Active colloidal catalysts inspired by glutathione peroxidase (GPx) were synthesized by integration of catalytically active selenium (Se) moieties into aqueous microgels.A diselenide crosslinker (Se X-linker) was successfully synthesized and incorporated into microgels through precipitation polymerization, along with the conventional crosslinker N,N'methylenebis(acrylamide) (BIS). Diselenide bonds within the microgels were cleaved through oxidation by H 2 O 2 and converted to seleninic acid whilst maintaining the intact microgel microstructure.T hrough this approach catalytically active microgels with variable amounts of seleninic acid were synthesized.R emarkably,t he microgels exhibited higher catalytic activity and selectivity at lowr eaction temperatures than the molecular Se catalyst in amodel oxidation reaction of acrolein to acrylic acid and methyl acrylate.
Using a simple π-conjugated trimer, EDOT-phenylene-EDOT (where EDOT = 3,4-ethylenedioxythiophene), we evaluate the effect that fluorine substituents have upon changes in conformation, conjugation and oxidation potentials in π-conjugated structures. These variations are assessed as a function of the fluorine atom's propensity to feature in hydrogen and/or halogen bonding with other heteroatoms. The molecular motif was chosen because the EDOT unit presents the possibility of competing O•••X or S•••X non-covalent contacts (where X = H or F). Such non-bonding interactions are acknowledged to be highly influential in dictating molecular and polymer morphology and inducing changes in certain physical properties. We studied four compounds, beginning with an unsubstituted bridging phenylene ring and then adding one, two, or four fluorine units to the parent molecule. Our studies involve single crystal XRD studies, cyclic voltammetry, absorption spectroscopy and density functional theory calculations to identify the dominant non-covalent interactions and elucidate their effects on the molecules described. Experimental studies have also been carried out on the corresponding electrochemically synthesized polymers to confirm that these non-covalent interactions and their effects persist in polymers. Our findings show that hydrogen bonding and halogen bonding feature in these molecules and their corresponding polymers.
The mathematical model has been developed to calculate the content of higher alcohols and esters depending on wort initial concentration and fermentation temperature. The process was optimized in accordance with the developed model. To obtain high-quality beer via high-gravity brewing technology the wort concentration was found to be 14-15 % relative to dry matter and main fermentation temperature of 284–285 K.
In the context of controlled delivery and release, proteins constitute a delicate class of cargo requiring advanced delivery platforms and protection. We here show that mechanoresponsive diselenide-crosslinked microgels undergo controlled...
Abstract. 1 The effect of main fermentation temperature on a young beer taste has been studied within the range of 282-292 K for high-density wort with the concentration of 14-18 % dry matter. The taste is provided by the content of aromatics -by-products of fermentation: acetaldehyde, vicinal diketones, n-propanol, n-butanol, ibutanol, 2-methyl-butanol, 3-methyl butanol, ethyl acetate and isoamyl acetate.
Catalytic performance of Se-containing organic substances, namely methylseleninic acid, benzeneseleninic acid, phenylselenol and diphenyldiselenide, has been tested as potential catalysts for unsaturated aldehydes oxidation by hydrogen peroxide. All tested substances proved to be active in the acrolein oxidation reaction but showed different efficiency regarding used solvents and the products of reaction-acrylic acid or methyl acrylate. Optimal catalyst, reaction conditions and solvent for acrylic acid synthesis have been determined.
Systematic studies of acrolein oxidation and oxidative alkoxylation catalyzed by Se-modified microgel catalysts at mild reaction conditions were conducted. Se-modified microgels proved to be highly active colloidal catalysts and exhibited...
In order to enhance the range of processable alloys of laser-based powder bed fusion, reinforced alloys have gained focus. Satelliting is a recently introduced method for adding fine additives to larger parent powder particles using a bonding agent. Satellited particles prevent a local demixing due to size and density effects of the powder. In this study, the satelliting method is used for the additivation of Cr3C2 to AISI H13 tool steel via a functional polymer binder (pectin). The investigation includes a detailed binder analysis and comparison to the previously used PVA binder as well as processability in PBF-LB and the microstructure of the alloy. The results reveal that pectin is a suitable binder for the satelliting process and the demixing behavior that appears when using a simple powder blend can be significantly reduced. However, the alloy is enriched with carbon, which results in austenite being retained. Thus, in future research, a reduced binder content will be investigated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.