FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2989069682> ?p ?o ?g. }

• W2989069682 abstract "Comprising 20–30% of the shells of crustaceans, α-chitin has been shown to provide a wide range of valuable products such as therapeutic substances, platform molecules and functional materials. However, the polysaccharide’s crystallinity has been poorly studied, and this has limited its widespread utilization thus far.Filling that research gap, this thesis reports a new mechanochemical method of ball milling which amorphizes α-chitin in a controlled way. Using powder XRD to measure the polysaccharide’s crystallinity index (CrI%), a low balls-to-chitin (BtC) steel system was found to reduce CrI by an average of 6.0 units in regular milling times with good precision (±2.5 CrI units). That data set was correlated for the first time with FT-IR intensity ratios showing an unaffected degree of acetylation (DA), a steady decrease of glycosidic linkage content and α-chitin’s characteristic amide I split. The behaviour of the latter was rationalized as an experimental indicator for the weakening of the polysaccharide’s intermolecular hydrogen bonding network which is hypothesized to arise from the distribution of the average collision force within the nanofibril structure.The combination of increased collision frequency along with the presence of a solid acid catalyst (kaolinite) provided optimum mechanochemical conditions for efficient conversion of α-chitin into water-soluble products. The latter were analysed with a MALDI-TOF-MS method developed in Memorial University revealing oligomers of N-acetyl-D-glucosamine (NAG) with degrees of polymerization (DP) of 1 to 5. The monomer and dimer reached yields of 5.1 and 3.9 wt.%, respectively, within 6 h, which compare well with yields of glucose and cellobiose from literature for cellulose ball milling. The products of this solvent-free oligomerization process were complemented by colorimetric approximations of reducing ends as well as size exclusion chromatography observations. This analysis is expected to stimulate future research for the sustainable production of these likely biologically active chitooligosaccharides.In parallel, the inevitable fraction of higher MW chitin resulting from the ball milling process has been shown to conveniently solubilize in cold NaOH. An optimum concentration of 19 wt.% of the alkali was found to dissolve ~5 wt.% high MW/crystallinity α-chitin via a freeze-thaw process at −28°C and give films of acceptable mechanical properties after a simple casting treatment with HCl. Practically, this method avoids some of the disadvantages of organic-salt-solution solvents like the need for a costly recycling/purification treatment, their life cycle issues, the high temperatures, and the long stirring times. At the same time, it can quickly create homogeneous solutions of predictable viscosities in the 1–10 wt.% range allowing for more efficient and controlled chitin deacetylation." @default.
• W2989069682 created "2019-11-22" @default.
• W2989069682 creator A5089656843 @default.
• W2989069682 date "2019-03-01" @default.
• W2989069682 modified "2023-09-27" @default.
• W2989069682 title "Mechanochemical transformations of α-chitin" @default.
• W2989069682 hasPublicationYear "2019" @default.
• W2989069682 type Work @default.
• W2989069682 sameAs 2989069682 @default.
• W2989069682 citedByCount "0" @default.
• W2989069682 crossrefType "dissertation" @default.
• W2989069682 hasAuthorship W2989069682A5089656843 @default.
• W2989069682 hasConcept C100817775 @default.
• W2989069682 hasConcept C112887158 @default.
• W2989069682 hasConcept C11432220 @default.
• W2989069682 hasConcept C127413603 @default.
• W2989069682 hasConcept C166940927 @default.
• W2989069682 hasConcept C166950319 @default.
• W2989069682 hasConcept C171250308 @default.
• W2989069682 hasConcept C178790620 @default.
• W2989069682 hasConcept C185592680 @default.
• W2989069682 hasConcept C188027245 @default.
• W2989069682 hasConcept C191516044 @default.
• W2989069682 hasConcept C192562407 @default.
• W2989069682 hasConcept C2779732960 @default.
• W2989069682 hasConcept C2781088250 @default.
• W2989069682 hasConcept C32909587 @default.
• W2989069682 hasConcept C42360764 @default.
• W2989069682 hasConcept C44228677 @default.
• W2989069682 hasConcept C46275449 @default.
• W2989069682 hasConcept C521977710 @default.
• W2989069682 hasConcept C8010536 @default.
• W2989069682 hasConceptScore W2989069682C100817775 @default.
• W2989069682 hasConceptScore W2989069682C112887158 @default.
• W2989069682 hasConceptScore W2989069682C11432220 @default.
• W2989069682 hasConceptScore W2989069682C127413603 @default.
• W2989069682 hasConceptScore W2989069682C166940927 @default.
• W2989069682 hasConceptScore W2989069682C166950319 @default.
• W2989069682 hasConceptScore W2989069682C171250308 @default.
• W2989069682 hasConceptScore W2989069682C178790620 @default.
• W2989069682 hasConceptScore W2989069682C185592680 @default.
• W2989069682 hasConceptScore W2989069682C188027245 @default.
• W2989069682 hasConceptScore W2989069682C191516044 @default.
• W2989069682 hasConceptScore W2989069682C192562407 @default.
• W2989069682 hasConceptScore W2989069682C2779732960 @default.
• W2989069682 hasConceptScore W2989069682C2781088250 @default.
• W2989069682 hasConceptScore W2989069682C32909587 @default.
• W2989069682 hasConceptScore W2989069682C42360764 @default.
• W2989069682 hasConceptScore W2989069682C44228677 @default.
• W2989069682 hasConceptScore W2989069682C46275449 @default.
• W2989069682 hasConceptScore W2989069682C521977710 @default.
• W2989069682 hasConceptScore W2989069682C8010536 @default.
• W2989069682 hasLocation W29890696821 @default.
• W2989069682 hasOpenAccess W2989069682 @default.
• W2989069682 hasPrimaryLocation W29890696821 @default.
• W2989069682 hasRelatedWork W1635434970 @default.
• W2989069682 hasRelatedWork W1972805223 @default.
• W2989069682 hasRelatedWork W1982720018 @default.
• W2989069682 hasRelatedWork W2023185550 @default.
• W2989069682 hasRelatedWork W2061930775 @default.
• W2989069682 hasRelatedWork W2071620383 @default.
• W2989069682 hasRelatedWork W2081869653 @default.
• W2989069682 hasRelatedWork W2083812153 @default.
• W2989069682 hasRelatedWork W2109015680 @default.
• W2989069682 hasRelatedWork W2110453294 @default.
• W2989069682 hasRelatedWork W2162365627 @default.
• W2989069682 hasRelatedWork W2203639280 @default.
• W2989069682 hasRelatedWork W2239391550 @default.
• W2989069682 hasRelatedWork W2361835224 @default.
• W2989069682 hasRelatedWork W2368067794 @default.
• W2989069682 hasRelatedWork W2388599239 @default.
• W2989069682 hasRelatedWork W2616140103 @default.
• W2989069682 hasRelatedWork W3147048000 @default.
• W2989069682 hasRelatedWork W2185008859 @default.
• W2989069682 hasRelatedWork W2871784351 @default.
• W2989069682 isParatext "false" @default.
• W2989069682 isRetracted "false" @default.
• W2989069682 magId "2989069682" @default.
• W2989069682 workType "dissertation" @default.