous n-alkyltrimethylammonium bromide solutions (alkyl chain lengths 10-16) were studied over a wide range of particle and surfactant concentrations. The surfactant molecules adsorb tail-on on the particle surface, which provides the colloidal stability through electrostatic repulsion. In the stable region of each diagram, bimodal particle size distributions (50 and 500 nm) are found at lower surfactant concentration, which give way to monomodal distributions (50 nm) at higher concentration.

A comparative study on the dispersion stability of aminofunctionalised silica nanoparticles made from sodium silicate.

A method to prevent the irreversible agglomeration of silica nanoparticles prepared from sodium silicate, which occurs upon treatment with trialkoxy silanes, is presented. Electrostatic stabilisation is maintained by using mixtures of 3-aminopropyltrimethoxysilane and the cationic derivative N-trimethoxysilylpropyl-N,N,N-trimethylammoniumchloride (TMAPS), which gives rise to stable dispersions of aminofunctionalised particles with unusually high amine content. The particles can be isolated and redispersed without significant increase in particle size.

The dispersion-stability diagram of boehmite nanoparticles in aqueous AOT solutions.

The dispersion stability of hydrophilic boehmite nanoparticles in aqueous sodium bis(2-ethylhexyl) sulfosuccinate (AOT) solutions was studied in a wide range of particle and surfactant concentrations. The two experimental parameters significantly influence the dispersion stability and span a stability diagram. With increasing surfactant concentration and decreasing particle concentration, the system changes from stable via moderately stable to unstable and back.

Synthesis, structural analysis, and visualization of a library of dendronized polyphenylacetylenes.

A library of eleven high cis-content cis-transoidal polyphenylacetylenes (PPAs) dendronized with self-assembling dendrons was prepared from a library of fifteen convergently synthesized macromonomers. Using [Rh(C triple bond CPh)(nbd)(PPh(3))(2)] (nbd=2,5-norbornadiene) in the presence of 10 equiv of N,N-dimethylaminopyridine, predictive control over molecular weight and narrow molecular weight distribution are obtained. The PPA backbone serves as a helical scaffold for the self-assembling dendrons.

NiCl(2)(dppe)-catalyzed cross-coupling of aryl mesylates, arenesulfonates, and halides with arylboronic acids.

An investigation of the NiCl(2)(dppe)-, NiCl(2)(dppb)-, NiCl(2)(dppf)-, NiCl(2)(PCy(3))(2)-, and NiCl(2)(PPh(3))(2)-catalyzed cross-coupling of the previously unreported aryl mesylates, and of aryl arenesulfonates, chlorides, bromides, and iodides containing electron-withdrawing and electron-donating substituents with aryl boronic acids, in the absence of a reducing agent, is reported. NiCl(2)(dppe) was the only catalyst that exhibited high and solvent-independent activity in the two solvents investigated, toluene and dioxane. NiCl(2)(dppe) with an excess of dppe, NiCl(2)(dppe)/dppe, was reactive in the cross-coupling of electron-poor aryl mesylates, tosylates, chlorides, bromides, and iodides.

Aqueous room temperature metal-catalyzed living radical polymerization of vinyl chloride.

This paper describes the room-temperature living radical polymerization (LRP) of vinyl chloride in H2O/THF in the presence of Cu0 or CuI salts as catalysts, tren or PEI as ligands, and iodoform as initiator. The disproportionation reaction 2CuI + L --> Cu0 + CuII(L) is the crucial step, as it continuously provides the active species for both the initiation (Cu0) and the reversible termination step (CuII). Mn was found to increase linearly with conversion and is in good agreement with Mth, with the Mw/Mn being approximately 1.